Prai Swing Bridge
A rare engineering novelty in Asia
A marvel of engineering, this “swing bridge” is built over the Prai River specifically to allow trains to cross over, connecting the Butterworth Railway Terminal on the northern side to other rail destinations further south in Malaysia. The bridge also opens up occasionally for large barges, ships and ferries that need to pass through along the river. It is operated by Keretapi Tanah Melayu (KTM), the national railway company.
The bridge is located very near the mouth of the river where it opens to the Penang Channel. It was first built in 1964 and renovated in 2013. The renovation in fact entailed a wholesale replacement of the bridge with newer technology powered by electro-hydraulics. Austrian bridge building company, Waagner-Biro, undertook the project on both occasions.
The novelty of the structure is that when it opens up it does not do so in a vertical manner, but actually swings horizontally parallel to the water level.
Wrought out of 1,100 tonnes of steel, the swing bridge rotates fully on its axis in just two minutes. As the 13 metre wide structure swings open, it reveals two watercourses that allow vessels to navigate through. Trains cross the bridge at a maximum speed of 60 kilometres per hour.
The Prai Swing Bridge is one of only four major swing bridges in Asia, the others being in Calcutta and Goa in India, and Da Nang in Vietnam.
The bridge is connected by submerged cables to a control tower in Prai from where railway officials monitor incoming and outgoing railway traffic, and control the opening up of the bridge when marine vessels need to pass through the river.