Inverlochan

Ever since travelling by train across Rannoch Moor during the late 1960s I have wanted to create a model scene representing at least a tiny bit of that awesome expanse of moorland. So Inverlochan Moor materialized to occupy the upper reaches of my model railway. Perhaps trying to do this on a baseboard only 14" wide should be considered madness, and I think it is possible only by positioning the scene at its present viewing height (about 4'6") and the extensive use of backscenes

Plan of Inverlochan

A shallow cutting separates the viaduct scene at Glenclachan from Loch na Cailliche, which is the centrepiece of the Moor. In fact there isn't very much else to Inverlochan Moor, as the line disappears into another cutting after crossing the causeway across the Loch's outlet. At this viewing height the slight rise in the ground either side of the Loch is enough to detract the eye from the scenery beyond. What does continue along all eight feet of the baseboard is the backscene which is based on transparencies of Rannoch Moor. By contrast the area around Inverlochan and the colliery is an ugly black slash in the landscape, an impression which is strengthened by the backscene showing a black sky and rain. Inverlochan is a bit cramped because of all the buildings, but again this result in a nice contrast to the wide open spaces of the Moor.

Apart from providing the basis for the coal-carrying theme of the C&DR, the completed Highlands section of the layout is a good setting to show off trains in a landscape. Both Rae Bridge and Dunalistair have a station as their main theme which inevitably restricts train observation. The combined Glenclachan and Inverlochan scenes provide about 5 metres of uninterrupted train viewing on a high tableland broken by the great ravine and its viaduct, with the trains dwarfed by the landscape as they should be. Using a backscene considerably increases the feeling of distance which is essential to capture the wide open spaces of the Highlands.

Passenger train from Glenclachan approaching Loch na Cailliche.

Goods train on the causeway through Loch na Cailliche (photo by Mick Thornton).

Close-up of the causeway and the bridge.

Goods train departing from Inverlochan (photo by Jan van Mourik).

Prototype coal mining and the model

Although the underground workings of a coal mine are very interesting (including their rail transport systems), the part of a colliery that matters most for railway modelling is on the surface. Apart from drift mining, where workable coal seams are accessed by burrowing into hill sides, or surface mining, most coal mining takes place deep below the surface where higher quality coal is found. These deep workings consist of a maze of galleries and are accessed by vertical shafts. During the 1700s steam pumping gear enabled shafts a few hundred feet deep to be worked under tolerably dry conditions, and from the mid-1800s it became possible to get at high quality coal like anthracite which is often down over a thousand feet. Apart from the main working shaft usually there are separate pumping and ventilating shafts, but these may be a few hundred yards away.

On the surface a mine shaft can be spotted by its headframe with large wheels (called sheaves) at the top. The rope passes from one lift cage across the corresponding sheave to the winding drum, around which it takes a number of turns before passing to the other cage. The cages are more or less balanced by gravity, each having a tail rope to balance the weight of the winding ropes. The winding drum is powered by a steam engine or by electricity. The large diameter of the sheaves (and of the drum) is necessary because the winding gear will have to run at considerable speed in order to lift the coal through hundreds of feet at a reasonable rate. Smaller wheels would harm the heavy steel wire ropes the lift cages are suspended from.

Pithead and winding engine house of Inverlochan colliery (photo by Jan van Mourik).

Shunting behind the station (photo by Jan van Mourik).

The screening house (photo by Jan van Mourik).

Engine over the ashpit (photo by Mick Thornton).

Collieries vary in size, the larger ones having an output of thousands of tons a day and extensive on site processing industry. High quality coal will probably be treated extensively with washing and crushing plants, and sorted into different grades using vibrating screens, conveyor belts and hoppers. Low grade coal is used to make briquettes, powdered coal or coke. Large, modern mines have done away with much of the old technology. The lift cages that used to bring up coal tubs have often been replaced by high capacity skips hoisted to the surface, and much of the underground and surface workings is highly mechanized.

By contrast, the small mine formerly at Drumlemble near Machrihanish in Kintyre produced about 22,000 tons a year or less than a hundred tons a day. This corresponds to a twenty-wagon narrow gauge train or about five standard gauge wagon loads. Here processing on site may be limited to sorting into household coal and coarse chunks perhaps only fit for steam raising. The processing plant is much smaller and this type of working is much more suitable for most model layouts.

Inevitably the model as designed by me has its limitations. All I had space for was the headframe with its built-on screening plant, a boiler house and the pumping engine. There is a high-level tramway taking care of the loaded and empty coal tubs, and to the right are the remains of an old shaft. Towards the rear are the station and a small signal box. Thinking of a way to get the coal tubs into the screening plant called for some hard reasoning as I did have very little to go on. The system used in larger collieries, where the loaded tubs are hauled up by cable-powered hooks grabbing each tub, slamming it into the discharge tipper and bumping the previous (empty) tub out so it can gravitate back to the pithead, obviously was unsuitable for this model.

