In a September 2011 article, the Casper Star-Tribune gave details of the world’s largest truck body by volume, which was manufactured by Casper-based Western Technology Services (Westech) and is known as the Flow Control Body. It has a massive volume of 470.4 m³ at a coal density of 0.86 t/m³. It was installed on a Liebherr T282C truck, while normally has a nominal 363 t capacity, at Peabody Energy’s North Antelope Rochelle mine in Wyoming. At the given coal density, the body can hold a total weight of 404.544 t or 447 short tons. This is enough coal to fill more than 4.5 standard coal rail cars.

The truck body was custom-built by Westech’s engineers after a request from Peabody Energy for a customised vehicle for North Antelope Rochelle, which is located north of Douglas. Ultimately Peabody wants to use fewer large-capacity trucks to haul the same amount of coal, meaning fewer numbers of costly wheels and tyres as well as drivers. This is also the only current option to increase payload given that the truck OEMs have no near term plans to build trucks with a nominal capacity of greater than 363 t or 400 short tons. The Flow Control Body is a patent-pending design which controls the flow of coal using ripples engineered into the floor of the body. This means the coal volume isn’t unloaded too quickly, which can cause excessive coal dust creation. Westech is an Austin Engineering company, and builds more than 500 bodies a year for customers in Wyoming and around the world. The company stated that it has more orders for haul bodies of that size from Peabody which are set to be manufactured in 2012. There are also plans to display the body on a new Liebherr truck at MINExpo in Las Vegas in September 2012. The company makes truck body sizes from 25 t to over 400 t. In addition to the Wyoming site, Austin Engineering has three manufacturing facilities in Australia.