Hetty Shaft - steam winding engine

Image: © Chris Allen Taken: 21 Sep 2019

This was built in 1875 as part of the Great Western Colliery but by closure in 1983 was operated by the NCB as part of the Lewis Merthyr - Ty Mawr complex. The winding engine on the Hetty Shaft was built by Barker and Cope of Kidsgrove and wound with flat ropes. It was later rebuilt by Worsley Mesnes and latterly wound with round wire ropes. Although built for steam operation, it finished life on compressed air provided by large compressors nearby that supplied the whole complex, including a winding engine at Lewis Merthyr. As rebuilt the engine has piston valve cylinders 34" diameter by 6' stroke and fitted with Mellings patent expansion gear. There are three eccentrics visible on the right and mounted on a separate shaft driven by a slotted link from the crankpin. Two drive onto Allan straight link reversing motion. The top of the link is seen near bottom right. The third eccentric operates the expansion gear and operates in conjunction with a governor. The parallel sections of the drum are believed to date from 1909 and are 15' in diameter and flank the original central brake path 20' diameter. There is only one pair of brake posts with the brake applied by weight and taken off by steam. The brake gear is painted white as a legacy of the Markham disaster in 1973 when 18 miners were killed due to a critical component failure in the brake gear. The white paint is to facilitate magnetic particle non-destructive testing. The vertical pillar with roman numerals on the right is the 'miniature' that indicates the position of the cages in the shaft. Final decking is facilitated by marks on the drum. The engine is being preserved by volunteers and is run with a hired in compressor on the heritage open days each year. Visitors are very welcome and you can ask to have a drive at low speed (there not being enough air for faster winding).

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