Function
Vertical injectors and jetting sleds are used to bury the cable where the sediment can be fluidised (for example sand, soft clays). Vertical injectors are used for simultaneous lay and burial of the cable. Jetting sleds are mostly used for post-lay burial.
What it costs*
The provision of the vertical injector or jetting sled is usually part of the cable installation contract scope.
Who supplies them
The vertical injector or jetting sled is usually provided by the cable installation contractor.
Manufacturers: Miah, Royal IHC and Seatools.
Rental: ETA Subsea Specialists, Global Marine and Modus.
Key facts
Vertical injectors can bury the cable down to 10 m below sea bed level using a high pressure jetting system in soft sediment. They are generally fixed on the side of the vessel. A vertical injector is made up of a header and extension section as well as a burial section, the shoe injector, which contains the jetting nozzles.
Jetting sleds can bury the cable down to 4 m below the sea bed. They are usually equipped with a hydraulic actuation system that ensures the cable is buried at the required depth. An eduction system allows the removal of excess material in the trench once the fluidisation has been carried out. Jetting sleds are deployed using a crane and can therefore be mobilised on a large range of vessels.
What’s in it
- Shoe injector
- High-pressure jetting nozzles
- Cable depressor detector
- Pressure sensors
- Skids
- Positioning system receptor