Armored 
Medical Research Laboratory 
Fort Knox, Kelnituc^v 
Second Partial Report On 
PROJECT NO, 5-12 - Seating Designing and Placing in Relation 
to Fatigue 
SUBJECT; SEATS FOR TRUCK (4 z 4) £ TON (PEEP) 
Project No. 5-12 
17 February 1946 ARMORED,MEDICAL RESEARCH LABORATORY 
Fort Knox, Kentucky 
Project No* £-12 
SPMEA 7U9*2-12 
17 February 19^5 
SEATS FOR TRUCK (Ji x U \ TON (PEEP) 
lo PROJECT NOc £-12 - Seating Designing and Placing in Relation to 
Fatigue* Second partial reporto 
a* Authority: Letter Commanding General, Headquarters Armored Force, 
Fort Knox, Kentucky, Pile U00*112/6 GNOHD, dated September 2h, 19U2. 
bo Purpose: To determine the physiological adequacy of seats in the 
J Ton Truck (Peep) and to indicate desired improvements0 
2o DISCUSSION: 
Complaints of excessive fatigue and of backache are common from 
drivers and passengers of Ton and other trucks after approximately one hour’s 
driving over improved roads and after even shorter periods of driving cross- 
country or over rough roads* Decreased efficiency and often disability are the 
direct result of such back fatigue* Medical attention with hospitalization and 
specialized treatment is not uncommonly required* In one recent hospital survey, 
90$ of low back injuries seen from one service were from this service’s truck 
organizationso Much can be done to improve this situation by furnishing more 
adequate seats* 
3o TEST PROCEDURE: 
The (I; x U) i Ton truck was driven over a variety of terrains with and 
without extra passengers* Subjective reactions were obtained at various time 
intervals with standard seats and seats modified by addition of padding, altered 
shape and size of back, bucket seats, etc, Spring cushions, hair felt pads and 
sponge rubber pads of various thickness were also compared* Men from training 
and combat areas were interviewed* 
ho CONCLUSIONS: 
a* Driver and passenger seats of the J Ton Truck (Peep) do not provide 
sufficient anchorage, support or cushioning to protect occupants adequately from 
low back injury when truck is travelling over moderately rough terrain* Over 
rough terrain, vibration and shock to the occupants is severe* 
b* Vibration and shock can be reduced by (1) increased padding of seat 
cushion and back rest, (2) improved design of back rest to insure better anchorage 
and fit* RECOMMENDATIONS; 
a0 That all seat cushions for Truck, Ton be two (2M) inches of 
sponge rubber or equivalents 
b0 That backs of driver and front passenger seats be of shape and 
size shown in Fig„ A, and have a minimum cushioning of one and one quarter 
inch sponge rubber or equivalent 
Co That back of rear passenger’s seat have minimum of one and one 
quarter (1^M) inch sponge rubber or equivalent and be designed to provide 
anchorage as nearly equivalent to that of driver’s seat as is possible within 
space limitations-, 
do That padding be covered with water-proof covering of otherwise 
suitable characteristics„ 
Conclusions and recommendations are concurred in by Headquarters, Armored 
Center, Fo W0 Makinney, Colonel, QSC, Chief of Staff0 
Submitted by: 
Major Lester B0 Roberts, SnC 
Captain Wendell E0 Mann, MAC 
APPROVED 
WtLtARD MACHW 
Colonel, Medical Corps 
Commanding 
1 Incl. - Figo A0* SEAT BACK 
armored medical research laboratory 
FORT KNOK. KENTUCKY 
Ekiginehrin/g Section 
SCALE 6“ - I'O *' 
DATE