Near to the Grange Pit and opposite where the T.M.S. Garage was built were the Coke Ovens, believed to have originally been built by a German firm. That is why during the first World War people were afraid the zeppelins would attempt to drop their bombs on the site. However, the nearest place to receive a bomb in the first war was at the Knicker Bocker Lane by Town Kelloe.
Across the way was a reservoir which, sad to say, was the cause of a few drownings. It was created by the water being pumped from the pit. The ovens were closed down for a few years, relit in the 40 - 50's but finally closed in the early 60's. In its last phase, an aerial flight was erected for Transport over to the reservoir which is now no more. The ovens produced gas and petrol. According to Mr. George Dawson, the gas was sent to Hartlepool in a pipe line parallel to the railway. Trimdon people did not have any, they just had their fires alight by the Colliery free coal. During the Second World War two airmen had to bate out by parachute, and thought they were in for a dunking when they saw the reservoir water, however they came safely down on land.