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).
Calculations and specifications for Goshawk chassis springing.
| Identifier | ExFiles\Box 49\3\ Scan178 | |
| Date | 6th March 1923 | |
| R.R. 199 (250T) (S.D.676 19-7-17) MP 180865. X4261 Hs. {Lord Ernest Hives - Chair} c. Mr Booth. I.S MAR 6 1923 RECEIVED BY3-P5.3.23. GOSHAWK SPRINGING. I have been trying to get you this afternoon to talk the above question over again. We find that it is quite impossible to calculate springs and bring them, either front or rear, within the two types of springs we have specified at present, in accordance with the springs you are actually running. The springs we actually have on order which are being delivered are as follows;- Front 550 and 600. Rear 800 and 900. In order to keep matters as straight as we can we are calculating springs on the following basis;- Total body load and spares, 25% on the front and 75% on the rear. In accordance with R's instructions, we are never allowing for more than 4 passengers and 2 cwt. of luggage, and even when 6 passengers are specified we ignore 2 of these, and then to meet R's requirements we take only one half of the remaining 4 passengers and one half of the luggage. You will observe that this tends in itself to make the springs too light, and its effect is to reduce clearances between the axles and the buffers. In addition to this, to use both front springs on a chassis it means that we have to use the 550 lb. spring on a chassis when possibly it really demands a 590 lb. spring. In one case of the rear we fit an 800 lb. spring where the calculation calls for 840 lb. From this you will observe that our springs are on the light side, even for Mr Royce's weights, and that we cannot help ourselves in this matter without scrapping all the 550 lb. front springs, a course which we cannot, at the moment, adopt, because we have no excess of any type of spring and therefore we are bound to use 550 and 600 lb. front springs for open and closed bodies respectively, practically ignoring the deflection condition and the fact that the springs are approximately 10% over-loaded, even on Mr Royce's generous allowances. contd. | ||