389
HELICAL SPRINGS,
Recoil Springs for 3" Experimental Carriage, Manufactured at Rock Island Arsenal.
No. 10311.
DESCRIPTION OF SPRING.
....inches.. 3.13
......do........37
......do.... 19.50
......do........60
5 pounds 6£ ounces
Exterior diameter of coil
Diameter of bar........
Height unloaded........
Distance between coils... Weight.................
Height. |	Load sus- ! tained.	Remarks.
Inches.	Pounds.	
17.81	100	Initial load.
17.26	150	Central rod 2¡" diameter within the spring.
16.80	200	
16.33	250	Loads applied and released without jarring.
15.52	300	
14.99	350	
14.34	400	
13.58	450	
12.77	500	
10.87	600	
9.80	700	
8.79	800	
7.88	900	Closed down.
7.82	1,000	
7.81	900	
7.81	800	
8.12	700	
9.84	600	
11.39	500	
12.88	400	
14.47	300	
16. 07	200	
17.70	100	
Spring continuously jarred with mallets as the loads were changed.		
17.70	100	Initial load.
16.03	200	
14.58	300	
13.08	400	
11.60	500	
10.42	600	
9.01	700	
7.86	800	Spring generally closed down, a few coils partly open.
7.81	820	
7.82	800	
8.54	700	
9.99	600	
11.50	500	
12.99	400	
14.65	300	
16.30	200	
17.88	100	
Center ro<	l turned down to 2" diameter.	
17.77	100	Initial load.
16.29	200	Loads applied and released without jarring.
14.71	300	
13.23	400	
11.60	500	
10.03	600	
8.47	700	
8.07	750	
7.79	800	Spring closed.
7.77	850	
7.79	800	
8.10	750	
8.58	700	
9.90	600	
11.48	500	
13.04	400	
14.68	300	
16.24	200	
17.93	100	
		
17.76	100	Initial load. Loads applied and released without jarring.
16 17	200