3850

3850 was built at Swindon in 1942.

BR motive power depot allocations since 1948.

Date Arrived	Depot
January 1948	Westbury
March 1948	Severn Tunnel Junction
February 1959	Aberdare
December 1963	Banbury
October 1964	Oswestry
January 1965	Croes Newydd

Whilst at Severn tunnel Junction and Aberdare 3850 spent some month in storage.

After withdrawal 3850 from Croes Newydd (Wrexham) in August 1965 3850 spent 20 years at Woodham’s scrapyard in Barry before going to the West Somerset Railway in the 1980s as the first engine to be purchased by the Group which has now become the Dinmore Manor Locomotive Ltd. For various reasons its return to traffic was protracted one and took two further decades to complete – it returned to steam in 2006.

3850 was working on the West Somerset Railway before being taken out of service in 2015 for overhaul and transported to Toddington for the overhaul to be undertaken on the Gloucestershire Warwickshire Railway.

As the locomotive has completed over 82,000 miles since it returned to steam in 2006 it is considered that significant work will be required in order to have 3850 running again. The front end of the locomotive is to be replaced as the cylinder blocks are cracked from top to bottom and the extension frames bent. The latter is thought to be due to being involved in a collision in its BR service.

Whilst the boiler and wheelsets will be sent away to be worked on it is anticipated that the rest will be undertaken at Toddington.

As part of restoring the locomotive to its original condition the driving wheelset is being swapped with those on 2874 which had acquired those fitted to the later Churchward engines when overhauled by BR.

Due to the cylinder block being cracked a new one is being cast by Coupe Foundry in Preston.

By early 2018 the driving wheelsets have had their tyres and axle journals re-profiled and it was planned that reassembling the bottom end would begin in the summer of 2018.

The boiler from classmate 3845 is planned to be overhauled by Riley & Son (E) Ltd and used on 3850 as it is in slightly better condition than the boiler on 3850. The boiler from 3850 will be worked on by volunteers later.

The first of two new cylinders for the locomotive were cast at the Shakespeare Foundry in April 2018.

In April 2019 the owners disclosed that the entire front end replaced as part of the overhaul and that the total cost of the overhaul of the locomotive was estimated to be £400,000.

In December 2023 it was reported that the boiler had been overhauled by Riley & Son at Heywood and returned to the Gloucestershire Warwickshire Railway.