The Bailey Bridge was a British-designed portable pre-fabricated truss bridge, designed for use by military engineering units to bridge gaps up to 200 feet wide. The bridges were introduced into service in 1942 and first used by Allied units in combat beginning in 1943 during the Second World War. The design was unique in that:

• Construction required no tools or heavy equipment.

• Bridge components were small enough to be carried in trucks and even man portable over short distances.

• The bridge was strong enough to bear the weight of vehicles up to 70 tons (Bridge Classification 70).

History

A civil servant in the British War Office named Donald Bailey is credited with the design. After presenting one of the model bridges he built as a hobby to his bosses, it was felt that there was merit in the design. The bridge was first employed in Sicily in 1943, and the very first Bailey Bridge built under fire was at Leonforte in Jul. (The website of the Royal Engineers states that the first bridge built "in contact with the enemy" was in North Africa in November 1942.) A total of 38 Bailey bridges were built by the Allies during the Battle of Sicily in addition to 20 Small Box Girder Bridges (SBG). In Italy, 2,832 Bailey Bridges were constructed by the Allies. The Bailey could also be used in conjunction with pontoons, and 19 such bridges were built in Italy. The longest Bailey Bridge constructed in Italy was 1,126 feet long, and built over the Sangro in December 1943.

By the time of D-Day in Normandy, production had been increased and the US were also building bridge components under license. Bailey was knighted, and the bridge design would soldier on into the 21st Century.

Men of The Stormont, Dundas and Glengarry Highlanders cross a small pathway built on the side of a Bailey Bridge in Normandy, July 1944. LAC Photo.

The North Nova Scotia Highlanders cross London Bridge, a Bailey bridge across the Odon River south of Caen, France, on 18 July 1944.

Design Features

• Modular design: bridges could be built to varying lengths and strengths as needed (doubling or tripling side panels and roadbeds, for example, was possible)

• No heavy equipment needed: almost all previous types of military bridge required cranes for assembly, the Bailey did not.

• Interchangeable parts: despite being produced by different factories, the parts were interchangeable

• Lightweight - each part could be moved by a small group of men

Components

The Bailey Bridge consisted of basic parts:

• The deck of the bridge consisted of a number of 19-foot wide transoms that ran across the bridge.

• 10 foot long stringers ran between the transoms, forming a square.

• The bridge's strength was provided by side panels (as at right), which were 10 feet long cross-braced beams placed vertically above the stringers, and clamped to the stringers to hold them in place.

• Ribands were placed on top of the completed structural frame, and wood planking placed on top of the ribands to provide a roadbed. (Wood planking was replaced by steel later in the war, which was less susceptible to damage from metal vehicle tracks.)

Each unit constructed of these components created a single 10 foot long section of bridge, with a 12 foot wide roadbed.

Bridges

After one section was complete it was typically pushed forward over rollers on the bridgehead, and another section built behind it. The two were then connected together with pins pounded into holes in the corners of the panels.

For added strength several panels (and transoms) could be bolted on either side of the bridge, up to three. Another solution was to stack the panels vertically. With three panels across and two high, the Bailey Bridge could support tanks over a 200 foot span.

Another feature of the Bailey bridge was its ability to be "launched" from one side of a gap. In this system the front-most portion of the bridge was angled up with wedges into a launching nose and most of the bridge was left without the roadbed and ribands. The bridge was then placed on rollers and simply pushed across the gap, using manpower or a truck or tracked vehicle, at which point the roller was removed with the help of jacks and the ribands and roadbed installed, along with any additional panels and transoms that were necessary.

Bailey Bridge erected in Surinam in 1976; the tripling of the side panels can be seen, as can the wooden planking and ribands visible through the (deteriorating) planks. Wikipedia photo.

Sappers of the Royal Canadian Engineers lay decking on Blackfriars Bridge over the Rhine at, Rees, Germany, on 30 March 1945.
Library and Archives Canada photo.

Colour

Bridge were painted in a drab colour; in May 1944 First Canadian Army operational orders stated that while vehicles in the Canadian Army would generally be painted olive drab (see Vehicle Markings for more information), Bailey bridging equipment would remain painted in "standard Camouflage Colour No. 2 to distinguish them from American made Bailey bridges."