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Lentz Valve Gear on LNER C7 (NER Class Z) Atlantics

Posted: Sun Feb 11, 2007 7:14 pm
by richard
I've been corresponding with Richard Carr over the past few days. Richard is writing a history of Paxman, and is currently working on Lentz valve gear (licensed and sold by Paxman). Our books are vague or contradict each other as regards the C7s that had Lentz valve gear fitted.

No. 732 had Lentz rotary cam valve gear fitted in December 1933.
No. 2212 (the Uniflow engine) was rebuilt in 1934: the Uniflow was removed and Lentz valve gear was fitted.

"The Gresley Influence" by Geoffrey Hughes says the Lentz valve gear was removed along with other 'experiments' (water feed heater, boosters, etc).
"LNER Steam" by OS Nock barely mentions the gear and doesn't saying anything about it being removed.
The RCTS volume implies that both engines kept the gear until withdrawal.
It does not mention any rebuilding with piston valves.
Hoole's "The North-Eastern Atlantics" (Roundhouse Books) gives quite a detailed history which implies they were withdrawn with Lentz valve gear intact.

Does anyone have any other sources - eg. Yeadon's?
I only remembered I had a copy of Hoole's book when I started to write this post - now I've found it, I think it has the correct history, and Hughes has incorrectly grouped all the modifications together.


Richard

Posted: Fri Feb 23, 2007 5:06 pm
by Colombo
Richard,

The only further information that I have is from Brian Haresnape's "Gresley Locomotives" which has a photo of 2212 at Gateshead shed in 1937.

He says that it was rebuilt in 1936 from the Uniflow Cylinder arrangement with an improved Lentz gear with 7 exhaust positions rather than 5, as had been fitted to the D49s and to 732 in 1933.

Hows the weather in Houston?. Florida was very nice last week.

Colombo