NCC Class B3
The LMS 'Class B3' 4-4-0 passenger steam locomotives were rebuilds of Belfast and Northern Counties Railway two-cylinder compound locomotives. They operated services throughout the NCC's broad gauge system in the north-east of Ireland.
History
The locomotives that comprised the Northern Counties Committee Class B3 were rebuilds of two classes of BNCR "Light Compounds". These had been built by Beyer, Peacock & Company in the 1890s to the design of the BNCR Locomotive Engineer Bowman Malcolm. The first two members of the class were originally Class C Light Compound 2-4-0s. Rebuilding began with No. 28 in 1927 and No. 21 in the following year. The other three Class B3 locomotives were derived from Class B Light Compounds whose only original difference was that they had always been 4-4-0s and not 2-4-0s.However, before alteration to Class B3, Nos. 60 and 61 had already undergone an earlier rebuilding to become Class B1 compounds in 1921 to be followed by No. 51 in August 1926. By contrast, No. 24 was rebuilt as a simple in February 1925 to become the solitary member of the somewhat ephemeral Class B2.
All five engines had cylinders with piston valves and retained their driving wheels. The first three members of the class had boilers rated at but Nos.60 and 61 had the advantage of boilers.
During rebuilding, they were fitted with LMS standard boilers that had to be placed higher than the originals to allow the firebox and ash pan to clear the rear driving wheel axle. The smokebox saddle was extended accordingly to offer support. The closely coupled driving wheels accentuated the appearance of the high-pitched boiler, earning these engines the nickname of "Whippet" because of a perceived resemblance to the breed of racing dog.
All members of the class were officially named after Ulster counties.
No. 28 was withdrawn in December 1938, having run just over a quarter million miles in her rebuilt form. The remaining locomotives served throughout World War II and were scrapped in 1946–1947.
Building and withdrawal data
The following table summarises the rebuilding and renumbering history of the Class B3 locomotives.| Original No. | Class | Date Built | Date Rebuilt | Class | Rebuilt to B3 | New No. | Name | Scrapped |
| 51 | C | 1926 August | B1 | 21 | County Down | |||
| 24 | B | 1925 February | B2 | 24 | County Londonderry | |||
| 58 | C | — | — | 28 | County Tyrone | |||
| 60 | B | 1921 | B1 | 60 | County Donegal | |||
| 61 | B | 1921 | B1 | 61 | County Antrim |