Fire departments are constantly being challenged to do more with less, particularly with respect to the financial resources required to provide for adequate staffing and training of our personnel. Capital projects for new fire stations and apparatus have often been put off year after year due to the current state of the economy and local conditions. None the less fire suppression forces across the nation have continued to provide emergency services to the communities that they serve.
In both volunteer and career departments staffing levels have been difficult to maintain even in communities which have not been directly impacted by the current recession. The days of riding out with a full crew of eight to ten personnel are in many instances gone with minimum staffing being the order of the day. Staffing levels relates directly to the number of seating positions required on each piece of apparatus and ultimately the size of the cab area itself and the cost of the apparatus. Both of these factors drive the wheelbase and overall length of the apparatus and have an impact on the turning radius and maneuverability of the vehicle. Several apparatus manufacturers have developed new cab designs which have addressed some of the space and safety concerns that have been problematic in the past. In future articles of the Apparatus Architect series will be review and comment on these new improved designs.
Like any good student of history we need to have a clear understanding of how these different cab designs and features developed over the years. Most departments have been operating with four door cab apparatus for some time, however the available space for crew seating, tools and equipment have changed dramatically just since the decade of the 1970’s when NFPA standards covering apparatus design and configurations was not nearly as comprehensive as the current 1901 Standard. Today it is not uncommon to have both cabs and apparatus bodies measure 100 inches in width with an average pumper exceeding 32 feet in length. In the past “bigger was not always better” and resulted in much smaller, compact apparatus.
Starting in the late 1960’s with the advent of diesel engines replacing gasoline power custom cab design began to change. Apparatus cabs produced during this period typically were 76 inches wide with an individual bucket style seat for the driver together with a short bench seat for two personnel including the officer. Two rear facing seats often referred to as jump seats or buckets on either side of the engine enclosure measured just 18 to 19 inches wide with little room to maneuver. As some open cab apparatus was still being acquired this restricted space in the jump seats was not much of a concern as elbow room and seating comfort while minimal was considered acceptable. These cab designs were distinctive with large painted fenders extending beyond the cab side panels. During the war years many departments modified these open cab units with makeshift plywood roofs and enclosures and consequently open cab apparatus quickly fell out of favor with all but a few departments.
While four door cab apparatus would not be required until the early 1990’s some departments such as those in New York City began to specify enclosed cab apparatus as early as 1968. During 1971 FDNY took delivery of forty Mack CF model pumpers that came equipped with four door cab enclosures to protect the crew. The CF cab measured 92 inches wide on the exterior with 83 inches of interior space. Engineers at Mack realized that space in the jump seat area was at a premium and as a result designed an engine cover with angled side walls which greatly increased the room for personnel riding in these positions. Prior to the advent of fully enclosed cabs the engine box which was fabricated from aluminum or steel tread plate became a popular area to mount self contained breathing apparatus and hand tools.
Department’s who staffed their apparatus with five or six personnel would often have these individuals ride in a seated or standing position opposite the rear facing jump seats. Certainly these riding positions where not safe as personnel were exposed to weather, traffic and other hazards. The popularity of this type of seating position lead to the development of various types of safety bars, gates and doors to protect personnel riding in these locations. Apparatus manufactures who built their own custom cabs such as Crown, Hahn, Maxim, Peter Pirsch and
Ward LaFrance had developed wider profile cabs to increase the space for the driver, officer and crew areas, with seating for up to six personnel with four door cabs. Diesel engines in a V style configuration required more room inside of the engine enclosure which also impacted the available space in the jump seat area. Higher powered engines at that time were in the range of 450 horsepower which required larger radiators and cooling packages to provide optimum performance.
Cab forward apparatus continued to be the predominant design until 1983 when Spartan Motors introduced their Gladiator model chassis which located the engine up front in between the driver and officer’s seats. This design provided adequate cooling for the high horsepower diesel engines and opened up the entire rear cab area for multiple seating configurations. Shortly thereafter the Young Fire Equipment in Lancaster, New York introduced their Crusader II mid-engine chassis. The first Young built four door raised roof cab was delivered to the Bailey’s Cross Roads Fire Company in Virginia on a 175 inch wheelbase with a clutch controlled fire pump located under the cab floor. By removing the engine from the cab area increased space was available in the front for map books, computer terminals and other equipment.
