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HomeMy WebLinkAboutHarvest Analysis final - Upper Kobuk Valley est 2010
 
 
 
 
 Submitted
to:
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
2
 
 Table
of
Contents
 Executive
Summary
–
Key
Findings ...............................................................................4
 Key
findings ..................................................................................................................................................................4
 Introduction .................................................................................................................5
 Purpose ...........................................................................................................................................................................5
 Field
Review .................................................................................................................................................................5
 Regional
Overview .....................................................................................................................................................6
 Review
of
Biomass
Heat
Systems
and
Links
to
Harvest
Systems .........................................................6
 Stick­Fired
Boilers .....................................................................................................................................................7
 Chip­Fired
Boilers ......................................................................................................................................................8
 Ambler
Heating
Systems .........................................................................................................................................8
 Shungnak
Heating
Systems ...................................................................................................................................9
 Kobuk
Heating
Systems.........................................................................................................................................10
 Effects
of
moisture
content
on
biomass
utilization...................................................................................11
 Sustainable
Forest
Management ......................................................................................................................13
 Native
Allotments ....................................................................................................................................................13
 Review
of
Harvest
Equipment
Types ..........................................................................13
 Timber
Harvest
Overview ...................................................................................................................................13
 Wood
Fuel
Management ......................................................................................................................................14
 Harvesting
System
Component
Activities ....................................................................................................15
 Chip
fired
boiler
wood
requirements
and
harvest
scenarios ................................................................15
 Stick
fired
boiler
wood
requirements
and
harvest
scenarios ...............................................................16
 Timber
Harvest
–
Tree
Felling ...........................................................................................................................17
 Timber
Harvest
–
Skidding,
Decking,
Loading
and
Transport.............................................................18
 Wood
transport
–
alternative ............................................................................................................................21
 Wood
Chip
Production ..........................................................................................................................................22
 Whole
tree
hauling..................................................................................................................................................22
 Chipping .......................................................................................................................................................................23
 Cord
Wood
&
Fire
Wood
Production ..............................................................................................................24
 Cord
Wood
Processing ...........................................................................................................................................24
 Firewood
production..............................................................................................................................................24
 Harvest
Equipment
Recommendations
by
Village ......................................................25
 Ambler .........................................................................................................................................................................25
 Chip
system
harvest
requirements ...................................................................................................................25
 Cordwood
system
harvest
requirements .......................................................................................................26
 Ambler
–
Recommended
Harvest
System ....................................................................................................27
 Shungnak ....................................................................................................................................................................28
 Chip
harvest
system
requirements ...................................................................................................................28
 Cord
wood
harvest
system
requirements ......................................................................................................28
 Kobuk ...........................................................................................................................................................................29
 Chip
system
harvest
requirements ...................................................................................................................29
 Cord
wood
harvest
system
requirements ......................................................................................................29
 Shungnak
and
Kobuk
Recommended
Harvest
System ...........................................................................30
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
3
 Appendix ...................................................................................................................32
 Transportation
System
Analysis ......................................................................................................................32
 Background ................................................................................................................................................................32
 Log
Rafting
in
spring
and
summer ..................................................................................................................32
 Winter
Hauling
and
Transport
on
Ice ............................................................................................................33
 NEED
TO
KNOW
ABOUT
THE
ICE ....................................................................................................................34
 How
thick
is
the
ice?...............................................................................................................................................34
 How
thick
does
the
ice
need
to
be?...................................................................................................................34
 Minimum
ice
thickness
required
to
support
a
load ..................................................................................34
 Basic
Procedures
of
Safety
on
Ice .....................................................................................................................35
 SAFE
OPERATIONS
ON
THE
ICE
COVER .......................................................................................................36
 Equipment
and
Loading/
Unloading
Point
Considerations ..................................................................36
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
4
 
 
 Executive
Summary
–
Key
Findings
 The
purpose
of
this
report
is
to
integrate
the
various
key
components
of
a
biomass
 system
to
a
review
of
various
types
of
harvest
equipment
that
could
be
used
to
 support
the
harvesting
component.


This
should
be
considered
as
a
starting
point
 for
equipment
selection.

Local
input
has
not
been
gained
in
the
development
of
this
 document.

In
addition,
other
villages
will
have
similar
equipment
tested
prior
to
 implementation
in
the
Upper
Kobuk
and
could
influence
future
thoughts
on
 equipment
configuration.
 
 Type
of
harvest
equipment
is
directly
linked
to
the
type
(stick
fired
or
Chip
fired
 boiler)
of
boilers
installed
and
the
scale
of
the
installation
or
amount
of
wood
 required
to
operate
the
system.

The
stick‐fired
boiler
requires
round
wood
that
 must
be
fed
into
the
boiler
by
hand
and
a
chip‐fired
system
requires
chips
of
set
 specifications
that
will
be
fed
automatically
into
the
boiler.

Harvest
system
 requirements
are
discussed
for
each.

In
addition,
size
and
amount
of
equipment
 required
are
determined
by
the
size
of
the
project
and
wood
required
to
run
the
 system
for
a
year.
 Key
findings
 1. There
should
be
two
sets
of
harvest
equipment
for
the
Upper
Kobuk:
one
for
 Ambler
and
one
for
Shungnak
and
Kobuk
to
share;
 2. All
pieces
of
equipment
should
be
able
to
multi‐task
and
there
should
be
 some
redundancy
in
the
equipment
for
working
in
remote
conditions;
 3. A
team
of
two
can
utilize
the
equipment
components
suggested
to
produce
 the
entire
amount
of
wood
needed
for
Ambler
and
a
team
of
three
would
be
 required
for
Kobuk/Shungnak;
 4. Harvesting
may
occur
in
both
summer
and
winter;
however
most
wood
will
 be
moved
during
the
winter
when
the
ground
is
frozen;
 5. 
A
system
of
harvesting
based
on
time
of
year
and
summer
vs
winter
 harvesting
sites
should
be
developed
through
a
five
year
harvest
plan;
 6. Modeled
costs
of
wood
production
for
either
chip
or
cordwood
production
is
 much
lower
than
costs
used
in
the
feasibility
studies.


This
creates
a
very
 robust
conservative
model
for
development
of
a
harvest
system,
with
plenty
 of
room
for
learning
how
best
to
produce
wood
locally;
 7. A
very
robust
harvest
system
for
Amber
will
cost
just
under
$500,000
and
for
 Kobuk/Shungnak
$700,000.

This
is
based
on
an
all‐new
maximum
 productivity
system
linked
with
the
largest
chip
system.


If
cordwood
boilers
 are
selected,
there
is
not
a
need
for
a
chipper
and
can
reduce
both
costs
by
 $70,000.
 
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
5
 Introduction
 Purpose
 The
purpose
of
this
report
is
for
Alaska
Wood
Energy
Associates
(AWEA)
to
develop
 an
assessment
of
harvest
equipment
and
methods
that
integrate
the
wood
feedstock
 requirements
described
in
the
boiler
feasibility
report
and
the
forest
management
 requirements
described
in
the
biomass
assessment
report.

If
village‐scale
district
 heating
systems
are
selected
as
a
means
to
reduce
oil
usage
for
heat
in
a
village,
 wood
chips
are
required
in
an
automated
system.

The
system
requirements
then
 dictate
the
type
of
equipment
needed
for
an
annual
supply
of
chips
and
appropriate
 species
mixes
to
assure
that
the
forest
is
managed
sustainably.

If
smaller
building
 systems
or
small
district
heating
systems
are
selected
then
hand
fed
stick‐fired
 systems
will
result.

The
system
requirements
then
dictate
cordwood
and
a
different
 type
of
management
and
harvest
system.

A
successful
biomass
project
requires
 integrating
all
of
the
system
components
including:
  A
sustainable
forest
management
strategy;
  An
economically
viable
and
practical
harvest
system
that
will
work
in
the
 local
landscape
conditions;
  A
wood
storage
and
handling
system
that
meets
the
requirements
of
the
 boiler
selected;
  Boiler
type
and
size
that
fits
the
end
scale
selected
for
a
specific
village;
  Business
management
system
that
integrates
all
of
the
components
that
fit
 with
the
capacity
and
interests
of
the
village.
 
 This
report
will
integrate
the
biomass
assessment
report
with
the
boiler
feasibility
 report
and
discuss
the
various
components
of
harvest
systems
and
costs
and
relate
 them
to
the
various
size
boiler
systems
that
have
been
modeled
for
the
Upper
Kobuk
 villages.


 Field
Review
 A
field
review
of
landscape
conditions
was
conducted
in
March
2010
and
again
in
 July
2010.

The
purpose
was
to
assess
travel
conditions
for
various
types
of
 equipment
based
on
snow
depth
in
winter
or
the
amount
of
wet
ground
and
streams
 in
summer.

Snow
machines
were
used
in
March
to
survey
the
areas
around
Ambler,
 Shungnak,
and
Kobuk
as
well
as
travel
between
all
of
the
villages.

Snowfall
was
 considered
to
be
much
less
than
normal
and
in
some
areas
very
little
snow
was
on
 the
ground.

In
other
places,
there
were
snowdrifts
up
to
three
feet.

Four
wheelers
 were
used
in
the
summer
survey
to
access
lands
around
each
of
the
villages
during
a
 biomass
assessment
field
trip.

Except
for
selected
sites
for
summer
harvesting,
 most
wood
hauling
will
need
to
be
conducted
during
the
winter
months
when
the
 ground
is
frozen.


However
with
proper
planning,
establishment
of
appropriate
 trails
on
ridges,
redevelopment
of
small
bridges
and
dry
soil
conditions
in
forest
 stands,
a
significant
amount
of
work
can
be
done
during
the
summer
months
as
well.

 Hauling
wood
into
Shungnak
will
almost
be
exclusively
done
during
winter
due
to
 wetlands
surrounding
the
village
and
types
of
trail
systems.
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
6
 
 Regional
Overview
 The
villages
of
Ambler,
Shungnak,
and
Kobuk
are
located
in
the
upper
Kobuk
River
 valley,
above
the
Arctic
Circle,
and
at
the
northwestern
edge
of
the
range
of
white
 spruce
(Picea
glauca)
and
black
spruce
(Picea
mariana),
as
well
as
aspen
(Populus
 tremuloides),
cottonwood
(Populus
balsamifera)
and
birch
(Betula
papyrifera).

The
 spruces
are
the
only
conifer
tree
species
in
the
area,
but
in
addition
to
aspen,
 cottonwood,
and
birch
(the
largest
hardwoods)
there
are
a
variety
of
willows
and
 alders
that
grow
principally
in
wet
areas,
such
as
flood
plains
and
braided
stream
 channels.

In
all
cases,
each
of
these
species
could
be
suitable
to
use
as
wood
fuel
for
 both
stick‐fired
boilers
and
for
chip
fired
boilers.

Moisture
content
is
the
key
issue,
 however,
cottonwood
may
not
be
as
desirable
as
other
hardwoods
for
stick‐fired
 boilers.

 
 Due
to
the
small
average
tree
size,
a
harvest
system
that
could
handle
stem
 diameters
up
to
14
inches
would
be
adequate
to
process
most
of
the
woody
biomass
 found
in
the
project
area.

The
topography
is
rolling
but
gentle,
and
in
most
sites
 observed,
the
forest
soil
is
capable
of
supporting
ground
based
harvest
systems
in
 summer
and
winter
conditions.

However,
transportation
to
those
sites
will
have
to
 be
planned
for
summer
because
of
wetlands
and
creek
crossings.

Thus,
summer
 harvesting
and
transport
are
more
limited,
but
can
be
accomplished
with
proper
 trail
development
and
planning.
 
 This
area
of
Alaska
is
remote.

The
principle
means
of
transportation
to
reach
these
 communities
is
by
small
local
airline
or
charter
aircraft
from
Kotzebue,
 approximately
140
miles
due
west.

In
years
when
river
levels
are
adequate,
 occasional
barge
transportation
is
available
to
carry
supplies
such
as
construction
 materials
or
fuel
to
these
communities.

There
is
no
road
infrastructure
connecting
 these
communities;
however,
in
summer,
boat
travel
on
the
river
is
possible,
and
in
 winter,
ATV,
snow
machine,
and
vehicle
travel
over
the
ice
on
the
river
is
possible.

 There
are
quite
a
few
roads
out
of
Kobuk
connecting
to
mining
areas,
which
will
 help
support
harvest
over
a
larger
landscape
to
support
both
Kobuk
and
Shungnak.

 Review
of
Biomass
Heat
Systems
and
Links
to
Harvest
Systems
 Alaska
Wood
Energy
Associates
has
produced
a
boiler
feasibility
study
that
 describes
the
various
configurations
of
boilers
that
are
feasible
for
each
village
and
 for
each
building.


AWEA
reviewed
the
feasibility
of
individual
stick‐fired
boilers
for
 each
commercial
building,
neighborhoods
of
9
or
more
houses,
and
for
several
 commercial
building
hooked
together
in
a
small
district
heat
system
for
each
village.


 Many
different
combinations
proved
to
be
feasible
from
an
economic
and
forest
 sustainability
perspective.

A
description
of
the
two
levels
of
harvest
to
support
the
 various
potential
systems
follows.

In
each
village,
the
largest
systems
are
chip‐fired
 automated
systems
with
associated
district
heating
systems.

These
systems
will
 require
an
automated
harvesting
approach
to
support
the
requirements
of
chip
 boilers.

