Model of the detaching hook patented by Edward Ormerod in 1867. The detaching hook was a safety device that was designed to prevent the miners' lift cage being drawn past the landing stage and over the headgear wheels in the event of an overwind.
If an overwind occurred, the hook was made so that it released itself from the winding rope and engine. In doing so it safely located itself in a bell-mouthed cylinder secured in the pit head frame work. Once in place, it held the miners' cage firmly underneath thereby preventing it from falling back down the mine shaft.
The first hook was made by Ormerod at a small forge next to the Gibfield Colliery and went into use there in 1868. The hook provided a cheap, simple and extremely reliable solution to the often fatal problem of overwinding. Since its invention it has prevented the loss of thousands of lives in mines around the world.