<Li> Sidelifter semi-trailers have 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 . Also known as a Sideloader . </Li> <Li> Side Bay trailers have a series of roll - up or panel doors down each side . Each door opens into individual compartments . These trailers are most commonly used in the beverage distribution industry . </Li> <Li> Tank chassis or "tanker" trailers are used for hauling liquids such as gasoline and alcohol, or various types of gases . They are similar in principle to intermodal trailers but with a very different frame intended to be attached to a liquid or gas tank, hence the name . Some are designed with a lowered centre of gravity to ensure greater stability . Generally bottom loaded with the ability to recover any waste vapor for safety reasons . </Li> <Li> A "frac" tank trailer has a single and fixed axle, and is typically used during hydraulic fracturing at oil wells or for petrochemical industries . It is shaped like a wedge, and when it is unhitched, its bottom side lies flat on the ground . </Li>

What is the cube of a 53 foot trailer