WWI Small Box Respirator

Hey guys, WWI Small Box Respirator.
According to the information I have been able to find online, the black metal piece is a flutter valve protector, introduced in late 1916 through to 1917. This design was dropped after that as it did not find favour in field.
The respirator box is a US made one as they were the only one using green and yellow filter boxes. It is common to find British made SBR's with US filters as the US was given many British masks for use in the field. I am also including period pics of British soldiers using the SBR's with the flutter valve protector as many people believe that these were US only SBR's.

I have reproduced some information Joe Sweeney has posted over at The Great War forum for ease of reference for our members regarding the contents of the SBR's




From August 1916 through August 1917 the canister was filled with animal charcoal and "Old Formula" granules. In August 1917 the fill was changed to three mixed layers of wood charcoal and "F" granules separated by thin pads of cotton wadding. This canister became known as the N.C. canister. By October 1917 the top layer of wadding was changed to cellulose wadding. The final modification occurred in January 1918 with the layer of cotton wadding being moved to the top of the canister to better prevent dust from being drawn into the breathing tube. Each modification was meant to improve performance in the face on new agents being introduced.

Initially the charcoal was made of animal bones. However, supplies proved to be inadequate to the demand. So in 1917 experiments were conducted to find a suitable replacement. It was found that Birchwood made an acceptable charcoal. By mid 1917 all charcoal was being made out of wood.

Granules actually came in three types.

The first or "Old Formula" granule was made of caustic soda, keiselguhr, lime, bleaching powder and alkaline sodium manganate. This formula was found to have a poor performance against arsine and had a fairly short life.

The second became known as the "F" granule. It was made up of Portland cement, keiselguhr, lime and alkaline sodium permanganate.

The third was "white" granules. This granule was made the same way as the F granule with the exception of the permanganate which at first provide difficult to procure. This type of granule was made in low quantity and was only a stopgap measure when F granules were not available.