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).
Results of four sequential tests (Nos. 3, 4, 5, and 6) on a fabric disc coupling attachment.
| Identifier | ExFiles\Box 5\5\ 05-page17 | |
| Date | 15th July 1929 guessed | |
| -3- TEST No 3. It was suggested that the spigoted-stud attachment of the fabric to the spiders was too solid, and that this was the probable cause of the early failure of Nos. 2A and 2B. For this test a fabric was fitted up to the spiders by three plain bolts and three taper headed bolts as shown in G.73370. After 20 mins. when one of the nuts had slackened the coupling was stripped and examined. Several of the plate screws were found to be either threadless or broken. The fabric was re-assembled and the test continued. After a further 30 mins. the fabric collapsed. TOTAL TIME RUN. 50 Mins. REVERSALS. 36,382. TEST No 4. This test was carried out in a similar manner to No 3. a fabric disc having riveted plates replacing the screwed standard type. After 1 hr 20 mins. running it was found that the taper headed bolts were working loose - there being no locking device for these on the spiders which we were using - and the rig was stopped. When examined the disc had not suffered any apparent damage, and after providing a locking device for the bolts the test was continued, the fabric collapsing after a further 45 min. although the rivets and plates were O.K. TOTAL TIME RUN 2 hrs. 5 mins. REVERSALS 149,914. TEST No 5. The rig was restored to the spigoted-stud arrangement Ex. 3958. the disc plates in this case being secured by shouldered rivets - No. 2240 - in place of G.73372. rivets. TOTAL TIME RUN 3 hrs 55 mins. REVERSAL 174,209. The fabric collapsed, the plates and rivets being O.K. TEST No 6. This was a repeat test of No 5. the conditions being the same. TOTAL TIME RUN 3 hrs. 46 mins. REVERSALS 168,912. | ||