If
there
are
several
stick
fired
systems
or
some
larger
systems
selected,
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
7
 then
an
automated
harvest
system
will
be
required
to
meet
the
needs
of
cord
wood
 boilers.

This
document
will
address
the
machine
requirements
of
the
largest
 automated
chip
systems
and
the
largest
stick
systems.

 Stick‐Fired
Boilers
 
Stick‐fired
boilers
burn
round
or
split
wood
in
relatively
straight
pieces.
The
wood
 is
minimally
processed,
being
selected
for
a
range
of
diameters
and
trimmed
only
 for
length.
If
the
diameter
of
the
wood
is
too
large,
the
wood
may
be
split.
Although
 the
processing
is
minimal
(compared
to
chipping),
it
is
generally
all
done
manually
 (some
splitting
may
be
done
with
a
machine).
Nevertheless,
at
the
assumed
unit
 costs,
stick‐wood
is
the
cheapest
energy
source
available
to
the
villages
for
 generating
thermal
energy.
 
 However,
utilizing
stick‐wood
results
in
much
of
the
available
biomass
not
being
 used.
Wood
that
is
too
large
or
too
small,
smaller
tops
and
limbs
that
are
bent
 and/or
tangled,
or
tops,
which
contain
leaves,
cones,
or
needles,
are
generally
too
 difficult
to
handle
in
a
stick‐fired
boiler.
Typically,
stick
fired
boilers
use
similar
 species
as
woodstoves,
thus
the
primary
species
to
be
used
are
spruce,
birch
and,
in
 some
cases,
aspen.

Cottonwood
may
be
burned,
but
BTU
density
is
much
less
than
 the
other
species.

The
burn
chamber
of
the
boilers
is
designed
for
straight
stick‐ wood
of
about
4
feet
in
length.
The
wood
used
is
generally
air‐dried
to,
hopefully,
 25%
moisture
content,
“seasoned
for
one
year”.


The
stick‐fired
boilers
used
as
the
 basis
of
evaluation
for
this
study
are
models
manufactured
by
Garn.

A
number
of
 Garn
Boilers
are
already
installed
in
Alaska.

 
 The
Garn
boilers
are
manually
fed.
For
each
burn,
the
operator
must
load
the
 combustion
chamber
with
new
stick‐wood,
and
manually
start
the
fire.
Once
the
fire
 is
lit,
the
chamber
door
is
shut,
and
the
fire
burns
until
all
the
fuel
is
consumed.
 However,
as
noted
above,
it
would
take
a
little
over
two
hours
of
burn
to
fully
heat
 the
storage
tank.

A
single
load
of
wood
will
not
burn
for
two
hours,
meaning
that
 each
burn
must
consist
of
more
than
one
load
of
wood.

In
addition,
during
the
time
 the
burn
is
taking
place,
heat
is
being
extracted
from
the
tank
to
meet
the
heating
 load.

Although
a
“burn”
is
treated
as
a
single
event
in
this
study,
it
is
important
to
 note
that
at
or
near
peak
load,
a
burn
could
take
as
long
as
three
hours
to
complete,
 and
require
two
to
three
“reloads”
of
the
combustion
chamber.
(A
complete
burn
is
 defined
herein
as
burning
enough
fuel
to
raise
the
storage
tank
from
120
deg
F
to
 200
deg
F,
even
as
heat
is
being
extracted
from
the
tank
for
ongoing
heating.)
Thus,
 although
the
number
of
burns
is
limited
(in
this
study)
to
no
more
than
four
a
day,
 this
could
still
imply
roughly
9
‐
10
hours
a
day
of
loading
and
burning
the
 combustion
chamber.
 
 As
with
any
stick‐fired
appliance,
the
fuel
should
be
kept
dry,
and
should
be
located
 close
to
the
point
of
use.
Therefore,
any
building
or
structure
constructed
to
house
 the
boiler
should
have
sufficient
space
to
stack
cordwood.
The
amount
of
wood
to
be
 stored
within
the
building
(as
opposed
to
in
a
wood
yard)
depends
on
the
site
 conditions.
In
harsh
conditions,
it
may
be
desirable
to
store
several
days’
worth
of
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
8
 cordwood
(at
peak
load
consumption
rate)
in
the
boiler
building,
in
case
weather
 keeps
the
operator
from
being
able
to
re‐stock
the
building
from
the
wood
yard.
On
 the
other
hand,
in
all
cases,
the
existing
oil‐fired
system
is
assumed
to
be
left
in
place
 as
back
up,
so
this
may
limit
how
much
wood
the
operator
chooses
to
store
in
the
 boiler
building.

Regardless
of
how
much
wood
is
stored
in
the
boiler
building,
 considerable
manual
labor
will
be
required
to
get
the
sticks
from
the
wood
yard
to
 the
building;
labor
to
load,
unload,
and
stack
the
wood.
Because
no
equipment
is
 required
once
the
stick‐wood
reaches
the
yard,
the
material
handling,
though
labor
 intensive,
is
not
subject
to
equipment
breakdowns.

 Chip‐Fired
Boilers

 These
automated
boilers
burn
chipped
biomass,
which
can
come
from
virtually
any
 size
of
tree,
or
any
part
of
the
tree,
although
there
are
sometimes
limits
on
the
 amount
of
needles
and
leaves.
The
fuel
is
more
highly
processed
than
stick‐wood
in
 order
to
achieve
uniform
chip
size,
and
thus
slightly
more
expensive
on
a
unit
basis.
 Fuel
is
dried
in
the
woods
for
one
year
to
reach
an
ideal
moisture
content
of
below
 25%.
The
flip
side
of
the
higher
cost
of
processing
is
that
a
much
higher
fraction
of
 the
available
biomass
(tops,
limbs,
cones,
needles,
etc)
can
generally
be
used
in
a
 chip‐fired
boiler.

This
is
especially
important
in
an
area
where
biomass
yields
are
 low.
 
 An
automated
boiler
is
intended
to
run
for
long
periods
with
no
supervision
and
is
 dependent
on
its
material
handling
systems.
Fuel
must
be
introduced
into
the
boiler
 automatically,
and
the
ash
removed.
Weismann
boilers
can
provide
the
systems
 needed
to
fuel
and
de‐ash
the
boilers,
but
the
trade‐off
for
this
automation
is
 additional
maintenance,
and
more
potential
failure
points.
In
order
to
make
chip‐ fired
boilers
feasible
in
the
interior
of
Alaska,
it
will
be
important
to
minimize
the
 length
of
the
material
handling
“chain”,
as
well
as
the
number
of
moving
parts.
 Ideally,
a
single
auger
would
pull
fuel
out
of
a
fuel
bin,
which
would
be
manually
 filled
periodically
(manual
here
implies
a
person
running
a
front
loader
or
similar
 machine).
The
chips
would
slide
by
gravity
to
the
auger
inlet,
minimizing
failure
 points.
In
practice,
the
feed
process
can
be
fully
automated,
but
this
is
not
feasible
 on
the
scale
of
boiler
plants
considered
in
this
study,
and
it
presents
too
many
 potential
points
of
failure.

 
 Chip
fired
boilers
being
considered
can
take
up
to
50%
moisture
fuel.

However,
a
 realistic
and
more
efficient
use
of
biomass
would
be
to
dry
the
fuel
to
25%.

This
has
 a
significant
impact
on
the
amount
of
BTUs
recovered
from
fuel
used
and
can
reduce
 the
harvest
impact.

 Ambler
Heating
Systems
 Three
scenarios
for
chip‐fired
district
heating
systems
were
modeled
for
Ambler.

In
 addition,
multiple
scenarios
were
modeled
on
a
building‐by‐building
basis,
 comparing
chip‐fired
boilers
to
stick
fired
boilers.

The
results
are
discussed
in
 Boiler
Feasibility
Report,
and
model
output
can
be
found
in
Appendix
A.

The
largest
 chip‐fired
system
will
heat
nine
commercial
buildings
including
the
school
complex,
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
9
 water
treatment
plant,
sewer
heat
trace,
new
NANA
office
building,
tribal
office,
 clinic,
city
office
buildings
and
a
9
house
subdivision.

These
buildings
together
use
 an
estimated
67,616
gallons
of
fuel
oil
annually.


The
district
heating
system
will
 displace
99%
of
the
fuel.

The
cost
of
the
district
heating
system
is
projected
to
be
 $2.6
million
dollars
with
a
Net
Simple
Payback
(NSP)
of
11.1
years.

The
system
is
 projected
to
require
773
tons
of
wood
chips
at
25%
moisture
and
will
require
 harvesting
approximately
62
acres
annually
at
approximately
20
tons
to
the
acre
on
 average.

Projecting
a
realistic
rotation
time
of
40
years
to
produce
35
tons
to
the
 acre
with
some
forest
management,
impacted
area
is
2480
acres.

If
35
tons
per
acre
 can
be
produced
on
managed
acres,
then
the
amount
of
acres
required
to
support
 the
entire
system
is
reduced
to
only
883
acres
on
a
40‐year
rotation.
 
 The
largest
individual
stick
fired
system
modeled,
and
one
that
is
practical,
was
 installation
of
2
Garn
stick‐fired
boilers
to
heat
the
school
complex,
water
treatment
 plant
and
the
sewer
system.

The
system
would
displace
92%
of
the
estimated
 43,000
gallons
used
annually,
which
is
39,824
gallons
of
fuel.


The
projected
cost
of
 the
system
would
be
$559,390
and
the
NSP
would
be
4.43
years.

The
system
would
 require
332
cords
of
wood
annually,
which
is
approximately
20
acres
harvested
 annually.

This
would
be
800
acres
over
a
40‐year
rotation.

The
density
of
 cottonwood
is
such
that
this
species
would
probably
not
be
used
for
cord
wood
 boilers,
although
could
be.

Thus,
the
target
species
would
be
aspen,
birch,
black
 spruce
and
white
spruce.
 Shungnak
Heating
Systems
 Four
scenarios
for
chip‐fired
district
heating
systems
were
modeled
for
Shungnak.

 In
addition,
multiple
scenarios
were
modeled
on
a
building‐by‐building
basis
 comparing
chip‐fired
boilers
to
stick
fired
boilers.

The
results
are
discussed
in
 Boiler
Feasibility
Report
and
model
output
can
be
found
in
Appendix
B.
 
 The
largest
chip‐fired
system
will
heat
five
commercial
buildings
including
the
 school
complex,
water
treatment
plant,
new
proposed
NANA
office
building,
city
 office,
clinic
and
44
houses
in
subdivisions.

These
buildings
together
use
an
 estimated
77,833
gallons
of
fuel
oil
annually.


The
district
heating
system
will
 displace
98%
of
the
fuel.

The
cost
of
the
system
is
projected
to
be
$3.4
million
 dollars
with
a
Net
Simple
Payback
(NSP)
of
12.5
years.

The
system
is
projected
to
 require
885
tons
of
wood
chips
annually
at
25%
moisture
and
will
require
 harvesting
approximately
70.5
acres
annually
at
approximately
20
tons
to
the
acre
 on
average.

Projecting
a
realistic
rotation
time
of
40
years
to
produce
35
tons
to
the
 acre
with
forest
management,
impacted
area
is
2820
acres
for
40
years.

If
35
tons
 per
acre
can
be
produced
on
managed
acres,
then
the
amount
of
acres
required
to
 support
the
entire
system
is
reduced
to
only
1011
acres
on
a
40‐year
rotation.
 
 The
two
largest
individual
stick
fired
systems
modeled,
and
that
was
practical,
was
 installation
of
a
Garn
stick‐fired
boiler
to
heat
the
school
and
one
to
heat
the
new
 NANA
office
building.

Together
these
two
individual
systems
would
displace
93.5%
 of
the
estimated
36,000
gallons
used
annually,
which
is
33,661
gallons
of
fuel.


The
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
10
 projected
cost
of
the
school
system
would
be
$348,728
and
the
NSP
would
be
9.72
 years.

The
system
would
require
174
cords
of
wood
annually,
which
is
 approximately
9
acres
harvested
annually.

This
would
be
360
acres
over
a
40‐year
 rotation.

The
projected
cost
of
the
NANA
Office
building
system
would
be
$264,261
 and
the
NSP
would
be
approximately
3.33
years.

The
system
would
require
102
 cords
of
25%
moisture
wood,
which
is
approximately
5‐6
acres.

The
target
species
 are
aspen,
birch,
black
spruce
and
white
spruce.

If
35
tons
per
acre
of
wood
(aspen
 and
birch)
can
be
grown
to
4
inch
diameter
in
a
40
year
rotation,
as
anticipated
 through
forest
management,
then
the
amount
of
acres
for
both
systems
would
be
 approximately
315
acres
of
land.

 Kobuk
Heating
Systems
 Four
scenarios
for
chip‐fired
district
heating
systems
were
modeled
for
Kobuk.

In
 addition,
multiple
scenarios
were
modeled
on
a
building‐by‐building
basis
 comparing
chip‐fired
boilers
to
stick
fired
boilers.

The
results
are
discussed
in
 Boiler
Feasibility
Report
and
model
output
can
be
found
in
Appendix
B.
 
 The
largest
chip‐fired
system
will
heat
five
commercial
buildings
including
the
 school
complex,
water
treatment
plant,
new
proposed
NANA
office
building,
city
 office,
clinic
and
a
9
house
in
subdivision.

These
buildings
together
use
an
estimated
 44,441
gallons
of
fuel
oil
annually.


The
district
heating
system
will
displace
98%
of
 the
fuel.

