Van Bodies
Many details go into the so-called simple box. Here are some of them.
Tom Berg
Equipment Editor
One of the most common truck bodies on the road is the van, more properly called the dry freight van because it's dry freight that usually goes in it. The van is ubiquitous because it can haul a lot of things while protecting cargo from weather and theft. Vans may look simple, but the folks who build them put a lot of thought into them because customers expect to pay as little as possible. And they count on them lasting for many years with little maintenance and few repairs.
A consideration right now is the rising cost of rolled steel, a component in some body types. Steel prices are reportedly up by 15% to 50%. Fortunately, van bodies don't use a lot of steel by weight, so likely won't see a spike in prices.
Aside from price, the van body's size and layout are determined by what you haul and how the cargo is loaded and unloaded. Who you buy from, whether a local body maker or a national organization, also matters. While pondering construction specifications, several categories should spring to mind: Wall design, flooring and the structure under it, door type, accessories like handles, steps and liftgates, and electrical wiring and fixtures. Let's look at some of them.
WALL MATERIALS
Today, body sides and front walls are most often made of aluminum sheeting with aluminum or steel vertical supporting posts - commonly called sheet & post or S&P. Other materials available are steel sheeting on steel posts, and fiberglass-reinforced plastic (FRP) over a plywood core ("fiberglass-reinforced plywood" is a misnomer). Metal sheets come in several gauges and FRP-plywood in various thicknesses to satisfy varying strength requirements and body lengths. There is also a new type of wall made with DuraPlate composite sheets (see sidebar).
Each material has advantages and disadvantages in operations and maintenance. FRP plywood, for example, weighs more but is considered stronger than aluminum, and doesn't need side posts. Moreover, the FRP wall has integral scuff liners. If extra side posts are needed to bolster an aluminum-sheet wall against bulging cargo or to support shelving, then an FRP wall becomes less of a weight consideration and its strength more important. S&P with aluminum sheets is often chosen for its light weight and ease of assembly and repair.
In choosing steel or aluminum, weight and cost are the considerations. Aluminum of course weighs less, but costs more. If steel is the choice, it must be insulated where it contacts with the aluminum sheeting to avoid corrosion through electrolysis. Inside-post or outside-post? The inside-post type presents a smoother exterior wall for better appearance, improved aerodynamics and easier washing. The outside-post type leaves the interior smooth for loading, and usually eliminates the need to fill up the spaces between inside posts with plywood or other liner materials.
Another question is color. Most van sides are pre-painted white before assembly. White is practical because it's highly visible, doesn't show dirt and presents a good base for graphics. Many other pre-painted colors are also available, but the vehicle might be worth less at trade-in time.
ROOFING AND AERODYNAMICS
Sheet aluminum supported by bows is the most common type of van roof construction. But one or more panels of translucent fiberglass are often spec'd to act as skylights. At night, you'll need to illuminate the interior with electric lights. There are many different types, and you'll want to consider them as well as their wiring requirements.
The upper edge at the front of the body is often curved to provide some aerodynamic advantage over square edges, which catch wind. Air drag is a real consumer of engine power and fuel, so smoothing the upper edge makes sense in most cases; it might not if the truck stays in dense urban surroundings where it sits a lot and runs at slow speeds when it is moving. But the next owner might take the truck on the highway, so you could gain a few bucks in resale if the body is set up for it.
Trucks that spend a lot of freeway time definitely can use aerodynamic improvers. Your fuel bill can be cut 5% to 10% by adding roof-mounted or nose-mounted appendages. These can pay for themselves quickly in saved fuel. And they might protect the body in a collision with an overhanging tree branch or roof, though the aero improver might sacrifice itself in the process.
FLOOR SUPPORTS
Forklift loading of cargo is often used today because it's fast. But forklifts themselves are heavy and run on narrow tires. Drivers are not gentle folks, and think nothing of beating up the body. So the floor must hold up under concentrated loads, especially at the rear of the vehicle where the 'lift first bangs aboard. Longitudinal rails under the floors need to be beefed up. These rails rest directly on the truck chassis' main rails, and are either C-channels or I-beams. The I-beam type is stronger, so is the most likely choice for use under forklifts.
