Pipeline laying operations often have a requirement to simultaneously duel lay pipes of different or equal diameters, which will ensure the lines stay grouped on the seabed or simplify burial operation.

For pipes with different diameters, there is usually a main pipeline with a much smaller service line or umbilical, that requires supporting along the main pipe by means of a clamping arrangement, this is known as Piggybacking.

Alternatively, if the pipes are flexible (and maybe more than 2 in mumber) the lines can be held together at regular intervals using a system of bundles clamps.

Finally for duel pipe laying operations, where a uniform distance between pipes of an equal diameter must be maintanined, spacers are usually deployed.

Bundle clamps are of two main types 'Standard' and 'Flat Pack'. Standard bundle clamps consist of a single moulding designed to accommodate the various lines that are then held in place using a metallic band system. Flat Pack bundle clamps are typically used where the lines are smaller and closer in size and consists of two similar mouldings designed to bolt around the pipelines using corrosion resistant fasteners.

Pipeline spacers are simple blocks designed to suit the pipe diameter and maintain the required spacing. They are installed between the two pipes using a metallic banding system.