The
cost
of
the
system
is
projected
to
be
$2.2
million
dollars
with
a
Net
 Simple
Payback
(NSP)
of
14.1
years.

The
system
is
projected
to
require
630
tons
of
 wood
chips
annually
at
25%
moisture
and
will
require
harvesting
approximately
50
 acres
annually
at
approximately
20
tons
to
the
acre
on
average.

Projecting
a
 realistic
rotation
time
of
40
years
to
produce
35
tons
to
the
acre
with
forest
 management,
impacted
area
is
2000
acres
for
40
years.

If
35
tons
per
acre
can
be
 produced
on
managed
acres,
then
the
required
land
base
to
support
the
entire
 system
is
reduced
to
only
720
acres
on
a
40‐year
rotation.
 
 The
2
largest
individual
stick
fired
systems
modeled,
and
that
were
practical,
was
 installation
of
the
largest
model
of
Garn
stick‐fired
boilers
to
heat
the
school,
water
 treatment
plant,
teacher
housing
and
the
City
Office
and
the
middle
size
Garn
to
heat
 the
NANA
office
building.

The
systems
would
displace
92.9%
of
the
estimated
 36,500
gallons
used
annually,
which
is
33,911
gallons
of
fuel.


The
projected
cost
of
 the
school
complex
system
would
be
$441,706
and
the
NSP
would
be
6.83
years.

 The
system
would
require
179
cords
of
wood
annually,
which
is
approximately
9
 acres
harvested
annually.

This
would
be
360
acres
over
a
40‐year
rotation.

The
 projected
cost
of
the
NANA
office
building
system
would
be
$264,261
and
the
NSP
 would
be
approximately
3.33
years.

The
system
would
require
102
cords
of
25%
 moisture
wood,
which
is
approximately
5‐6
acres
or
240
acres
over
a
rotation.

The
 target
species
would
be
aspen,
birch,
black
spruce
and
white
spruce.

If
35
tons
per
 acre
of
wood
(aspen
and
birch)
can
be
grown
to
4‐5
inch
diameter
in
a
40
year
 rotation,
as
anticipated
through
forest
management,
then
the
amount
of
acres
for
 both
systems
would
be
approximately
321
acres
of
land.

 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
11
 
 Effects
of
moisture
content
on
biomass
utilization
 This
discussion
is
not
meant
to
be
a
detailed
treatise
on
the
issue
of
moisture
 content
of
wood
relative
to
combustion,
but
to
create
an
awareness
of
how
the
 forest
management
and
wood
harvest
systems
will
impact
the
amount
of
wood
 required
and
efficiencies
of
wood
heating
systems
in
a
village,
relative
to
moisture
 content
of
wood
when
burned.
 
 The
amount
of
biomass
required
to
fuel
a
district
heating
system
depends
on
the
 total
BTU
demand
of
the
system
and
the
efficiency
of
the
burning
process.

Most
 modern
boilers,
both
stick
and
chip
fired,
are
essentially
as
efficient
as
possible
for
 wood
at
80‐85%.

Oil
boilers,
in
comparison,
are
typically
85%
efficient
when
 operating
properly.

Wood
burners
of
all
sorts
will
specify
an
ideal
range
of
moisture
 contents
for
fuel.

Most
standard
gasifying
boilers
can
burn
from
10%
‐
55%
 moisture
content,
but
typically
have
an
ideal
range
of
20‐30%
moisture
 requirements.


Actual
BTUs
in
wood
is
species
dependent,
but
only
slightly.

Species
 differ
only
by
about
10%
based
on
weight
and
moisture,
so
for
this
discussion,
we
 assume
that
local
species
in
the
Upper
Kobuk
area
are
similar
in
BTU
amounts
based
 on
weight.

However,
density
of
wood
makes
some
wood
heavier
in
smaller
volume
 that
others,
for
instance,
a
pound
of
birch
at
20%
moisture
is
much
smaller
than
a
 pound
of
cottonwood
at
20%
moisture.
 
 However,
there
are
significant
differences
in
recoverable
BTUs
through
the
 combustion
process
based
on
the
moisture
content
of
the
wood
going
into
the
 combustor,
whether
in
cord
wood
or
in
chips.


This
is
simply
because
the
combustor
 cannot
burn
water
and
must
“dry”
the
fuel
in
the
burning
process.

For
instance,
if
a
 40‐pound
armload
of
split
firewood
for
a
wood
stove
at
20%
moisture
(seasoned),
 adds
approximately
one
gallon
of
water
into
a
wood
stove
with
the
wood,

at
40%
 moisture
content,
the
amount
would
be
two
gallons
of
water.

The
wood
stove
must
 dry
the
wood
to
burn
it
during
the
combustion
process,
thus
the
amount
of
heat
 captured
for
heating
is
much
less
(Table
1).
 
 Green,
freshly
cut,
wood
is
typically
45‐60%
moisture
content.
It
follows
that
if
 wood
is
harvested,
chipped
and
delivered
to
the
boiler,
recoverable
BTUs
will
range
 from
3825‐3400
BTUs/lb
(Table
1).

Chips
do
not
dry
very
effectively
in
a
pile
and,
 in
fact,
begin
to
compost
over
time.

Chip
dryers
can
be
installed
in
the
system,
 however,
a
significant
amount
of
energy
is
required
for
drying.

If
wood
is
 “seasoned”,
air‐dried
to
20‐25%
moisture
content,
then
chipped
and
injected
into
 the
system
the
amount
of
recoverable
BTUs
in
the
system
essentially
doubles
to
 6800
BTUs/LB.

This
is
a
significant
point
in
the
development
of
a
Biomass
Energy
 System
that
is
using
local
resources
to
power
the
system.

However,
conservative
 moisture
content
on
average
will
be
from
25%‐35%.

AWEA
recommends
boilers
 capable
of
burning
up
to
50%
moisture,
since
management
systems
do
not
always
 work
to
the
ideal
level.
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
12
 Table
1.

Effects
of
moisture
on
deliverable
BTUs
 The
Effect
of
Fuel
Moisture
on
Deliverable
Wood
Heat

 Moisture
Content
 (MC)
wet
basis
 (%)
 0
15
20
25
30
35
40
45
50
55
 Higher
Heating
 Value
as
fired
 Btus/lb
 8,500
7,275
6,800
6,375
5,950
5,525
5,100
4,575
4,250
3,825
 
 Actual
annual
wood
demand
can
vary
depending
on
whether
a
management
 strategy
is
developed
to
“dry”
or
“season”
wood.


As
described
above,
moisture
 content
of
the
wood
going
into
the
boiler
has
a
tremendous
affect
on
the
number
of
 tons
of
wood
chips
required
annually
to
operate
the
heat
system.

In
addition,
the
 number
of
acres
to
secure
the
required
wood
varies
with
tons
per
acre
of
wood
 growing
on
the
site
and
the
type
of
harvest
strategy
for
regeneration,
either
thinning
 or
patch
clear‐cut.


 
 For
example
annual
wood
demand
for
the
largest
chip
system
modeled
in
Ambler
 ranges
from
1300
green
tons
at
50%
moisture
down
to
773
tons
per
year
at
25%
 moisture.

Difference
in
acres
harvested
is
not
large
on
annual
bases,
which
are
70
 acres
at
50%
moisture
and
62
acres
at
25%
moisture.

However,
over
a
40
year
 rotation
the
difference
in
the
total
acreage
needed
to
fuel
the
system
is
2800
acres
 for
50%
moisture
fuel
and
2480
for
25%
fuel.

By
managing
for
seasoned
wood,
 number
of
acres
impacted
by
harvest
is
reduced
by
11.5%.


Our
range
of
estimates
 is
from
12
‐20%
reductions
in
the
number
of
acres
needed
to
support
a
biomass
 project,
if
wood
is
dried
to
25%
moisture
prior
to
feeding
the
boiler.

An
additional
 benefit
of
drying
wood
in
the
forest
is
the
reduced
cost
of
wood
delivery.


Moving
 green
wood
at
50%
moisture
is
heavier,
and
moving
water
costs
both
in
equipment
 wear
and
tear
and
cost
of
fuel.
 
 Cost
of
wood
delivered
to
the
boiler
has
been
modeled
for
off
road
villages,
 depending
on
types
of
equipment
used,
economies
of
scale
and
local
conditions.

The
 Upper
Kobuk,
like
all
interior
rural
villages,
has
few
roads
and
must
deal
with
the
 local
terrain
and
weather
conditions.


Harvesting
and
wood
hauling
will
likely
occur
 during
late
summer
months
after
the
ground
has
had
time
to
dry,
and
during
winter
 months
after
freeze
up.

Delivered
costs
are
conservatively
expected
to
be
as
high
as
 $175‐$200
per
green
ton
for
wood
chips.

Even
at
this
high
cost,
wood
energy
 systems
appear
to
be
financially
feasible
if
well
designed.

Final
feasibility
depends
 on
the
inherent
efficiency
of
the
system
installed.

A
critical
component
of
the
 system
is
a
well‐designed
harvest
system
and
sustainable
forest
management
 program.

Drying
wood
to
25‐35%
moisture
can
occur
if
properly
managed
and
 decked
for
a
year
in
advance
of
use.

If
the
forest
is
managed
properly
and
targeted
 toward
the
fastest
growing
trees,
which
are
cottonwood,
aspen
and
birch,
then
a
 biomass
rotation
is
achievable
in
forty
years.

However,
if
stick
fired
boilers
are
 used,
the
target
species
will
be
spruce,
aspen
and
birch.

Cottonwood
can
be
burned
 in
these
boilers,
but
the
volume
of
wood
required
for
BTU
value
is
high,
even
when
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
13
 dried
to
25%
moisture.

Thus,
at
any
single
loading
of
the
boiler,
the
actual
number
 of
BTUs
is
less
with
cottonwood.
 Sustainable
Forest
Management
 A
five‐year
harvest
plan
should
be
developed
with
specific
harvest
locations
 mapped
in
a
GIS
system.

The
plan
should
be
maintained
in
a
company
GIS
system.

 Since
actual
annual
harvest
plans
must
adapted
to
weather
and
site
conditions
and
 these
will
change,
an
annual
update
of
the
five‐year
plan
should
be
completed.


So
 harvesting
is
based
on
an
annual
and
a
five‐year
plan
with
an
annual
update.
 
 Forest
management
and
regeneration
will
be
accomplished
through
stump
 regeneration
of
hardwoods
including
cottonwood,
birch
and
aspen.

Each
stand
 should
be
surveyed
after
three
years
to
make
sure
that
the
stand
is
properly
 regenerating.

If
regeneration
is
not
being
accomplished,
then
a
plan
can
be
made
for
 augmenting
the
stand
with
rooted
cuttings.

These
are
simply
hardwood
cuttings
 that
have
been
rooted
the
prior
year
then
planted
the
following
spring.

This
is
a
 simple
inexpensive
method
for
enhancing
natural
regeneration.
 Native
Allotments

 Native
allotments
should
be
indentified
in
the
GIS
system
during
development
of
the
 annual
and
five‐year
harvest
plan.

Harvesting
should
avoid
travel
across
allotments
 and
harvesting
on
allotments
unless
allotment
owners
should
want
to
develop
 agreements
with
the
harvesting
group.

 Review
of
Harvest
Equipment
Types
 Timber
Harvest
Overview
 The primary timber harvest review will be based on the largest chip fired heating systems modeled for each village. At the level of harvest summarized above, mechanized systems will need to be used taking the harvesting process beyond subsistence wood gathering process of snow machine, wood sleds, and chain saws. This discussion will describe the systems required to support the larger heat systems to provide the greatest economy of scale, financially, for both chip systems and cordwood. Smaller system configurations with greater manual labor associated with them can be used to harvest smaller cordwood systems. The cordwood systems will be described based on the assumption that a midsize scale of fuel oil displacement will occur using stick-fired boilers, probably in multiple locations within a village. These system descriptions will allow for future discussion of harvest requirements needed to support the scale of the biomass heating system chosen for future installation. Another assumption of the harvest assessment is that Ambler will be a stand-alone harvest system and Kobuk and Shungnak will share a harvest system for both villages. This increases the economy of scale for the harvest system, as the same land base will serve both of the western villages. It is necessary to plan for both summer and winter harvesting in order to meet these production goals, particularly in the first few years. However, most hauling from the Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
14
 woods will be done in winter conditions when the ground is frozen. Accordingly, the harvest system must be capable of working well in the extreme temperature ranges and types of terrain found in the Upper Kobuk Valley. The forest is widely distributed over the ownership of the NANA Regional Corporation. However, Ambler has significant forest close to and surrounding the village. Kobuk and Shungnak have forest near the villages, but Shungnak will require the longest hauling distance and will only be able to have wood delivered in the winter when the wet tundra surrounding the village is frozen. The road system in this area is limited to within a short distance of each village, except Kobuk, where mining roads allow much greater access to the forest. Economics severely limit the feasibility of road construction for the harvest activities, so the harvest program must be able to operate in a remote, roadless setting utilizing permanent trails developed with the harvest equipment, as needed, to supply annual harvest needs. The harvest system as a whole must be flexible enough to be used in both summer and winter applications. All machines should be integrated into a system and each machine should have multiple applications and multiple attachments. A key issue is determining how much woody biomass will be produced during each season. Summer activities will require mobilization and wood fuel transport based on where equipment can travel around wetlands and/or cross streams to “dry summer harvesting stands”, and winter harvesting can only occur when the ground is frozen solid enough to support the expected load weights. Ice travel is discussed in detail below. Rivers can be used as travel corridors only when safe operations are implemented. In some situations, the river can be used as a road, in others, there may only be a need to cross the river. Operations must be located and configured where they can be carried out both efficiently and safely during each season. We assume that most of the transport of wood from the field to the village will occur during winter months when the ground is frozen. Each
harvest
site
will
have
its
own
set
of
unique
circumstances
that
will
influence
 harvest
implementation.
The
operations
manager
must
learn
how
to
recognize
site
 characteristics
and
risks
in
order
to
make
preparations
to
address
any
specific
 challenges
well
in
advance
of
mobilizing
equipment
and
personnel.

