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).
Standardisation of parts for a big end bearing bush (AC.9 die cast).
| Identifier | ExFiles\Box 171\5\ img053 | |
| Date | 9th May 1938 | |
| RR 755B (10H) (49868) 19/10/37 C.E.Co. COMPLETED 22.9.38. BENTLEY STANDARDISATION OF PARTS Date Issued 9.5.38. Sheet No. B.14. Drg. No. EB.3377. L.O.P.S. Description: BIG END BEARING BUSH (AC.9 DIE CAST). Purpose: Ease of casting with consequent reduction in scrap also reduced material cost by die casting approx. to size. Brief Report and Remarks: The AC.9 material was evolved for ease of casting as compared with previous bearing alloys in AC. material. Bearings in this AC.9 material were run over 40 hrs. severe endurance conditions both in die-cast and centri cast form to reduce material cost on a B.II unit. Of the two types, the die-cast were the best and almost unmarked after the run whereas the centri-cast although very good revealed slight crack in one big-end and was characteristic of centri-cast alloys previously tried. Old Parts: Material £1.2.11. Labour £0.2.11. Burden £0.5.1. Total £1.10.11. New Parts: Material £0.7.5. Labour £0.3.1. Burden £0.5.5. Total £0.15.11. Decrease in Cost £ 0.15.0. G/RL 16/6/38 Production Position and Comments: Cost of Tools £ 10.0.0d. Big end bearing bush (A.C.9. die cast) replacing A.C.j. Bearings provide a saving of 15/- per chassis and involve a die Cost of £10.0.0d. Existing bushes will be absorbed at 55th. chassis in 'M' series and it is therefore proposed to introduce A.C.9. bushes at this point. Tool cost will be recovered after producing 14 chassis i.e. at the 69th chassis in 'M' series. There will also be a reduction in indirect charges because casting scrap will be reduced when using A.C.9. material. RHC.{R. H. Coverley - Production Engineer} Authorisation to Proceed. Introduce on the 55th Chassis in M Series. Sg.{Arthur F. Sidgreaves - MD} Signature Date 20/9/38 Hs.{Lord Ernest Hives - Chair} Signature Date 20/9/38 | ||