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).
The failures and repairs of a 'Jackall' jacking system, detailing issues with valves, jacks, and pipe connections.
| Identifier | ExFiles\Box 139\2\ scan0344 | |
| Date | 3rd October 1935 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} X116b Hs{Lord Ernest Hives - Chair}/Bwg.{J. C. Bowring}11/KW.3.10.35. "Jackall" Jacking System - 21-G-IV. Pressure Pump. The release failure on the above system was due to the fitting of incorrect valves. Brass valves were fitted, whereas copper-lead valves should have been. Brass Valves do not vulcanize to the rubber retainer satisfactorily, and it was found that all three valves had worked loose and were therefore not following up on the release. It was intended that just the valves and retainer should be changed, but unfortunately a union was broken off the casting in removing same, and so a complete new unit was fitted. Attached is a rough sketch giving an idea of the valve layout. Jacks. The nearside rear and offside front Jacks failed in France through leakage down the ram sleeves. These Jacks were replaced, only to find that the offside rear and nearside front Jacks leaked likewise. These were also replaced. It is suspected that the rams are undersized and we now await Smith's report on this query. Having completed the system we ran into further trouble with the pipe connections to the nearside front Jack and junction box. The method employed in making the joint is by an Olive. The pipe end is also flared, but on three occasions the pipe blew out, due to the fact that the pipes were not flared enough. This type of joint seems most unsatisfactory for high pressure once the connection has been broken. | ||