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).
History of bonnet catch springs for 20HP and 40/50HP chassis, seeking final approval for production.
| Identifier | ExFiles\Box 102\6\ scan0039 | |
| Date | 16th July 1926 | |
| To Hs.{Lord Ernest Hives - Chair} X5260 BY/SS{S. Smith}1/DB.{Donald Bastow - Suspensions}16.7.26. Re 20HP & 40/50HP Chassis - Bonnet Catches. We give below the history of springs fitted to the 20HP type of Bonnet Catches. As there appears to be some doubt as to what is actually required for production, will you please state which springs receive your final approval for both 20HP and 40/50HP | Spring | Load in Position | Rate | Remarks | | :--- | :--- | :--- | :--- | | E.50698. | 7.5 lbs. | 23.3 lbs. | To original LeC.1403. | | E.51600. | 20 lbs. | 43 lbs. | Asked for by Hs.{Lord Ernest Hives - Chair} and fitted on all 20HP chassis. | | E.51619. | 25 lbs. | 84 lbs. | Asked for by Hs.{Lord Ernest Hives - Chair} Rejected by R.{Sir Henry Royce} Ordered for 20HP Series "K". | | E.75126. | 22.5 lbs. | 47.6 lbs. | Lower rated spring asked for by R.{Sir Henry Royce} Fitted to 12-EX. | BY/SS.{S. Smith} | ||