As
part
of
the
 development
process
for
a
wood
energy
program,
a
five‐year
harvest
plan
should
be
 developed.


This
plan
should
be
updated
annually
based
on
the
previous
year’s
 management
activities. Wood
Fuel
Management
 Moisture
content
of
wood
and
its
impacts
on
efficiency
have
been
discussed
 previously.

Because
of
these
efficiencies,
it
makes
sense
to
manage
the
harvest
and
 wood
feeding
systems
to
as
low
moisture
content
as
possible.


A
realistic
goal
is
to
 store
wood
in
the
round
for
at
least
one
summer
season.

Hopefully,
the
wood
will
 dry
to
25%
moisture
or
less.

One
scenario
would
be
to
harvest
wood
in
the
early
 spring
while
the
ground
is
still
frozen
and
deck
the
wood
in
the
forest
where
it
is
 felled
in
loose
piles;
or
while
the
ground
is
still
frozen
the
harvested
wood
can
be
 processed
into
whole
tree
logs
and
brought
to
a
staging
wood
yard
near
the
village
 for
drying.

Before
green
up
in
spring
is
the
time
of
year
the
wood
has
the
lowest
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
15
 moisture
content,
especially
the
hardwoods.

The
wood
will
then
dry
during
the
 summer
season
to
various
levels
of
moisture
content,
depending
on
the
weather
 conditions.

Depending
on
the
travel
conditions
from
the
site
to
the
village,
whole
 trees
may
be
moved
to
the
wood
yard
in
town
and
chipped
into
storage
or
stored
for
 future
chipping
in
a
wood
yard.

In
some
cases,
moving
whole
trees
may
not
be
 practical
because
of
trail
limitations.

In
that
case,
tops
are
cut
off
the
trees
and
logs
 are
moved
into
the
village
to
be
chipped.


The
trade
off
is
that
logs
are
easier
to
 move
than
whole
trees,
but
require
more
time
to
manufacture
and
adds
cost.

Also,
 depending
on
species,
tops
and
limbs
may
be
15‐25%
of
the
tree,
thus
if
only
logs
 are
hauled,
a
portion
of
the
potential
biomass
will
be
left
in
the
woods.

These
 decisions
are
site
and
terrain
specific,
but
equipment
components
should
be
 developed
to
make
the
most
efficient
use
of
biomass.

Of
course,
if
stick‐fired
boilers
 are
selected,
all
tops
will
be
removed
and
logs
only
will
be
transported.
 
 A
second
scenario
is
to
chip
trees
in
the
field
and
move
chips.


This
process
is
more
 complicated
and
requires
specialized
equipment.


Chipping
in
the
forest
is
being
 done
more
and
more
in
Europe
as
a
more
efficient
overall
process.


The
approach
 has
been
recommended
for
Fort
Yukon
as
one
option,
and
most
likely
will
be
tried.

 This
option
will
not
be
recommended
for
the
Upper
Kobuk
villages
at
this
time
 because
of
the
logistics
of
moving
a
chipper
into
the
field
and
the
specific
equipment
 required
to
store
and
haul
chips
from
the
field,
rather
than
logs
or
whole
tree
 hauling.

If
proven
in
Fort
Yukon,
and
the
economy
of
scale
is
such
in
the
Upper
 Kobuk,
the
systems
described
in
this
report
can
be
augmented
to
achieve
this
 approach.
 Harvesting
System
Component
Activities
 There
are
many
options
for
how
to
harvest
trees
with
an
automated
system.

The
 system
depends
on
what
the
end
product
is
for
feeding
the
boiler
as
well
as
how
the
 processing
is
to
be
done.

Linkage
between
the
harvest
system
and
the
boiler
is
 critical.

Integrating
the
harvest
system
equipment
into
landscape
conditions
is
also
 critical
for
success.
 Chip
fired
boiler
wood
requirements
and
harvest
scenarios
 A
chip‐fired
boiler
requires
clean
chips
free
of
leaves,
dirt,
rocks,
etc.,
preferably
at
 25%
moisture
content.


Dirt
contamination
can
cause
clinker
build
up
in
the
boiler,
 and
storage
and
transportation
methods
should
take
this
into
consideration.

Chip
 fired
boilers
have
an
automatic
feed
that
is
adjusted
to
the
correct
speed
for
the
 specific
demand
placed
on
the
boiler.

Ideally,
chips
are
uniform
in
size
at
1‐2
inch
 squares
or
rectangles
and
approximately
¼
to
½
thick.

This
helps
the
feeding
 mechanism
insert
wood
smoothly
into
the
boiler.

Ten
to
twenty
percent
variations
 are
acceptable,
however,
long
stringers
will
need
to
be
filtered
out
of
the
mix
as
it
 proceeds
into
the
boiler.

An
automated
de‐asher
is
part
of
the
automated
system.

 Chip
quality
is
a
process
that
starts
with
harvesting
the
tree
and
is
integral
 throughout
the
harvesting
system.

A
well‐maintained
chipper
is
essential.
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
16
 An
automated
system
for
producing
chips
is
essential
at
the
scale
of
demand
 modeled
for
the
boiler
systems
in
Ambler,
and
then
in
Kobuk
and
Shungnak.

The
 system
components
include
the
following
activities:
  Felling:

Tree
felling
is
laying
the
tree
on
the
ground,
and
can
be
 accomplished
with
several
different
types
of
felling
heads
and
 carriers/machines;
  Skidding
and
Decking:

Whole
trees
are
then
skidded
and
decked
in
lose
piles
 for
drying/seasoning;
  Transporting:

If
possible
whole
trees
are
then
loaded
and
hauled
to
the
 village
along
previously
designated
trails
with
special
types
of
equipment
for
 whole
tree
hauling.

If
hauling
whole
trees
is
not
possible
from
a
specific
site,
 the
trees
must
be
processed
in
the
woods
cutting
limbs
and
tops
off
and
 loading
on
a
log
trailer;
  Unloading
and
Storing:

The
whole
trees
or
logs
will
then
be
unloaded
into
a
 temporary
storage
wood
yard
to
wait
for
chipping,
ideally
in
a
location
where
 they
can
the
be
chipped
directly
into
storage;
  Chip
Processing
and
Storing:

A
wood
chipper
will
need
to
be
large
enough
to
 handle
multiple
whole
trees
at
once
and
requires
a
method
to
feed
the
trees
 into
the
chipper.

Once
chips
are
in
dry
storage,
a
machine
is
required
to
fill
 the
boiler
chip‐feeding
bin.

This
machine
can
and
should
be
one
of
the
 harvest
system
pieces
of
equipment.
 
Figure
1.

Example
of
good
quality
clean
chips
required
to
feed
an
automated
boiler
system.
 Stick
fired
boiler
wood
requirements
and
harvest
scenarios
 A
stick‐fired
boiler
requires
four‐foot
length
round
logs
typically
3‐8
inches
in
 diameter
as
they
must
be
hand
fed
into
the
boiler
burn
box.

Shorter
lengths
work
as
 well,
as
does
split
firewood.


However,
the
best
product
is
one
that
can
be
handled
 easily
and
can
fill
the
firebox
completely
with
limited
spaces.

This
allows
for
 maximum
number
of
BTUs
to
go
into
the
boiler
at
any
one
firing
and
increase
burn
 efficiency.

Any
component
discussed
below
can
be
done
in
the
traditional
way
by
 hand
labor
if
the
system
requirements
are
small
enough.

This
discussion,
however,
 will
assume
that
the
boiler,
or
multiple
boilers,
requirements
are
large
enough
to
 require
an
automated
system.
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
17
 An
automated
harvest
system
that
produces
cordwood
for
a
stick‐fired
boiler
must
 perform
the
following
tasks:
  Tree
felling
is
cutting
the
tree
and
laying
it
on
the
ground;
  The
tree
is
then
skidded
into
piles
and
decked
for
drying;
  The
tree
must
then
be
delimbed
and
cut
into
manageable
lengths,
typically
in
 4‐foot
increments
for
ease
of
cutting,
once
delivered
to
the
storage/boiler
 site.

If
long
lengths
are
made
initially,
this
step
can
be
done
while
cutting
as
 well.
  The
8‐12
foot
logs
are
then
loaded
for
transport
to
the
village
along
 previously
designated
trails;
  The
logs
are
unloaded
into
a
wood
yard
and
stored
for
further
processing
 into
correct
lengths
(which
can
be
done
with
chain
saws)
and
stored
for
 feeding
the
boiler;
or
if
multiple
stick
fired
boilers
are
in
use
at
multiple
sites,
 the
logs
need
to
transported
to
storage
at
specific
sites
next
to
boilers.

This
 local
storage
should
be
covered,
but
not
heated.
 Timber
Harvest
–
Tree
Felling
 Fuel wood harvesting systems in the Upper Kobuk must be able to efficiently produce both stick firewood and wood chips depending on system demands. The majority of stick firewood in the Upper Kobuk is white and black spruce, birch, and aspen to be used in stick-fired boilers. Wood chips can be produced from all tree species and some willow species. Much of the standing forest inventory of woody biomass is in hardwood species such as aspen, cottonwood and birch. The weight and financial limitations will influence the maximum size of trees that the equipment can safely handle. It is anticipated that the majority of timber harvested will be whole tree, when possible, to move whole trees to the village for chipping. In this case, it is likely that the largest diameter that will be mechanically harvested is 12” to 14” diameter at breast height (DBH) the smallest trees will be 3”-8” DBH. Hydraulically powered tree shears provide the most economical and reliable option to mechanically fell timber of this size. A skid steer machine (on tracks with sheers) is an excellent felling mechanism. The picture in Figure 1 is a wheeled skid steer. Tracts can be added or the machine can be purchased set up with tracks. Smaller shears can be mounted on 60 hp excavators with the hydraulic plumbing and controls suitable for this purpose. The excavator-mounted shears would be suitable to harvest 3”-10” DBH stems such as smaller black spruce, poplar, aspen and birch. Figure 1 has an excavator with a “cut to length harvest head” for making logs. This type head not only will cut the tree but also will strip the limbs and cut the log into prescribed lengths and place them in a pile. If large amounts of cordwood are the product needed, this type of machine and harvester head is the most efficient. If whole trees are to be piled and then moved to the village for chipping, the skid steer with a shear head is the most efficient machine configuration. It is important to note that these tree size limitations are smaller than some of trees in the forest. The decision of whether or not to hand fell the larger stems will be made on-site. It is likely that in many cases the larger stems will simply be left standing while the smaller stems are harvested, achieving a desirable partial cut harvest pattern in some areas. Also Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
18
 the managed future forest stand is expected to be 4”-8” DBH at harvest maturity. Note
the
guarding
on
the
excavator
in
Figure
2.

This
is
a
safety
requirement
for
 machines
that
work
in
forestry.

 A Fecon skid steer in Figure 2 has the guarding required for a skid steer shear harvester on tracks. The skid steer below is for illustrating the shear and would require tracks rather than tires.
 


Figure
2.

Skid
steer
machine
with
felling
shears
for
felling
trees
(left)
and
a
small
excavator
for
 felling,
limbing
and
cutting
to
length
trees
into
logs
(right)
armored
for
wood
harvesting.
 Timber
Harvest
–
Skidding,
Decking,
Loading
and
Transport

 Once
the
tree
is
felled,
it
will
need
to
be
skidded
and
decked
to
dry
or
“season”,
 ideally
for
at
least
a
summer
season,
to
reduce
moisture
in
the
wood.


After
a
 season,
the
wood
will
be
moved
to
the
village
in
form
of
a
log
or
whole
tree,
if
 chipping.

Leaves
and
needles
will
be
gone
from
the
tree
at
this
point.

By
utilizing
 whole
tree
for
chips,
the
process
increases
actual
biomass
utilization
by
15‐30%
 depending
on
size
and
species
of
the
tree
harvested
and
by
utilizing
tops
and
limbs.

 Also,
there
is
greater
cost
in
manufacturing
logs
in
the
woods
for
transport.

 However,
transport
of
logs
is
simpler
than
whole
tree
transport.

The
best
system
 will
be
able
to
do
both,
and
the
decision
of
whole
tree
versus
logs
will
be
determined
 by
the
site
and
travel
corridor
conditions.

It
will
be
most
efficient
if
the
 management
process
is
directed
toward
whole
tree
harvesting
and
transport.
 
 The
machine
that
does
these
tasks
needs
to
be
versatile,
reliable
and
have
low
track
 pressure
on
the
ground.

Two
types
of
machines
are
possible
to
use:

An
articulated
 4
wheel
drive
tractor
that
has
hydraulics
on
the
front
and
back
and
can
operate
 equally
in
either
direction;
and
a
modern
tracked
skid
steer
machine.

Both
are
ideal
 for
these
applications.

