A boilermaker is a trained craftsman who produces steel fabrications from plates and tubes. The name originated from craftsmen who would fabricate boilers, but they may work on projects as diverse as bridges to blast furnaces to the construction of mining equipment. The trade of Boilermaker evolved from the industrial blacksmith and was known in the early 19th century as a "boilersmith". The involvement of boilermakers in the shipbuilding and engineering industries came about because of the changeover from wood to iron as a construction material. It was easier (and cheaper) to utilize the boilermaker's skills to construct the ship as they were already present in the shipyard constructing iron boilers for wooden steamships. This utilization of skills extended to virtually everything that was large and made of iron, or later, steel. In the UK this virtual monopoly over the key skill of the industrial revolution led to them being termed 'the labour aristocracy' by historians.