Some of the least expensive and seldom addressed accoutrements on a fire truck are the adjustable shelves and trays provided in its exterior equipment compartments. They don’t get serious attention until one unexpectedly goes south along with all the equipment loaded on it.
Dumping the contents of a shelf or tray is usually because of improper tightening of the shelving brackets. Seldom do trays, shelves, and their brackets fail on their own—but, they can. Annoying is loading equipment on a shelf and noticing a month later there’s an obvious bending or deformation in it. Equally aggravating is having a new rig delivered and the equipment anticipated to be carried on the shelving and trays does not fit.
Equipment not fitting and shelving deformation can be attributed to inadequate purchasing specifications. Unless a performance specification was written, most problems are the responsibility of the apparatus purchasing committee (APC). If they wrote the specs, they own the problem. If a requirement is not in writing, it does not exist. Specification verbiage for shelving and trays can be as brief as, “Each compartment shall be equipped with one adjustable shelf and one slide-out tray.” Others can be almost 400 words long.
Terminology can be the bane of specification writers. Is there a difference between a shelf and a tray? I define a shelf as a flat piece of metal, wood, or polypropylene that could—but is not necessarily required to—have an upward or downward facing “lip” on at least one side. A tray is a shelf with upward facing lips on all four sides.
Purchasers must specify if shelves and trays are expected to be adjustable and to what height in a compartment. Except for specifying if tray slide-out mechanisms are located on its sides or underneath the tray, they are not addressed. There are too many variables. Ask the vendors what is available, their costs, ratings, and how much room they take up.
Shelving material, weight capacities, methods of mounting (unistrut), brackets, and types of hardware are also left to the vendors to explain. Several apparatus manufacturers were asked to comment. Responding are Ken Sebo, pumper business development manager for Pierce Manufacturing Inc.; Pete Hoherchak, senior product manager for KME; Tim Dean, president of PolyBilt; and Mike Watts, national sales manager for Toyne.
Bebo says that regardless of the body material, Pierce recommends aluminum shelving and unistrut. “Through testing in our applications, we have developed aluminum shelves to meet capacity to weight rating needed,” he says.
1 This Pierce has a heavy-gauge shelf with no lips in the upper section. A two-piece webbed strap with hook-and-loop and deadman loops are used to prevent the suction sleeves and strainer from sliding into the door. The slide-out tray has formed 2-inch lips. (Photo courtesy of Pierce.)
Hoherchak adds, “KME uses aluminum due to weight. Stainless works, but aluminum is lighter and more cost-effective. It’s also easier to deal with scratches and blemishes over the life of the truck on aluminum shelves. Scratches and scrapes on stainless do not ‘buff out’ easily.”
2 Vertical dividers in a compartment allow flexibility by enabling adjustable shelving to be provided on each side at different heights. Finding storage for single-piece traffic cones favored by many departments can be difficult. Cones are probably one of the few pieces of equipment used every time the rig stops on the road. They should be easy to access. (Photo courtesy of KME.)
Dean states, “Polyprene material is FDA-approved, so it can be cleaned of bloodborne pathogens. And, it does not have to be painted.”
Watts says, “Toyne recommends aluminum. Shelving does not come in contact with the body, so aluminum will work just fine on stainless bodies. One shelf material doesn’t really have an advantage over another.”
Regarding weight ratings for shelves and trays, Hoherchak says, “Depending on a shelf’s size and intended load, extra support may be needed to keep it from bending. If it slides in and out, the size and arrangement of the slides will be bigger. KME designs trays based on a point load. Realistically, though, it’s hard to get 500 pounds in a single point. There’s not always a difference in a shelf’s rating based on its configuration.”
Bebo adds, “Pierce used to have 250-pound shelves, but this was seldom requested, so we standardized on 500 pounds. Evenly distributing the weight is ideal, but we understand equipment load is not always even. Conversation of how equipment is installed helps us design shelves to meet the needs of a customer. Pierce validates shelves and mounting as part of a system. Test data should be available from the manufacturer to validate the capacity of the shelf and mounting.”
“For Toyne, it would be the thickness of the aluminum: 1⁄8 inch for the lighter load and 3⁄16 inch for the heavier load,” says Watts. “How the shelf is formed also has a bearing on the sturdiness of the shelf. The weight calculation is usually based on a distributed load.”
Dean states, “Our Polyprene shelves are made with longevity in mind. We use a minimum 0.5-inch material. For heavier applications, we can use 0.75-inch-thick material as well as add floor brace flanges for additional strength. Ideally, weight should be evenly distributed on a shelf. But, we can accommodate a custom application. With our Pro Lock method of locking in our material before welding, we can brace our shelves with extra floor flange for superior strength and accommodate a heavier load even if it is not equally distributed across the floor plane.”
