What is a Bailey bridge, constructed in Wayanad after landslides?

What is a Bailey bridge?

Simply, it is a type of modular bridge, one whose parts are pre-built so that they need minimal construction work and can be assembled quickly when needed.

A US Army Engineer School manual notes that the Bailey bridge originated during wartime. Donald Coleman Bailey, an English civil engineer, invented it during World War 2 (1939-45).

The manual says, “In 1941, Bailey gave his first sketch of the bridge to the British War Office… The Bailey bridge used in World War II was designed to be moved, rebuilt, or replaced in several hours, even under enemy fire. It was used widely and well by Allied armies in Italy and northwest Europe, 1943-45. British Field Marshal Lord Bernard Law Montgomery said: ‘Without the Bailey bridge, we should not have won the war. It was the best thing in that line we ever had.’”

Work on a Bailey bridge during World War 2. (Via Wikimedia Commons/
U.S. National Archives and Records Administration)

How the Bailey bridge works

The pre-fabricated parts in a Bailey bridge include light steel panels linked through pins, which are big, screw-like objects. These help establish the guardrails of the bridge. Through the guardrails on either side, workers place beams to form the deck or path of the bridge. All beams were constructed such that they would lock in on the guardrails to ensure stability.

After that, the bridge can be extended, and the lightness of the parts allows it to be mobile. No heavy installation equipment is needed. In disaster relief situations, this is ideal because parts can be transported in small trucks — something also of use during wartime.

India and the Bailey bridge

In a publication from India’s Defence Research and Development Organisation (DRDO), MR Joshi, Former Director of the Research & Development Establishment (Engineers) in Pune wrote, “The Indian armed forces, and particularly the Indian Army carried on the British legacy and thus inherited a large inventory of the Bailey bridge.”

Such bridges were used in the 1971 war with Pakistan for the liberation of Bangladesh. Joshi wrote that it was only afterwards that bridging equipment began arriving in India, the first being from the then-Soviet Union.

In the past, Bailey bridges have also been constructed in a strategically important village along the India-China border in Arunachal Pradesh, and in Uttarakhand in 2021 after flash floods hit the state.