Collett followed Churchward and in 1924 produced the Castle Class developed from the Stars. Widely proclaimed as the best locos Swindon had ever produced, it would take many years for their performance to be surpassed. Collets original Kings were initially only slightly better than the castles - but better enough for 29 to be built. It was not until the late 1940’s, under British Rail ownership that the Kings received small, but very effective design changes that truly set them at the top of the locomotive performance tables.
The King was to some a ‘Super Castle’. Initially, a slightly bigger boiler and modified front bogie were the only apparent visual differences. Cylinder diameters, smaller wheels (by 3”) and super heaters element quantities gave the rest of the changes. It was in 1946 that an ‘oval’ sided double chimney was tried, and the results lead to the straight style adopted by BR.
3 of this class have been preserved, namely:
6000 King George V, 6023 King Edward II, 6024 King Edward I
Length :-682 mm (2’2 7/8”) (over buffers)
Track radius :-2.6 m (8ft 6”) minimum
Weight, :-dry. 10 - 12 lb (5 - 5.5 Kg) Approx. (Current estimate)
Fuel :-Alcohol (Methylated spirit) supplied by constant level feed
system to a multi-tube ‘strand wick’ burner.
Coal, sitting on traditional stainless steel grate and ashpan.
drop down fire door on backhead, Shovel & poker
Boiler :-Internally fired, multi flue, with safety valve and superheater
Built from copper and bronze, silver soldered throughout.
Tested to 13bar (200psi)
Maximum safe working pressure 6.86 bar (100psi)
Controls :- l oco: Regulator, blower, pressure gauge.
Spirit Boilers:- low water level test valve
Coal boilers :- Water gauge with glass
Tender :- Water pump bypass, fuel valve.
Cylinders :- Two, Outside, 12.7mm bore x 24mm stroke (1/2” x 15/16” )
Valvegear :- Slip eccentric, slide valves
Lubrication :-Displacement (Rosco) type.
Water feeds :-Tender carries water in rear tank containing hand pump.
Loco has axle pump driven from driving axle.
Main loco axleboxes individually sprung.
Bogie axleboxes individually sprung.
Buffers and coupling hooks sprung.