Watts states, “Similar to shelving, aluminum struts work well on stainless bodies when properly isolated. Stainless is an option at Toyne. Bolted struts are best for future changes. The same sized unistrut is used for various shelf ratings. Two work best on the full-depth compartments, and one is usually adequate for the shallow-depth compartments. It is the rating on the fasteners that is most important. Most unistrut is extruded aluminum and is very strong.”
Dean says Polybilt can mount its Polyprene shelves with aluminum unistruts or Polyprene shelf mounts—whichever the customer prefers. “When using our Polyprene mounting system, we can make the sliding mounts 0.75 inch to gain more usable compartment width,” he says.
3 This polypropylene body features bolt-in vertical aluminum unistruts, integral formed poly tracking on the rear walls to mount equipment or tool boards, polypropylene shelving trays with job-specific lip heights, as well as aluminum slide-out trays. (Photo courtesy of PolyBilt.)
Hoherchak says, “Bolted or welded unistrut will work. Stainless unistrut must be formed, so it’s less common. KME uses extruded aluminum struts due to the weight. Remember, the unistrut is in compression loading, and there are multiple unistruts per shelf, so the load is shared. State the rating of the shelf and have the builder choose the strength, rating, and type of tightening hardware and brackets required to meet that rating. It is good practice for two struts on each side wall. Usually there is one on half-depth compartments due to space.”
4 To the right of the vertical divider, this rig features three adjustable shelves/trays. The middle is full-through, accommodating a stokes basket, and the lower is a pull-out. The arrows point to two different slide mechanisms presumably designed for a specific pound rating. Seldom seen but efficient is the vertical tool board on the left slide-out tray. (Photo courtesy of KME.)
Bebo adds, “Pierce uses a combination of different techniques to mount unistrut-style track in the body depending on where it is used. The capacity of the shelf should be specified, and let the manufacturer determine the size based on the load requirements needed. Test data should be available from manufacturers to validate the capacity of the shelf and mounting. We have not seen requests for shelves above 500 pounds. If requested, a design would be validated at that time. Pierce does not rate unistrut capacity. Pierce’s system is performance-based and tested to meet the capacity required. We always use a minimum of two unistrut style of tracks. Two is also our standard in half-depth compartments.”
5 This Pierce has a tool board mounted on the rear wall of a half-depth upper compartment. Easily adjustable and removable equipment mounting brackets provided on it and a fully adjustable shelf in front of it allow flexibility down the road in adding or relocating equipment. (Photo courtesy of Pierce.)
6 The arrows point to another method of forming side lips on shelves to provide additional support and a dual mounting point to attach the shelf to the unistrut. Adjustable shelving inside equipment compartments allows access to wiring and light assemblies. (Photo courtesy of Toyne.)
HAT-SECTION REINFORCEMENTS AND LIPS UP OR DOWN
Dean says PolyBilt shelving typically is designed with lips facing up on all four sides. “We can design and integrate floor flanges that greatly increase the floor strength of our Polyprene shelves,” he says.
Watts adds, “Usually there is no advantage to hat sections underneath a shelf.”
Bebo says the majority of Pierce shelves are designed with lips up to provide a 500-pound capacity. “Special designs are developed and may carry a reduced capacity if cross sections are reduced,” he says. “Special design considerations are used when customers have special applications.”
Hoherchak says, “There’s not usually a difference in a shelf’s rating based on its configuration. Hat sections can be used if the shelf is very wide.
WORDS OF WISDOM FOR PURCHASERS
Dean: “Define your shelving load requirements, and PolyBilt will customize the shelving to accommodate the equipment and ensure a long-lasting and trouble-free service life.”
Watts: “Manufacturers that are informed of what is going to be stored on a shelf will make sure the design will hold that load. No two manufacturers do things alike, so it is important to maximize the layout in the body of the chosen manufacturer.”
Bebo: “Pierce finds most times customers do a good job specifying what they want for shelves and trays. As a purchaser sits down and writes a specification, it is OK to be generic defining quantity and finish of a shelf and a slide-out tray initially. Most builders can provide the shelves and trays needed to meet the intent of the equipment stored in a specific body compartment. However, any special requirements should be identified ahead of time if they could have design implications on the truck.”
Shelves and trays will perform to each individual manufacturer’s standard unless the purchaser specifically requires a level of performance. Purchasing specifications should be definitive enough to denote that level while not being overly descriptive to the point of eliminating otherwise qualified bidders.
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.