 B-train

In the road transport or trucking industry a B-train (or interlink in South Africa, B-double in Australia and tandem tractor-trailer, tandem rig or double in the United States) consists of two trailers linked together by a fifth wheel, and are up to long.The fifth wheel coupling is located at the rear of the lead, or first trailer and is mounted on a "tail" section commonly located immediately above the lead trailer axles.