Casgliadau Arlein

Detaching hook from Merthyr Vale Colliery. Ormerod type which has three plates held together by a centre pin instead of four as in the King and Humble type. The copper rivet which passes through the plates is seen below the centre pin in both types. It holds the plates in position until the hook is pulled up through the detaching plate, when the protruding lower limbs are pressed together and the rivet is sheared allowing the upper limbs to open and release the shackle.