GSR Classes 372 and 393

Following the end of World War I, many munitions manufacturers (including the Royal Arsenal) had been made redundant, and it was proposed by the British government that they begin building steam locomotives instead. In November 1919, the Ministry of Munitions made an order for 50 2-6-0s and 50 2-8-0s to designs meant for a post-war nationalised railway system that hadn't materialised. The drawings were found to be incomplete and the order was amended to 100 locomotives of the SECR N class, a similar design.^[4]

The initial asking price for a locomotive and tender was £14,000, but with little interest the price soon fell. The first buyer was the Midland Great Western Railway, which bought 12 kits in March 1923 for £24,000. Even before the first kit had been assembled, the MGWR's successor, Great Southern Railways, expressed interest in acquiring more engines and in 1927 bought 15 more kits and four spare boilers for £34,000, an average cost of around £2,200 per locomotive — cheaper than it was to construct just one of the boilers.^[4]

The first entered service as MGWR number 49 but the company then became part of the new Great Southern Railways and the locomotive was renumbered 375 and the remaining 11 kits were completed as GSR engines.^[5] The final one of the batch, number 383, was the last locomotive completed at Broadstone.^[5] The GSR designated them Class 372 or Class K1.

As a result of their low chimneys, the locomotives tended to become quite dirty from the smoke. Although this was solved with the British examples by fitting smoke deflectors, no such action was taken. Their cabs, designed for the British loading gauge, were also considered cramped by Irish standards; despite this, the locomotives high route availability and capable steaming abilities earned it popularity with crews.^[4]

Being designed to operate freight services in Southern England, the class' abilities were stretched working heavy express trains. This was combatted by building the final six kits with 6 ft (1.8 m) driving wheels, essentially becoming the Irish equivalent of the SR U Class. The engines, numbered 393–398, became the Class 393.^[5] The number 392 was never assigned, but was probably meant for a spare kit that was rediscovered in Inchicore in 1963.^[4]

Córas Iompair Éireann succeeded the GSR in 1945 (and was nationalised in 1950), retaining the same classification system and numbering for its locomotives. In 1954 CIÉ withdrew four of the 1924 327s, but in the winter of 1954–55 CIÉ overhauled another seven of the class for further service.^[6]

In the 1950s CIÉ continued to operate freight trains without continuous brake.^[7] On 21 December 1955, number 375 was in charge of such an unfitted train consisting of 32 wagons laden with sugar beet.^[7] The train was on the line between Waterford and Limerick Junction on CIÉ's Southern section when it ran away descending the gradient to Cahir.^[7] The signalman diverted the runaway train into a siding to protect a mail train that was standing in the station.^[7] 375 smashed through the buffer stop at the end of the siding and onto the viaduct over the River Suir beyond the station, demolishing the first span of the viaduct.^[7] The locomotive and 22 of the wagons plunged into the river, killing the driver and fireman.^[7] 375 was recovered from the river but considered beyond economic repair and scrapped.^[7]

CIÉ withdrew the Class 393 and remaining Class 372 by 1965.