Some
of
the
manufacturers
produce
skid
steer
configurations
 of
their
machines
that
are
built
to
fit
the
needs
of
forestry
applications.
Either
 machine
must
have
all
the
safety
specifications
mandated
by
OSHA,
particularly
 with
regard
to
cab
roll
over
protection
and
guarded
windshields.

 
 Skid
steer
machines
also
have
the
versatility
of
being
able
to
use
the
many
skid
steer
 attachments
that
are
available
for
a
wide
variety
of
applications.
We
noted
above
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
19
 that
this
type
of
machine
is
ideal
for
whole
tree
felling.

Caterpillar,
ASV,
Bobcat,
 Fecon,
and
Takeuchi
are
all
popular
machines
with
high
flow
options
and
“forestry
 packages”
(undercarriage
guarding,
Roll
Over
Protection,
etc.)
available.
Of
these,
 Fecon
seems
to
lead
in
the
development
of
some
of
their
smaller
models
such
as
the
 FTX100L
and
FTX148L
specifically
for
these
types
of
forestry
use.
These
Fecon
 models
are
well
suited
for
commercial
forestry
applications
in
the
Upper
Kobuk.
 Figure
3.

A
Fecon
skid
steer
with
a
front
grapple
for
loading
(left),
the
machine
also
could
have
a
 front
shear
as
in
Figure
1
and
other
attachments
for
skidding.

The
JCB
C4X
tractor
is
4‐wheel
drive
 and
a
perfect
compliment
to
work
with
the
skid
steer
or
as
a
stand‐alone
integrated
harvesting
 machine.
 
 They
can
be
used
as
a
carrier
for
log
skidding
with
grapple
or
cable
arch,
as
a
tow
 vehicle
for
a
small
log
forwarding
trailer,
as
well
as
a
log
loader
with
front‐end
 grapples
(Figure
3).

One
machine
can
be
used
to
fell,
skid,
and
load
logs
if
called
 upon
to
do
so.

This
type
of
versatility
is
critical
for
remote
operations
such
as
the
 Upper
Kobuk. 
 Like
all
skid
steer
machines
manufactured
today,
the
Fecon
models
can
employ
most
 attachments
made
for
these
types
of
machines.
It
is
highly
recommended
that
 several
attachments
be
purchased
for
this
program.
These
include
a
rake
grapple,
 gravel
bucket,
dozer
blade,
14”
felling
shears,
snow
blower,
and
firewood
processor
 for
the
front
end
of
the
machine.
A
rotating
logging
grapple
should
also
be
 purchased
for
the
back
of
the
machine.

These
attachments
are
a
relatively
low
cost
 option
to
make
the
skid
steer
a
very
versatile
machine
that
can
reliably
accomplish
a
 variety
of
tasks.
This
versatility
will
prove
to
be
an
invaluable
asset
over
the
life
of
 the
project,
supplying
the
proper
tools
for
specific
situations
as
they
come
up,
 without
having
to
use
a
different
machine
for
each
specific
task.
 
 The
Fecon,
depending
on
proximity
to
adequately
sized
trees
(>6”),
would
require
 200‐300
hrs
(based
on
30
trees
per
hour
at
300
lbs
per
tree)
to
fell
and
pile
the
 minimum
annual
requirements
for
Ambler.
The
time
needed
to
skid
this
material
to
 a
load‐out
area
will obviously depend on distance. The
Fecon
alone
could
 theoretically
provide
the
minimum
annual
harvesting
requirements,
staged
for
 winter
shipment,
within
the
hours
allotted
for
spring
and
summer
harvesting.
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
20
 Using
a
4‐wheel
drive
tractor
(Figure
3)
is
an
option
to
assist
the
skid
steer
and
with
 similar
capacity
in
the
felling,
decking,
and
hauling
activities
and
would
serve
as
the
 primary
loader/unloader
and
trailer
hauler
for
transport.

Two
models
in
particular
 meet
minimum
specifications,
including:
  Four
Wheel
Drive
with
front
and
rear
tires
equal
size;
  Operator
ability
to
rotate
for
convenient
front
or
rear
operation;

  Hp
and
hydraulic
capability
to
accommodate
Kesla
Shear/
Grapple
 attachments,
load
and
unload
log
transport
trailers,
and
pull
trailers
of
 biomass
over
ice
roads
and
snow
trails
with
chains
in
the
Upper
Kobuk.


 
 There
are
two
models
of
tractors
that
could
effectively
be
used.
The
models
are
the
 New
Holland
TV
6070,
145
or
140,
and
the
JCB
4CX
(Figure
3).

The
New
Holland
is
 an
agricultural
tractor
that
lists
new
at
$100,000.
It
articulates
and
has
a
PTO
on
 both
the
front
and
rear
as
well
as
hydraulic
hook‐ups
and
valving.
The
JCB
lists
for
 $116,000
with
cab,
loader
and
14’
backhoe
(it
cannot
be
purchased
new
without
a
 backhoe).

Either
will
accommodate
shears,
delimbing
and
cut
to
length
 attachments,
grapple
loader
and
many
similar
attachments
as
the
Fecon
skid
steer.

 This
configuration
would
permit
the
tractor
to
fell
(if
needed)
and
shear
standing
 timber
up
to
9”
or
10”,
delimb
and
cut
to
length,
load
and
unload
trees
on/off
a
 trailer
it
pulls
(10
ton
trailer
is
$12,000),
pull
the
loaded
trailer
to
the
village,
feed
 the
chipper.

Figure
4
is
an
example
of
a
tractor,
trailer
and
loader
system
that
is
a
 great
transport
system.

These
systems
have
been
developed
and
proven
in
Finland,
 and
thus
are
suitable
for
the
terrain
in
the
upper
Kobuk.

Snow
depth
should
not
be
 an
issue
on
maintained
snow
packed
trails.

However,
the
tractor
must
not
be
used
 in
wet
boggy
conditions,
even
though
it
is
4‐wheel
drive.
 
 A
tractor
can
also
be
used
as
the
harvesting
machine
with
either
a
cut
to
length
 harvesting
head
attached
to
a
loading
crane
or
a
harvesting
shear
attached
to
the
 loading
crane
(Figure
5).

With
this
configuration
a
tractor
can
become
the
exclusive
 machine
in
the
harvest
system,
which
can
cut
whole
trees
or
cut
to
length
logs,
skid,
 pile,
load/unload,
haul
and
feed
the
chipper.

This
is
a
quite
versatile
capability.
 
 
 
 
 
 
 
 
 
 
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
21
 

 Figure
4.

Tractor,
10‐ton
log
trailer,
and
hydraulic
loader
grapple
(left).

Same
log
trailer
with
track
 on
back
tires
(right).

Trailer
can
come
with
PTO
driven
trailer
assist
for
moving
the
trailer
in
snow.

 The
trailer
above
has
loader
hydraulics
connected
to
the
tractor
but
mounted
on
the
trailer;
another
 configuration
is
a
trailer
with
a
self‐operating
loader
that
runs
on
a
small
engine
mounted
on
the
 tongue
of
the
trailer.
 
Figure
5.

Demonstrates
a
tractor
with
a
harvesting
and
cut
to
length
head
(left)
similar
to
what
is
on
 an
excavator
in
Figure
2.

Felling
shear
(right)
that
will
also
work
with
the
tractor
for
whole
tree
 harvesting.

The
same
arm
with
a
grapple
can
unload
and
load
trailers.
 Wood
transport
–
alternative
 Figure
6
is
a
Morooka
1500VD,
a
proven
track
machine
in
the
arctic.

This
machine
 comes
as
a
dump,
but
can
be
outfitted
with
hook
lift
mechanism
that
can
slide
on
 and
off
for
transporting
logs
or
bins
of
chips.

It
has
the
capacity
to
pull
a
10‐ton
log
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
22
 trailer
while
hauling
a
log
bunk
on
the
rear.

The
Morooka
is
versatile
with
rear
 hydraulics
for
potentially
connecting
to
a
hydraulic
loader.


If
there
are
concerns
 about
transporting
logs
in
winter
with
chains
on
a
tired
tractor,
this
could
be
the
 machine
to
take
the
place
of
the
tractor
as
the
primary
hauling
mechanism.

The
 machine
has
strong
towing
power
and
can
tow
a
similar
trailer
to
the
tractor
system
 described
as
well
as
a
log
bunk
on
the
back.

However,
the
machine
cannot
do
nearly
 as
many
tasks
as
the
tractor
described
above.

 
 
 
Figure
6.

Morooka
with
a
hook
lift
system
(left)
that
can
be
substituted
with
a
log
bunk
and

(right)
 Morooka
traveling
across
Norton
Sound
in
winter.

Above
is
an
example
of
loading
a
log
bunk
onto
a
 truck
(just
for
an
example)
rather
than
a
Morooka.

The
principle
is
the
same
however;
the
one
that
 would
go
with
the
Morooka
is
of
course
smaller.
 Wood
Chip
Production

 Whole
tree
hauling
 Whole
tree
hauling
is
specifically
for
making
chips
for
chip
boilers.

Whole
tree
 chipping
(with
limbs)
will
increase
the
efficiency
of
wood
utilization
from
a
stand
by
 20‐30%.

Whole
log
(entire
tree
minus
limbs)
will
increase
utilization
by
10‐20%.

 For
an
example
of
the
magnitude
of
transport
round
trips
from
the
woods:
Ambler
 will
require
94,
9‐ton
loads
over
the
frozen
ground,
providing
the
minimum
annual
 quantity
for
the
largest
proposed
village
heating
system.


Thus,
hauling
needs
to
be
 efficient.


Whole
tree
hauling
(with
limbs)
is
probably
not
feasible,
as
stacking
trees
 with
limbs
on
the
types
of
log
bunk
trailers
will
be
impractical.


However,
whole
log
 hauling
(entire
log
no
limbs)
is
quite
possible
as
shown
in
Figure
7.

The
 configurations
in
the
photos
are
solely
for
illustration
and
are
too
large
for
the
needs
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
23
 of
the
Upper
Kobuk.

If
log
trailers
long
enough
for
whole
log
hauling
are
not
 available,
an
extension
dolly
can
be
manufactured
that
will
work
effectively
as
a
 trailer
extension.

A
second
method
that
has
some
potential
is
the
use
of
a
clam
bunk
 and,
essentially,
dragging
the
whole
logs.


This
type
of
activity
will
be
winter
only,
as
 a
summer
application
will
add
dirt
to
the
logs.
Dirt
increases
wear
on
the
chipper
 and
causes
problems
for
the
boiler.
 
 
Figure
7.

Examples
(although
too
large
for
Upper
Kobuk)
of
a
whole
log
forwarder
(left)
and
a
clam
 bunk
for
dragging
whole
logs
with
a
tractor.

Both
of
these
concepts,
if
used,
would
be
scaled
to
a
 tractor
size.
 Chipping
 Chipping
capacity
is
a
function
of
horsepower
(hp)
and
infeed
opening.
 A
good
rule
 of
thumb
is
10
hp
per
ton
per
hour
capability.

For
Ambler,
using
a
chipper
at
ten
 tons
per
hour,
the
system
would
have
to
be
operated
a
total
of
85
hours
per
year
to
 produce
the
needed
chips.
There
are
several
models
that
can
do
this:
a
Vermeer
 rated
at
122
hp,
the
small
Woodsman
at
84
hp
and
the
larger
Woodsman
790
is
170
 hp.
The
minimum
production
from
the
three
is
8
tons
per
hour,
more
than
enough
 for
an
850
ton
per
year
requirement.


The
tractor
with
the
grapple
can
feed
the
 chipper. 
 Chipping
is,
to
a
certain
degree,
a
simpler
process
than
log
production
when
the
end
 use
of
the
chips
is
as
fuel
and
the
chip
specifications
are
such
that
they
allow
whole
 log
chipping.

Whole
tree
chipping
is
highly
preferred
whenever
a
single
machine,
 such
as
a
Morbark
20/36
Whole
Tree
Chipper
(Figure
8)
can
conceivably
carry
out
 this
task
rather
efficiently.
This
chipper,
and
others
like
it,
are
small
enough
to
fit
the
 physical
parameters
discussed
above
and
are
able
to
accept
materials
up
to
16”
in
 diameter.

The
chip
feed
system
for
the
boiler
must
be
able
to
reliably
operate
with
 some
percentage
of
bark
mixed
in
with
the
wood
chips.
Also,
chippers
tend
to
need

 regular
maintenance,
particularly
so
with
the
chipper
knives.
An
operation
that
 relies
heavily
on
a
whole
tree
chipper
should
anticipate
these
maintenance
needs
 and
be
suited
with
extra
parts
and
any
special
tools
that
may
be
necessary
for
 keeping
the
chipper
in
production.

Purchasing
several
sets
of
blades
and
an
 automated
blade‐sharpening
grinder
will
be
critical
for
efficient
production
of
good
 quality
chips. 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
24
 
Figure
8.

Mobark
chipper
of
sufficient
size
to
support
the
production
of
all
three
villages
if
a
decision
 was
made
to
transport
during
winter
between
villages.
 Cord
Wood
&
Fire
Wood
Production

 Cord
Wood
Processing
 Trees
that
will
be
used
for
stick
cord
wood
will
need
to
be
limbed
and
cut
into
 lengths
divisible
by
four
feet,
if
the
stem
will
be
going
into
a
Garn
stick
fired
boiler.

 It
is
desirable
for
this
process
to
be
done
mechanically
for
economic
and
safety
 reasons.

But,
if
the
volume
needed
is
small
enough,
then
hand
labor
can
be
used.

