Ruston & Hornsby 40DL diesel-mechanical 3-speed 0-4-0, works number 194771 (built in Lincoln) was part of a batch of small diesel locomotives built under contract for theAir Ministry in 1939.

The locomotive was moved to the ammunition and bomb storage facility known as RAF Chilmark in Wiltshire. This site had an extensive 2ft gauge rail system, with tracks entering the underground bunker bomb stores. Munitions were loaded onto a variety of wagons and specialist trucks. Bala Lake Railway still has an example of the metal bodied, drop-side, dual-bogie Hudson wagons used for moving ammunition at sites like RAF Chilmark.

Chilmark Quarries and its underground limestone minesand the surrounding land were acquired by the Air Ministry in 1936 and served as a bomb store, RAF Chilmark, throughout WWII.

Close to the village of Chilamark the huge quarry workings had been supplied the stone for the building of Salisbury Cathedral.There was a standard-gauge transfer station at Ham Cross, with afour mile spur from Chilmark to the BR connection at Dinton which utilises part of the old double track main line from Exeter to Salisbury.

Much of the underground railway, within the individual bomb stores was operated by battery electric locos, one of which was Baguley Drewery 3703, now preserved on the Golden Valley Railway in Derbyshire - link.

The above ground system also served the Chilmark Stone Mine that was located within RAF Chilmark.

The first consignment of war stores arrived in May 1937, unlike most other WWII RAF depots, Chilmark continued in use after the war. In 1994 supplies were transferred to the Nato depot at Glen Douglas in Scotland, prior to the complete closure of Chilmark in April 1995 with the loss of 200 jobs

RAF Chilmark was finally decommissioned in 1996 and most of the remaining 2ft gauge railway equipment disposed of in a MOD tender. The stone quarries are still operational - read more.

The loco was purchased in 1976 and heavily rebuilt following its December arrival at Llanuwchllyn, when the fire-supression equipment was removed and the cabrebuilt.

An example of how the loco may have looked before this rebuild can be seen at Hollycombe which is home to "Jack" another ex-RAF Chilmark RH loco, complete with fire supression equipment.

The loco was offically named Chilmark in deference to its source and nameplates were cast and added. For many years, Chilmark was the main works-train locomotive, being quite a favourite of the many volunteers. George Barnes adapted a furrow plough to allow it to be attached to Chilmark's buffer beam to help create the shouldered trackused throiughout the Bala Lake Railway.

Due to mechanical failures, Chilmark was taken out of service, occassionally being pushed around by Merionnydd when ballast ploughing was required. Eventually it was discovered that the locos gearbox and engine block had extensive damage and would either need replacing or major rebuilding/repair and Chilmark got shoved to the back of the carriage shed at Llanuwchllyn.

Chilmark, bodywork partially restored at back of carriage shed authors collection

Some cosmetic work was undertaken on the bodywork (during the early 1990's) to extend its life. Llittle happened until at the turn of the century (2000) members of the Hampshire NG Railway (who were also volunteers at BLR) offered to take the engine and gearbox apart with a view to refurbishing the worn/damaged components.

Following many false dawns, Chilmark was finally brought back to full working condition in 2008 and painted to an excellent standard by Roger Hine in the new BLR diesel fleet "corporate colour scheme". It is now hoped Chilmark will resume its role of works train locomotive.