Fire apparatus has evolved to a point where in some instances we are operating with vehicles that are pushing the legal weight limits imposed for interstate highways. Vehicle dimensions such as overall length and height of units have become so large that in some instances the physical size of the vehicle has made it difficult to work from with attack lines and equipment literally out of reach of the average fire fighter. Recent anthropometric studies have concluded that the 95 percent fire fighter does not fit well into current cab seating which also impacts the position and location of handrails and stepping surfaces.
We can all probably remember viewing a piece of apparatus that was on display at a local fire show and thought to ourselves “Why on earth did they do that”? The level of customization on fire apparatus is in large part dependent upon the perceived needs of the department and the ability of manufacturers to develop new and innovative components that catch our attention. While not to demean their capabilities on the fire ground, combination apparatus such as rescue engines and quints have fostered the concept that departments can combine a number of components, tools and equipment into one vehicle that will bring the entire toolbox to the incident. As a result many all hazards agencies have embraced the multi-purpose apparatus as the answer to their needs to carry the majority of their equipment on a single unit. The issue becomes one of when does a piece of apparatus become too large and cumbersome to operate, either within the first due area or in other neighboring jurisdictions.
In part, the size of apparatus is related to our staffing models and deployment practices. Where many departments are fortunate to provide four person staffing on engines and trucks, all too often we operate with less than optimal staffing which results in five to six units at the scene with twelve personnel tasked to do everything. This common scenario has caused some departments to acquire multi-purpose apparatus to carry more tools and equipment on a single unit as staffing does not permit the response of other vehicles. These combination units may work well in wide open areas in front of strip malls but in some communities the square foot area of residential homes has grown to the point where the life safety and fire potential is a greater concern. This is further complicated when roadway access for apparatus is very limited due to driveway layout, grades and decorative stonework which impedes apparatus. More than ever apparatus committees must evaluate the service needs of their first due areas and temper this with some practical application of situational awareness to provide for a well-designed apparatus.
The NFPA 1901 standard in Table 12.1.2 provides some excellent guidance as to the minimum equipment payload weights that should be considered for the various types of apparatus. For pumpers with enclosed compartment space of less than 250 cubic feet the minimum equipment allowance is 2000 pounds and increases to 2500 pounds for larger bodies. As these payload allowances are a minimum, the fire department must clearly identify their requirements for hose, tools and appliances when developing their specifications. Combination apparatus such as rescue-engines and single axle quints are particularly vulnerable for being overweight if the equipment weight has not been determined early on in the process.
Overweight fire apparatus is not limited to combination apparatus nor any particular style of vehicle. Unfortunately, there are many pieces of apparatus operating today that are overloaded as the equipment compliment was not specified and over a period of time, additional tools are mounted on the apparatus which can result in poor braking and vehicle performance. Over the past three years as a result of numerous fleet studies many departments were surprised to find out that after each of their units were weighted on certified scales that one or more vehicles were overweight, in some cases with no personnel on board. Not every one of these incidents had a happy ending with some units having to be taken out of service with changes in equipment and hose compliments, reduction in water tank size or new axles, tires and suspension components installed.
During the specification development process the apparatus committee after determining the mission of the apparatus should review the tool and equipment requirements starting with an inventory of existing apparatus. While the NFPA 1901 Standard lists basic equipment requirements for engine, ladder and special service units, this equipment loading typically does not capture all of the tools and appliances that departments will require on their front line units. For example, it is one thing to call for a hydraulic rescue tool compartment to include reels and sufficient slide trays to accommodate fire department supplied equipment and another to detail the specific make, model, size and weight of this equipment to insure that sufficient compartment space and weight is available to safely carry these tools.
Most apparatus manufacturers have developed body designs with specific compartment dimensions based upon the capacity of the water tank and hose bed to provide different lengths in order to meet fire department’s needs. The apparatus committee should inquire as to the various options to determine the best match for the overall length of the body and how this may impact the wheelbase and turning radius for the completed unit. Often departments simply choose the largest size body available and then work backwards to make the tools and equipment fit within the allocated space. This often results in mega-sized apparatus that carries everything but does not allow access to tight areas within the community or simply cannot maneuver in locations where older vehicles could easily fit.
When reading through manufacturer’s specifications remember that all dimensions are not necessarily equal. Some specifications state the overall compartment dimensions in inches for the height, width the depth of each area. These numbers while impressive may not take into consideration the loss of height due to headers or the roll door shutter and the clear door opening past hinged doors or trim pieces. In addition the depth of each compartment should be the clear useable space for equipment storage with the door closed. The use of slide out trays for easier access to equipment must allow not only for the height of the slide mechanisms and thickness of the tray itself but the side clearances required to pass thru the door opening. Some of these dimensions are normally not provided in specifications provided by the apparatus manufacturer’s and will have to be determined after consultation with sales personnel and their engineering staff.
After the specific compartment dimensions are established you can begin to lay out your tools and equipment within each compartment area. If you had already developed the apparatus inventory of equipment including dimensions and weights there are several methods that you can use to lay out each compartment shelf, tray and tool board space. Several manufacturers and equipment mounting companies can provide a computer aided drawing (CAD) for each area within the compartment body. These CAD drawings can be of great assistance to determine ahead of time, before any metal is sheared to insure that your equipment can be safely mounted in each location. Another technique which can be accomplished in the fire station is to mark out on the apparatus bay floor with tape each surface area such as an adjustable shelf, tray or wall area and locate the desired equipment within the space. Documentation of this work should include digital images and a listing of the appliances and equipment for each location.
