Developing Apparatus Specifications
Volunteers Corner
Fire companies or departments are continually upgrading equipment in order to provide improved service. However, fire apparatus are steadily increasing in cost while funds for their acquisition are becoming more difficult to obtain. In addition, the complaints on quality and lasting performance seem to be more prevalent.
Many of the problems that occur can be limited by adequate preparation and the development of clear, detailed performance specifications. In order to purchase apparatus that will meet our particular needs, the individual(s) or committee preparing the specifications must be clear on the purpose of the unit. If it is merely to win awards or have a larger unit than the neighboring department’s, the task is easy. But, if it is to be a cost effective, efficient fire suppression unit, work must begin with a detailed survey on the role of the unit in the suppression operations of the department. This will include determining areas where the present apparatus can be improved in capability.
The performance necessary for firefighting activities in the locale must be written into the specifications in order to insure that the apparatus will be able to do the job. Unfortunately, quality of workmanship cannot be written into specifications. A careful study of prospective manufacturers’ latest deliveries will be in order. This should include inspecting the underside of the apparatus, reviewing construction techniques, and talking with the day-to-day users.
A basic error made by many departments in order to save money is to purchase a chassis too small for the payload it will be expected to carry. This leads to underpowered, overweight apparatus generally with poor handling characteristics due to improper weight distribution, commonly known as a “dawg.” The manufacturer receives the blame for the “camel” that was the product of improper planning prior to purchase.
Safety for the personnel who will be responding on the unit is often an overlooked factor in many new units. Charlie Rule, former chief of Alexandria, VA, recently editorialized a number of considerations pertaining to future liability. Too few new units provide enclosed riding areas for all firefighters. Although seat belts may be supplied, there are no requirements for their use except in New York State, which has just initiated a seat belt law for motor vehicles. Restraining bars for jump seats are more economical than a workman’s compensation or liability suit. Perhaps fire departments should demand an apparatus design without a back step in order to remove the temptation of firefighters to ride in the open.
New fire apparatus must be practical. This will be the result of good manufacturer design and engineering, and adequate specifications that require performance. The ease of operation and working convenience are essential to the unit. Ladders, hard sleeves, minor tools, and hosebeds must be located so that they are practical to use. Apparatus must be designed to meet the needs of the local community. This may require specific water tank sizes, hoseloads, extinguishing agents, or piping and fittings.
There is a belief that bigger is better in the apparatus realm. This is not always true, especially if the practicability is lost. Recent deliveries include many 1,250-gpm and 1,500-gpm pumpers that have a maximum of two 2 1/2-inch threaded nozzles and several 1 1/2-inch threaded nozzles. How can they discharge the capacity of the pump? Another limitation is the size and/or number of lines the hosebed is designed to carry. The hosebed must be planned so that a sufficient number of lines, long enough for most local situations, are provided to either lay supply lines delivering the capacity to the pump or to discharge the full pump capacity when pumping. The above lays must have sufficient support fittings, adapters, hose clamps, and gated intakes to operate efficiently.
In addition to selecting a practical apparatus, a versatile one should be specified. The apparatus should have the ability to make forward, reverse, and split hose lays. Split hosebeds should be capable of being joined to make a long single lay. Preconnected lines must be provided in a variety of hose sizes and lengths. The capability to provide a “blitz” attack using medium and heavy lines should be considered. This may include a movable master stream or “bomb” line.
The need to extend lines for long stretches to reach garden apartments, condominiums, or tenements cannot be overlooked. Wyed lines may be desirable for this extension operation so that two lines are available. One line can be stretched to the room adjacent to the fire room to provide internal exposure protection while the other line is used for firefighting. Another form of versatility is the use of hose reels to supplement or replace the standard hosebed. Reels are certainly not as labor intensive when rebedding hose. Dual reels capable of storing a fourand five-inch hose are also a possibility and can be advantageous for large capacity water supply pumpers.
An area that should not be sacrificed is the piping arrangement on the apparatus. Once it is installed, it usually is never replaced. This piping includes: tank to pump supply lines; intake piping, especially from front and rear connections; and discharge piping, especially to rear discharges. To eliminate excessive bends in piping to rear preconnected discharges it may be advisable to place the discharge in the front of the hosebed rather than run piping to the rear of the apparatus. The 10 feet of hose remaining in the hosebed is less expensive than the cost of permanent piping.
The standard side discharges on the pumper can also be used to supply preconnects in cross lays and save the cost of additional valves, swivels, and piping. These discharges generally go unused by most departments. Another important consideration is the size of the piping for preconnects. If 1¾-or 2-inch hose is in use, larger size piping than l 1/2-inch will be necessary for the increased flows. The specifications should include the maximum flow and pressure that would be needed at the outlet, and the maximum pressure loss allowable in the piping. An example would be specifying that a rear discharge flow 200-gpm at a pressure of 150 psi with a maximum pressure loss between the pump and the discharge not to exceed 25 psi.
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If rural operations that include drafting from portable tanks are anticipated, gated intakes should be considered on all sides of the apparatus. This greatly enhances positioning and attack options. These gated intakes must be capable of supplying to the pump the quantities of water that will be discharged during a fire. The standard 2 1/2-inch gated intake will rarely be adequate. A maximum pipe size should be used; installation labor, not pipe size, is costly. Perhaps the recent concept of 4-inch or larger intake and discharge pipes completely circling the chassis with large diameter gated inlets and outlets on all sides has merit.
On many occasions it will be better to put a little more investment behind the sheet metal and drop some of the chrome, frills, and window dressing. Rather than a three-axle monster, a bit smaller, very practical, and more versatile unit that is a super firebuster may be the answer for your department.
