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).
Test report comparing the durability of different fabric couplings on non-spigoted and spigoted spiders.
| Identifier | ExFiles\Box 47\2\ Scan447 | |
| Date | 19th December 1930 guessed | |
| -2- FABRIC COUPLING TESTS. NON SPIGOTED SPIDERS. | Reversals. | Hrs. Run. | Condition. | |---|---|---| | Screwed Plate Coupling. | 12,700 | 20 mins. | Collapsed. | | Screwed Plate Coupling. | 32,000 | 0 hrs. 50mins. | " | | Rivetted Plate Coupling. | 80,000 | 2 hrs. 5 mins. | " | SPIGOTED SPIDERS. | Reversals. | Hrs. Run. | Condition. | |---|---|---| | Screwed Plate Couplings. | 46,600 | 1 hr. 20mins. | Collapsed. | | Screwed Plate Couplings. | 82,400 | 2 hrs. 20mins. | " | | Rivetted Plate Couplings. | 770,000 | 21hrs. 52mins. | " | | ||