What we've gathered so far is this:
In 1954, the world's first powered roof support (that wasn't a single-leg prop) was installed at the Ormonde mine in the old No 5 area, the East Midlands Area, based in Nottinghamshire.
The Gullick chock was developed by the company's chief mining engineer, Tom Seaman who produced the first powered support by using 4 Dowty props in a frame.
The support ram is single acting and was used for support advance only. One in 4 supports had a double acting ram, which made these units "pusher" supports. Supports had a 0.5 inch feed hose and initially the fluid from the chocks was discharged into the waste. It was said, "the time to operate each chock was only slightly greater than 1 minute".
Anyone with more information please contact ILN at firstname.lastname@example.org