This locomotive was built in 1948 by Robert Stephenson & Hawthorn for the Leicester Gas Department. In May 1949 the Leicester Gas Department was taken over by the nationalised East Midlands Gas Board.
The locomotive was given the name Mars No 2 in line with the names given to other locomotives there – Mars,Jupiter, Sirius and Orion.
Mars No 2 was the last steam locomotive supplied there and one of only two that remained in service there beyond 1958. The first two locomotives based at Leicester Gas Works were scrapped in 1936 and 1937. By 1953 three of the five remaining steam locomotives there were being stored.
In 1957 a Rushton & Hornsby diesel locomotive was acquired to work on the site and was given the name Mars. At this time only one locomotive was required for the whole of the shunting duties so that the steam locomotive Mars No 2 was retained as a standby and was only used when the diesel was under repair.
In July 1968 rail traffic to the site ceased and whilst the diesel locomotive was towed to the East Midlands Gas Board’s Litchurch works at Derby the steam locomotive remained at Leicester. Gas production at the plant ceased in May 1969, with the onset of natural gas, but the plant continued to be maintained for a further twelve months for use as standby if required. Demolition of the retort houses and the older gas holders commenced in the summer of 1972 but the site is still used, and will continue to be used, for compression of North Sea gas for onward transmission to surrounding districts, and as far away as Northampton.
Following the cessation of rail traffic in 1968 the locomotive was left to stand forlorn in the works yard, and remained there for the next year and a half, although its fate had already been decreed.
Shortly after its withdrawal someone in authority at the East Midlands Gas Board (Emgas) enquiring if the Leicester Railway Society (LRS) would accept the locomotive for preservation. At the same time the Director of Leicester Museums approached someone else in authority at Emgas offering to preserve the locomotive! As everyone who has had a hand in the preservation of a locomotive knows, the whole exercise is fraught with difficulties, not least the acquisition of a suitable site to house the it. As Leicester Museums already had a temporary (but full) railway museum, and a permanent one in course of planning, a compromise solution was evolved.
It was planned that the locomotive would become one of the exhibits in the projected East Midlands Museum of Technology at Abbey Meadows, Leicester, and the LRS would be responsible for its restoration and maintenance. At this stage, envisaged that the locomotive would be a working exhibit on a short stretch of track.
The Museum had nowhere to keep the locomotive as the building planned for the storage and restoration of exhibits had not then been commenced. The locomotive was moved from the Leicester gasworks to Abbey Meadows in February 1970, where it once again stood out in the open gathering rust.
Eventually the locomotive was put on display at the Snibston Discovery Museum which opened in 1992. In 2015 Leicester Council announced that the museum was going to close.
It is believed that the locomotive is now in store on the former site of the Snibston Discovery Park.