A trailer is a vehicle on wheels, attached to a tractor or truck and used for hauling cargo. Trailers come in a wide variety of sizes and types, but the most common is the 53′ single temp swing door reefer (or “reefer” for short). In the trucking industry, the term “trailer” is also used to refer to a vehicle that is configured to transport temperature sensitive goods, such as refrigerated foods or pharmaceuticals. Many carriers operate a mix of both reefer and dry van trailers in their fleets, depending on the cargo they carry and market.
Trailers are often highly condensed versions of the feature film they promote, with a focus on the most dramatic scenes and key characters. Using special effects, music and a limited number of shots, trailers try to create an impression that will draw people into the theater when the feature is released. There are dozens of companies, usually located in Los Angeles and New York City, that specialize in the creation of movie trailers.
Occasionally, some trailers incorporate material that does not appear in the final film. This is called a “special shoot”, and it is a popular way to add suspense to a preview. One of the most famous examples occurred in the 1960s trailer for Alfred Hitchcock’s Psycho. The trailer showed the soft-spoken director giving viewers a tour of the Bates Motel, then throwing back the shower curtain to reveal Vera Miles with a blood-curdling scream. In actuality, Miles was replaced by Janet Leigh in the shower scene in the film.
Other trailers contain special effects that do not occur in the film, such as a shot of a T-800 Terminator being assembled. This is sometimes called a “blooper” or out-take, and it has become an important part of many movie trailers. The film company will sometimes include these scenes in a DVD extras section of the movie or on the official website for the film.
Some trailers also use music that does not appear on the soundtrack of the feature film. This is a common practice because the trailers are typically created before the composer has been hired to write the score.
Another trailer term is Logistics Track or “e-track”, which are slotted aluminum rails that run on both sides of a trailer. The rails are designed to accept logistics straps or load bars, and they may be fitted with plastic pads to protect the cargo. The track is a key safety component of any trailer, and it helps to prevent galvanic corrosion when steel trailer sub-assemblies like upper couplers or crossmembers are connected to aluminum parts like the top rails. Galvanic corrosion occurs when these dissimilar metals are exposed to water or other liquids that have an electric charge, and it can cause rust, structural damage or failure. A specialized process called “galvanizing” can reduce the likelihood of such corrosion.