The floor material is also a matter for consideration. Flooring is usually apitong hardwood, assembled from many individual pieces. Sometimes less costly pine is used. The wood's thickness will vary according to the service, as will its surface treatment. Polished hardwood is used in household goods vans, for example, while rougher apitong will be found in general commodities vans. Diamond-plate steel and composites are sometimes ordered by users with special needs.
To protect walls and ceilings from forklift damage, many types of wall liners and scuffboards are available. These range from plywood to high-tech plastic sheeting. Generally speaking, the more you pay for the liners or scuffboards, the longer you can expect them to last. The more modern materials also weigh less.
DOORS AND CURTAINS
Sometimes side loading and unloading is required. One or more side doors have to be built into the body, usually at curbside. But which side is curbside? If this is an urban truck running on one-way streets, doors on both sides might be needed.
Or will a "soft-side" body work better? Common in Europe, curtain-siders, as they're also known, have been limited to specialty hauling in North America. There are several kinds now on the market. Most are built on a flatbed chassis, but one curtainside can be applied to a van body, with the other side using standard side construction. The common curtain-sider uses folding fabric sides with a sheet metal roof and standard van-type nose and rear doors. The curtain runs in tracks on the edge of the floor and along the ceiling.
Rear doors can be roll-up (also called "overhead") or swing type. Roll-up rear doors are convenient when many pick up and delivery stops are part of a truck's routine. Swing doors are stronger, cost less and are sufficient when most loading and unloading is done at docks.
Overhead doors consist of horizontal panels hinged together so the door bends as it rolls through the tight-radius curve at the roof. Panels are usually of metal. Overhead doors need strong tracks, tough wheels and other hardware to ensure smooth and long-lasting operation.
Swing doors need quality hardware for durability and reliability. For example, there must be enough hinges to avoid door sag, and strong racking rails and latch mechanisms for tight closure and good security. Extra hinges keep the door square to the body and ensure a tight seal when it's latched. When closed tightly, the doors add rigidity to the body and help it last longer, too.
Swing-door construction is usually "plymetal," with a plywood core covered by aluminum or steel (sometimes stainless steel) sheeting. Plastic or other materials can also cover the core, and the core itself may use materials other than plywood (honeycomb aluminum or foam, for instance) to cut weight or supply insulation.
LIGHTS & ACCESSORIES
Lighting is always a consideration in body building, and let us start with the admonition to plug body wiring into sockets provided on most truck chassis these days. Cutting chassis wiring and splicing into it is risky because it can interrupt circuitry and cause problems among truck components and accessories. Yet many body builders - especially local concerns who cannot or will not train their people to do it right - continue their old, disruptive ways. Don't let them.
For exterior lights, a good general rule is to use the minimum number of lights required by federal standards, but use top quality fixtures and wiring to avoid problems. The clearance lamps at the upper-front corners, especially the one at the right-front, often get bashed by tree branches and other obstructions. So "armored" lamps are in order here. On longer trucks you might include mid-body turn signals, which give extra warning of your drivers' intentions. Red-and-white reflective taping, such as that used on trailers, might also be used on trucks - especially if they run at night.
Extra steps and handles can prevent drivers and helpers from painful slips and falls. Most vans are built without them, but this can be poor economy when it comes time to pay workers' compensation and health insurance premiums. At the very least, a non-slip surface should be incorporated into the upper face of the horizontal rear-impact guard or bumper, if the truck has one.
Lift gates are needed in operations where deliveries and pick ups of heavy commodities are done away from the docks. Installation involve special modifications on the rear door sill and, of course, at attachment points. Special electrical and hydraulic equipment is also needed, and careful attention should be given to placement of operating switches, handles and buttons. These, too, are addressed in industry standards, and lift gate manufacturers are well acquainted with them because they helped truck operators write them.
The basic material for lift gates is steel, making them a heavy appendage. The rear axle sometimes must be closer to the body's rear to shoulder some of then liftgate's weight. Aluminum gates are also available and can cut many pounds off a vehicle's tare weight.
DETAILS, DETAILS!
From the above sampling of the many details involved in spec'ing the common van body, you can see that this is not just a "box." You'll be smart to at least look closely at any manufacturer's "standard" body to make sure it meets your present and future hauling needs, and to alter it to make it a more productive vehicle.
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