Before colliery baths a tub in front of the fireplace was the common practice. The water had to be boiled on the hob in a bucket and shared by the entire family working in the colliery. The Merthyr Express of June 24th 1916 proudly announced the new Treharris pit-head baths as the finest in the kingdom. The baths, first erected in South Wales, were the results of visits to France, Belgium and Germany by workmen and employers. The men's bathroom contained 70 shower baths and a further 16 in the boy's section. A well equipped and convenient ambulance room was also under the same roof in order to facilitate the treatment of injured men.

Source:
Merthyr Tydfil Public Library (1997) "Valley Lives, book 4: coal mining in Merthyr Tydfil and District".