Back to Basics July 2010

How much air do you have? The chest gauge needs to be checked consistently to ensure adequate air supply at all times. The hose going to the regulator has a coupling on it that allows the firefighter to disconnect from it.   The coupling has been disconnected and can now be inserted into another auxiliary air line connection. An example of both a RIT pack and a regular SCBA being used as a RIT pack.

Among the tactical considerations during a rapid intervention team operation is making sure we increase the mayday firefighter’s chances of survival. We can do this by applying the acronym AWARE to every rescue of a mayday firefighter. AWARE stands for air, water, a radio and extrication. This acronym helps the incident commander and it helps the RIT members remember what to address first, second, third and last with respect to the rescue. We will explore each of these important and crucial ingredients in the next few issues. For starters, let’s look at the letter A – for air.

When a mayday is declared by a firefighter there are two things going against the rapid intervention team from the start – time and air supply. The mayday firefighter’s air supply is our primary concern and this issue needs to be addressed right away. RIT members need to find out from the mayday firefighter how much air he has left. Hopefully, the mayday firefighter has been keeping tabs on his air supply and will know immediately how much he has left; if not, RIT members need to ask him (see photo 1). If RIT members are unable to ask about air supply because the mayday firefighter cannot respond or is unable to communicate, they can pick up clues by listening to the radio transmissions from the mayday firefighter. RIT members will be able to hear whether the vibra alert is going off or if the whistle or bell indicating low air is sounding. If there is no alarm sound in the background then it means the mayday firefighter still has a sufficient air supply that has not met the quarter alarm. If RIT members hear radio transmissions that are not muffled by the face piece, and silence in the background as far as the SCBA is concerned, then they know that the air supply has ended and the mayday firefighter has taken off his face piece. A good example of this is the video regarding the Houston, Texas, captain who declared a mayday during a highrise fire on March 28, 2007. The vibra alert can be heard during his radio transmissions. After a while there is no sound except the captain gasping for air, indicating that he had taken off his SCBA face piece. The incident commander knew that the captain was out of air from hearing him say so and from the background noise of his radio transmissions. This video can be found at  www.thebravestonline.com/news.html?view=1&id=1619   

The initial RIT team needs to bring a supply of air for the mayday firefighter. This can be accomplished by using RIT packs, which contain 45-minute or 60-minute air cylinders, an auxiliary fill line, a spare face piece and an airline with a RIT connection. The auxiliary airline allows the mayday firefighter to breathe directly from the new air supply. Some SCBA manufacturers provide an auxiliary hose with a male end to connect with another auxiliary hose (this would be the same as having a fresh cylinder on your back, although the cylinder may be next to you). This auxiliary connection is also on the low-pressure hose that goes to the regulator, as you can see in photo 2. The firefighter needs only to disconnect the regulator hose from his SCBA and connect it to the RIT SCBA, as seen in photo 3.

The RIT hose line works on the principle of equalization. Once the RIT connector has been connected with the mayday firefighter’s SCBA cylinder, an equalization process occurs and each cylinder balances itself with an equal amount of air in both cylinders. This process – known as crash filling the cylinder – offers only a limited amount of time and air supply compared to a complete cylinder and it can be very dangerous because there is a chance of cylinder explosion. The only time you should ever crash fill an SCBA is during a life-or-death situation. Every SCBA, regardless of manufacturer, will have a universal RIT connector on the back.  

The simplest and sometimes easiest RIT pack to use is a spare SCBA with all of the harnesses retracted and tucked away. This is the cheapest option, in contrast to expensive and sometimes bulky RIT packs. Once initial contact has been made with the mayday firefighter, a check of his air supply must be done along with transferring the new air supply to the old one. The new air supply will buy the mayday firefighter more time and will also allow RIT members the time to complete the operation.
Bringing in just one air supply does not guarantee that the mayday firefighter will survive. Depending on the complexity of the operation, the mayday firefighter may require multiple air changes. Ensuring that the RIT staging area is well stocked with spare SCBA cylinders is essential. It is also important to make sure that the initial RIT air pack being brought in is fully charged and that all of the required components are present and working. A half full cylinder, a missing RIT connection or a damaged air line will serve no good. It is the responsibility of RIT members to make sure that their equipment is ready to go at all times.

A supplied air breathing apparatus can also be used in certain situations. If there is no fire or high heat exposure, then an air line from a SCBA air cart can be used. This alleviates the need to bring in bottles to conduct changeovers when each cylinder has been depleted. The downside to using a supplied air line is the entanglement factor of the air line and the possibility of the air line being cut by sharp objects. If there is high heat exposure, the air line will be certain to break down from the heat.
 
A supply of air is vital to the success of the RIT operation and to the survival of the mayday firefighter and completes the requirement of the letter A in the acronym AWARE. In October we will look at the remaining letters of AWARE and explore what is required and expected.
 
Mark van der Feyst is an 11-year veteran of the fire service. He works for the City of Woodstock Fire Department in Ontario and is an instructor teaching in Canada and the U.S. He is a local level suppression instructor for the Pennsylvania State Fire Academy, an instructor for the Justice Institute of BC and a professor of fire science for Lambton College in Ontario. He can be contacted at  Mark@FireStarTraining.com