HOMEPAGE PERSONAL PROFILE HISTORICAL REVIEW HOWEBRIDGE MRS BOOTHSTOWN MRS PURPOSE OF A MRS MOBILE WINDING ENGINE AMPUTATION KIT OFFICERS AND STAFF SELECTION OF RESCUEMEN BREATHING APP PRIME FEATURES OF BA GENERAL CONDUCT OXYGEN RESUSCITATORS HEAT AND HUMIDITY RESCUE COMMS CANARIES AND LAMPS SELF RESCUERS SEFA BREATHING APPARATUS PROTO BREATHING APPARATUS AERORLOX BREATHING APPARATUS SALVUS BREATHING APPARATUS SAVOX BREATHING APPARATUS MINOX BREATHING APPARATUS ANTIPOYS TUBE APPARATUS

The Lancashire Mines Rescue Service BREATHING APPARATUS. Photograph on the left shows members of the newly formed Permanent Corps outside the Howebridge Rescue Station in 1932. Photograph on the right shows Jack Fairhurst (Instructor) inspecting a team in the Boothstown No. 1. Observation Hall just prior to the team starting a gallery training session in 1933. The Proto Self Contained Oxygen Breathing Apparatus is worn in both photographs. ------------------------------------------------------------------------------------------------------------------------------------------ BREATHING APPARATUS. Breathing apparatus, fall into two categories:- (1) “Open Circuit” and (2) “Closed Circuit”. In the open circuit type, exhaled air passes directly out to the atmosphere. The air is not re-breathed, therefore, no purifying chemical is needed, to absorb the exhaled CO2 gas. In the open circuit type, compressed air (rather than compressed oxygen) is generally used and carried on the wearer’s back in a comparatively large metal tank. The tank, needed to be large to supply all the air needed at every seperate inhalation, during each wearing session. Open circuit sets, by comparison are fairly simple in design, easy to use and straightforward to maintain. A valuable advantage with the ‘open’ circuit type is that it lends itself to the use of a full-face mask, which can be fitted with a rubber diapragm that facilitates the use of speech. However there are also disadvantages with full-face masks. Not all wearers have the same facial contours and the desirable, airtight seal around the face, is sometimes difficult to achieve. However, the use of speech is definitely a big plus. A typical open circuit set would have a duration of about 45 minutes to one hour. The Mines Rescue Service have always preferred “Closed Circuit” types of apparatus that offer longer duration for less weight. All ‘closed’ sets used by the Mines Rescue Service had to have a minimum duration of 2 hours, plus a 30 minute safety margin. All closed circuit types use liquid or compressed, medical grade oxygen. At each inhalation, more or less 100 per cent oxygen is drawn into the lungs and about 94 per. cent oxygen is exhaled together, with about 6 per cent of CO2. This exhaled “air” is passed over a chemical that absorbs the CO2 and that 6 per cent deficiency of oxygen is made up by a small, but regular supply from the oxygen cylinder, to restore the breathable gas content, to 100 per cent oxygen. In this way nothing is lost to the atmosphere and the wearer continues to breathe almost 100 per cent oxygen for the full duration of his equipment. On all the compressed oxygen sets, a booster known as the “By-pass Valve” gave more oxygen on demand than the regulated amount, whenever the wearer needed it and a "Relief Valve" was fitted to release excess pressure within the breathing circuit, during rest periods for example when the wearer was exerting less energy and therefore, required less oxygen. All the compressed oxygen types of apparatus could be safely used underwater, up to about 10 feet in depth. Though they were not originally designed for this type of work, they have been used, to negotiate flooded, underground roadways, for instance. -------------------------------------------------------------------------------------------------------------------------------------------