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).
Durability testing specifications for ward connections, bonnets, and thermometers.
| Identifier | ExFiles\Box 148\2\ scan0067 | |
| Date | 19th November 1938 guessed | |
| for new construction LTRH (crossed out) ④ Ward connections Three sets to cover at least 30,000 miles each without failing + be in service for at least one year each without showing serious deterioration. ⑤ Bonnets :- 2 Steel bonnets - → 3 to be in service for at least 1 year each without signs of rusting or corrosion, + two to cover at least 30,000 miles (either steel or aluminium) without defects such as indentation of rest strip, knocks, squeaking or binding of hinges occurring. ⑥ Thermometers + a basic thermostats at least one of any new type to complete at least 30,000 miles each (crossed out) & at least three to be in service for a minimum period of 1 year. | ||