The upfront work conducted at this point in the design process can alleviate some of the issues that crop up later and can cost a great deal of time and money to solve once the apparatus goes into production. This work is particularly important if your department is working on the design for an apparatus which will be combining the equipment from several pieces of apparatus into a single unit. The apparatus manufacturer will be able to validate your requested tool and equipment locations while providing an accurate analysis of the anticipated in service weight of the apparatus prior to construction. Failure to provide this level of detail during the design phase can lead to unbalanced side to side weight or overloaded apparatus which in some cases cannot be easily modified to insure a safe vehicle.
One of the requirements within the specification boiler plate should be for each bidder to provide a detailed weight analysis of the apparatus as proposed. This analysis would provide information on the front and rear axle loading based upon the weight of the equipment provided by the fire department. This analysis would then be compared to the actual vehicle weight when delivered to the department and prior to acceptance the vehicle would be weighted with all hose, tools and equipment to insure that the vehicle was within the rated axle and chassis GVWR. Typical specification verbiage would read as follows:
“Each bidder’s proposal shall provide a complete weight analysis indicating the estimated front and rear axle weights for the loaded vehicle including full fuel, water and foam tanks, six (6) personnel the specified hose load and a minimum of 2500 pounds of tools and equipment. This analysis shall detail the weight of the major components, hose and equipment showing the weight applied to each of the vehicle axles. A general statement indicating the front and rear delivery weights from the factory shall not be considered as acceptable.”
While tool and equipment mounting is one of the last items to accomplish prior to placing the unit into service consideration must be given to how this work is going to be conducted. Some departments have historically left this work to the individual fire companies with mixed results. Others have tasked this work to be conducted by the department shops and mechanics to provide some standardization in tool and equipment placement. Apparatus committees should consider including a specific amount for tool and equipment mounting into the final specifications to insure that the complete inventory will be properly and safely secured in the cab and body compartments. A statement similar to the following could be included:
“Each bidder shall include an amount of seven thousand dollars ($7000.00) for tool and equipment mounting of fire department supplied equipment including hydraulic rescue tools as listed in the attached specifications. The tool mounts whether custom fabricated or commercially purchased hardware shall be approved by the Fire Department. All tools shall be made available to the successful bidder after completion of the final inspection and shall be conducted under the supervision of the Fire Department final to final acceptance and payment for the apparatus.”
When working on new apparatus specifications the department should develop a complete equipment inventory, plan the space allocation needed to safely accommodate and secure this equipment and not fall into the common trap to acquire the largest body style available with the hope that everything will work out. Considering the life cycle of the apparatus with leaving some open space for future equipment, the cost of tool and equipment mounting is nominal when compared to some of the more costly components that are installed on new units.
With the increasing services provided by many departments the apparatus compartment space can be at a premium within a short period of time after placing the vehicle into service. Careful planning during the specification process including developing the hose, tool and equipment inventory including weights will reduce the opportunities to end up with an oversized apparatus with resulting weight and performance concerns.
Photo Captions for Article #2: All images by Tom W. Shand
#1. Placing map books in an area near the officer’s seat was accomplished on this unit operated by the West End Fire Company in Shippensburg, Pennsylvania. Note the mounting for the portable radio and hand light on the engine tunnel.
#2. Long handle tools such as roof hooks and be mounted on the exterior of the cab adjacent to the crew cab door for easy deployment. Note the stainless steel scuff panels to protect the paint surface on Truck 809 from Bladensburg, Maryland.
#3. Pike pole and hook mounting on pumpers can be accomplished using the rear cab wall as on Engine 15-1 from Shippensburg, Pennsylvania. Note the aluminum tread plate step over the pump panel area.
#4. High side body compartments can have pegboard or similar material provided in the reduced depth sections to permit mounting of hand tools and appliances.
#5. Well laid out compartments such as shown on Morningside, Maryland’s Rescue Engine 27 is the result of planning throughout the specification process.
#6. The use of swing out tool boards enables equipment to be mounted on each side with flexibility to be changed as needs dictate. Note the mounting of the floor mounted saws and rear wall tools on the Camp Pendleton Marine Corps Base heavy rescue.
#7. Weight balance front to rear as well as side to side is critical when determining where to mount fixed and portable equipment in rescue bodies.
#8. The clear width of compartment openings should be determined when laying out equipment mounting inside of slide out trays. Note the efficient use of space to mount the forcible entry tools.
#9. A combination of slide out trays, fixes shelf and modules provided space for ventilation equipment on this San Diego ladder truck.
#10. Efficient use of walkway storage on this heavy rescue for roof hooks, 16 foot roof ladder, 28 foot extension ladder and small attic ladder.
#11. The pump panel area on this Syracuse, New York engine was laid out to provide a logical space for all components as well as maintenance access on each side of the vehicle. Note the non-slip full width pump panel step surface.
#12. Low hose bed design on Engine 281 from West Lanham Hills, Maryland with fixed steps to access the hose bed area. Note the recess mounted warning lights in the rear step and angled corners to improve swing clearance.
Tom W. Shand
April 4, 2015