 The
best
machine
configuration
is
the
four‐wheel
tractor
with
a
cut‐to‐length
head,
 a
grapple
and
a
PTO
driven
log
bunk
trailer
(Figures
4&5).
 Firewood
production
 In
development
of
an
automated
harvest
system
for
a
village,
there
is
the
 opportunity
to
develop
a
woodstove
firewood
production
process.

A
key
issue
that
 must
be
understood
at
the
beginning
is
that
this
production
system
can
deliver
 seasoned,
cut
and
split
firewood
to
a
residence
at
a
significantly
lower
cost
than
 local
wood
haulers.

Figuring
out
a
fair
and
appropriate
implementation
is
beyond
 the
scope
of
this
report.

This
can
be
done
in
conjunction
with
either
a
chip
 production
system
or
a
cord
wood
production
system.

In
some
cases
both
maybe
 instituted
in
a
village.
 
 There
are
several
manufacturers
of
firewood
processing
equipment
that
produce
 equipment
capable
of
meeting
the
expected
production
needs
of
the
Upper
Kobuk
 Villages.
These
are
stand‐alone
machines
that
produce
cut
and
split
firewood
from
 logs.

Most
of
these
machines
(Figure
9),
such
as
Blockbuster,
Multitek,
and
Cord
 King,
are
portable
and
have
a
conveyor
system
that
loads
a
truck
as
the
wood
is
 being
processed.
As
a
system,
these
units
cost
anywhere
between
$30,000
to
over
 $100,000,
depending
on
size
and
configuration.
Due
to
their
size
(processor
and
 conveyor),
transportation
costs
will
be
comparatively
high,
particularly
to
rural
 Alaska.
There
are
two
difficulties
with
processing
firewood
with
these
types
of
 machines.
First,
the
initial
purchase
and
transportation
cost
of
the
machine
is
high
in
 light
of
the
comparatively
low
annual
production
needs.
Second,
the
machines
will
 be
difficult
to
transport
and
operate
anywhere
but
in
the
village
itself,
thus
requiring
 logs
to
be
transported
from
the
woods
to
the
village
for
processing
in
most
cases.
 Firewood
processing
in
the
village
is
anticipated
to
be
more
practical
than
in
the
 forest
in
many
instances,
based
on
conditions
in
the
Upper
Kobuk.

The
option
to
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
25
 produce
firewood
in
the
field
or
in
the
village
is
practical
with
a
firewood
processing
 attachment
that
can
be
mounted
on
a
tracked
skid
steer
such
as
the
Fecon
 mentioned
earlier.

Hahn
Machinery
has
recently
made
such
an
attachment
available
 (Figure
9).
Capable
of
producing
up
to
2
cords
per
hour
in
small
logs,
at
a
purchase
 price
of
$23,000,
the
FP160
Firewood
Processor
seems
an
ideal
fit
for
the
project.
 
 
Figure
9.


Example
of
an
automated
firewood
producer
(left)
and
the
Hahn
skid
steer
mounted
firewood
 producer
(center
and
right).
 Harvest
Equipment
Recommendations
by
Village
 Ambler
 Chip
system
harvest
requirements
 The
largest
chip
system
in
Ambler
will
displace
68,022
gallons
of
heating
fuel
 annually
and
will
require
773
tons
of
chips
at
25%
moisture
content
to
operate
the
 automated
boiler.

Total
capital
cost
of
the
system
is
approximately
$2.5
million
 dollars
with
a
net
present
value
of
approximately
$4.0
million.

Harvest
will
require
 approximately:
390
hours
for
felling,
limbing
and
piling;
305
hours
for
loading,
 hauling,
and
unloading
(7
mile
average
distance
and
5
mph
average
speed);
and,
 finally,
155
hours
(5
tons/hour)
for
chipping.

This
is
a
total
of
850
hours
of
labor
for
 harvesting
and
delivering
wood
chips
to
the
system.

Two
men
will
be
used,
for
 safety
purposes,
so
a
total
of
1700
hours
at
$25
per
hour
is
$42,500
for
base
labor
 without
benefits.

One
of
the
two
men
conducting
the
harvest
will
be
trained
as
a
 boiler
operator
for
a
chip‐fired
system.

The
recommended
boilers
can
be
remotely
 monitored
and
needs
a
brief
check
daily
during
the
workweek
similar
to
a
diesel
 power
plant.


Typically
chips
must
be
added
to
the
chip
bin
(depending
on
design)
 once
every
other
week.

The
boiler
has
an
automated
tube
cleaning
system
and
auto
 de‐ashing.

Ashes
will
need
to
be
dumped
every
2
weeks
as
well.

Monthly
normal
 operating
time
is
approximately
20
hours.

This
time
will
apply
to
Kobuk
and
 Shungnak
as
well.
 
 Annual
insurance
is
estimated
at
$20,000
and
$6000
for
fuel
and
maintenance
for
 machines;
the
cost
of
a
delivered
ton
of
25%
moisture
fuel
is
slightly
less
than
$90
 per
ton.

The
models
were
developed
using
$175
per
ton
to
be
extremely
 conservative.

However,
the
capital
costs
of
machinery
are
not
accounted
for
here,
 assuming
they
have
been
bought
with
grant
funds.


 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
26
 Cordwood
system
harvest
requirements
 If
only
cordwood
systems
are
used
to
their
maximum
benefit
in
Ambler,
given
a
 reasonable
payback,
there
would
be
four
cord
wood
boilers
installed.

The
Northern
 subdivision
would
require
one
Garn
boiler
and
approximately
68
cords
of
fuel
 annually.

The
school
complex,
water
treatment
plant
and
the
sewer
trace
would
be
 one
small
system
and
require
two
Garn
boilers
and
330
cords
of
wood
annually.

 The
new
NANA
office
building
would
require
one
Garn
boiler
and
106
cords
of
wood
 annually.

A
total
of
504
cords
of
wood
are
required.


Total
capital
costs
of
the
boiler
 systems
are
approximately
$1.4
million.


 
 Harvest
will
require
approximately:
252
hours
for
felling,
limbing
and
piling
16’
 logs;
205
hours
for
loading,
hauling
and
unloading
(using
same
parameters
as
 above);
and
200
hours
to
cut
to
4’
lengths
and
split
for
the
boiler.

This
is
a
total
of
 657
hours
times
2
employees
for
a
total
of
1314
hours
for
harvesting
and
delivery
of
 wood
to
the
village
costing
$32,850
in
labor
without
benefits.

With
an
assumed
cost
 of
$25,000
for
insurance
and
$5000
for
fuel
and
maintenance;
the
cost
of
a
delivered
 cord
of
firewood
at
25%
moisture
is
approximately
$125
per
cord.

The
model
to
 develop
the
economics
of
the
boiler
systems
was
based
on
a
standard
of
$250
per
 cord.

Neither
capital
cost
of
the
equipment
nor
replacement
costs
are
included
in
 these
calculations.
 
 Feeding
the
boiler
is
manual
and
will
require
multiple
burns
per
day.


The
coldest
 days
will
require
up
to
four
burns
per
day
based
on
the
feasibility
models
developed
 for
the
Upper
Kobuk.

Each
load
and
ignition
process
takes
about
20
minutes
per
 boiler,
if
the
stoking
wood
and
fire
starter
are
readily
available
at
the
boiler.

A
burn
 takes
two
hours,
but
does
not
require
attendance
once
the
fire
is
going
well.

Ideally,
 burns
should
be
scheduled
at
equal
intervals
throughout
the
entire
day/night
cycle.

 A
middle
of
the
night
burn
may
not
be
possible.

A
more
realistic
schedule
may
be
to
 burn
early
morning,
mid
morning,
mid
afternoon
and
late
evening.


If
a
centralized
 business
is
developed
to
manage
the
burn
process
for
burns
at
all
the
boiler
 installations,
then
overall
labor
costs
will
be
reduced
for
each.


 
 The
time
of
feeding
the
boilers
throughout
the
cold
season
is
estimated
at
30
 minutes
per
burn
per
boiler.


In
the
shoulder
months,
a
boiler
may
be
burned
only
 once
every
two
days,
and
on
coldest
days
4
times
during
one
day.

We
will
use
an
 average
of
two
burns
per
day
for
the
entire
242‐day
burn
season,
mid‐September
to
 mid‐May.

There
are
a
total
of
4
boilers
so
there
would
be
a
total
of
1936
burns
 during
the
season.

This
will
equate
to
approximately
968
hours
for
burns,
not
 counting
moving
wood
to
the
various
installations.

At
$25
per
hour
the
labor
for
 feeding
and
igniting
the
boilers
is
$24,200
annually.

On
a
per
cord
basis
this
is
 approximately
$50
per
cord,
bringing
the
cost
of
harvesting
and
feeding
the
boilers
 to
approximately
$175
per
cord
conservatively.

However,
the
financial
modeling
 was
done
with
the
standard
$250
per
cord.
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
27
 Ambler
–
Recommended
Harvest
System

 Equipment
redundancy
is
a
key
attribute
for
a
successful
operation
in
remote
 Alaska,
as
is
the
ability
for
one
machine
to
do
multiple
tasks.

The
system
 recommended
(Table
3)
is
a
maximum
system
to
meet
the
needs
of
a
chip‐fired
 system
in
Ambler
to
produce
773
(25%
moisture)
tons
of
wood
chips
annually.

 Since
there
are
two
machines,
one
with
tracks
and
one
with
chained
wheels,
 production
should
not
be
problematic
during
times
of
deeper
snow.


A
plan
for
 initiating
and
maintaining
major
trails
to
where
the
annual
wood
supply
is
located
 should
be
developed,
however.
 
 Machine Attachment Cost Total Machine & Attachments Fecon TRX100L $118,000 Bucket $2,500 Brush Rake $4,800 Grapple $5,800 Dozer Blade $4,700 Pallet forks $900 Hahn firewood processor $26,000 14" tree shear $12,000 Sub Total Fecon $174,700 $174,700 JCB 4CX Tractor Backhoe - Loader $116,000 Loading Crane 305T $26,500 Grapple $11,500 Snow Blower $6,000 Stroke Harvester $28,000 2-9 ton Kesla log bunk Trailers $26,500 Trailer Tracks $18,000 Tractor guarding $12,000 sub total Tractor $244,500 $244,500 Morbark Chipper $70,000 $70,000 Total $489,200 
 Table
3.

Maximum
set
of
machines,
attachments
and
costs
of
a
recommended
harvesting
system
for

 Ambler
to
supply
773
tons
of
wood
chips
annually.
(Freight
is
not
included)
 
 If
a
cordwood
system
only
were
to
be
developed
as
a
minimal
system,
which
could
 do
the
work,
it
would
be
the
JCB
4CX
Tractor,
with
all
the
recommended
 attachments.


It
would
then
be
necessary
for
the
Hahn
firewood
processor
listed
 under
the
Fecon
Attachments
to
be
used
with
the
tractor.

Preliminary
review
shows
 that
it
would
work
with
the
tractor;
however,
this
needs
to
be
confirmed
with
both
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
28
 equipment
companies.

At
this
point,
freight
has
not
been
calculated
for
delivery
of
 the
equipment.
 Shungnak

 Chip
harvest
system
requirements
 The
largest
chip
system
in
Shungnak
will
displace
77,883
gallons
of
heating
fuel
 annually
and
will
require
885
tons
of
chips
at
25%
moisture
content
to
operate
the
 automated
chip
boiler.

Total
capital
cost
of
the
system
is
approximately
$3.4
million
 dollars
with
a
net
present
value
of
approximately
$4.8
million.

Harvest
will
require
 approximately:
445
hours
for
felling,
limbing
and
piling;
240
hours
for
loading,
 hauling,
and
unloading
(10
mile
average
distance
and
5
mph
average
speed);
and,
 finally,
177
hours
(5
tons/hour)
for
chipping.

This
is
a
total
of
862
hours
of
labor
for
 harvesting
and
delivering
wood
chips
to
the
system.

Based
on
labor
of
$25/hour
 with
two
people
working
this
is
$43,100
in
labor
without
benefits.

With
an
 estimated
$20,000
annual
insurance
and
$6000
for
fuel
and
maintenance
for
 machines;
the
cost
of
a
delivered
ton
of
25%
moisture
fuel
is
less
than
$90
per
ton.

 The
models
were
developed
using
$175
per
ton
to
be
extremely
conservative
since
 these
are
estimated
costs
and
times.
 Cord
wood
harvest
system
requirements
 If
only
cordwood
systems
are
used
to
their
maximum
benefit
in
Shungnak,
given
a
 reasonable
payback,
there
would
be
six
cord
wood
boilers
installed.

The
Alley
 Street
subdivision
will
require
one
garn
boiler
and
95
cords
annually.

The
Jim
 Street
subdivision
will
require
one
garn
boiler
and
104
cords
of
wood
annually.

The
 Andy
Land
subdivision
would
be
connected
with
the
water
treatment
plant
and
 require
one
Garn
Boiler
and
99
cords
of
wood.

The
Back
Street
subdivision
would
 be
connected
with
the
Clinic
and
require
one
Garn
boiler
and
only
49
cords
of
wood
 annually.
The
new
NANA
office
building
would
require
one
Garn
boiler
and
102
 cords
of
wood
annually.

A
total
of
623
cords
of
wood
are
required
annually.


Total
 capital
costs
of
the
boiler
systems
are
approximately
$3.09
million.

The
costs
are
 high
due
to
the
amount
of
piping
and
costs
to
hook
up
individual
houses.

