Can Rear-Mount Quints Lay LDH?
The Weirton Heights (WV) Volunteer Fire Department has used 5-inch large-diameter hose (LDH) as its standard supply line since 1972. Previously, our department used smaller-diameter hoses, but due to the low-pressure hydrant system in our jurisdiction, we switched to LDH to maximize water flow. After 19 years of experience, we are convinced that LDH is the most effective water delivery system available.
In 1985 we took delivery of a quint with a rear-mounted 100-foot aerial ladder. This unit replaced two other trucks—one a 1,250-gpm quad and the other a tractor-drawn 100-foot aerial. The manufacturer of our new quint assured us that the apparatus could lay out LDH as well as smallerdiameter hose.
Quints with rear-mounted aerials carry supply hose in one of three ways: in side compartments, which sacrifices compartment space and limits the amount of hose that can be carried; in hosebeds built forward of the turntable, which involves feeding the hose through an opening under and to the side of the turntable; and in a hosebed forward of the turntable, from which the hose is fed out to the rear of the apparatus through a chute that runs under the turntable Our quint carries hose in the third manner. This preserves our compartment space for equipment and offers adequate hose-carrying capacity. However, it presented us with several unexpected problems.
We were very disappointed when our brand new quarter-miilion-dollar battle-wagon sustained damage on its first run because of our attempt to lay LDH! On its first lay at a fire, the largecouplings of theLDH knocked off the under-ladder spotlight and nearly destroyed the roller that was supposed to guide the hose into the chute. On another occasion, as the truck was laying hose around a 90-degree intersection, a coupling snagged the diamond plate around the chute on the rear of the truck and pulled it from the body frame.
We heard similar complaints from other owners of rear-mount quints with similar hosebed design, so the problem was not unique to our truck. After some trial and error, we found some solutions.
The problem of the couplings striking the under-ladder spotlight could be solved by moving the light to the side, out of line with the hose playing into the chute, or to the rear of the chute. We moved it to the rear.
The problem of the couplings snagging the diamond plate also was relatively easy to solve. We had a machine shop fashion a piece of angle that butted the chute perfectly and bent around, shielding the diamond plate.
The final problem of the LDH not feeding into the chute smoothly took some ingenuity to solve. First, a deflector was manufactured for the opening of the chute for the hose to pass beneath, preventing the couplings from slamming into the roller. This consisted of mounting a piece of thick rubber mat cut to match the shape of the chute down to the point where it angles to the rear of the truck to a bracket rising above the slot to the chute. We used rubber, but any type of sturdy yet flexible material will do.
Then we devised a hose load that would feed the couplings directly to the chute using a modified flat load. The load is begun at the front of the bed and the hose is stacked with alternating folds along one side until a set of couplings is reached. The couplings are brought to the center front of the bed in line with the chute and placed so that they do not have to turn or flip when played out toward the chute.
The hose is then laid to the opposite side of the bed and another section is stacked. The next set of couplings encountered is taken to the center front of the bed and placed directly behind the previous couplings. They also are positioned so that they will not have to turn when they play out. The next section of hose is then stacked adjacent to the first stack. The process continues, with hose stacks alternating sides until they reach the row of couplings in the center. If space is available, an extra section of hose can be laid loosely across the load. If you load an extra section, be careful to switch from one side of the couplings to the other at the very rear of the load so that the hose cannot snag a coupling.
We have found it is easier to load LDH over the side of the truck than to feed it through the chute. When the hose load is complete, a pike pole is guided up the chute and the last coupling is pulled down the chute with the aid of a piece of webbing or a rope hose tool.
When loading the LDH for playing out through a chute, it is important to arrange the couplings directly in line with the chute for smooth entrance and place them so they do not have to turn or flip, as they may ricochet violently.
Since adopting this method, we have played out the entire load without a problem. In fact, it laid out straighter than with a standard pumper. However, use caution at 90-degree turns. It is best to pause and have someone pull slack at that point to prevent pressure binding of the hose as the truck changes directions.
We also had a problem with the door on the rear of the truck to the chute opening and ground ladders, which was designed to lift up out of the way. Unfortunately, the weight of the door and normal driving vibrations caused the brackets to pull out of the aluminum bodywork. This was solved by having the hinge plate moved so that the door opens down instead of up.
A department with LDH loaded in the side compartments of its quint had hangup problems when laying hose. An examination of the hose load showed that the couplings were placed in position as encountered. When members attempted to lay hose, the couplings would ride up over each other and jam the load. This problem was solved by loading couplings as described in the previous load. The first coupling was set forward in the bed. The next layer of hose was placed with the folds alternating, long and short, to prevent bowing. When the next couplings were encountered, they were set to the rear of the first. All couplings were placed so that they did not have to flip or turn when being played out. Caution was exercised not to load too much hose so couplings would not strike the bodywork-reinforcing angles at the top of the compartments.
Quints are excellent firefighting machines. When set up properly, they can lay LDH effectively. However, simple problems left unsolved can become a department headache. If you are encountering any of the problems mentioned in this article, consider our approach —it worked for us.