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).
Comparison of design specifications for five, six, and seven plate springs.
| Identifier | ExFiles\Box 52\2\ Scan284 | |
| Date | 28th May 1931 | |
| May 28th. 1931. Suggestion. | Designed to give ---|--- First | Load = 700 lbs. (A) | Free Camber = 3.5" positive. Five Plate Spring. | Loaded Camber = .5" " | Deflection | due to load. = 3 Inches. Second. | Load. = 700 lbs. (B) | Free Camber = 3.625" positive. Six Plate Spring. | Loaded Camber= .5" " | Deflection | due to load.= 3.125 Inches. Third. | Load. = 700 lbs. (C) | Free Camber = 3.75" positive. Seven Plate Spring. | Loaded Camber= .5" " | Deflection | due to load.= 3.25 Inches. | ||