Style 'B' signal box index

The Westinghouse Brake & Saxby Signal Co. Ltd produced the Style 'B' mechanically locked lever frame from 1902, The styel 'B' lever frame was developed from the style 'A' lever frame of 1902. The first style 'B' was installed at Harton Colliery [South Shields 4½ miles [8 km] NNW of Sunderland ] in Dec 1902.

The follow on Style 'K' lever frame was introduced in 1912, and there is not much difference between the two, the 'B' lever frames were only used abroad until 1923. The 'K' lever frame of course was designated to be the "all-electric" version whereas the B had first been designed for electro-pneumatic use at sites which Southport Chapel Street was.

As far as the differences between B and K go there aren't really any other than the K usually had a greater number of contact bands because these were normally used for all-electric installations whereas the B was first designed for electro-pneumatic operation. Both had teak casing but LT companies often went for steel, similar to the L and N styles. I guess there were probably subtle changes to materials and parts between the B and K as there was a time separation between the first Bs and the introduction of the K so opportunity would have been taken to make improvements or economies. So the answer is that I've not come across any significant difference, it's more a case of marketing a "new" version by Westinghouse at the time because it's also not unknown for Ks to be used on electro-pneumatic jobs. Hope this helps Regards Mark

The table below in green shows the locations of the frames supplied and installed by Westinghouse Brake & Saxby Signal Co. Ltd

Westinghouse Supplied & Installed Style 'B' Power Lever Frames used in the UK
Signal Box Name	Railway	notes	Capacity	Point Levers	Signal Levers	Special Levers	Spare Levers	open	closed
Southport Chapel Street	L.M.S Railway		87	?	?	?	?	1917	20th March 1994
St Lukes box	L.M.S Railway		103	?	?	?	?	1918	30th Nov 1969
Harton Colliery			?	?	?	?	?	Dec 1902
Aldgate East	London Transport		15					1906	18 May 1946
Angel	London Transport		11					1919	22 January 1959
Archway	London Transport		15					22/06/1907	12 September 1992
Bethnal Green	London Transport	to Bolton Abbey	11					18 November 1946	10th November 1999
Camdon Town	London Transport		7 - 1946 34 - 1924					18 November 1946	23 July 1955
Canal Junction	London Transport		23					1950	24/03/1995
Charing Cross	London Transport		12					22 June 1907	09 June 1951.
Colindale	London Transport		15					01 January 1922	23/07/1961
Covent Garden	London Transport	to SVR museum	12	1	11		0	15 December 1906	13 October 1979
Cromwell Road	London Transport		15					01 January 1922	13 May 1961
Ealing Common	London Transport		23					10th March 1925	5th November 1960
Hyde Park Corner	London Transport		23	3	13	2	3	1931	12th May 1979
Lambeth North	London Transport		11					1939	10th Aug 1991
Liverpool Street	London Transport		23					1937	9th Mar 1997
Paddington	London Transport		8					1939	??
Piccadilly Circus	London Transport		8					1939	??
Queens Park	London Transport		27	10	11	4	2	26th March 1905	8th October 1990
Shoreditch	London Transport		47?					1913	19th May1928
Preserved Frames
Acton signal school	London Transport	London Transport
Bolton Abbey	Embassy Steam Railway	London Transport	23
Covent Garden	SVR museum	London Transport	12	1	11		0		Kidderminster Museum