Coltness Iron Works near Newmains, around 1900

This view looking towards the north-east shows a line of six blast furnaces with a train of Caledonian Railway wagons in front. To the left we can see a gas processing plant and the domed structure to the right is one of the hot blast stoves where air was heated before being forced through the the furnaces.

You can just see the ends of two large-bore pipes that run the lengh of the row of furnaces. The lower one is the 'hot blast main' that carries the hot air to the furnaces while the lower one carries waste gases that have been piped down from the furnace tops. These gases are piped into underground flues and then back up into the stoves to recycle the heat they contain.