Ty-Mawr Colliery, Pontypridd
At Hopkinstown, on the A4058 west of Pontypridd
Also known as Hetty Shaft or Hetty Pit
Has a twin-cylinder horizontal winding engine by Barker and Cope and dated 1875. This is being restored by volunteers, and is demonstrated running on compressed air on occasional open days, when visitors are made most welcome.
At some point the engine was modified by replacing the original cylinders and their drop valves with new cylinders having large piston valves. This was done by the Worsley Mesnes Co. The installation of the large diameter piston valves outboard of the cylinders, and the presence of piston tail rods, has greatly encroached on the space available for visitors! George Watkins notes that the winder originally had flat ropes, but was changed to round ropes in 1909, requiring wider drums, and that this necessitated mounting the eccentrics outboard of the cranks. Each set of three eccentrics is on a separate shaft driven its own crank. The former narrower width of the engine is indicated by the presence of fluted handrail columns inboard of the eccentrics (see first photo).
Originally called Gyfeillion Colliery, sunk in 1848. Hetty shaft was sunk by the Great Western Colliery Company in 1875. The engine raised coal from a depth of 360m. By 1923 the seams were worked out, and thereafter, until 1983, Hetty Shaft was used as an emergency shaft for Ty Mawr and Lewis Merthyr collieries, the engine being run on compressed air.
1876 'THE GREAT WESTERN COLLIERY, PONTYPRIDD. .... The directors of the Great Western Colliery, Pontypridd, and their friends paid a visit yesterday to the above colliery for purpose of starting a new winding engine manufactured by Messrs Barker and Cope, Kidsgrove. The engines, which are of 600-horse power, were started in the presence of a large company of ladies and gentelmen by Hetty Snow, step-daughter of Mr G. S. Bryant, chairman of the company. The new pit sunk to steam coal was christened by her "Hetty Snow". ......'
1893 'THE PONTYPRIDD DISASTER. The inquest upon the bodies of those killed in the Great Western Colliery concluded on Saturday afternoon, before Messrs. R. J. Rhys and E. B. Reece. The coroner's jury at two o'clock returned the following verdict in writing :—'We find that the accident at Great Western Colliery on April 11, 1893, was caused by a spark or sparks emitted from the brake of a hauling engine at the top of the hard heading, which came in contact with some inflammable substance in its neighbourhood, and we do not attribute any negligence to any of the officials either before or after the accident, and that the 61 men who lost their lives did so by suffocation by the smoke arising from the fire, that Jesse Titley lost his life by falling down the 4ft. landing at the bottom of the seam at Tymawr shaft." They also recommended (1) that one of the codes of regulations drawn up by Dr. Hughes Bramwell be sent to the Home Secretary, with the object that those or similar ones should be adopted in other collieries. (2) That sufficient width or surface for break power be provided at all hauling engines, so as to prevent undue friction ; and (3) that every care should be exercised in letting down full journey upon the east hard heading in the Great Western Colliery at a uniform rate of speed.'
1896 'The Federated Institution of Mining Engineers commenced its seventh annual general meeting at Carddi yesterday afternoon, .......'. Presentation by 'Mr Hugh Bramwell, on "The Compound Winding-engine at the Great Western Colliery Company's Tymawr Pit"....' Daily Gazette for Middlesbrough, 16 September 1896
1923 'Great Western Colliery Co. A new modern air compressor of large capacity has been installed and put to work at the Tymawr Colliery to replace the existing compressors erected many years ago. This has enabled the Company to consider the introduction of underground conveyors the working faces where the conditions are favourable for them, and a commencement has been made with this work.' 
Sources of Information
- British Listed Buildings, Hetty Engine House, Pontypridd
- Western Daily Press, 16 June 1876
- Lancaster Gazette, 6 May 1893
- Western Daily Press, 21 March 1924