A failure in the bitumen trace heating system on an asphalt plant resulted in the pipework cooling.  After the trace heating was repaired the pipework was brought back to the operating temperature.  The plant was then started successfully, mixing 6 tonnes without any problems. However, as the manager passed by the bitumen system, he observed bitumen leaking beneath the pump cover box.  He promptly notified the plant operator, leading to the shutdown of the equipment. It was also discovered that some of the bitumen, which was at a temperature of circa 130 - 140 degrees, had enveloped an airline that ruptured causing a spray of the bitumen. See full incident alert for more information.