Building a bridge to connect 30 million people

The landscape of Bangladesh, India’s neighbor to the east, is generally characterized by wide plains cut through by countless rivers. The Padma River, a continuation of the Indian Ganges, and the larger Brahmaputra River, which comes from the north, divide the country into three regions. The name Padma refers today primarily to the section that begins in the middle of the country where the Ganges and the Brahmaputra meet and ends in the south where it opens into the Bay of Bengal.

The lower section of the Padma consists of an almost perfectly straight river bed between 3 and 8 kilometers wide, frequently with meandering sand banks running through the flat regions. Due to the high rate of flow, however, the channels through these sand banks can be up to 30 meters deep.

When rivers separate rather than connect people

The most economically developed areas are the densely population centers around the two major cities of Dhaka in the middle of the country and Chittagong in the southeast, while some other regions lag behind significantly. Economic development is often hindered by the fact that there are only a few bridge connections between these parts of the country. To date, there have only been two bridges over the Padma, both in the western part of Bangladesh. The first is the Hardinge railway bridge, built during the era of British colonialism at the start of the 20th century. The Lalon-Shah Bridge for automobile traffic was built not far from this in the year 2004.

Further downstream, there have never been any bridges. In many places, unreliable ferry crossings with ships in “adventurous” condition were the only way to get across the wide river branches. Accidents have been common in the past due to the sometimes technically inadequate condition of the ferries. Nevertheless, the majority of passenger and goods transports between the capital region of Dhaka and the southwestern part of the country take place by ferry.
Moreover, the insufficient road and rail infrastructure and the lack of bridges are also reasons why Bangladesh – a country with a relatively small land area – has an exceptionally high number of regional airports.

Great potential despite a high cost

Officially named the “Padma Multipurpose Bridge Project (PMBP),” the bridge is expected to change the lives of almost 30 million people, according to one study. The new road and rail transport connections created by this bridge south of Dhaka will allow goods to be transported from the ports of Chittagong in the southeast and Mongla in the southwest at much lower cost. The distance from the capital city of Dhaka to almost all major destinations in the southwest part of the country will be reduced by 100 kilometers or more, while the travel time will be reduced by 3 hours per trip. Many manufacturers and service providers will have access to new sales markets thanks to the new crossing. But such positive side effects are still a long way off.

The Padma bridge will have a huge impact

Technical masterpiece in a challenging environment

The construction of a bridge on the lower reaches of the Padma has been under consideration for a long time. It quickly became clear that it would be the largest infrastructure project in the history of the country. In the past, such a project appeared impossible to realize due to the large scale of the kilometers-wide river that has also changed its course many times in the past. The river delta is in continuous flux – sand banks, currents, bank erosion and side branches can change or move every few years. 

The success of other major bridge projects (Bangabandhu Bridge in 1998, Lalon-Shah Bridge in 2004) at narrower locations further upstream may have served as encouragement for the multiple feasibility studies conducted starting in the year 2000. The initial designs called for bridge beams of concrete and a cable-stayed bridge with a span of no more than 180 meters. This planning was eventually changed based on higher traffic forecasts. It was decided to build a steel girder bridge with a single rail line in the lower deck and a four-lane road on the upper deck. 

42 massive concrete pillars, 4 lanes of traffic and a “three-rail track”

The official kick-off for the bridge construction finally came at the end of 2015. Construction work on the access routes began even before this. The road connections leading up to the bridge from either side are between 720 m and 875 m long. The railway ramps are 2.36 km and 2.96 km long and connect to a bridge that consists of 41 steel girders. The span of the individual elements is 150 m, and each of them weighs 3,376 tons. These steel girders were put into place on 42 massive concrete pillars by special ships. The concrete pillars themselves rest on a total of 262 steel pilings. These have a diameter of about three meters, are filled with concrete and driven deep into the ground beneath the river bed.

The railway section is designed as a single three-rail track so that it can be traveled by the wide gauge and metric gauge trains used in Bangladesh. With a clearance beneath the bridge of 18.3 m, it poses no hindrance to river traffic. But this infrastructure project also rates superlatives when describing the cost as well. The cost forecasts were revised upwards many times, and the expenditures of 3.962 billion dollars are four times higher than the originally projected construction costs for the bridge. On the other hand, the estimated economic benefit amounts to roughly 5.942 billion US dollars. According to these estimates, the finished bridge could increase annual economic growth in Bangladesh by about 1%.

Delayed by the pandemic

The 41st and final girder was placed on its concrete pillars on December 10th, 2020, accompanied by a formal ceremony. Nevertheless, the official and “final” end to the construction project was postponed in May 2021 by one year to June 2023. The COVID-19 pandemic was blamed for the delay. However, officials have given assurances that the bridge will be opened at least for road traffic already in June 2022. Opening of the railway line should follow some time after. The connection to the existing rail network has still not been built.

It remains to be seen how the bridge will finally impact the economic performance and transportation situation of this extremely poor country. We definitely hope for many positive effects, but whatever happens, this exciting mega-project has already left a lasting impression.