Oleg - Spitfire Cockpit.

[BOBC]

Biggs...Hey BOBC, slightly off topic but do you know what version of propeller we should be seeing in SOW? the deHavilland 2- pitch or the Rotol Constant speed.

I thought in the early part of 1940 most of the spits were fitted with de Havilland but by the late spring they were producing them with the better performing constant speed.

I asked Oleg a while ago but I dont think I got a definitive answer.

Information I have managed to obtain now (and thanks to those suppliers of same, summarised says:-
By Dunkirk almost all of the RAF home fighter force had De Havilland variable pitch (2 settings, three blader). According to Al Deere, in "Nine Lives," 54 Squadron were trialling Rotol constant-speed props, during the Dunkirk evacuation
The Rotol (hydraulic) constant speed was introduced for production of MkII Spits and retrofitted to MkI from June 1940. It's a manual constant speed (ie. fully variable )
The constant-speed propeller (same propeller but with internal adjustments) modifications were carried out in the field from June 26th to August 15th on 1,051 Spits and Hurris by De Havilland engineers and squadron staff as the further performance advantages were obvious by then over the 2 speed props..
de-Havilland propellers were licence-built Hamilton designs, Rotol being a home-designed product.
The Hamilton Standard is electric and less prone to overspeeding in dives; it came later.
Rotol were a bit further ahead with their constand speed propeller developments during the first year of the war.
The Rotol electric props utilised the Curtiss Electric-designed propeller pitch change mechanism for their electric props, presumably as an alternative to hyydraulic should any serious production problems arrive with the hydraulic types.

BOBC