Small Box Respirator (SBR)
The SBR was designed in 1916 and began to see service by the end of that year. It was the logical result of British gasmask design and was totally effective at filtering all the gases used between 1914 - 1918 (Interestingly though PH hoods were reissued late in the war to deal with gases that blistered the skin since the SBR didn't give full facial protection). Indeed the design was so successful that its principles were used in all later masks designed up until 1944. It worked by filtering dangerous gases through a cannister of charcoal and gauze impregnated with neutralizing chemical agents. A canvas covered rubber hose attached the mask to the cannister. The mask was made of thinly rubberised canvas. The whole lot was contained in a square bag. The bag hung from an adjustable strap. Thus in areas where gas attack was unlikely the strap would be lengthened and the bag slung over the wearer's shoulder. In the front lines the strap would be shortened and the bag worn over the head and hanging against the wearer's chest in the 'alert' postion. The string allowed the bag to be tied around the man to prevent it bouncing around. As with the PH hood the SBR was worn over all other equipment. These photographs are of an orginal British SBR. The small tin contains anti-dimming compound which was applied to the inside of the eyepieces to try and prevent them steaming up. This example is unusual as the compound was normally contained in a metal tube inside a rectangular carboard box. The folded card contains a record of the mask's use. The soldier was expected to fill it in so that he would know when the SBR's limited lifespan was over and a replacement was needed. On the front of the card are strips of sticking plaster for making emergency field repairs to the mask and hose.