Now that the last of the backdrops have been installed, I am doing research for the scenery that we want to represent. In the back corner, I have a place where the narrow-gauge slate quarry line disappears (to conceal its short length) just in front of the concave backdrop and I need something that is redolent of the Nantlle valley.
At the end of the valley is a classic framed view of Yr Wyddfa (Snowdon) but in front of that I need a mine. Slate mining in this valley was an open-cast affair, so the features to be observed are open pits, pumping beam engines to keep them clear of water, vast spoil heaps of waste shaped into what the locals called “Pyramids” with inclines up them to move waste and finished goods, and a relatively unique type of crane to get the slate to ground level -> the Blondin.
The pyramids were a way of concentrating the waste to maximize the area available for mining. They were large, smooth sided and flat-topped and slate workshops and engines were frequently built on top. As they expanded, they would cover over the narrow-gauge tracks so needing tunnels. All that is perfect for our disguise purposes, the narrow-guage line will go into a tunnel in a pyramid (presumably to emerge hidden on the other side). By placing workshops and incline houses on the top of it we can disguise the corner with view blockers.
Named for the legendary high-wire act at the circus and Niagara Falls, the Blondin consisted of a thick wire strung between towers on two high-points on either side of the pit (often one was atop a pyramid) and along this ran a “carriage” hauled backwards and forwards with a pair of wires connected to a drum on one side. The carriage was a set of sheaves/pulleys that were held in a frame on top of the main wire (often three in a row). This carriage also held pulleys under the wire that led down to a hook block that would move up and down vertically into the pit and was connected back to the engine house from both ends. This was so that, as the carriage processed along the wire, the hook remained at the same height relative to it.
The plan is to create a working Blondin over a pit that exploits the fact that at this point the tracks are almost a foot above datum. By dropping the pit down enough the base will not be visible to viewers, and so will appear as deep as they can imagine. The real pits could be 400 ft deep!