House-built engine

The only technologies at this time that could support the weight of an engine's beam were masonry and timber-framing, as the work of either shipwrights or millwrights.

Often the floor did not span the full length of the house and formed a gallery above the bottom chamber.

This vertical engine placed the cylinder above the crankshaft and the crosshead above that, with a return connecting rod.

[7] Even with adequate labour, masonry construction is a slower process than delivery of machinery alone.

Where brick foundations were constructed, it was recommended that at least fifteen days were allowed before the weight of the engine was placed onto them.

This could be supported by a single brickwork pier, without needed careful alignment by its masons.

[10] Some engine makers, such as Robey & Co. of Lincoln, developed a distinctive form of cantilevered cast iron bed for their large medium speed engines that formed both the crosshead trunk guide and the crank bearings, thus permitting a similar single plinth foundation.

These had six beams, arranged radially around the tunnel shaft, and passing in two groups of three through a pair of internal walls, just above ground level.

[12] The last Cornish engine built, at Dorothea Quarry in 1905,[2] has a through-wall beam supported on a wall 5 ft 6in thick.