Christmas is well gone and past, and so this series of posts on South Caradon mine has restarted. Winter brought with it one of those amazing clear air days last weekend, no mist, no drizzle no rain, just pure blue light. And so, armed with a camera and Christmas cake and set off to Caradon hill to update some of my photographs of the mine.
South Caradon Mine’s best preserved engine house
Jope’s Shaft pumping engine house is the best preserved on South Caradon Mine, with its ivy clad engine house and chimney still standing to full height. It is fascinating engine house, packed with features.
Jope’s shaft is located on the south western corner of Caradon Hill , overlooking the entrance to Seaton Coombe.
It possibly housed one of the few Sims compound engines built in Cornwall the shaft was also historically important as the site of the last man engine to be built.
This is no ordinary engine house. This is an engine house with it has its plug door located at a level higher than normal instead of being on the same floor as the cylinder bed it hangs precariously one level up. Why this should be seems to a subject of disagreement, with two conflicting theories.
The engine transfer theory
This 60″ engine was built in New for South Garras lead mine in 1855 at Landeryou’s shaft. That mine was not a success, and the engine was sold to South Caradon in 1862.
Kenneth Brown in his excellent exploring Cornish Mines book (vol 2) explains that sometimes plug doorways were placed in a raised position when the cylinder was set down into loading to reduce the height of the engine house. This arrangement resulted in a raised engine driver’s position.
This was not case at Jope’s but may have been the case at South Gerras.
The Sims engine theory
This is the explanation given by Adam Sharpe in the Minion’s study (cau). The study states that the engine was a Sim’s compound, a design of engine that William West, South Caradon’s engineer, was an enthusiast of.
This was single acting Cornish engine in which the smaller steam cylinder was mounted above a larger low pressure cylinder, with the pistons having a common rod.
The engine was devised by James Sims in the 1840s. The duty was rarely more than a conventional engine, and its complexity and difficult maintenance meant that most Sims compound engines had short lives.
Which theory is correct?
When it comes to Cornish engines Kenneth Brown was rarely wrong. This is a pity in this case, for Sims engine at South Caradon would be a wonderful example of Wests’s Sim’s compound installations. If you have more information, or comments, or views on the engine please pass me a message to share on this site.
Features to be found
This is a engine house rich in features.
The three piece granite Bedstone is still in place within the engine house, the cylinder holding down bolt holes clearly visible. Beyond the stones the cockpit/cataract pit is still open (the underfloor space were the valve timing mechanism was located). The eduction pipe is opening can be seen at the base of the bob wall, and on the western wing wall the opening for the steam pipe down to the boiler house is obvious.
To the west of the engine house is clearly defined remains of the Boilerhouse, a house which has evidence of a third boiler was added later in the engine’s life.
The Chimney putlog holes
The stack at Jope’s has one of the best examples of putlog holes in Cornwall. These holes in the side of the chimney are the remains of a crude form of scaffolding used to build the structure. Planks were inserted in the holes as the chimney rose skywards to give the masons safe footholds.
Many other fascinating remains surround the engine house, but these I will leave to a later post when I resurrect the map of the Jope’s shaft area.
This blog is written to enhance the enjoyment of those exploring Cornwall’s amazing landscape and history. It is not intended as a guide for walkers. If you are exploring industrial landscapes in Cornwall, please check the rights of way with the latest Ordnance Survey map, and take great care of yourself and anyone else accompanying you. Despite of all the due care and diligence shown by landowners, any open access ground can be dangerous to those not ensuring aware of the risks around them. So look after yourself.