We delved deep into our artefacts listings and found this little beauty. A nice example of a Hydraulic Prop. There were two main suppliers of hydraulic props, Dowty and W E & F Dobson Ltd.
Dowty began making hydraulic pit props in 1948, by 1957 they had made their millionth pit prop. The original factory was in Tewskesbury Dowty bought Bonser Engineering in Hucknall and produced mining equiptment. This link will take you to a more in depth history of Dowty in Hucknall https://www.dowtyheritage.org.uk/content/category/dowty-group/dowty-hucknall
The other manufacturer was WE & F Dobson Ltd based in Basford, Nottingham. It was bought by Hardwick Industries in 1951. Hardwick Industries was the company formed from Hardwick Colliery Company after nationalisation according to Grace’s Guide to Industrial History. They began developing Hydraulic mining supports in 1953. In 1961 they employed around 250 people. This link will give more information on Dobson https://www.gracesguide.co.uk/W._E._and_F._Dobson
Both companies were extremely competitive and provided employment to people in Nottinghamshire