A Mines Rescue Team Members Belted Harness.
A Siebe Gorman Proto MK 4.
It has the “ACME RESCUE” rubber bulb whistle, nose clip, shoulder straps a large front pocket to hold the breathing apparatus and a bolted bracket at the back to hold the oxygen tank. Made from canvas, leather felt and iron. (back view).
Below is an original N.C.B. Mines Rescue signalling instructions card.