Volunteer Collection Spotlight: Pyrene Foam Making Branch Pipe and Knapsack Tank

What is a fire fighting foam pipe doing in a coal mining collection? Some objects in our collection tell you exactly what they are. Others make you scratch your head.

At the Museum, we have a large archive of both large and small artifacts which have been acquired from the various coal mines of the now extinct Yorkshire coal field. For many of these items, their use and purpose are obvious, but some are a little more obscure.  One such artefact is a Pyrene No. 2 Foam Making Branch Pipe. This item would normally have been found on a local authority fire appliance where it would be used to produce foam for smothering an oil or flammable liquid fire. Why it should have been in the possession of a coal mine can only be speculated.

In the early 1900’s tests had been carried out at some mines into using foam to try and extinguish underground coal seam fires using foam to remove oxygen and thus starve a fire.  These had very little success and were abandoned. The only other explanation is that this piece of equipment was used by a coal mine surface workers to deal with fires in bulk stored oil and diesel tanks, which would have been in the pit yard. The successful operation of this piece of equipment requires expertise and therefore frequent practice. The ratio of water to foam needs to be accurately set in order to produce the correct consistency of foam to smother a fire.  The wrong ratio could result in the produced foam being too wet and therefore exacerbate a flammable liquid fire.  The branch pipe is fed from a pressured  water supply, usually a fire service pump, via 70mm hose at 7 to 10 bar (150psi) This pressure creates a vacuum as it enters the branch pipe via a venturi, which causes foam compound to be sucked from the foam container and mixed with the water to produce thick stable foam at the nozzle, that can then cover, like a blanket, a flammable liquid fire and cut off the air and thus extinguish the fire.

Our second item below is a knapsack tank for protein foam compound. It is called this because it has a harness and is meant to be carried on the back of the person operating the Pyrene No. 2 foam branch pipe.

Designed to be worn like a rucksack, it held protein-based foam compound and would have been carried by the person operating the branch pipe.

And what exactly was inside?

The protein foam compound was made by mixing animal byproducts, typically hoof and horn meal, feather meal, blood meal and other slaughterhouse waste proteins.   These very unpleasant ingredients produce, when mixed in the correct ratio, in a foam branch pipe, a thick creamy foam which has very stable bubbles that do not burst easily and have strong heat resistance. Unfortunately, the odour of the compound is not very pleasant and because it is protein based has a limited shelf life.

Why not come and discover more unexpected objects and the stories behind them at the National Coal Mining Museum for England. You never know what hidden piece of history might spark your curiosity next.