WW2 Type 1 Radium Deck Marker

[Equi]

This is one of the first radium markers I got in my collection.

During WW2, the Navy employed Type 1 and Type 3 luminous markers on boats serving as deck and personnel markers. This is the Type 1 variant, which is essentially just the clip-on type of marker missing the clip.
These Type 1 disks were fitted with a metal ring on the back with two screws. These rings would be welded to bulkheads to hold the marker on. By 1951, the Navy had switched to Strontium-90 based luminous markers to replace the dangerous dose rates from radium. From the information I have gathered, the last year radium markers were produced was 1954 before fully switching to Sr-90.

This specific disk is missing the screws and bulkhead ring on the back. It was likely removed off the ship and kept by a soldier. The phosphor inside the plastic housing has sadly broken up in spots. This marker is very weak radiation wise compared to others I have seen.

Currently, this is the only Type 1 deck marker I have in my collection.