﻿34 



BULLETIN 17, U. S. DEPAKTMENT OF AGRICULTURE. 



The insulation of the car in relation to temperature is its most vul- 

 nerable and its most important part, the construction of the ice 

 bunker coming next in importance. In the past the insulation has 

 not been sufficiently heavy to maintain the low temperatures pro- 

 duced by the refrigerant, and the source of refrigeration, the bunker, 

 has not been able to distribute its product evenly throughout the car. 



p^ K5* ■ 



LEGEND. 



I/ 1 - - THERMOGRAPH. TOP OF LOAO, BUNKER END, M/DDLE. 

 "^ „ BOTTOM " " » » . " 



JJ J THERMOGRAPH TOR OF LOAD, BUNKER END, NEXT TO S/DE WALL 



-pj-j / THERMOGRAPH TOR OF LOAD, CENTER OF CAR, M/DDLE 



111 ^ „ BOTTOM" " » » '- " 



( ELECTR/C THERMOMETER TOP OF LOAD, BUNKER END, M/DDLE, OUTS/DE OF BARREL 



IV" <-■-'-»- " « BOTTOM " « " " »» « " " 



[ n -n /NS/DE CENTER OF SAMEBARREL, BUNKER END, M/DDLL\ 



^j j - ELECTR/C THERMOMETER /NS/DE TOP HALF OF BARREL } NEXT TO S/DE WALL. HALFWAr BETWEEN BUNKER ANO CENTER 



\ " " " BOTTOM " " SAME BARREL. 



C ELECTR/C THERMOMETER ON TOP OF BARREL , CENTER OF CAR, M/DDLE 



VI \ -' - '-'- " " UNDER " " " " " t 



I " « /NS/DE CENTER OF SAME BARREL. 



II&V{ ATMOSPHER/C TEMPERATURE 



Fig. 19. — Thermograph and electric thermometer records (warm weather), floor insulation of car wet. 



The insulation in the side walls and floors of the cars used by six 

 different lines shows no radical differences in quantity or quality, 

 though the general construction in certain cases is preferable. The 

 roofs are varied in the essentials of construction. Theoretically it is 

 the roof of the car which is most severely taxed to prevent the trans- 

 mission of heat. A critical study of the types of roof construction as 

 given in the foregoing pages indicates that the most efficient cars 

 studied were those with the roofs which were the best insulated and 

 built. It is probable that in the future more attention will be paid to 

 both roof and floor insulation and that the floor will be built with the 

 insulation more effectively protected against moisture. 



