“Tow” and “Tow” are redirected here. For walking conditions, see the tip. For surfing technique, see Tow Surfing. For the automotive engineering term (homonym), see convergence. For other uses, see Tow (disambiguation).
This article is about the trailer. For towing techniques, see Vehicle recovery § Types of towing. For towed vehicles, see Towing.
The trailer varies greatly in scale and type, on land, water, and air. Here a large ballast tractor pulls a heavy load (here a transformer) using a drawbar
Towing means coupling two or more objects together so that they can be towed by one or more designated power sources. The towing source can be a motorized land vehicle, boat, animal, or person, and the cargo can be anything that can be towed. These can be attached using a chain, rope, bar, hitch, three-point, fifth wheel, linkage, drawbar, built-in platform, or other means to hold objects together while in motion.
Towing can be as simple as a tractor pulling a tree trunk. The most familiar way is the transport of disabled or sick vehicles by a tow truck or “crane”. Other familiar forms are the tractor-trailer combination and cargo or leisure vehicles coupled by ball or pivot tow hooks and trunnions to smaller trucks and cars. At the other extreme are extremely heavy tank recovery vehicles and huge ballast tractors that carry heavy loads of up to millions of pounds.
Necessarily, government and industry standards have been developed for conveyors, lighting, and couplings to ensure the safety and interoperability of towing equipment.
Historically, barges were towed along rivers or canals with ropes pulled by men or draft animals that walked along the towpaths along the banks. Later came the chain boats. Today, tugboats are used to maneuver larger ships and barges. Over thousands of years, the shipping industry has refined towing to become a science.
Airplanes can also tow other airplanes. Gliders for the transport of troops and cargo are towed behind powered aircraft, which is still a popular means of lifting modern pleasure gliders.
Types of trailers
Main article: Trailer (vehicle)
Travel trailers are a familiar type of recreational vehicle
Lowboys carry very heavy loads
Many motor boats fit on a trailer.
This section refers to towing a loading device behind a truck or car.
Most trailers fall into one of three categories:
Small trailers that attach to cars and small trucks (SUVs, minivans, etc.):
The small enclosed trailers are completely covered on four sides and a roof. These types of trailers are generally used to transport livestock as they protect the contents from the elements. People also rent these types of trailers to move boxes, furniture, and other materials.
Boat trailers are specifically used for towing boats. These types of trailers are designed to be easily loaded in and out of the water and are purchased based on the specific type and style of boat they will be carrying. They are open trailers that have a special shape to hold and protect boats, but because of this specialty, they are a unique category.
Recreational vehicles (RVs) are commercial vehicles or trucks that are often equipped with living facilities. While some are self-propelled (integrated truck chassis), many are designed as trailers to be attached to a tow bar. These trailer hitches are common on the back of many cars and trucks, and RV trailers are commonly used for camping trips or road trips. In the UK, caravans are known as caravans.
Trailers designed to be towed in a “large bed” (18 wheel) tractor-trailer configuration, available in many configurations:
Flat or open floor trailers, which are platforms without sides or stakes. This type of trailer works well for hauling large or unconventional items. Some are small enough to be towed behind cars.
Tanker trailers, which are trailers designed to hold liquids such as milk, water, or fuel.
Container trailers are standard intermodal “boxes” that can be equipped with a trolley (wheeled cart) and a front support; therefore they can be used in a standard tractor and trailer combination. Containers are also stacked on ships and used as rail cars.
Containerless articulated truck trailer boxes are also fairly common and work much like the containers, above, but often with the bracket and cart permanently integrated into the box.
Trailers for special applications that may require a specialized vehicle, such as a farm tractor; military truck, tank or personal transport; or an unusually large “big truck”. Non-motorized wagons pulled by a locomotive can also be considered in this category.