These pithead baths were built in the Big Pit coal mine in Torfaen in 1939, and they had a great impact on the lives of miners and their families.
Before these baths were built, miners would travel to work, work their shift and return home in the same clothes. The clothes would be dirty, damp and smelly by the time the miner started the journey home (usually on foot or on a bus) and he would have to wait until he got home before being able to wash in a tin bath in front of the fire or out on the bailey-the back yard.
'Clean' and 'dirty' lockers
But things changed when the pithead baths were introduced. At last, the miners could wash and get changed in the coal mine before returning home. Now, every miner had two sets of clothes - ordinary clothes and work clothes - and a 'clean' and 'dirty' locker in different parts of the baths.
He would arrive at the pit wearing his ordinary clothes, get undressed and leave them in his 'clean' locker in one part of the building. He would then take some soap and a towel with him to the 'dirty' locker and leave them there before getting changed into his work clothes ready for his shift underground.
At the end of his shift, he would take off his work clothes and leave them in the 'dirty' locker where they would be dried, ready for his next shift, by the warm air blowing through the lockers.
The miner would wash himself clean in the baths before putting on the clothes from the 'clean' locker and returning home.
Soap, towels... and change
Despite the fact that the 1911 Coal Mines Act stated that the owners of mines had to provide pithead baths if a majority of two thirds of the workers wanted them, the baths were generally very slow to appear in the mines of South Wales.
One reason for this is that the miners would have to pay a proportion of their wages each week towards the baths.
But they received money for soap and towels in the baths and during the Second World War they had extra rations of soap.
After 1947, when British coal mines were nationalised and when the National Coal Board was established, pithead baths were built in every mine.
There is no doubt that the pithead baths had a major impact on the home life and work life of miners and their families in the early and mid 20th century.
Now the pithead baths at Big Pit are used as an exhibition to tell the story of mines in south Wales.