Armored 
Medical Research Laboratory 
Fo»t Kniox, Kentucky 
Report On 
PROJECT NO. 42 - LETTER REPORT ON TEST OF PACK. FIELD, CARGO; 
PaCK, FIELD, COMBAT; AND SUSPENDERS, PaCK, 
FIELD, CARGO AND COMBAT 
Project Mo. 42 
29 August 1944 ARMORED MEDICAL RESEARCH LABORATORY 
fori Knox, Kentucky 
Project No, 42 
File 727 SPMEA 
29 August 1944 
/ 1® PROJECT: No U2 - Letter Report on Test ofnek, Field, Cargo 
fpack, Field, Combatand Field, Cargo and Combat.^ 
a0 Authority; Letter, Office of The Surgeon General, 8 July 19-V+. 
b0 Purpose; To determine the physiologic effects of Packs, 
Field, Cargo; Packs, Field, Combat; and Suspenders, Pack, Field, Cargo 
end Combat, upon the men wearing them0 
2o DISCUSSION: 
. a0 Thirty-six (3b) of the subject items ’.ere issued to lance 
corporals and sergeants in training at the Armored Replacement Training 
Center, and wore carried by them on an overnight problem consisting of a 
five (5) mile road march, night bivouac, and five (5) mile road march 
returningo Fourteen (ll) of the men carried the combat portion of the . 
pack only, while twenty-two (22) men carried the full pack. 
be The combat pack, when carried alone, was surmounted by a 
blanket roll, and contained toilet articles, C and K rations, change of 
socks and underclothing, and a raincoat. The cargo pack when carried in 
addition, contained a blanket, shelter half, and additional clothing0 
It was estimated that the cargo and combat packs together weighed approxi- 
mately thirty-five (35) pounds. 
3o 0 ENERVATIONS : 
a0 VJhereas none of the men wearing the test pack complained 
of soreness in the clavicular region, almost all of the men carrying the 
pack, canvas, field,.193b, as controls, had some redness and soreness of 
this region0 
b. It was the opinion of all subjects that the test pack was 
to be preferred to any pack previously worn by these troops0 
a. Most of the subjects agreed what the test packs failed to 
ride as high on the shoulders ar would be desired. In many instances the 
upper portion of the pack was several inches below the last cervical 
spineo v'Aien this occurred the sensible weight of the pack was appreciably 
increased. Observers from the Jeffersonvilie 'hiartermaster Depot, who were present at the time of the test, gave assurance that an improved shoulder 
buckle is available to eliminate some of the suspender slippage which is 
in part responsible for the failure of the pack to maintain its position 
high on the backQ 
d, All men who carried the combat pack with the blanket and 
shelter half rolled in a shape around the superior and lateral 
surfaces of the pack, pointed out that the projection of the blanket 
interfered with carrying the rifle„ The rifle strap was caused to ride 
over the head of the humerus and to stand away from the side of the body 
by several inches. Frequent adjustment was necessary to prevent the rifle 
from falling off the shoulder» 
U• COifTBT: 
It does not seem to be mechanically p c side to keep any pack 
riding at the optimal height on the back when t r v rbed by suspenders of 
the present type0 Some lessening of the tendency for the pack to drop 
down and the cartridge celt to pull up in front ,.L -1.t be achieved by 
crossing the suspender straps over the chest, instead of having thorn 
hang vertically from the shoulder to the cartridge belt as at present* 
5* CvSICLSSICNS: 
iio The pack, field, combat; pack, field, cargo; and sue coders, 
pack, field, cargo and combat, are superior to 1 n ■ a -k. now in use 
inasmuch as they are loss likely to cause shoulde i. ritatlon and pain, 
b0 Tie common objection that the pack rides low on the back has 
not been overcome; it seems unlikely, even wit; she inclusion of the new 
shoulder buckle, that it will be entirely prevented. 
Co The excess width of the blanket roll ur.d shelter half when 
attached to the pack, combat, forces the slung rifle away from the body, 
and necessitates frequent adjustment to keep it on lie shoulder. 
6. KECCiff.rSNDMTIOIJ: 
a« That consideration be given to designing the pack suspenders 
so that they cross in front of the chest before attaching to the cartridge 
belt. By this means it is possible that the pad might be secured higher on 
the back, its sensible weight diminished, and the objectionable upward pull 
on the cartridge belt in front reduced* b0 That six (6) pad: suspenders, designed to cross the crest, 
oe fabricated and sent to the 1'moratory for tcst0 
Subi.ii t ted o; : 
Captain Arthur Freedaian, M. C, 
hPPP.ovld hs 
WILLn tD ’'nC.lL.rii 
Colonel, MedicCorps 
Goman ding