The Bailey bridge
Invented in Christchurch, the Bailey bridge ‘made an immense contribution towards final victory in World War 2’. John Newth tells its story.
Published in June ’16
Rivers have been crucial strategic features throughout the history of war, from the Rubicon to the Rhine. They form a natural barrier once the permanent bridges have been destroyed by a retreating army, and troops attempting to cross by boat are highly vulnerable. A temporary bridging system which is strong, easily portable and quick to assemble is therefore a potent weapon, and just such a system was invented in Christchurch during World War 2: the Bailey bridge. At the approach to Christchurch
on Barrack Road stands one of the distinctive panels that made up the bridge, which has also received the accolade of having a nearby pub named after it.
The panel is positioned there because it is close to the old Christchurch Barracks. Lewis Tregonwell is remembered today as the ‘founder’ of Bournemouth, but his contemporaries knew him best as the commander of the Dorset Yeomanry. It was he who built the barracks in 1794 to house his troops who were patrolling the south coast against the threat of a French invasion. The buildings, of which the guard house, stable block and officers’ mess survive, also housed dragoons who helped the excise men to combat smuggling; this connection is remembered in the name of Dragoon Way.
In 1918, the Royal Engineers moved to Christchurch Barracks, including the Bridge Company, which in 1925 changed its name to the Experimental Bridging Establishment (EBE). Bridging had become more important with the invention of tanks, which were much heavier than any load a military bridge had had to carry in the past. Most bridges of that time were of the floating pontoon type, which were cumbersome and slow to assemble. After the war, EBE, along with the Experimental Tunnelling Establishment and the Experimental Demolition Establishment, changed its name again to MEXE: the Military Engineering Experimental Establishment.
EBE employed some civilians, including a young engineer called Donald Bailey, who joined in 1928 after graduating from Sheffield University and working for Rowntrees of York, the London, Midland & Scottish Railway, and Sheffield City Council. He must have wondered whether he had done the right thing as the defence cuts of the early 1930s reduced the staff of EBE to himself, one RE officer, a draughtsman and fourteen men in the workshop; there even survives a Treasury memo entitled ‘Is Mr Bailey really necessary?’ Donald Bailey proved so necessary that he was knighted in 1946, became director of MEXE in 1957 and then moved on to be Dean of the Royal Military College at Shrivenham, before returning to live in Christchurch until his death in 1985.
This distinguished career had its roots in a journey in late 1940 from Cambridge, where Bailey had gone for a meeting. He was as aware as anyone that the existing pontoon or box girder bridges were slow to assemble and were hardly strong enough to bear the 26 tons of the Matilda, then the most common infantry tank; they certainly would not be able to carry the much heavier Churchill tank that was about to be deployed. On his way home, Bailey sketched some ideas literally on the back of an envelope. It is a striking example of how things can be speeded up in wartime that a prototype was being tested within months and that operational units were receiving bridges barely a year after those sketches on the envelope.
One problem with the development was finding anything heavy enough to test the bridge. This was eventually solved by placing on it one tank with another on top, filled with pig iron! An early version still spans Mother Siller’s Channel on Stanpit Marsh, but the first real test came on 1 May 1941, when a seventy-foot bridge was constructed across the Stour near EBE; it took only 36 minutes from the start of the operation until a lorry could cross safely.
A Bailey bridge is basically modular, made up of ten-foot by five-foot panels pinned together. Parallel lines of joined panels are connected by transoms on which the roadway, between ten and twelve feet wide, can be laid. A walkway can be added to the outside of the bridge so that infantry and vehicles can cross simultaneously. Need more strength? Double or even triple up the panels on each side and increase the number of transoms. Panels could also be bolted on top of each other.
Flexibility was not the only asset of the Bailey bridge. It was specifically designed so that every part would fit into a standard three-ton Army lorry. No part weighed more than 570 lbs, so by the use of special handles could be carried with reasonable ease by six fit men. Standardisation and the simplicity of the design meant that almost any engineering firm could make the panels, and 650 did so during World War 2. The bridge could be fixed or could float on pontoons.
The method of creating the bridge did not change much from the technique used for that first trial across the Stour in May 1941. As a panel was bolted on at the back, the front of the bridge was pushed out on rollers from the near bank almost to the point of balance, being held across the gap on the cantilever principle (unless it was being supported on pontoons) until it reached the other side.
This product of Christchurch proved itself time and time again on the battlefields of World War 2, during which over 200 miles of Bailey bridge were used. During the Italian campaign, the river Trigno was crossed by a 300-foot Bailey bridge within 36 hours of the bridgehead being cleared of the enemy. In north-west Europe, between 18 and 21 July 1944, five bridges were thrown across the River Orne and the Caen Canal under intense fire during the break-out from the D-Day bridgehead. A 1154-foot pontoon bridge was built across the Chindwin River in Burma in December 1944 on General Slim’s orders. The record of the 4000-foot pontoon bridge constructed across the River Maas (Meuse) at Gennep in Holland in early 1945 was soon beaten by the bridges known as ‘Tyne’ and ‘Tees’ across the Rhine at Rees, completed just as the war ended and spanning 5000 feet.
These bridges continued to be used long after 1945, and it has been said that ‘Tyne’ and ‘Tees’ were significant factors in Germany’s economic recovery. The Bailey bridge and its successors have continued to prove their worth in disaster zones, in developing countries and in difficult terrain. However, once the war was over, claims were made that Donald Bailey had drawn heavily on earlier designers’ work. There was no suggestion of intentional impropriety by Bailey, but the claims were pursued and in 1954 a New Zealand-born engineer, Archibald Hamilton, was awarded £10,000 (about £250,000 in today’s values) by the Royal Commission on Awards to Inventors, while General Martel of the Royal Engineers received £500.
General Eisenhower considered the Bailey bridge one of the three most important developments of World War 2, alongside the heavy bomber and radar. It certainly ranks with radar and the jet engine as one of the outstanding British inventions of the 1930s and 1940s. After the war, Field Marshal Montgomery wrote: ‘The Bailey bridge made an immense contribution towards final victory in World War 2. As far as my own operations were concerned, with the Eighth Army in Italy and with 21 Army Group in north-west Europe, I could never have maintained the speed and tempo of forward movement without large supplies of Bailey bridging.’ And it all began in Christchurch.