The Apparatus Architect - Part 32: Frequently Asked Questions of the Apparatus Architects

Aug. 1, 2007
Tom Shand and Michael Wilbur answer questions frequently asked by Firehouse readers.

This month, we depart from our usual format to answer some of your most commonly asked questions.

Top-mounted vs. side-mounted pump panels. I have been assigned to our apparatus committee and have been elected chairman. We are doing a complete fleet replacement of eight engines. We are considering the differences between top-mounted pump panels and traditional side-mounted pump panels. We have used only side-mounted pump panels in our history. We are concerned about safety of our drivers and crews. We are also tasked with getting smaller and more maneuverable fire engines. We currently have engines with 176-inch wheelbases and overall length of 30 feet.

Our staffing levels of three-person engine and truck companies are another consideration. We need the pump operator to assist with hooking up supply hose as well as being able to help out with air bottle changes and other tasks. This is somewhat unorthodox, but our staffing levels make this a reality. We have some members who have worked with top-mount pumps panels and like them. Most of the crews would like to change to top-mount pump panels, or at least try them out.

What insights to the operational issues of having top-mount vs. side-mount pump panels do you have experience with? I am sure there are many departments that have had one and switched to the other. Do you have comments on the switch and whether it was beneficial? Our committee would appreciate any help that you are able to give us. Thank you. —Mike R.

First of all, we are firm believers in short-wheelbase pumpers that are capable of carrying your needed personnel, hose and equipment in a safe manner. While we are not personally familiar with your department's units, if you look closely at some of the major urban departments in the United States (Los Angeles City, Chicago, FDNY, Washington, DC) and others, you will more often than not find that these busy jurisdictions operate predominantly side-mount pumpers for several reasons:

  1. The side-mount pumper generally affords the shortest wheelbase possible. FDNY uses 185-inch-wheelbase, LAFD uses a 175-inch-wheelbase and the DCFD uses 163.5-inch-wheelbase rigs. Top-mount designs add between 20 and 28 inches to the wheelbase and overall length, depending on the specific manufacturer's design.
  2. A side-mount pumper allows you to position crosslay hosebeds lower to the ground, generally around 64 to 66 inches as they can be dropped low in front or over the fire pump. Top-mount pump panels require hosebeds to be above and behind the pump or used as "speedlays" in front of the pump, which often add nine to 12 inches to the wheelbase.
  3. Whether your department utilizes a straight or reverse lay as its principal attack method, the engineer can break or connect the supply line or open or close an intake or discharge valve from the ground without having to climb up or down on the top-mount walkway.
  4. If you are going to go with a top-mount panel configuration, we would recommend that you specify vertically hinged pump access panels on each side of the unit to improve maintenance access to the pump and piping.
  5. To our knowledge, there have been no definitive studies evaluating the pros and cons of top mounts, nor have there been any safety-related studies that prove that top-mounted fire pumps are safer with attendant lower incidents of accidents than side- or rear-mounted pumps.

Window tinting. I'm trying to find out the pros and cons of aftermarket window tinting on fire apparatus. Is there some kind of standard? Does it off gas when heated any more than anything else in the cab would? Any other input would be greatly appreciated. Thank you — Steve M.

There generally are no problems with the aftermarket tint; however, in most cases, the standard "dark tint" available from the various builders is sufficient to keep the inside of the unit cool. Unless you are located in the desert Southwest or areas of Southern California, the standard dark tint application should be adequate. We hope that this information is useful to you.

Multiplexing. Please let me know where I can find information pertaining to multiplexing now being installed on fire apparatus. I would like to stay away from some tech items and keep things as simple as possible, but few apparatus manufacturers make this an option. Do you have any suggestions? Thank you. — Jim C.

The apparatus industry now uses several different systems for multiplexing. Pierce has developed its own system and offers this as an option on its line of rigs. Other builders use outside-built components manufactured by Class 1 or Weldon Industries. You can find information on these systems at the companies' websites. Most other builders offer multiplexing as an option on their units. Some builders, such as Crimson and Spartan, have standardized this electrical hardware. We would suggest that you visit company websites to read up on what they offer, especially the Class 1 and Weldon sites to review their technical information.

Backup cameras and rear-step height and length. We are a career department with 132 personnel and nine stations covering about 68 square miles. We run about 8,000 calls per year. I am a driver and have been in the fire service for about 16 years. I do the apparatus specs for our department along with my deputy chief. We are in the process of replacing our frontline apparatus and have a few questions. I was wondering what your thoughts were on rear backup cameras and their placement. We have one on a recently purchased apparatus and have had backing issues with it. We don't have a lot of experience with them and now they want to cut it from the spec because of this issue. Also, we lowered our hosebed to a 60-inch height to keep the firefighters from having to stand on the tailboard, but now there are some complaints that the tailboard is too short. It is 14 inches long. I know that there seems to be a trend of shortening tailboards, but we did it to keep the firefighters from having to step on the tailboard to reach the hose. Also, we did it to keep the length down for agility and we deal with hills that average 20 degrees and up to 28, so our angles are important. Any thoughts that you have would be appreciated. Thank you. — Carmine L.

We have had good experience with backup cameras. Color monitors make it much easier for the driver to back up the unit in tight locations. While we personally always prefer to have a backup person whenever a unit is going to move, we know that this does not always happen. The additional cost is well worth it when compared to having to do bodywork on rigs that get into accidents. Twenty-eight percent of all apparatus accidents happened in reverse last year, so we could use all the help we can get.

With respect to the rear step, 14 inches is a little too short if you are going to stand on the step to load hose or stretch a line. We would suggest that you use a 16-inch-deep step and angle the sides of the hosebed to improve the rear swing clearance of the unit. The additional two inches should not adversely impact the angle of departure and should reduce any rear-step complaints.

The rear hosebed height is important and at 60 inches you should be able to stretch a line off the hosebed with little difficulty. If we can help you with anything else, please let us know. Stay safe.

If you would like to have your apparatus questions answered in print or on line please contact the Apparatus Architects through Firehouse® Magazine or

TOM SHAND, a Firehouse® contributing editor, is a 33-year veteran of the fire service and works with Michael Wilbur at Emergency Vehicle Response, consulting on a variety of fire apparatus and fire department master-planning issues. He is employed by Seagrave Fire Apparatus LLC as a regional sales manager. MICHAEL WILBUR, a Firehouse® contributing editor, is a lieutenant in the New York City Fire Department, assigned to Ladder Company 27 in the Bronx, and has served on the FDNY Apparatus Purchasing Committee. He consults on a variety of apparatus-related issues around the country. For further information, access his website at

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