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 windings for Derby & Springfield cutouts.
| Identifier | ExFiles\Box 43\1\ Scan024 | |
| Date | 5th October 1927 | |
| X.5988 5.10.27. DERBY & SPRINGFIELD CUTOUTS. X8740 Comparison of windings. Shunt amp x turns; Derby 420. Springfield 280. Series amps/sq." section of wire:- Derby 3000, Springfield 3750. Series winding appears suitable magnetically for use with shunt coil designed. --- EFC. | ||