The Bailey bridge

According to General Eisenhower, World War II had three major inventions that contributed the most to the victory in Europe: the heavy bomber, the radar and the Bailey bridge. Why was the latter one, an ingenious invention, so important for the Allies? On the frontlines, the retreating Axis forces have frequently exercised the tactic of scorched earth and have destroyed or mined bridges behind them to slow down the Allied armies chasing them. Sometimes bridges were destroyed by Allied bombings or artillery bombardment. Winning a war is not only about firepower and weapons but also about getting the tanks, the troops and war materiel when and where they are needed.
 
In order to address this issue and to ensure the movement and speed of their forces and the constant flow of supplies, they decided to develop a new type of modular mobile bridge. Of course, this was not the first time that such an idea came into being and military bridges already existed. At the same time, there was another new development that made military engineers rethink earlier designs: the new tanks got heavier and heavier due to their thicker armor and larger guns. The heavy Churchill tank, for example, weighed in at 40 tons, while the Sherman was 30 tons. A portable, pre-fabricated truss bridge that could be carried on trucks, the Bailey bridge could be easily assembled from wooden and steel bridge elements on site without the use of heavy equipment such as a crane, and it could carry up to 70 tons.

It was a British civil engineer, Donald Coleman Bailey, a model bridge assembler by hobby from Rotherham, who came up with the idea and managed to convince his colleagues at the British War Office to use it. He had been working for the War Office as a civil servant since 1928 at the Engineering Experimental Establishment in Christchurch. He developed the bridge years before the start of the war but he was called upon to prepare a prototype only in February 1941. Many saw a close resemblance to the famous Meccano model construction toy sets with which his son and other children of the time played a lot.

The War Office had the following specifications: It had to be easy to build, flexible and made up of welded, interoperable materials of maximum 600 pounds / 270 kg which could be carried by a 3-ton truck or six men. The bridge had several standard and specialized elements, but it rested on three main parts: panels, transoms and stringers covered with planks. The modular design made it possible to adjust the length and strength of the bridge.
 
It was ingenious because its parts could be transported on trucks, and it was easy for soldiers to assemble it by hand using only ropes, pulleys, jacks and hammers. Moreover, two footways for infantry ran on the outside of the roadway to separate foot and wheeled traffic. If it was damaged by shells or bombs, the damaged section could be easily removed and a new one inserted. They were so crucial for the war effort that even Field Marshall Montgomery is reported to have said "without the Bailey bridge, we should not have won the war."
 
The Bailey bridge was assembled entirely on one bank and then pushed across the river, supporting itself without any underpinning. The whole structure rested on free-turning rollers during assembly. While it was launched from one bank, the simple rule was to keep more weight on the bank than was extended over the gap at any one time. The front part, or launching nose, was a skeleton structure that went across the river first. Because the nose sagged some as it was pushed across, the nose section was given an upward tilt when the sections were being put together. All that was needed on the far bank was a pair of rollers to receive the nose. The rest of the bridge provided a counterbalance to prevent it from falling into the gap. When the nose had reached the far bank, the skeleton was dismantled section by section, as complete sections were added from the back and pushed forward. The parts of the bridge proper at the end were fully floored and braced.

Beyond the normal design, there were other variants of the bridge. Some were used as suspension bridges, others as pontoon bridges. Assault or mobile versions were carried by specialized armored vehicles, like the Funnies (Read our earlier article – Hobart’s Funnies).

The testing of the prototype started in May 1941 on the Mother Siller's Channel at Stanpit Marsh. The prototype remained there and you can still cross the channel on it. Shortly after, it took the engineers 36 minutes to erect a 70-foot / 21 m bridge over the river Stour. When the production started in July 1940, around 650 companies took part in the production of the bridge. Many of them had a completely different portfolio, like producing window frames or canoe paddles, before getting involved in this project. The elements were shipped to Cumbria to train troops in assembling the bridges in different settings, like at night or in combat situations. The first bridge installed in actual action was built in November 1942 over the Medjerda River in Tunisia. The Bailey bridge gained prominence when the Allied forces were crossing countries laced with rivers whose bridges had been blown up by the retreating German forces. More than two thousand Bailey bridges were used during the campaign in northwestern Europe and was frequently in use in other theaters, for instance in Italy when the Allies broke through the Germans’ Gustav Line at Monte Cassino.

During the three months of the Battle of Normandy, thirty bridges were erected in the vicinity of Caen only. Not far away from the famous Pegasus Bridge, British Royal Engineers constructed the first bridge of this kind in Normandy on the night of June 7 on the Caen Canal at Bénouville. It was named London Bridge or London 1. Even Prime Minister Winston Churchill entered Germany through crossing the Rhine on a Bailey bridge on March 26, 1945.

During the war, 20,000 panels were produced monthly at the maximum of manufacturing capacity meaning that around 700,000 panels weighing 490,000 tons were used altogether.
 
Donald Bailey became the director of the Experimental Bridging Establishment in 1945. The same year, an interesting short film was shot by Pathé introducing Bailey with his iconic pipe.

As a recognition of his contribution to the war effort, he was knighted in 1946. He became the first civilian director of the Military Engineering Experimental Establishment in 1957. He retired in 1966 after a stroke and lived in Christchurch until his death in 1985. His memory was not forgotten by the locals. There is a commemorative panel dedicated to him in Christchurch close to the Bailey roundabout, and hungry travelers can also enjoy a good meal in the Bailey Bridge Restaurant on the other side of the road on Bailey Drive.

A commemorative panel and the Bailey Bridge Restaurant in Christchurch (Photos: public domain, pubswith.com)

Many of the panels were sold as surplus after WWII and several of the originals are still in use in numerous countries. Though not in use anymore, but an element of an original Bailey bridge, used in 1944 by the Allies, is on display at the Pegasus Bridge Memorial in Ranville, Normandy.

Several companies started improving the original design at the expiration of the patent in 1970. The bridge was used by NATO forces in the Balkan Wars during the break-up of Yugoslavia in the 1990s, and by Coalition forces in the Gulf Wars. An Acrow 700XS Panel Bridge was used in the removal of debris following the 9/11 terror attacks at “Ground Zero” in New York. Our mechanically inclined readers can find a detailed American field manual (No. 5-277) for the M2 Bailey bridge by clicking here.

Bailey bridges made it into movie theaters, too. The assembly of one of them can be seen in the 1977 war film A Bridge Too Far, when the Allied soldiers have to cross the river Son after the Germans have demolished the local bridge. It is mentioned by the actors several times, for instance when Lt. Colonel J.O.E. Vandeleur, played by Michael Caine, asks the following: “When you refer to Bailey crap I take it you mean that glorious, precision-made, British-built bridge which is the envy of the civilized world?”

Today, improved Bailey-type bridges are still in use in many parts of the world. In developing countries, they bring communities together, boost businesses in its vicinity or can even make the daily life of people looking for basic amenities less dangerous. Oftentimes, they are used by emergency response teams after natural disasters, like the Technisches Hilfswerk (the German Federal Agency for Technical Relief) did in Germany in the recent floods in August 2021.