Site Records

Site Name: Lords Bridge (FFD4) Forward Filling Depot

Cambridge Road
Nr. Barton, Cambridgeshire
OS Grid Ref: TL391536

Sub Brit site visit 16th December 2003

[Source: Nick Catford]

At the end of 1954, it was decided by the Government and Ministry of Supply that all stocks of mustard gas and other poison gases would be destroyed but the American solution of dumping at sea would not be used by us. Up to then the method used by the RAF had been to burn such material in the open on concrete pads in remote sites such as Harpur Hill in Derbyshire and Bowes Moor in Yorkshire. This was a most unsatisfactory method as large volumes of smoke were produced, and not all the mustard was consumed. Some remained as vapour distributed to the atmosphere and there was contamination of the concrete and surrounding ground.

At 09.55 on 11th January 1955 there was a serious explosion at Lord's Bridge. The 130 tons of Runcol (Y23) in K tank had been diluted with benzine to make it more effective by penetrating the skin but this also made it highly explosive. For some unknown reason, an aircraftman had been using an oxy-acetylene torch in the vicinity with the result that there had been a tremendous explosion followed by a fire. The area was immediately evacuated and RAF personnel arrived to fight the fire which was brought under control and extinguished by 10.20. A black cloud of smoke and mustard gas vapour was distributed over the countryside.

Test rig at Randal for burning mustard
'K' pot was found to be completely shattered; the top had burst and was hurled to one side. 20 tons of mustard was lost although no signs of contamination were found around the tank or in the nearby streams or water bore hole. Meticulous safety precautions were then observed - the remaining liquid in the pot was protected by a thick layer of foam and was inspected at regular intervals day and night until it could be transferred into 'J' pot. The damaged pot was then capped with a raft of concrete and soil. Just under three tons of mustard was taken to Porton Down where it was destroyed and the remainder was taken to Randel in March 1955 where a test rig had been set up to burn the remainder of the mustard from Lords Bridge.

A Royal Air Force fireman, Corporal John Saunders, was later decorated with the George Medal for his courage in fighting the fire.

Having donned his anti-gas equipment and in spite of the risk of poisonous fumes from the blaze, he stood his ground on the edge of the crater, personally directing a stream of foam on to the remains of 'K' tank for 30 minutes until the flames were subdued. His citation recorded that he "undoubtedly prevented what may have been a major disaster from the spread of toxic vapour over a wide area".

John Saunders

The site commander, Flight Lieutenant Edward Campbell, was awarded the MBE (military division) for his "high degree of courage" and valour in directing his men and searching for survivors. It was due in part to his action that there were no injuries to either service personnel or civilians.

Once all the mustard had been removed the site was decontaminated in March 1957 by treating the entire area with bleach and harrowing surrounding areas to a depth of 18", watering in bleach in layers. Metal and tools were cleaned with carbon tetrachloride, cement and stone with bleach and water. The depot was then sold to Cambridge University although the area surrounding the site of the pots remained in RAF hands and 'J' pot was not collapsed and filled with debris, sand and clay until 1991. As the contents were not fully checked at this time, both pots were fully excavated and all the residual contamination removed in 1996.


The original entrance to the depot was from the A603 road along a concrete road running parallel to the southern boundary of the ammunition park. The domestic camp was on the north side of this road at its junction with the A603. This consisted of a picket post, accommodation blocks for airmen, sergeants and officers, canteen and ablutions block. This site was leveled during the construction of the MRAO One Mile telescope which involves movable dishes on a mile length of rail track.

Photo:Toxic and non-toxic mess rooms (left), toxic change and bath house (centre) and workshop (right).
Photo by Nick Catford

The FFD is at the end of the 500 yards road. Most of the buildings are used by Mullard for storage and the empty storage shed is used for the construction of new dishes for the radio telescopes. The original chain link fence still surrounds the site, once through the gate there is a substantial guardhouse and office block on the right, originally there was a store opposite but this has been demolished. Just beyond the guardhouse there is a 'T' junction. The brick built charging building is straight ahead. This has been re-roofed in recent years and a small brick building on the roof with a water tank on top of it as been removed. All original internal fittings have been stripped out but the covered ways linking to the empty storage shed to the north and the bonding shed to the south have both been retained although that to the south has been blocked at either end. The two bay empty storage building still retains its original corrugate metal cladding although it is now a little shabby. The 'L' shaped bonding building has been re-clad in recent years. At some FFD's this building has an internal rail loading bay but at Lords Bridge this is external with a platform on the south side of the building

Plan of Lords Bridge FFD

On the west side of the empty storage shed there is a single storey brick built workshop with three unconnected identical rooms, the adjacent boiler house has now been demolished. At the south west corner of the empty storage shed is the sub station with a blast wall in front of the entrance. This is still in use.

There are a further two single storey brick buildings on the west side of the bonding building. The larger is the toxic change bath house where the workforce would have changed their clothes and bathed at the end of each shift. The smaller building is the toxic and non toxic mess room; this is divided into two sections each with its own entrance

Photo:Bonding building and the railway loading platform
Photo by Nick Catford

The storage pots were located on the east side of the site and their position is clearly visible as a large depression in the ground. The standard gauge railway line entered the site on the north east side and ran along the eastern perimeter fence past the two storage pots. There is still a short section of track embedded in the road on the south east side of the site.

There is a small single storey brick building located between the two pots. This is divided into two sections. One half of the building was a chemical store, the other half was an emergency bathroom for decontamination if there was an accident at one of the pots. This is the only building on the site that is disused, empty and open.

In the undergrowth outside the eastern perimeter fence is the mixing tank which resembles a sewage filter bed. It is unclear exactly what purpose this served but a plan of the Norton Disney FFD shows a network of pipes running to this tank which appears to be a collecting tank for contaminated wash water. There is still evidence of a pipe running towards the tank from the charging building.

On the east side of the charging building there is a low circular concrete platform, this is the top of the emergency water supply tank.

The original pump house over the well has been demolished and two new buildings have been constructed on the site. This is now operated as a pumping station by Anglia Water and is within its own secure compound.


  • Bob Jenner
  • After the Battle No. 79 (1993) No 79, Pages 12 - 33 'Poison Gas manufacture in the UK'
  • Operational record book for 95 Maintenance Unit, RAF
  • Declaration for chemical weapns production facilities (UK Government report - United Kingdom of Great Britain and Northern Ireland declaration of past activities realting to its former offensive chemical weapons programme)
  • Airfield Review - Journal of the Airfield Research Group 'The supply of explosives and ammunition to the RAF Part 3'

For further pictures of Lords Bridge FFD click here
For information and photographs of the Lords Bridge Air Ammunition Park click here
For information and pictures of thr Mullard Radio Astronomy Observatory click here
For information and pictures of Lords Bridge Station click here

See also WW2 & Cold War history of Britain web site

[Source: Nick Catford]

Home Page
Last updated: Tuesday, 04-Jan-2011 14:55:35 GMT
© 1998-2004 Subterranea Britannica