In 1903, the Chief Mechanical Engineer, Dugald Drummond, oversaw the construction of a large motive power depot in the town; replacing the existing maintenance and repair shops at Northam, Southampton.
Like most of the railway works, Eastleigh was heavily involved in the war effort, producing, in 1938, sets of parts to convert Blenheim bombers so that they could be used as fighters.
The works was also part of a joint venture with other workshops, railway and private, to produce Horsa gliders for the D-Day airborne assault.
It also produced 1,500 anti-tank gun barrels and, with Brighton railway works, 240 multiple rocket launchers, plus landing craft, fuel tenders and harbour launches.
Under the regime of Oliver Bulleid, after 1937, Eastleigh works constructed all thirty of the SR Merchant Navy Class and six of the West Country 4-6-2.
During the Second World War, Eastleigh works built 23 examples of the London Midland and Scottish Railway designed 8F 2-8-0s.
[12] In 2007 Knights Rail Services (KRS) began operations on site, using it to store off lease rolling stock, as well as undertake repairs and refurbishments.
It started in 2004 when Arlington Fleet Services Ltd was established by a group of railway engineering professionals[18] to perform rail vehicle maintenance including heavy repair.