Semi-Trailer Types

http://en.wikipedia.org/wiki/Semi-trailer

Different types of semi-trailers are designed to haul different cargoes.

Common widths are 8 feet (2.44 m), and 2.6 metres (8 ft 6.4 in).

Box
The most common type of trailer. Also called a van trailer.
Standard lengths in North America are 28 ft 0 in (8.53 m), 32 ft 0 in (9.75 m), 34 ft 0 in (10.36 m), 36 ft 0 in (10.97 m), 40 ft 0 in (12.19 m), 45 ft 0 in (13.72 m), 48 ft 0 in (14.63 m) and 53 ft 0 in (16.15 m).

Bus
A bus bodied trailer hitched to a tractor unit to form a trailer bus, a simple alternative to building a rigid bus.

Car-carrying trailer
Carries multiple cars; usually new cars from the manufacturer. In the U.S., car carriers often carry used vehicles, as well.

Curtain sider
A curtain sider is similar to a box trailer except that the sides are movable curtains made of reinforced fabric coated with a waterproof coating. The purpose of a curtain sider is to allow the security and weather resistance of a box trailer with the ease of loading of a flatbed.

Drop-deck trailer
A drop-deck trailer is a trailer on which the floor drops down a level once clear of the tractor unit; the most common types of drop-deck trailer are flatbeds and curtain siders.

Double decker
Double deckers or deckers are trailers with either a fixed, hinged or moveable second floor to enable them to carry more palletised goods. In general a double decker can carry 40 pallets, as opposed to 26 for a standard trailer. Double deck trailers are generally a stepped box or curtain siders, with box trailers having either a fixed or movable (floating) deck, and curtain sides having either a fixed or hinged second deck; this hinged second deck generally swings into a position down the length of the trailer, and can be divided into 2 or 3 sections to allow greater load flexibility.

Dry Bulk
Resembles a big tanker, but is used for sugar, flour, and other dry powder materials.

Flatbed
Consists of just a load floor and removable side rails and a bulkhead in front to protect the tractor in the event of a load shift. Can haul almost anything that can be stacked on and strapped down.

Lowboy
Type of flatbed in which the load floor is as close to the ground as possible. Most commonly used to haul heavy equipment, cranes, bulldozers, etc.

Reefer – see Refrigerator truck
Box trailer with a heating/cooling unit (reefer) attached. Used for hauling produce, ice cream, etc.

Sidelifter
Semi-trailer with hydraulic cranes mounted at both ends of the chassis allowing for the loading and unloading of shipping containers without the need of a forklift or other container handling equipment.

Tanker – see Tank truck
Used for hauling liquids such as gasoline, milk, orange juice, and alcohol.

Frac
A type of tank trailer with a single and fixed axle, typically used during hydraulic fracturing at oil wells.