Net
Simple
 paybacks
range
from
3.33
years
to
10.5
years
for
the
various
installed
systems.
 
 Harvest
will
require
approximately:
315
hours
for
felling,
limbing
(cut
to
length)
 and
piling;
247
hours
for
loading,
hauling
and
unloading
(using
same
parameters
as
 above);
and
200
hours
to
cut
to
length
and
split
for
the
boiler.

This
is
a
total
of
762
 hours
times
2
employees
for
a
total
of
1524
hours
for
harvesting
and
delivery
of
 wood
to
the
village
costing
$38,100
without
benefits.

With
$25,000
for
insurance
 and
$5000
for
fuel;
the
cost
of
a
delivered
cord
of
firewood
at
25%
moisture
is
 approximately
$110
per
cord.

The
model
to
develop
the
economics
of
the
boiler
 systems
was
based
on
a
standard
of
$250
per
cord.

Neither
capital
cost
of
the
 equipment
nor
replacement
costs
are
included
in
these
calculations.
 
 Feeding
the
boiler
is
manual
and
will
require
multiple
burns
per
day.


The
coldest
 days
will
require
up
to
four
burns
per
day
based
on
the
feasibility
models
developed
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
29
 for
the
Upper
Kobuk.

Each
load
and
ignition
process
takes
about
30
minutes
per
 boiler,
if
the
stoking
wood
and
fire
starter
are
readily
available
at
the
boiler.

A
burn
 takes
two
hours,
but
does
not
require
attendance
once
the
fire
is
going
well.

Ideally,
 burns
should
be
scheduled
at
equal
intervals
throughout
the
entire
day/night
cycle.

 A
middle
of
the
night
burn
may
not
be
possible.

A
more
realistic
schedule
may
be
to
 burn
early
morning,
mid
morning,
mid
afternoon
and
late
evening.


If
a
centralized
 business
is
developed
to
manage
the
burn
process
for
burns
at
all
the
boiler
 installations,
then
overall
labor
costs
will
be
reduced
for
each.


 
 The
time
of
feeding
the
boilers
throughout
the
cold
season
is
estimated
at
30
 minutes
per
burn
per
boiler.


In
the
shoulder
months,
a
boiler
may
be
burned
only
 once
every
two
days,
and
on
coldest
days
4
times
during
one
day.

We
will
use
an
 average
of
two
burns
per
day
for
the
entire
242‐day
burn
season,
mid‐September
to
 mid‐May.

There
are
a
total
of
6
boilers
so
there
would
be
a
total
of
2904
burns
 during
the
season.

This
will
equate
to
approximately
1452
hours
for
burns,
not
 counting
moving
wood
to
the
various
installations.

At
$25
per
hour
the
labor
for
 feeding
and
igniting
the
boilers
is
$36,300
annually.

On
a
per
cord
basis
this
is
 approximately
$60
per
cord
bringing
the
cost
of
harvesting
and
feeding
the
boilers
 to
approximately
$180
per
cord
conservatively.

However,
the
financial
modeling
 was
done
with
the
standard
$250
per
cord.
 Kobuk
 Chip
system
harvest
requirements
 The
largest
chip
system
in
Kobuk
will
displace
44.441
gallons
of
heating
fuel
 annually
and
will
require
630
tons
of
chips
at
25%
moisture
content
to
operate
the
 automated
boiler.

Total
capital
cost
of
the
system
is
approximately
$2.1
million
 dollars
with
a
net
present
value
of
approximately
$2.7
million.

Harvest
will
require
 approximately:
350
hours
for
felling,
limbing
and
piling;
280
hours
for
loading,
 hauling,
and
unloading
(7
mile
average
distance
and
5
mph
average
speed);
and,
 finally,
126
hours
(5
tons/hour)
for
chipping.

This
is
a
total
of
756
hours
of
labor
for
 harvesting
and
delivering
wood
chips
to
the
system.

Two
men
will
be
used
for
 safety
purposes
so
a
total
of
1512
hours
at
$25
per
hour
is
$37,800
for
base
labor
 without
benefits.

Annual
insurance
is
estimated
at
$20,000
and
$6000
for
fuel
for
 machines;
the
cost
of
a
delivered
ton
of
25%
moisture
fuel
is
approximately
$100
 per
ton.

The
models
were
developed
using
$175
per
ton
to
be
extremely
 conservative.

However,
the
capital
costs
of
machinery
are
not
accounted
for
here
 assuming
they
have
been
bought
with
grant
funds.
 Cord
wood
harvest
system
requirements
 If
only
cordwood
systems
are
used
to
their
maximum
benefit
in
Kobuk,
given
a
 reasonable
payback,
there
would
be
four
cord
wood
boilers
installed
displacing
a
 total
of
42,207
gallons
of
fuel
with
525
cords
of
wood.

The
HUD
subdivision
will
 require
one
garn
boiler
and
61
cords
of
wood
annually
to
heat
nine
homes
and
 displace
7200
gallons
of
fuel.

A
district
heating
system
that
would
link
the
school
 with
the
proposed
new
construction,
the
clinic,
the
new
NANA
office
building,
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
30
 teacher
housing
water
treatment
plant,
and
the
city
office
building
would
require
 two
Garn
boilers
and
a
total
of
285
cords
of
wood
to
displace
a
total
of
35,007
 gallons
of
fuel.


Total
capital
costs
of
the
boiler
systems
are
approximately
$1.2
 million.

Net
Simple
paybacks
range
from
4.56
years
for
the
district
heating
system
 to
11.24
years
for
the
subdivision.
 
 Harvest
will
require
approximately:
275
hours
for
felling,
delimbing
(cut
to
16’
 lengths)
and
piling;
210
hours
for
loading,
hauling
and
unloading
(using
same
 parameters
as
above);
and
200
hours
to
cut
to
length
and
split
for
the
boiler.

This
is
 a
total
of
685
hours
times
2
employees
for
a
total
of
1368
hours
for
harvesting
and
 delivery
of
wood
to
the
village
costing
$34,200
in
labor
without
benefits
at
$25
per
 hour.

Using
$25,000
for
insurance
and
$5000
for
fuel
and
maintenance;
the
cost
of
a
 delivered
cord
of
firewood
at
25%
moisture
is
less
than
$125
per
cord.

The
model
 to
develop
the
economics
of
the
boiler
systems
was
based
on
a
standard
of
$250
per
 cord.

Neither
capital
cost
of
the
equipment
nor
replacement
costs
are
included
in
 these
calculations.
 
 Feeding
the
boiler
is
manual
and
will
require
multiple
burns
per
day.


The
coldest
 days
will
require
up
to
four
burns
per
day
based
on
the
feasibility
models
developed
 for
the
Upper
Kobuk.

Each
load
and
ignition
process
takes
about
20
minutes
per
 boiler,
if
the
stoking
wood
and
fire
starter
are
readily
available
at
the
boiler.

A
burn
 takes
two
hours,
but
does
not
require
attendance
once
the
fire
is
going
well.

Ideally,
 burns
should
be
scheduled
at
equal
intervals
throughout
the
entire
day/night
cycle.

 A
middle
of
the
night
burn
may
not
be
possible.

A
more
realistic
schedule
may
be
to
 burn
early
morning,
mid
morning,
mid
afternoon
and
late
evening.


If
a
centralized
 business
is
developed
to
manage
the
burn
process
for
burns
at
all
the
boiler
 installations,
then
overall
labor
costs
will
be
reduced
for
each.


 
 The
time
of
feeding
the
boilers
throughout
the
cold
season
is
estimated
at
30
 minutes
per
burn
per
boiler.


In
the
shoulder
months,
a
boiler
may
be
burned
only
 once
every
two
days,
and
on
coldest
days
4
times
during
one
day.

We
will
use
an
 average
of
two
burns
per
day
for
the
entire
242‐day
burn
season,
mid‐September
to
 mid‐May.

There
are
a
total
of
3
boilers
so
there
would
be
a
total
of
1452
burns
 during
the
season.

This
will
equate
to
approximately
726
hours
for
burns,
not
 counting
moving
wood
to
the
various
installations.

At
$25
per
hour
the
labor
for
 feeding
and
igniting
the
boilers
is
$18,150
annually.

On
a
per
cord
basis
this
is
 approximately
$35
per
cord
bringing
the
cost
of
harvesting
and
feeding
the
boilers
 to
approximately
$155
per
cord
conservatively.

However,
the
financial
modeling
for
 the
boiler
feasibility
was
done
with
the
standard
$250
per
cord.
 Shungnak
and
Kobuk
Recommended
Harvest
System
 A
system
that
will
support
both
Shungnak
and
Kobuk
will
need
to
produce
a
little
 more
than
twice
as
much
wood
as
the
system
for
Ambler.

The
Ambler
system
has
 plenty
of
capacity
to
produce
the
wood,
but
for
the
two
villages
we
will
need
more
 hauling
capacity.

Thus
we
are
recommending
two
tractors
and
four
trailers.

Based
 on
the
results
of
the
boiler
modeling/feasibility
analysis,
the
best
fit
for
Shungnak
is
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
31
 a
chip
system
and
the
best
fit
for
Kobuk
is
a
cordwood
system.

However,
a
small
 chip
system
will
work
in
Kobuk
as
well.

A
chipper
could
serve
both
communities
if
 scheduled
correctly
and
moved
in
the
winter
across
frozen
ground
or
on
the
Kobuk
 River.
 
 The
proposed
system
is
again
a
maximum
system
with
redundancy
and
can
serve
 both
the
chip
and
cord
wood
boiler
requirements
for
both
communities.
 
 Machine Attachment Cost Total Machine & Attachments Fecon TRX100L $118,000 Bucket $2,500 Brush Rake $4,800 Grapple $5,800 Dozer Blade $4,700 Pallet forks $900 Hahn firewood processor $26,000 14" tree shear $12,000 Sub Total Fecon $174,700 $174,700 JCB 4CX Tractor x 2 Backhoe - Loader $232,000 2-Loading Crane 305T $53,000 2-Grapple $23,000 Snow Blower $6,000 Stroke Harvester $28,000 4-9 ton Kesla log bunk Trailers $53,000 2 Trailer Tracks $36,000 2 Tractor guarding $24,000 sub total Tractor $455,000 $455,000 Morbark Chipper $70,000 $70,000 Total $699,700 Table
3.

Maximum
set
of
machines,
attachments
and
costs
of
a
recommended
harvesting
system
for

 Shungnak
and
Kobuk
to
supply
1515
tons
of
wood
chips
annually.
(Freight
not
included)
 
 The
total
amount
of
cordwood
if
both
villages
were
to
choose
stick‐fired
boilers
is
 1148
cords
annually.

A
minimal
system
to
accomplish
the
tasks
would
delete
the
 chipper
and
the
skid
steer.

However,
we
would
recommend,
if
affordable,
to
keep
 the
skid
steer
to
support
the
tractors.

Again,
redundancy,
when
affordable,
makes
 for
a
more
robust
harvest
system
in
off
road
bush
Alaska.
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
32
 Appendix
 
 Transportation
System
Analysis
 Background
 A
critical
element
of
a
sustainable
woody
biomass
fuels
program
for
the
Upper
 Kobuk
Valley
is
the
safe
and
efficient
transport
of
equipment
and
wood
fuel
over
the
 river
systems
in
the
project
area
during
winter.
The
lack
of
road
access
to
the
forest
 resources
to
be
managed
and
harvested
for
this
alternative
energy
program
 requires
the
use
of
these
rivers
as
transportation
corridors.

The
local
knowledge
 base
of
water
and
ice
conditions
has
served
the
community
well.
The
residents
of
 Upper
Kobuk
Valley
use
the
rivers
regularly
for
transportation,
subsistence,
and
 recreation.
Ice
transportation
use,
however,
has
had
very
limited
application
for
 hauling
wood
and
equipment
at
an
industrial
scale.
It
is
vital
that
the
local
 knowledge
base
be
supplemented
with
a
more
detailed
understanding
of
how
to
 utilize
these
rivers
for
forestry
transportation
applications
in
a
safe
and
efficient
 manner.

The
simplest
use
is
in
developing
crossings;
however,
in
some
 circumstances
ice
roads
on
the
Kobuk
River
will
make
transport
of
wood
and
 equipment
much
more
efficient.

 This
analysis
begins
the
supplementation
of
the
local
knowledge
process.
The
size
of
 the
project
area
precludes
an
exhaustive
analysis
of
the
water
and
ice
conditions
for
 the
project
area.
In
addition,
there
is
a
lack
of
historic
ice
thickness
data
that
are
 available
on
other
rivers
in
the
state.

Significant
efforts
have
been
made
to
develop
 an
understanding
of
the
major
issues
that
may
be
encountered
by
a
wood
fuel
 project
when
it
utilizes
the
river
as
a
transport
corridor.

 There
are
three
basic
components
to
a
successful
wood
fuel
transportation
program
 on
ice:
Adequate
water
depth;
adequate
ice
thickness;
proper
equipment;
effective
 work
force.

This
analysis
addresses
the
ice
thickness
issues.
 Log
Rafting
in
spring
and
summer
 Assembling
wood
fuel
production
into
log
raft
form
for
transport
to
the
village
has
 attractive
possibilities
to
significantly
increase
program
efficiencies.
With
the
 proper
boat
towing
or
pushing
capacity,
several
tons
of
logs
could
be
moved
in
a
 single
tow
resulting
in
a
significant
reduction
in
fuel
oil
consumption
and
other
 hauling
costs.
 
