From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Spring load calculations and fitting instructions with an accompanying blueprint.
| Identifier | ExFiles\Box 67\4\ scan0134 | |
| Date | 7th July 1926 guessed | |
| contd :- -2- unacquainted with the job should consider .188 as applying to all springs and fit them accordingly. This would mean that the static load on the ball end with 2520 lbs. springs would be only 130 lbs. instead of 300 lbs. However, even if the correct amount of required set up is known, small errors in fitting will produce large differences in ball end load, owing to the tremendously high rating and small diameter of the springs employed. As an example, suppose the 3500 lbs. springs to be fitted with .160 initial set up instead of .188 (it is not easy to measure this set up accurately), and the 2500 lbs. spring with .220 instead of .250 static deflection. Then the ball load with the stronger springs is only 280 lbs. and contd :- Blueprint Text: F.5007 4.575 2.500 1.25 1.450 .425 COMPRESSED F.9876 E.17476 F 9771-5 K.5003 F.9874 K.4627 F.4968 F.6965 F.9875 EVERY NEW S.S. SPRING SHOULD HAVE DISTANCE X REQUIRED WHEN FITTING SPECIFIED NOTE. IF PLUG F4968 PROJECTS FROM TUBE F4613 BY AN AMOUNT LESS THAN .188 WHEN SPRINGS ARE FREE, USE WASHER F9843 SWEATED IN POSITION AS SHOWN. | ||