While some in the apparatus industry did not believe that these alternative engine designs
would prove popular by the tradition bound fire service within a few years other manufacturers were offering mid and rear engine chassis to increase crew seating options. Most notably Emergency One during 1985 introduced their Hush rear engine chassis which allowed seating positions for up to ten personnel. These cabs were 94 to 96 inches in width with virtually no fender area to maximize the available space inside of the crew seating area. For the first time fire departments now had the option to provide different seating arrangements and were not restricted to just four fixed seats inside of the cab.
At this time engine and pump technology was beginning to introduce computer and electronic components which required chassis and cab space for mounting and maintenance access. Cab width had pretty much remained constant at 94 to 96 inches for a number of years with minimal aesthetic exterior changes. Some departments operating with narrow fire station clearances began to recognize that while the wider cabs provided improved crew space these wider profile units had some difficulty maneuvering around in tight locations.
The NFPA 1901 standard in Section 14.1.9 provides some guidance as to the minimum dimensions required for seating arrangements inside of the cab. Each seating space must have a cushion that is at least 18 inches wide and 15 inches deep from the edge of the cushion to the vertical face of the seat back. In addition each seating position must have a minimum of 22 inches of width at the shoulder level. These dimensions are currently being studied and validated based upon a national anthropometric study of fire personnel conducted in cooperation with the National Fallen Firefighters Foundation. The results of this several year study will impact apparatus seating and seat belt design, protective gear, step heights and many other aspects of our daily activities. Some of the preliminary data from the study would indicate that the seat width to accommodate the 99 percentile 2011 firefighter would need to be 28 inches. The 28 inch seat width needed to accommodate the modern day bunkered up firefighter is going to have a dramatic impact on apparatus cab design.
As a part of the specification development process the apparatus committee should carefully review department standard operational guidelines including staffing levels and task assignments for each riding position. Just because you can specify a custom cab with seating for eight to ten personnel is no reason to require this arrangement for your next apparatus unless your department can regularly staff the apparatus at this level. The total number of seating positions on custom chassis apparatus impacts a number of areas including front axle, suspension and tire ratings, cab size and ultimately the overall length of the apparatus.
Following are a few questions that should be answered before setting out to design the interior cab layout for your new apparatus:
- 1. How many personnel will normally be assigned or will ride on this unit?
- 2. What map book, computer and resource materials will need to be readily available for the officer?
- 3. Where will personnel store their protective gear during non-emergency responses?
- 4. What tools and equipment will need to be mounted and secured either inside of the cab or immediately available in an adjacent area?
These responses to these questions and other will provide some insight as to what cab configuration will most benefit the department in terms of efficient use of space without compromising safety. In future articles we will review some of the current cab designs and discuss the importance of clear vision for the driver and officer seating positions, mounting of tools and equipment, stepping surfaces and other safety considerations.
Photo captions for AA Part 52:
All photos by Tom W. Shand
#1. This 1971 Young pumper once operated by the Allentown Road, Maryland fire department shows how SCBA and tools were mounted in the jump seat area. Note the wide fenders which reduced the width of the seating area.
#2. The angled side panels on this Mack CF model tower formerly operated by the Kentland, Maryland fire department provided additional room for personnel riding in the jump seats.
#3. Many departments carry an assortment of map books and other reference material inside of the cab that requires space on the engine cover or other areas on the cab interior.
#4. This engine formerly operated by the Union Fire Company in Carlisle, Pennsylvania utilized doors at the jump seat area to provide some protection for the crew. Note the SCBA’s and equipment mounted on top of the engine enclosure.
FIREHOUSE MAGAZINE November 2011
BY Tom W. Shand and Michael Wilbur