 There
are
at
least
two
important
unknowns
at
this
point
in
time
that
tend
to
 discourage
log
rafting
as
the
chief
form
of
wood
transport
in
the
early
stages
of
the
 program.
First
is
the
issue
of
obtaining
necessary
permits
for
these
activities,
and
 the
second
is
determining
volumes
of
wood
that
can
be
effectively
transported
in
 this
fashion
on
an
annual
basis.

It
is
important
to
realize
that
it
will
take
some
time
 to
develop
an
understanding
of
the
operational
issues
that
come
with
rafting
logs
in
 the
area.

It
seems
prudent
to
defer
the
complexities
of
rafting
until
a
later
time
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
33
 when
the
operation
can
better
handle
the
additional
responsibilities
that
come
with
 it.
 Winter
Hauling
and
Transport
on
Ice

 Hauling
cargo
over
ice
is
a
common
practice
throughout
the
Arctic.
Oilfield
 development
and
other
industrial
applications
have
used
winter
ice
conditions
to
 transport
equipment
and
other
goods
for
decades.
During
this
period,
a
 considerable
amount
of
useful
information
and
experience
has
been
developed
on
 how
to
haul
on
ice
efficiently
and
safely.
Ice
travel
in
the
Upper
Kobuk
using
snow
 machine
and
other
light
vehicles
is
common.
The
Upper
Kobuk
wood
fuel
program
 can
use
rivers
to
efficiently
haul
significant
volumes
of
wood
fuel
over
ice,
either
in
 simple
crossing
sites
or
as
a
road
for
longer
hauling.
To
date,
very
little
heavy
 hauling
has
occurred
over
river
ice
in
this
area,
and
thus
there
is
little
local
 knowledge
in
this
regard.
Ice
thickness
records
for
the
area
have
not
been
kept.

 However,
limited
data
indicates
that
during
certain
periods
each
winter,
ice
 thicknesses
at
the
point
of
measurement
exceeds
the
required
capacity
to
haul
wood
 fuel
safely.
Ice
strength
equations
and
tables
established
by
the
U.S.
Army
Cold
 Regions
Research
and
Engineering
Laboratory
and
others
correlate
ice
thickness
 and
other
parameters
to
the
load
carrying
capacity
of
the
ice.
Procedures
for
 measuring
thickness
and
determining
ice
quality
have
also
been
determined.
 Properly
applied,
this
information
can
empower
the
stakeholders
in
the
Upper
 Kobuk
wood
energy
project
with
the
ability
to
safely
haul
wood
fuel
and
equipment
 over
river
ice
for
more
than
three
months
out
of
the
year.
 
 
 
 Figure
10.

Well‐maintained
ice
road
in
Alaska.
(left).

Sampling
ice
depth
and
quality
on
the
Yukon
 River.
(right)
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
34
 NEED
TO
KNOW
ABOUT
THE
ICE
 It
is
important
to
use
systematic
observations
of
the
ice
sheet
to
determine
support
 of
a
load.
There
may
be
many
variations
in
the
structure,
thickness,
temperature,
 and
strength
of
a
floating
freshwater
ice
sheet.
 How
thick
is
the
ice?
 Ice
thickness
is
determined
by
drilling
holes
with
a
drill
or
ice
auger
(Figure
10).
 The
accepted
technique
is
to
drill
a
hole
to
check
ice
thickness
every
150
feet,
or
 where
needed
along
the
intended
path,
and
should
be
done
more
frequently
if
the
 ice
thickness
is
quite
variable.
Also
noted
is
whether
the
ice
in
each
hole
is
clear
 (sometimes
called
black
ice)
or
white
(due
to
air
bubbles—sometimes
called
snow
 ice).
The
thickness
of
both
kinds
of
ice
must
be
measured.

On
rivers,
the
ice
 thickness
and
quality
can
change
measurably
in
a
short
distance;
one
should
be
 particularly
alert
to
variations
in
ice
thickness
due
to
bends,
riffles
or
shallows,
 junctions
with
tributaries,
etc.

For
both
rivers
and
lakes,
warm
inflows
from
springs
 can
create
areas
of
thinner
ice.

The
ice
near
shores
can
either
be
thinner
(due
to
 warm
groundwater
inflow
or
the
insulating
effect
of
drifted
snow)
or
thicker
(due
to
 the
candle‐dipping
effect
of
variable
water
levels).

Differences
snow
cover
thickness
 on
top
of
the
ice
cover
may
mean
highly
variable
ice
thicknesses.


 
 Once
a
wood
harvesting
program
has
been
initiated,
monthly
measures
along
the
 major
travel
routes
should
be
established
to
obtain
ice
quality
and
thickness
data.

 This
data
set
will
help
the
wood
haulers
understand
when
and
where
they
can
most
 safely
haul
wood
and
allow
for
future
planning
of
hauling
timing.

The
process
will
 also
allow
for
development
of
the
dynamics
of
ice
thickness
variability
and
timing.
 How
thick
does
the
ice
need
to
be?
 Table
2
can
be
used
to
determine
the
minimum
thickness
for
transport.

The
load
is
 the
total
load
in
tons
(not
a
vehicle's
load
capacity)
of
both
the
equipment
and
the
 load.
The
table
is
valid
when
the
load
of
a
wheeled
or
tracked
vehicle
is
distributed
 over
a
reasonable
area
of
a
continuous
ice
sheet,
which
is
the
case
with
a
tractor
or
 Morooka
pulling
a
loaded
trailer.

The
larger
the
load,
the
greater
the
area
it
should
 cover
for
the
calculation
to
remain
valid.
Neither
large
loads
that
are
concentrated
in
 relatively
smaller
areas,
nor
loads
that
are
at
or
near
the
edge
of
a
large
opening
in
 the
ice,
are
safely
described
by
the
table.
In
such
cases,
seek
more
advice
or
simply
find
 another
route.
 Minimum
ice
thickness
required
to
support
a
load
 The
table
assumes
clear,
sound
ice.
If
white,
bubble­filled
ice
makes
up
part
or
all
of
 the
ice
thickness,
count
it
as
only
half
as
much
clear
ice.


A
tractor
16,000
pounds
and
 a
load
of
wood
and
trailer
20,800
is
a
total
of
18.4
tons
will
require
clear
ice
 thickness
of
18‐20
inches
for
a
safe
haul.
 
 
 
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
35
 Table
2.

Minimum
ice
thickness
required
 to
support
a
load

 Load
 (tons)

 Required
ice
thickness
 (inches)

 Distance
between
loads
 (feet)

 


 0.1

2

17

 1

4

34

 2

6

48

 3

7

58

 4

8

67

 5

9

75

 10

13

106

 20

18

149

 30

22

183

 40

26

211

 
 Basic
Procedures
of
Safety
on
Ice
 • Never
go
out
on
an
ice
cover
alone,
and
never
go
out
on
the
ice
if
there
is
any
 question
of
its
safety.
 • While
you
are
planning
the
haul,
obtain
the
record
of
air
temperature
for
the
 past
several
days
and
continue
observing
air
temperatures
while
the
ice
will
 be
used
to
support
loads.
 • Always
let
someone
know
of
your
plans
and
when
you
will
return.
 • When
you
arrive
at
the
water's
edge,
visually
survey
the
ice.
Look
for
open
 water
areas,
and
look
for
signs
of
recent
changes
in
water
levels:
ice
sloping
 down
from
the
bank
because
the
water
dropped,
or
wet
areas
on
the
ice
 because
the
water
rose
and
flooded
areas
of
the
ice
that
couldn't
float
 because
it
was
frozen
to
the
bottom
or
the
banks.
(If
the
ice
is
snow‐covered,
 look
for
wet
areas
in
the
snow.)
 • It
is
best
to
traverse
the
haul
route
with
a
snow
machine
first
to
make
sure
 that
all
conditions
are
the
same
as
the
last
ice
inspection.
 • Listen
for
loud
cracks
or
booms
coming
from
the
ice.
In
a
river
this
can
mean
 the
ice
is
about
to
break
up
or
move;
on
a
lake
larger
than
several
acres
such
 noises
may
be
harmless
responses
to
thermal
expansion
and
contraction.
 • It
is
best
to
maintain
an
easy
point
of
access
to
the
ice,
free
of
cracks
or
piled,
 broken
ice
on
both
ends
of
the
haul.
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
36
 • Near
shore,
listen
for
hollow
sounds
while
probing.
Ice
sloping
down
from
 the
bank
may
have
air
space
underneath.
This
is
not
safe;
ice
must
be
floating
 on
the
water
to
support
loads.
 • Only
after
you
have
learned
the
characteristics
of
the
ice
cover
should
any
 vehicle
be
taken
on
the
ice.
 SAFE
OPERATIONS
ON
THE
ICE
COVER
 If
using
an
enclosed
vehicle,
always
drive
with
the
windows
or
a
door
open
for
quick
 escape.

If
you
drive
across
wet
cracks,
your
path
should
be
as
close
to
perpendicular
 to
them
as
possible,
instead
of
parallel
to
them.
A
load
deflects
the
ice
slightly
into
a
 bowl
shape.
When
you
drive
on
floating
ice,
this
moving
bowl
generates
waves
in
 the
water.
The
ice
sheet
deflection
is
increased
when
the
speed
of
the
waves
equals
 the
vehicle
speed
and
the
ice
is
much
more
likely
to
break.
The
problem
is
more
 serious
for
thin
ice
and
shallow
water.
In
general
you
avoid
this
danger
by
driving
 below
15
mph.
When
there
are
two
loads
on
the
ice,
the
safe
distance
between
them
 is
about
100
times
the
ice
thickness
at
the
required
minimum
thickness.
This
is
 shown
in
the
third
column
of
table
2.
When
the
two
loads
are
different,
choose
the
 spacing
shown
for
the
larger
load.

At
ice
thicknesses
greater
than
the
required
 minimum,
this
spacing
can
be
reduced.
 A
loaded
ice
sheet
will
creep,
or
deform,
over
a
long
period
of
time,
without
any
 additional
load.
If
an
ice
sheet
has
to
be
loaded
for
a
long
period,
drill
a
hole
near
the load.
If
the
water
begins
to
flood
the
ice
through
the
hole,
move
the
load
 immediately.
Remember
this
if
your
vehicle
ever
becomes
disabled:
if
left
for
a
few
 days,
it
may
break
through
the
ice
as
a
result
of
long‐term
creep.
 Equipment
and
Loading/
Unloading
Point
Considerations
 Weight
limitations
for
equipment
and
cargo
apply
for
hauling
over
ice.
Thus
 production‐scheduling
risks
of
hauling
over
river
ice
due
to
inadequate
ice
thickness
 also
exist.
All
of
the
equipment
utilized
in
the
summer
months
will
also
be
used
in
 the
winter
production
period.
The
weight
limitations
based
on
smaller
efficient
 equipment
are
within
acceptable
parameters
for
ice
hauling.
For
example,
an
8
ton
 machine
will
need
less
than
13
inches
of
clear,
sound,
floating
ice
for
safe
transit,
 according
the
ice
strength
table.
Ice
thicknesses
exceeding
this
amount
are
common
 over
much
of
the
project
area
for
3
or
more
months
of
the
year,
according
to
 historical
records.
Thus,
the
machine
weights
anticipated
by
this
report
are
not
 expected
to
be
a
limiting
factor
for
hauling
over
ice.
Wood
fuel
loads
will
be
towed
 from
the
field
with
the
four‐wheel
drive
tractor
with
chains
on
tires
pulling
trailers.
 Heavier
loads
are
desired
whenever
possible
in
order
to
haul
more
wood
fuel
per
 trip
to
reduce
the
number
of
trips
necessary
to
meet
production
goals.
With
this
 system,
the
entire
load
weight
can
be
regulated
by
the
number
of
trailers
being
 towed
and
the
distance
between
each
one
in
order
to
comply
with
the
maximum
 load
capacity
of
the
ice
being
traversed.
Establishing
safe
routes
to
cross
a
river
on
 ice
is
another
strategy
that
has
the
capacity
to
reduce
risk
and
increase
efficiency.
By
 limiting
the
distance
equipment
and
wood
fuel
is
hauled
over
ice,
the
risk
of
an
 Wood
Harvest
Systems
Upper
Kobuk
Biomass
Program
 Alaska
Wood
Energy
Associates
 
 
37
 accident
or
production
interruption
due
to
inadequate
ice
thickness
can
be
 managed.
A
single
crossing
over
a
relatively
short
stretch
of
river
can
more
easily
be
 monitored
for
safe
ice
conditions
than
longer
stretches
over
river
segments
that
 may
have
varying
ice
thicknesses
and
quality.

However,
transporting
on
the
Kobuk
 River
between
Kobuk
and
Shungnak
could
be
advantageous
in
mid
winter
if
ice
 thickness
is
adequate.

 
 Ice
thickness
can
also
be
managed
on
a
specific
crossing
site
fairly
readily
by
 employing
ice
road
construction
and
maintenance
techniques
that
will
increase
ice
 thickness.
This
is
an
easier
task
for
a
200‐yard
river
crossing
than
a
10‐mile
long
 river
route.
Hauling
across
stretches
of
ice
where
the
operator
is
highly
confident
of
 capacity
to
support
the
load
weight
is
vital
to
the
entire
operation.
Consistent
load
 weights
being
systematically
transported,
carefully
monitored
with
managed
ice
 crossings,
will
significantly
increase
the
efficiency
of
the
Upper
Kobuk
Wood
Fuel
 Program.