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).
Comparative data sheet of physical and electrical properties for various base materials.
| Identifier | ExFiles\Box 61\1\ scan0242 | |
| Date | 26th April 1934 guessed | |
| Paper Base Fabric Base Asbestos Characteristics RITS. SWAN. SHIP. CROW. WHALE. VOLK. CARP. ASP. Specific Gravity. 1.34/1.38 1.34/1.38 1.34/1.38 1.34/1.38 1.34/1.38 1.34/1.38 1.34/1.38 1.84 Cubic ins. per pound. 20 20 20 20 20 20 20 15 Insulator Resistance. S47 over S47 S47 (A) (A) (A) (A) - Electric Strength S47 S47 S47 " " " " - Surface breakdown in air. S47 S47 S47 " " " " - Breakdown along laminae. S47 S47 S47 " " " " - Tensile strength (B) 12,000 10,000 9,000 10,500 12,500 12,500 16,000 - lbs per square inch lbs per square inch Compression on 1" cube crushed to first split. S47 S47 " 17 1/2 18 1/2 tons face up 9 tons edge up " " - Shear Strength. 10,500 9,000 9,500 11,500 12,500 " - lbs per square inch lbs per square inch Water Absorption. slightly S47 slightly 0.4% 0.4% B B - higher than S47 higher than S47 * Ship Brand is a thin material prepared specially for punching. | ||