Miners Self Rescuer – Small.
Size 4″ x 3″ x 2 1/2″ inches . This Self Rescuer MSA W265 was the first design. These rescuers were only effective against smoke and carbon monoxide in cases of fires underground. They would NOT protect you against mine gases such as Methane etc.
The Self Rescuers came in 2 sizes, the smaller of the two was the first issue, (late 1960s to the late 1970s) it would give you approximately 1 hours protection against smoke fumes long enough to get to fresh air. The taller one was a later issue (mid 1970s to the end of the 1980s) produced larger to give you more time to exit the mine. The rescuer was inside the sealed tin container and consisted of a Charcoal/Carbon filled filtered rubber apparatus with a rubber mouth piece, nose clip and head harness.
The W265 was introduced in 1969 after recommendations from many official enquiries and reports. The first to be adopted fully in the UK other than just trial use was the W265 (1 hour) superseded later by the W275 , then the W290 (90 minute, but some changes after the Cardowan explosion), W95 (up to 4 hours and uses noble metals rather than Hopcalite) and then right back to a tall model designated W65.
All of these other than the W95 use activated carbon as a drying agent, then hopcalite as the CO to CO2 converter, the W95 uses hopcalite as the drying agent, and noble metals (as in cat converter) as the CO / CO2 converter.