Twin Rig Trawling is used by demersal trawlers as a modern variation and expansion of the single demersal trawl. Generally speaking, twin rig gear operates with a lower headline height, so is best suited for species which stay close to or on the seabed. In Scotland, twin rig gear is used to target species such as nephrops, flat fish and monkfish.

The gear is rigged in a similar way to a single demersal trawl, in that trawl doors are used to provide the spread on the outer wings of the pair of nets. The main difference is use of a central wire from the boat to a large weight (the clump) located on shorter bridles between the two nets. This weight is often fitted with rollers or wheels to prevent unnecessary digging in on the seabed, and to help reduce drag.        

a. Trawl door

b. Central warp

c. Clump

d. Bridles