« Sheer lunacy! | Main | That sermon ..... »
April 14, 2005
Smoke helmet, anyone?
We tend to think of Self Contained Breathing Apparatus (SCBA to the cogniscenti!) as being a 20th Century invention - but this "Smoke Helmet" with its self-contained air tank was invented in the 1870's!
Leather "smoke helmet" with clear Mica Lenses in the eyepieces and a small steel airtank on the back.
Made of thick leather, this helmet was intended to be worn during entry to a building for rescue. The small airtank strapped to the back of the helmet blew a continuous stream of compressed air into the helmet which vented around the "skirt" where it sat on the wearers shoulders. This "positive" air pressure in the helmet kept the smoke out, and the "smoke diver" was able to enter the building to search for victims.
The problem is in the way the airtank was filled. It used an ordinary type of manual compression cylinder pump rather like a motor car tyre pump. There were no filters and a few minutes pumping brought it up to the required storage pressure. The downside is that the oil used to lubricate the pump is atomised and injected into the cylinder at the same time. This is then released again into the helmet during use - and we now know that, if breathed in, it can and probably will, cause cancer of the lungs, oesophagus, or throat.
Great idea, well ahead of it's time, but I do wonder how many of the users died of the cancer it could potentially cause. Come to think of it, I used to have to check an asbestos "Approach suit" at one time. Sometimes the things we think will protect us are just as dangerous as the thing we are trying to protect ourselves from.
Funny old world really!
Posted by The Gray Monk at April 14, 2005 09:18 AM