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 results for electrical breakdown of various materials under high voltage.
| Identifier | ExFiles\Box 52\1\ Scan120 | |
| Date | 8th December 1924 | |
| RR 238 (150 BKS.) (DB {Donald Bastow - Suspensions} 461-8-12-24) MP 306975 ROLLS-ROYCE LTD. INSTRUCTIONS. (4) To_________________________19__ Order No. WD {Mr Wood / Mr Whitehead} 92 (contd) Customer's No.___________ "Helsby" - Broke down at 17000 volts R.M.S. "Maconite" - Successfully withstood 19500 volts R.M.S. for 15 mins. ⑥ "Gloverite" - Failed after 2 hrs.. "Super Glover" - Failed after 8 hrs. "Helsby" - Failed after 7 1/2 hrs. "Maconite" - Failed after 2 1/2 hrs. ⑦ "Gloverite" - Broke down after 27 mins at 19200 volts R.M.S. "Super Glover" - Broke down after 14 mins at 19200 volts R.M.S. "Helsby" - Broke down after 20 mins at 19000 volts R.M.S. "Maconite" - Broke down after 29 mins at 19200 Volts R.M.S. Signed (contd) This Sheet must be filed on completion of the work. | ||