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).
Tyre tread print with corresponding area and load calculations.
| Identifier | ExFiles\Box 29\4\ Scan153 | |
| Date | 23th November 1933 guessed | |
| - DUNLOP FORT - SIZE 5.50/18 (28x5.50) TOTAL AREA = 22.70 SQ INS. ROAD CONTACT " = 18.14 SQ INS. GROOVE " = 4.56 " " SKID LINE LENGTH = 48" LOAD. = 8 CWTS | ||