When a large construction and mining company were plagued by the constant failure of the couplings on their underground mine trucks, they turned to Renold Hi-Tec Couplings, of Halifax, England, to provide a long term solution. For many years the company were fitting V type rubber-in-shear couplings between the engine and the gearbox. However, when the coupling failed, the truck was coming to a complete stop, often blocking an important access point. Renold recommended the HTB 4500, rubber-in-compression coupling. Its intrinsically fail safe, maintenance free and has severe shock load protection properties, coupled with a high temperature capability of up to 200 degrees Celsius. A rubber-in-compression coupling was also favored by the company as they can drive metal to metal to move the truck out of the way and continue mining if the rubber blocks disintegrate. This was illustrated when a problem with the oil circulation in the gearbox resulted in the gearbox overheating and destroying the rubber blocks in the coupling, however the truck could still be moved. Further orders will be fulfilled in 2011.