Number 30506 was one of the second batch of five ordered in March 1917, but not completed at Eastleigh until October 1920.  Once run in, holly green liveried 506 went to Nine Elms along with sisters 497-505, although she was to move to Strawberry Hill in 1922 and then on to Feltham in 1923, when the new marshalling yard was opened.

The S15’s went about their duties on heavy goods, and on Summer weekends were regularly rostered on relief passenger and seaside excursion trains.  The Southern Railway painted the S15’s in lined goods black when the E prefix was applied, but from 1928, the locomotives were painted in Maunsell lined green at their next overhaul.  E506 received her lined black livery at her second heavy overhaul in 1924, and did not return to a green livery until 1930.  Later she received the new smoke deflectors and in 1932, she lost the E-prefix to become 506 once again.

When the LBSCR 4-6-4 tank engines were rebuilt to the class N15X 4-6-0’s in 1934-36, our engine was one of a number of Urie S15’s that donated their tenders to the new locomotives.  In return for tender no. 3210, our engine received a Drummond eight-wheel 4,000 gallon watercart tender no. 221 of 1902 vintage from a class C8 4-4-0 that was being scrapped.

The next changes were the introduction of Bulleid’s unlined dark green livery in 1939 and wartime plain black livery in 1942.  This was followed by the replacement of the Urie stovepipe chimney with a Maunsell class U1 pattern chimney in 1945.  With the nationalisation of the railways, 506 received number 30506 and British Railways goods black in August 1949.

During 1956, the Drummond watercart was replaced by an Urie double bogie tender no. 859 from a withdrawn King Arthur locomotive.  She then ran with this until withdrawal on 5 January 1964 with 1.22 million miles under her belt.  A group of four S15’s were purchased by Woodham Brothers, and 506 was selected to haul the group on their final journey to the scrapyard in June 1964.  Unfortunately, 506 failed at Staines with a blown superheater element and did not arrive at the Barry scrapyard until August that year.

The society was formed in April 1972 and its primary goal, the saving of an Urie S15, was achieved when 30506 was purchased in March 1973.  A location for the engine and raising of the transportation costs meant that 30506 did not move to the Mid-Hants Railway until March 1976.  Whilst undergoing restoration, the boiler (no. 451) was examined on several occasions, but state-of-the-art metallurgical tests in 1979 determined that the cracking at the top of the firebox was not repairable, so the group returned to Barry and purchased a second boiler (no. 799) and this was eventually put on 506 in February 1981.

The restoration of 506 was sidelined for some years whilst the group overhauled LSWR class T9 4-4-0 no. 120 on behalf of the National Railway Museum and then worked on the restoration of one of the engines returned from Greece, both for use on the Mid-Hants Railway.  This resulted in 506 eventually returning to steam in 1987 and running on the Mid-Hants Railway for a full fourteen years before coming out of service in 2001.  After waiting some time to negotiate a new operating agreement with the railway, work has started on a heavy overhaul with the intention of returning her to steam in the next few years.