InterMoor’s subsea services experts provide cost-effective solutions for underwater projects using unconventional installation and intervention vessels.

Heave compensation advantages:

  •  Increase installation vessel pool
  •  Reduce installation time
  •  Reduce rig offline time
  •  Reduce vessel motions to increase weather windows
  •  Reduce motions when landing subsea components
  •  Reduce resonance
  •  Increase ROV manoeuvrability and decrease risk to ROV

Current applicable methods:

  •  Heave compensated landing system
  •  Passive heave compensation systems, suitable for AHV deployment and non-HC cranes

InterMoor’s compensated anchor-handler subsea installation method (CASIM) is an ideal solution for the deployment of subsea hardware. Easily transportable, CASIM requires less expensive vessel support, requires less deck space and demands fewer deck operations. Units are pre-charged at the surface to deliver the needed compensation for the load at depth. Each CASIM unit has a maximum stroke of 10 ft. CASIM can be sized to accommodate up to a 400T load.

Configuration Max load Overall length (retracted) Stroke length
Single 50 tonnes 11.5 ft. 9.8 ft.
Series (2) 50 tonnes 23 ft. 19.6 ft.
Parallel (2) 100 tonnes 11.5 ft. 9.8 ft.
Series parallel (4) 100 tonnes 23 ft. 19.6 ft.

Safe working load (SWL): 60 tonnes

Nominal max static dry load: 60 tonnes

Equipment weight: 20 tonnes

Overall dimensions: 23 ft. x 6 ft. x 7 ft

Stroke: 13 ft

Depth compensation: Included

Interface: ROV panel

Subsea adjustable: Increase/decrease pressure subsea

Damping: High and low setting

Spring rate: Stiff, medium and soft

Lock: Hydraulic lock on main rod


Specifically designed for trees, jumpers, manifolds and other subsea assets.

Heave compensated landing system

InterMoor is licensed to operate Shell’s heave compensated landing system.

The HCLS is designed for installing subsea equipment off the back of an anchor handling vessel (AHV).

  • Subsea equipment can be lowered or recovered through the water column with negligible heave motion
  • ROV manoeuvrability of the subsea package in the horizontal and vertical planes is dramatically increased
  • Dynamic amplification approaches zero due to the system being decoupled from the motions of the vessel
  • Considerable cost savings from using an AHV over chartering a construction vessel at callout rates or utilising rig time
  • Offshore installation time limited only by ROV operational parameters for weather conditions
  • Minimises offline rig time
  • Unsurpassed heave compensation
  • Functional in any metocean environment
  • For package weights from 0 kgs to virtually no maximum weight
  • Subsea package is virtually weightless during land-out, minimising risk of asset damage
  • Maximum ROV manoeuvrability 
  • Project management
  • Detailed engineering
  • Dynamic lowering analysis
  • Field layout design support
  • Operational procedures
  • In-line compensation units or buoy systems
  • Tools, equipment, and installation aids
  • Offshore personnel
  • Dockside services