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Spotlight

Most Popular Modular Bridge in the World

Wed, 10/21/2015 - 18:58

In the 1940s, at the height of the Second World War, the Allies’ strategists ran into a roadblock. The invasion of Nazioccupied Europe was being prepared after the retreat from Dunkirk and the victory in the Battle of Britain. However, speed was of the essence. The Nazi forces were so dug in that any invasion had to rely on speed and mobility. The Allies could not afford to get bogged down trying to ford rivers or rebuild bridges blown up by the enemy. Enter Donald Bailey. A civil servant with an engineering background, Bailey invented a modular bridge, built from panels made up of light but strong and versatile steel, which could be deployed without central support. It quickly became the standard military bridge for the British Army and the famed Marshal Montgomery declared that the Bailey Bridge made “an immense contribution towards ending the war.”

Today, Bailey’s legacy is kept alive by Mabey Bridge, a Welsh construction firm, which deploys its modular steel bridges in mining, oil and gas, and infrastructure projects. The most successful of its solutions is the Mabey Compact 200 Bridge, which is the most popular modular bridge in the world. A proud descendant of the Bailey Bridge due to its flexibility, ease to set up, resistance, and load-bearing ability, the Compact 200 has anchored Mabey Bridge’s global reach. Jonathan Benitez, the company’s Regional Sales Manager for Latin America, explains that it has a very simple means of installation, known as the cantilever launch method, allowing it to be set up by a team of untrained workers merely by mounting and pushing its panels into place. Although cranes can be used to get the Compact 200 in place more rapidly, this is not always possible. This is where the cantilever launch method allows for assembly by hand. Mabey Bridge can happily provide the technical training and assistance needed to get its bridges up safely and rapidly.

Once ordered, the Compact 200 will be delivered to clients in the form of ten-foot panels. These are first clasped together to form side trusses, and to allow for single or two-lane crossing options. Transverse steel transom beams are then placed between these to form a bolted steel deck system that was invented and patented by Mabey Bridge. Depending on the conditions in which the Compact 200 is deployed, it can come prepared for three standard widths. The 3.15m width makes up a single lane, the 4.2 width is designed to provide an extra wide single lane, and the 7.35m dimension is for two lanes. Pedestrians are also accounted for, since cantilevered footwalks are a standard design and internal pedestrian refuges provide a shelter, if the bridge needs to be rapidly cleared of foot traffic.

Aware that the needs of mining clients may vary widely, the Compact 200 can be augmented with various solutions. For example, its steel can be covered with a Durbar chequerplate finish to ensure passing vehicles will enjoy better surface grip and skid resistance. A client with better prediction ability can also ask Mabey Bridge to apply anti-skid surfacing even before the panels ship out. Furthermore, every structural component of the Compact 200 is hot-dip galvanized to ensure it will last for years with little wear and tear.

Given its modular design, the Compact 200 can easily be configured in a pedestrian or pipe support format, while its compatibility with Mabey Bridge’s Uniflote Pontoon system can provide a modular floating solution. The Compact 200 can be unrolled for single-span bridges of up to 70m, and while it can be stretched to longer, Mabey Bridge has other systems that might suit these bigger needs. However, the modular design of the Compact 200 means it can be configured for various designs, including multiple span bridges, double-story bridges, and overbridging. Another element that can be attractive to the mining industry is that, in case of an unfortunate mining accident in remote areas, the Compact 200 has been a mainstay for disaster relief, acting as a rapidly deployable emergency bridge.