Second World War Bridge Design Applied to MiningWed, 10/21/2015 - 17:43
Carrying a team of highly trained mining engineers, a car trundles along a mountain road. Heading away from a promising exploration site, one engineer pays attention to the road itself. Little more than a dirt track in places, it is certainly not suited to handle the traffic associated with a mining site, such as heavy trucks and earth-moving equipment. It crosses streams and little rivers and narrows when traversing a deep gorge. One Welsh company has specialized in helping mining companies ford these obstacles through its patented modular panel steel bridges. Mabey Bridge already has ten years of experience in Mexico due to its work with the Mexican federal and state governments on the road infrastructure sector. Now, the mining sector is becoming one of its most important sectors, due to the industry’s need for access roads to mine sites and the uneven geography of Mexico and Central America. Jonathan Benitez, Regional Sales Manager, Latin America of Mabey Bridge says that “a bridge can be an indispensable logistics asset for any mining company, which is why the company has invested in our local presence in Monterrey for two years now.”
For its bridging solutions to have full effect, Mabey Bridge looks to get involved since the first stages of a mining project. It finds its clients in two ways. Occasionally, mining companies approach it directly with their specific bridging needs, while other times, Mabey Bridge uses connections with mining contractors and EPC firms to find out where its panel bridges might be needed. Benitez explains that mining companies typically rely on EPC firms for their infrastructure needs, which is why Mabey Bridge maintains close ties to firms such as M3 who can recommend specific bridge solutions for different mining needs. Through this varied market presence, the company is currently in talks with Coeur Mining to deploy its bridges at the La Preciosa mine in Durango while Grupo Mexico has also expressed an interest.
The flagship product that has largely contributed to Mabey Bridge deploying operations in 140 countries is the Mabey Compact 200 bridge, which is now the most widely used modular bridge system in the world. Benitez explains that it is the flexibility of the Mabey Compact 200 that has allowed it to reach this popularity. “It is a modular solution with a very easy installation procedure called the cantilever launch method, which consists mainly of mounting and pushing. Its installation does not require a special qualified work force. We recently worked with B2Gold in Nicaragua, who installed this bridge with personnel that had never installed bridges before.”
While there are many factors involved in the design of a bridge, such as its length and live load, Benitez puts the cost of a 30m bridge capable of supporting heavy loads, such as the CAT 770 dump truck, at US$350,000. However, for that money, these bridges are made to last. Mabey Bridge is proud of its British heritage and feels that it is those roots that contribute to its bridges’ strength today. The R&D behind its bridges dates back to Sir Donald Bailey. A British engineer during the Second World War, Bailey invented a modular bridge that allowed for rapid cargo and troop movement, and was credited as one of the greatest inventions of the war. Mabey Bridge has kept the modularity of the original concept and extended the lengths that these bridges could span. “We created several models of modular bridges which can span up to 90m without central structures. Our raw material is steel of the highest strength from European mills. Moreover, the galvanizing process really gives the bridges their strength and long-term resistance to corrosion, considering that this is the main threat to steel,” says Benitez.
Benitez points to the examples of emergency deployments during natural disasters or exploration phases of mining projects as typical circumstances of temporary use. “In an exploration project, for example, a company needs a temporary bridge that can be dismantled, relocated, and reinstalled as the exploration campaign evolves. We already lease bridges for the US market and we are now working to develop this business in Mexico as well. We intend to roll out the leasing of bridges, which would include their installation, in 2015,” he explains. “A modular bridge can be set up ready to work within a week, while a concrete solution can take months. In the past, concrete and corbels were used to build bridges. However, these could not be reused, unlike our modular bridges. Our bridges also have a lower environmental impact since they do not require structures that interfere with the ecological systems of rivers, for example.” That final point can actually be reversed. Although Mabey Bridge has been chosen by mining companies for its temporary solutions, its modular panel design is tough enough to withstand years in the same spot without being removed. Mabey Bridge has installed temporary bridges in Central America that still stand today after 25 years. Although many companies see these bridges as temporary structures, the flexibility of a modular system means they can be provisional, semi-permanent, or even permanent.