5000 PSI Air Supply Truck in Miami
FEATURES
Photos by Doris Renee
An air supply truck to meet the requirements of the new 4500-psi pressure-demand breathing apparatus is now in service in the Miami Fire Department.
Built on a 23000-pound GVW chassis, the truck contains a 5000-psi, 65-cfm air compressor and a cascade system that holds a total of 3000 cubic feet of air at 5000 psi in five 600-cu-ft cylinders and an air purification system. The Mako KA-23-3DKH compressor automatically kicks in to maintain full pressure in the cascade system. Shutdown of the compressor is done either automatically or manually.
The new truck is the result of the concern first felt nearly three years ago by Louis DeChime, chief of support services, of the Miami Fire Department, about providing adequate breathing air for fire fighters working in the city’s increasing number of high-rise buildings.
The entire air supply system is controlled from a panel between two filling stations at the rear of the truck.
There are 32 breathing apparatus cylinders stored underneath the truck, 16 on each side, in storage bins with wheels that allow them to be converted to carts. A push of a button lowers to the ground one to four bins, each containing eight cylinders. The bin-carts are easily pulled, singlehanded, even across 4-inch hose on the fireground.
When cylinders are empty, they are returned to the carts, which are pulled back to the truck, placed in position under the chassis, and then lifted and locked into place pneumatically.
The carts can also be taken to the two filling stations at the rear of the truck. Blast shields protect men recharging air bottles at the filling stations in the event of a cylinder failure. The filling stations can be lowered or raised pneumatically for convenient loading. Each station can hold two cylinders.
If all the compartment doors are not closed and all the bin-carts and filling stations are not in road position, the truck’s air horn will sound and a bell will ring when the driver turns the ignition on to start the engine.
The alarm system also indicates such conditions as low oxygen level, a high carbon monoxide concentration, low oil pressure, high rpm, excessive operating temperature, high dew point and clogged condensate drains.
The compressed air meets grade E standard of The Compressed (las Association and the purification system cart ridges need be changed only every 336,000 cubic feet of air.
The compressor is air-cooled by two blowers that direct air through the interand after-coolers and across valve heads and cylinders at high velocity.
—photo by Doris Renee.
—photo by Robert Milnes