What I decided upon was a line of empties waiting on one track next to the pithead and another where the loaded tubs are marshalled into short rakes. A small locomotive is used to take these to the discharging bin inside the plant, which has a short stub protruding at the other end so the rake can be pushed through whilst discharging. Next to the bin is the sorting screen, a large sieve which is rocked back and forth by machinery. The coal drops into two hoppers, one over each low level track.

The colliery shunter pushes loaded tubs up the ramp towards the screening house. This loco is now replaced by a tiny Bagnall built by the late Reinier Hendriksen (photo by Jan van Mourik).

An empty train just arrived at the colliery (photo by Jan van Mourik).

The high level mine tramway. A battery electric loco at work (photo by Mick Thornton).

Close-up of the screening house. Note Bagnall engine by the late Reinier Hendriksen working the mine tramway.

Imagination at work again…

Across the mountains from Dunalistair, several hundred feet above sea level, lies the wilderness of Inverlochan Moor. On the far side of the moor, on an old military road built in the 1700s, the small Highland town of Craigcorrie is the inland terminus of the Craigcorrie & Dunalistair Railway. Craigcorrie would probably never have boasted a railway at all if not for the coalfield at Inverlochan, a few miles away.

Having climbed all the way from Dunalistair, through the glens by way of Rae Bridge, the railway at last reaches Glenclachan Road halt on the brink of the great Glenclachan ravine. The ravine is crossed by a half-timbered viaduct, and the line continues across rolling moorland, picking its way between numerous peat bogs, rocky patches, lochans and streams. Even constructing the light roadbed of a narrow gauge railway across that lot must have been a major engineering feat! About halfway a short causeway crosses the outlet of Loch na Cailliche, where reeds line the marshy shore. On a good day there is a beautiful view of wild clouds above the distant mountain tops peeping over the edge of the plateau. Otherwise the Moor is notorious for its fog, and after dark human beings have no business here, as the place is known to be haunted by a number of ancient clansmen who once fought a battle here. Having spent a foggy autumn night on the shores of Loch na Cailliche with a blown boiler tube, driver Angus Macnab returned with such an eerie tale that the ganger still looks over his shoulder when doing his rounds on that stretch of line.

In the low hills on the far side of the Moor at Inverlochan a small colliery produces the low-grade coal that is the lifeblood of the railway. When travelling on the train from Glenclachan the first sign of the mine is the shaft headgear. Then the splitting home signal appears and the colliery sidings swing off to the left, where the landscape is disfigured by mine buildings and spoil heaps. Coal has been worked here from the mid 19th century, and the dilapidated wooden headgear of old no.1 shaft still stands in the undergrowth near the sidings. The shaft has been built up to keep out the sheep, and is now used for ventilation purposes only. Its function is now taken over by no.2 pit, which is marked by a much taller steel headgear structure. Away by the railway overbridge the beam of the pumping engine solemnly nods day after day. A rusty corrugated iron screening house spans the sidings, and every now and then a roar and a cloud of coal dust mark another wagon loaded below the hoppers. In the meantime the screening machinery clatters away, sorting the coal into two grades: medium and coarse (or bad and worse, if Angus Macnab, who has to use the stuff in his firebox, is to be believed).

A goods train bound for Craigcorrie arrives at Inverlochan.

Shunting coal wagons under the hoppers.

A goods train bound for rae Bridge (photo by Mick Thornton).

The same photo from a different angle, showing the station (photo by Mick Thornton).

The coal tubs hauled to the surface are pushed manually into the holding track of the colliery tramway. When a string of them has accumulated, they are collected by the mine loco and pushed up the trestle into the screening house, where their contents are tipped into the screening tray. Any spoil that cannot be dumped into exhausted galleries underground is moved towards the spoil tip on the other side of the railway line to Craigcorrie. The colliery manager, after selling his Barclay to the distillery in Rae Bridge, has acquired a small Bagnall 0-4-0T to shunt the tramway. Twice a day a C&DR loco comes in with a string of empties, runs round, dumps its ashes into the pit and shunts the sidings. Then, in a huff and a cloud of steam, it takes off with about 15 loaded wagons up the gradient towards the Moor.

Although Inverlochan would normally qualify as a halt, it has a substantial stone station building because of the amount of traffic generated by the colliery. The station mainly serves the mine, as there is little local traffic with Craigcorrie only a few miles away. The siding behind the station building is used to unload machinery, explosives and pit props. At the change of every shift a crowd of miners discharges itself from a passenger train, the men coming off shift taking their place. To relieve the railway from having to time its passenger trains according to the colliery shifts, there is talk of running miners' specials. Trains continue from Inverlochan to Craigcorrie below an overbridge carrying a spoil tramway to the tip, a few hundred yards away.