On the morning of Sunday 30th of January 1938 shortly before 12:00 noon in Kelly's section of the Dumbreck No.1 pit near Kilsyth a fire broke out as a result of an electrical fault caused partly by a rock fall, trapping and killing 9 men from Kilsyth and the surrounding villages of Queenzieburn, Twechar and Croy.
The colliery was the property of Messrs. William Baird and Company, Limited and was situated one mile west of Kilsyth and was sunk in 1885. There were two shafts Nos.1 and 2 which were sunk to the Kilsyth Coking Coal at a depth of 225 fathoms. The No.1 Pit was the downcast and from it, only the Kilsyth Coking Coal was worked.
Ninety eight persons were employed underground, sixty eight on the day shift and fifteen on the back shift. Coal was wound only during the day shift and the output was about 110 tons per day. The No.2 Pit was the upcast and worked the coal from the Haughrigg and the Cloven Seams, at 109 and 140 fathoms receptively.
The Kilsyth Coking Coal was 2 feet 4 inches thick and had been extensively worked on the longwall system. The seam had a considerable dip to the south-east but the gradient varied considerably both in amount and direction. The main and side endless rope haulage roads as well as a length of airway known as Kelly's Return were almost level. Waddell's Jigger Brae rose from the side haulage road at 1 in 11 for a distance of 200 yards and then rose to 1 in 6 inbye. Kelly's Brae rose 1 in 4 at the outbye end for 110 yards which deceased to 1 in 6 at the inbye length. Auchinvole's Section had recently been won by two dipping mines and there were only two coal producing places.
The No.1 Pit was worked with safety lamps; the workmen wore electric cap lamps and searching was carried out in accordance with Section 35 of the Act.
The ventilation was produced by an exhaust fan at the surface. There was only one ventilating current in the seam. It went down the No.1 Pit, passed along the main haulage road to a junction known as the 'Circle' and along the side of the haulage road to the bottom of Waddell's Brae. At the 'Circle', a small quantity of air was directed round Auchinvole's Section coming back to join the main current at the 'undercast', which was in the course of construction, at he bottom of Patterson's Road.
At Waddell's Brae the air was split and about 7,000 cubic feet of air per minute passed up the brae to ventilate a small section which had ceased producing coal in early, January 1938. The other split amounted to about 4,500 cubic feet per minute and this ventilated Kelly's Section in which there were ten coal producing places on a longwall face which was advancing to the rise at an inclination of 1 in 6. The first working place on the intake side was on Stark's Level and was 2,028 yards from the shaft by the intake and haulage road. The distance to the shaft by the return airway was 1,615 yards, or 413 less than the route through the intake.
When Kelly's Section was being opened up, several faults and a 'want' were found in the seam and, at a point about 100 yards from the side haulage road, three roads were driven through the faulty ground. The main body of the intake air travelled up the companion road, 12 yards west of the haulage brae but some intake air was allowed to enter Smart's Level through a small airway driven in November 1937, 100 yards west of the brae. This was intended for local ventilation when Smart's Level was opened out. A considerable quantity of air scaled up the main haulage brae through canvas screens.
The return air from Kelly's Section travelled down a companion road on the east side of the haulage brae and along an old level, known as Kelly's return, the inbye end of which had last been used as a drawing road in September 1937. The air went to an overcast over Waddell's Brae and after passing the top of Patterson's Road, went direct to No.2 upcast shaft. There were doors at the air crossing which gave access to the return from Waddell's Brae.
Part of the main Return Airway and Patterson's Road had recently been enlarged. They were intended to be used as a mechanical haulage road for the conveyance of men when Auchinvole's Section was ready to produce coal, after which Kelly's Section was to be stopped.
The mechanical endless rope haulage ran from No.1 Pit to the foot of Kelly's Section. Waddell's and Kelly's Braes were both worked by over-tub self-acting endless rope haulages. There were three self-acting inclines on Kelly's Brae. The face haulages were 'cuddie braes', with the tubs hand drawn along the levels.
The seam was worked on the longwall method with roads set at 45 feet centres. A top brushing was taken, three feet thick in the ordinary roads and six feet thick in the main heading and in the levels. Neither coal cutters nor conveyors were used in Kelly's Section, but the coal was undercut by a longwall machine in Waddell's Section until the section stopped on the 22nd January 1938.
The electrical supply was both AC. and D.C. The A.C. equipment was obtained from the Company's Gartsherrie Works and the D.C. equipment was made on site. The A.C. system was 3,000 and 500 volts, earthed neutral and the D.C. system 440 volts earthed concentric. The major proportion of the plant, both above and below ground was concentric D.C., but A.C. was gradually being introduced to replace this. The A.C. was not involved in the accident. Lighting at the bottom of the pit was supplied from a D.C. motor generator at 110 volts by a separate cable in the shaft. The only lights off the D.C. concentric system were at the 'Circle'.