KNOCKSHINNOCH CASTLE
New Cumnock, Ayrshire.
7th September 1950.

The Pit

Because of the inclination of the seams and the decision of the previous owners, the New Cumnock Collieries Limited, to use locomotive haulage in the main roads leading to the bottom of the pit, the shaft was not sunk to a particular seam but to a suitable horizon from which almost level mines or stone drifts were driven as main haulage roads to give access to the seams that were to be worked, especially the Main Coal. In common with the coalfield as a whole, the area of coal to be worked by the colliery was heavily faulted and due to these disturbances the gradients of the seams varied from comparatively level to 1 in 2 and in parts even steeper. In addition the composition and thickness of the seams were subject to variation. This was particularly true in the Main Coal which was approximately eight feet thick in which there were three distinct coal beds which were separated by dirt bands and with either a strong sandstone or a relatively weak ‘calmstone’ forming the roof. Where the sandstone formed the roof, the full thickness of the seam was extracted and where the roof was calmstone the top leaf of the coal was left. The seams were naturally damp and it was not uncommon for the working places to be wet.

In the district where the disaster occurred , the No.5 Heading Section in the South Boig Area, the composition of the Main Coal remained reasonable constant and the coal lay in three beds which were known locally as the ‘head coal’, the ‘breast coal’ and the ‘bottom coal’, separated by dirt bands with a calmstone roof above the head coal. Above the calmstone there was another thin bed of coal known as the Pennyvenie Seam which was overlain by a bed of sandstone. The method of working was Stoop and Room, the rooms being driven 16 feet to 18 feet wide to form stoops approximately 100 feet square. The direction of advance of the No.5 Heading Section was to the south east towards the Southern Uplands Fault with the gradient steepening from 1 in 14 to 1 in 2 in the No.5 Heading which was the main haulage road for the district and was the leading place. Because the calmstone was weak and difficult to support the head coal was left to form the roof and only the breast coal and the bottom coal were extracted with the associated dirt bands which gave a working height of about 7 feet. The coal was blown from the solid by explosives and the shotholes were bored by electrical machines with approximately 18 holes being bored for each round of shots.

The faces advanced about 9 feet per shift and two shifts of coal getters were employed. The coal was hand loaded on to scraper conveyors which delivered to a series of belt conveyors, two in the No.5 Heading and one in the Belt Conveyor Heading. At a central loading point at the junction of this heading with the South Boig Mine, the coal was delivered into tubs which were hauled to the pit bottom by locomotives by way of the South Boig and the West Mines, both of which had a gradient dipping slightly towards the shaft. In the headings going steeply to the rise, the No.5 Heading, a short shaker conveyor was used next to the face. For several days before the accident this heading had been stopped and the shaker conveyor partly dismantled.

At the neighbouring Bank No.6 Colliery, the Main Coal was reached by a dipping drift driven from the surface, mostly in stone but partly in coal, with a gradient varying up to 1 in 3.6. The mouth of the drift lay approximately a mile to the south west of the Knockshinnoch Castle Colliery.

About 1944 a district in Bank No.6, known as the Waterhead Section, was worked to the rise by a longwall face. Later the Main Coal in Knockshinnoch Castle was also worked in the Waterhead Area towards Bank No.6 leaving a barrier of coal 200 feet wide between the two collieries. In order to facilitate drainage from the Knockshinnoch side, a roadway was driven into this barrier up to a point about 24 feet from the Bank No.6 workings. A borehole was then put through the remaining part of the barrier to carry the water. it was through this part of the mine that the escape road was driven, by which 116 men imprisoned by the disaster were eventually rescued.

Deposits of peat moss occurred on the surface in the immediate neighbourhood of both the collieries and were shown on the 6-inch Geological Survey Map of Ayrshire, Sheet XLII S.W. One such deposit was shown, part of which actually covered the place where the disaster originated. There was no previous history of an inrush of moss in the area but a few years before work had been carried on underground in Bank No.6 Colliery when Mr. J. Bone was the Agent, when a surface peat deposit had to be probed to determine its thickness in order to comply with the General Regulations of 1920, relating to precautions to be taken when working under a peat moss.