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The Rig: More on Fire Apparatus Dimensions

By Bill Adams

Specific dimensional requirements in fire apparatus purchasing specifications can be construed as operational or proprietary. I believe operational dimensions are essential and justifiable. Specifying the maximum overall height, width, and length of a new rig is a no-brainer. Dimensions should be based on the physical measurements of all the apparatus doors and bays in all of the purchaser’s stations. Don’t always believe old timers who say the bay doors are 12 x 14. When measuring door heights, check the clear height for the entire length of each bay. Older blueprints may not reflect renovations. It would be embarrassing if the new quint takes out a new ceiling mounted radiant heater at the back of the station. It could be catastrophic if it hits a newly installed overhead gas heater. Consider checking the stations of neighboring departments where you may stand by. Or, be forever destined to park outside—including during inclement weather. Such dimensions are not proprietary to any apparatus manufacturer (OEM). They are operational requirements necessary for the proper housing of the fire apparatus. Exceptions to them should immediately disqualify a bid. 

Other essential dimensions for the safe and efficient vehicle operation include a wall-to-wall or curb-to-curb turning radius and a maximum wheelbase. Ask vendors if their rigs today, with tight cramp angles and longer wheelbases, will perform equally as well or better than an older rig with a shorter wheelbase. Consider physically measuring the turning radius of your existing apparatus. Ask for demos; drive them throughout your district. Essential dimensions are not necessarily proprietary to a vendor. They are for the safe operation of the vehicle and should be included in purchasing specifications. A no-exception caveat is not unreasonable. 

Some dimensions specified for the cab and body can be subject to multiple interpretations depending on whether open or proprietary specifications are published. Proprietary, the most common, are geared toward one manufacturer. Astute spec writers will be explicit and definitive and sometimes crafty with verbiage to favor one manufacturer and eliminate all others. It happens all the time. The ethics of doing so are not being debated. 

Open specifications are for those soliciting true competitive bids. Dimensions in them are usually mandated for safe and efficient fireground operations. For example, measurements may be stipulated for the height of crosslays, hosebeds, ladders and hard suction hose. Locations and sizes of steps can be for safety reasons. Such dimensions are easily justified. 

Use caution when vendors help write purchasing specifications. Dimensions can be inadvertently or purposely incorporated into specification verbiage that have no direct purpose or intent except to show favoritism. Consider a traditional midship pump house. In my opinion, pump house sizes are probably the most common and least expensive area for an OEM to make adjustments to meet a specification’s overall length requirement. Specifying a minimum height from ground level to the bottom of crosslays on a midship-mounted pump house is an acceptable and defensible requirement. One purchaser’s specification included, “The pump module shall be 46 inches wide front to back, plus flex joints. The pump enclosure shall be 76 inches wide side to side, plus running boards.” For what earthly reason are those dimensions included other than to reflect one manufacturer’s standard configuration? Providing a bidder meets the overall length, wheelbase, and width measurements and operational criteria, who cares what the pump house measurements are? Why should an OEM with a 47-inch front to back or a 77-inch side to side measurement have to take an exception to the specifications and possibly be eliminated from consideration? 

Other questionable dimensions are found on custom cabs. There’s usually a fixed window on each side between the front and rear seats. One purchaser’s spec reads, “A window of not less than 16½ inches wide by 33½ inches high shall be installed in the sidewalls of the cab between the front and rear door.” Does specifying those exact window dimensions serve any logical purpose except to eliminate bidders? 

A critical concern in custom cab design is to prevent the motor from overheating. OEMs have engineered front and side grill openings specific to their particular cab design. How can a purchaser arbitrarily choose, and specify in square inches, the front and side grill openings and expect all bidders to comply or take exception? The same applies to windshields. If a purchaser specifies a minimum number of square inches for a windshield that more than likely is proprietary to one manufacturer, odds are seven other chassis manufacturers are not going to redesign their cab construction and windshield size to meet the requirement.

Some measurements in custom cabs including floor to ceiling heights, engine cover heights from the floor board, hip room for the driver’s and officer’s seat, and the distance from the engine tunnel to the rear wall of the cab can be interpreted as either proprietary or operational. Numerous valid arguments can be made for either. 

Some purchasers may reject bids because of an inordinate number of exceptions a bidder takes—regardless of their significance. It seems unfair if multiple exceptions must be taken because a bidder cannot meet the specific measurements of a competitor’s rig. It’s almost unjust if those exceptions do not compromise the operational characteristics or safe and efficient operation of the apparatus. Disclaimer: If a purchaser wants Brand A’s fire truck and I were selling Brand A, I would help write proprietary purchasing specs tighter than a coat of paint. If selling Brands B through Z, I would scream like a banshee saying the purchaser’s specifications were unfair. Vendors are caught between a rock and a hard place. So are purchasers. Good luck. 

BILL ADAMS is a member of the Fire Apparatus & Emergency Equipment editorial advisory board, a former fire apparatus salesman, and a past chief of the East Rochester (NY) Fire Department. He has 50 years of experience in the volunteer fire service.


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