Table Of ContentHistoric, Archive Document
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aTS198
.B3V33 f''
1995
Bags Packstock
united States Gravel for
Department of
Agriculture
Forest Service
Technology &
Development
Program
Q
2300-Recreation
June 1995
9523-2840-MTDC
Gravel Bags for Packstock
Brian Vachowski
ProjectLeader
Technology & Development Program
Missoula, Montana 59801
5E52A59
Gravel Bags for Packstock
June 1995
Thecontentsofthepublicationarenottobeusedforadvertising,publication,orpromotional
purposes. TheForestService,UnitedStatesDepartmentofAgriculturehasdevelopedthis
informationfortheguidanceofitsemployees,itscontractors,anditscooperatingfederaland
stateagencies,andisnotresponsiblefortheinterpretationoruseofthisinformationbyanyone
exceptitsownemployees. Theuseoftrade,firm,orcorporationnamesinthispublicationis
fortheinformationanconvenienceofthereader,anddoesnotconstituteanendorsementby
theDepartmentoranyproductorservicetotheexclusionofothersthatmaybesuitable.
TheForestServiceisadiverseorganizationcomittedtoequalopportunityinemploymentand
programdelivery.USDAprohibitsdiscriminationonthebasisofrace,color,nationalorigin,sex,
religion,age,disability,politicalaffiliationandfamilialstatus.Personsbelievingtheyhavebeen
discriminatedagainstshouldcontacttheSecretary,U.S.DepartmentofAgriculture,Washing-
ton,D.C.20250;orcall(202)720-7327(voice);or(202)720-1127(TDD).
Contents
Introduction 1
Gravel Bag Designs 2
Fruit Picking Bags 3
Testing 4
Gravel Bag Test Results 5
Recommended Design 6
Gravel Hauling Panniers 6
Sources 6
Fabrication Plans 7
Acknowledgment
‘TechnicalAssistance:
Maggie ‘Brinies, Missoula, Montana
IvanCarper, ‘Wallowa, Oregon
Alike 'Dolfay, Wenatchee, Washington
MTPC
Brenda‘Holland,
'
MVDC
QeorgeJackson,
“PattiJohnston, LewisandClarfNationalforest
Jim “Kautz, M“T“DC
PayMdls, Lewis andClarfNational[Forest
‘TaylorOrr, QallatinNational'Forest
“TonyPetrdli “NorthernpegionSmokejumper
,
ProfessionalWddemess OutfittersAssociation
MTDC
SaraLustgraaf,
Introduction
A fabric bag for hauling gravel or
fill material with packstock is
availableforForestServiceuse. IMMI
Replacement fill material is often
needed for trail work, especially for
turnpike construction and tread
itlpPpp
maintenance. Usingpackstocktohaul
IS®#!
gravel or other fill material is practical
when motorized equipment is
impractical or not allowed.
The Missoula Technology and
Development Center (MTDC) was
asked to develop plans, and fabricate
and test fabric bags that could be
mounted on packsaddles. MTDC
workedfromadesigndeveloped inthe
1970’s by retired Wallowa-Whitman
National Forest (R-6) employee Ivan
Carper. Missoula smokejumper Tony
Petrillifabricatedthe bagsforMTDC in
1994 and they were tested on a
partnership turnpike construction
projectonthe RockyMountain Ranger
Districtofthe Lewisand Clark National
Forest (R-1) that same year. MTDC
also tested and evaluated some bags
thatcloselyfollowedtheoriginalCarper
design built by the Professional
Wilderness Outfitters Association
(PWOA), and some off-the-shelf fruit
picking bags.
Included inthis reportaretestresults,
recommendations, a design pattern,
and some alternatives.
*
1
Gravel Bag Designs
Heavycanvas and liberal use of leatherand rivets for shortchains and a snap clip to fit a decker saddle. With
reinforcement around a steel hoop make up the basic design minor modifications, the bags could be rigged fora sawbuck
developed by Ivan Carper. MTDC modified the design in packsaddle.
several ways (Figure 1). Overall dimensions were keptthe
same as the original, but 16-ounce (455-gram) coated nylon Partners in the testing and work project, the Professional
Cordura™was used instead of canvas. MTDC did not use Wilderness Outfitters Association, also fabricated some
leatheror rivets, but relied instead on sewn seams, which gravel bags using the basic Carperdesign. Theirs featured
are stronger. MTDC also used tubular nylon instead of “trucktarp” fabric instead of canvas, manila release ropes,
manila rope forthe release cord. The bags were rigged with and rivets instead of sewn seams (Figure 2).
Figure 1.-Gravel bag design featuressewn seamsaround asteel Figure2.-Thisdesign issimilartothefirst, buthas riveted seams
hoop. Releasestrapwaschanged slightlyinfinal design. andtrucktarpfabric. Bagswerefilled one bucketatatime.
Glovesshould havebeenworn.
2
Fruit Picking Bags
Based on a reportfrom Mike Dolfay on theWenatchee
National Forest (R-6) thattrail contractor Pete Harvill had
been successfully using inexpensive, off-the-shelffruit
picking bagsto haul gravel with his string, we included two
differentsets ofthese bags in the test. These were Wells &
Wade #80Superpickingbag, and Citrus Bag with Rope
Hook. These bags (Figure 3), while admittedly not designed
to haul gravel on the side of a mule, readilyfit a decker
saddle with no modification. Instead of being released by
jerking a knot, the load
hadto be released by
getting close to the
animal and lifting the
loaded bag of gravel
enough to lift the hook
offthe side ofthe bag.
The hoop atthe top of
the bag was smaller
and not as strong as
the steel hoops on the
otherdesigns.
Figure3.—Fruit pickingbagsrequire liftingthe loadto releasethe
ropeclips.
3
Testing
For8 days in June, 1994, up to 24 outfitters believed the mules could stationed there, oneto hold the mule
head of mules packed gravel for a 3/4- handle that load forshort distances, but and the otherto unload it one side at a
mile (1.2-kilometer) stretch of new about 120 pounds (54 kilograms) per time. The packstring was separated
turnpike construction on the South Fork bag would be betterfor longer hauls. It during unloading. This proved to be the
Sun Trail No. 202. The packstock was easy to overload the animals. In most difficult procedure, since the
belonged to members of PWOA. They fact, the initial loads weighed 200 mules varied in temperamentand some
also provided workers at the gravel pounds (90 kilograms) per bag until were quite contentious.
source to work alongside the Forest they were bettercalibrated.
Service crew. Because of the difficulty of positioning
Because oftheirsmallerdimensions some ofthe mules exactlywhere the
Each bag wastested bycarryingabout and lighterconstruction, the fruit picking gravel was needed, the abilityto direct
eight loads perdayfor8 days (64 trips). bags could hold only about 80 pounds the flow of gravel from the bag by
The gravel was hauled from a river (36 kilograms) of gravel per bag. pulling the rope on the bottom was very
bottom gravel bar, up a hill useful (Figure 4). Also, by lifting up on
approximately 1/2 mile (.3 kilometer) to Each mule string was led through the the rope, the flow of gravel could be
the turnpike construction site. gravel pit area, with workers on each halted and redirected to a slightly
side filling bags a bucket at atime. The differentspot.
Both Carperdesign bagswere loaded bags were quiet, although the metal
with about 160 pounds (72 kilograms) buckets were not. When all the mules In all cases, the empty bags were left
per bag, fora total load of 320 pounds in the string were loaded, theywere led mounted on the packsaddles, tied and
(144 kilograms) per mule. The to the turnpike. Two workers were adjusted, readyforthe next load.
4
