Welcome to the final installment of our series where we have been taking an in-depth look at the special rigs on the road today. It’s been a fun journey through doubles, triples, oversized and low-clearance loads.
Today we will close out our look at special rigs by focusing on the final members of the herd. We’ll go from high center-of-gravity vehicles, which include liquid, livestock and reefer trailers, to the final look at any other type of specialized trailer out there today.
First up are livestock trailers. You see these big trailers lumbering down the highway, cows, pigs or other livestock inside. Livestock trailers have a flat door or double-drop frame. They are used exclusively to carry live animals, from cattle to sheep and pigs. Slots or holes in the sides of the trailer allow the animals to breathe. Some trailers will also have side doors, in addition to the rear doors.
Expect trailer length to vary for livestock trailers. They will also have a fixed tandem or spread axle. Trailers carrying smaller animals will often be converted to support multiple decks. This is necessary because live cargo shifts as the vehicle is in motion.
As a professional truck driver hauling live animals, you have to maintain a good speed and always keep the vehicle safely under control. Sudden jerking or swerving could not only cause a safety problem, but it could also harm the animals.
When stopping, make sure to lightly tap the brakes, then gradually apply. Never slam them or apply them too quickly. As with most other special rig types, you must have special training to haul livestock. It’s important to remember that the truck driver is responsible for the safety of the livestock while en route.
Refrigerated trailers – otherwise known as ‘reefers’ – come in two basic mounts, either nose or belly. Nose mounted reefers will have a refrigeration unit mounted on the upper front of the trailer. They have a characteristic bulge, akin to a giant barnacle attached to the front of the trailer. Belly mounts, as the name would imply, have a unit mounted to the bottom of the trailer.
Reefers are almost always van- or box-type trailers. Some might have racks or rails suspended from the roof to accommodate animal carcasses. Due to their unstable nature, handling takes special care.
Other reefer types have separate compartments to keep one set of cargo cool while other cargo is kept frozen. Floors, walls and roofs are all insulated and slotted floors allow for good air or gas circulation.
Reefer trailers will generally have their own engines and power sources. They are generally powered by diesel fuel or liquefied petroleum gas. They also have their own fuel tank.
When you are inspecting a reefer trailer, there are considerations to make. Always check for holes in walls, ceilings, floors ducts or doors and gaskets. Fuel, coolant and refrigerant levels should be checked on a regular basis and proper levels should be maintained to avoid damage to the cargo.
Special Cargo Rigs
Special cargo vehicles are any vehicles designed to haul one type of cargo. Two of the most common types of cargo vehicles are pole trailers and auto transporters.
Pole trailers are designed to specifically carry poles, girders, logs, or any other type of long or narrow freight. They can generally be made longer or shorter depending on the load being carried.
Auto transporters typically hold 6-10 vehicles. Sometimes you can find a rack atop the tractor itself. These trailers are also equipped with ramps at the rear for loading and unloading. They also have very low ground clearance.
Always remember that merely being able to identify a special rig is not the same as operating one. One must have proper training as each vehicle type has its own unique operating characteristics and hazards.
Looking for cargo securement requirements for these and other special cargo vehicles? Check Part 393, Subpart 1 of the FMCSRs for more information. Otherwise, always keep these tips in mind if you are ever behind the wheel of a special rig. Remember, special rigs take special care.