A Dowty Hydraulic Pit Prop.
This is a Dowty brand hydraulic pit-prop known as the “Dowty Duke”. There was an earlier design made by Dowty which had a different pumping mechanism and key.
Made from iron. Size 3′ feet x 5″ inches.
There were two types of hydraulic pit-prop of this same design used in the colliery in the 1970’s, a Dobson and a Dowty.
The two types of prop were practically identical apart from the operating keys and pump action control lug mechanism.
The operating key for the Dowty Prop (as seen left) had a solid bar handle with a flat angular head to fit into the slotted lug. Size of the key is 14 1/2″ long.
The Dobson Prop had a hollow bar operating key with a hooked end which fitted into a hole on the pump action control lug.
These hydraulic props were made in various sizes, two-foot, three-foot, four and five-feet heights. They also had detachable extension heads also in various sizes.