St Agnes Engine Houses

We are delighted to be undertaking renovation of the famous Engine Houses at St Agnes.

The mine buildings near Chapel Porth in St.Agnes are amongst the best known and most photographed in the county. In 2013 the National Trust, who own the land and buildings, secured grant funding from Natural England for the repair and restoration of these historic buildings.

PDP Green Consulting Ltd project were chosen to project manage the work and  KPK builders were selected to undertake the building works following a competitive tender exercise.

The main areas of work, which began in the spring of 2014, involved major repairs to Wheal Charlotte United engine house and the restoration of the remains of the Old Century tin streaming works in Chapel Coombe valley. Additional works including the treatment and replacement of wooden lintels and repointing at Wheal Coates, and repairs to the iconic engine house known as Towanroath, situated on the cliffs to the north of Chapel Porth.

Main Pictures

1 – A view into the conserved boilerhouse at Charlotte United mine. After the mine closed, the large iron boiler was probably removed through the partially demolished wall in the foreground. The hedge-like vertical stonework inside the structure is a short-lived later reuse of the building, perhaps an animal shelter.

2 – Most of the southern engine house wall at Charlotte United has entirely collapsed . Renovation work has included re-incorporation of timber into a surviving window head (and above a socket, to the left), to retain structural stability of the remaining masonry. Traditional lime mortar has been used to repoint the stonework.

3 – The boilerhouse wall at Charlotte United mine was in a particularly fragile state before conservation work took place. After vegetation was removed from the structure, all the masonry joints were raked out and repointed with traditional lime mortar. Some bulged parts of the wall were recorded, temporarily taken down and carefully rebuilt. Remains of a window jamb can be seen to the left.

4 – Charlotte United chimney stack (and most of the engine house walls) had largely been conserved in the 1980s. The upper parts of the chimney therefore only needed little attention during KPK’s works programme.

5 – A view of conservation works in progress at Charlotte United mine, with scaffolding on the engine house (centre and right) and boilerhouse (left).

6 – Excavation beneath the boilerhouse floor level at Charlotte United mine revealed a central soot-lined flue running the most of the length of the building. This flue allowed maximum heat transfer into the base of the iron boiler before the hot gasses were drawn around the sides of the boiler and then up the chimney. Behind the flue was a brick-lined inspection chamber opening into a lintelled drain. This contained a blow-down valve, formerly used to empty the boiler during maintenance periods.

Click here for a diagram of a typical boiler installation