Power, control & automation
Line tensioners – passive heave compensation, reeved to suit
Self-contained passive heave compensators that hold steady line tension as the vessel moves, reeved inline or at the dead end, single or multiple fall and configured for drilling, deployment and subsea duties.
A line tensioner is a passive heave compensator: it keeps the tension in a wire, umbilical or hose close to constant as the vessel heaves, protecting the line and the load below without any external power or active control. We design and supply line tensioners across a wide range of duties, and because we engineer the hydraulic and gas circuit, the reeving and the protection together, the unit behaves predictably across its whole stroke rather than only at one design point.
How it’s configured
- Reeved inline or at the dead end – fitted into the running line, or at the dead end of the wire, to suit the rig layout and the equipment being compensated.
- Single or multiple fall – reeved at the ratio that gives the heave stroke and line travel the operation needs from a compact cylinder.
- Air-over-oil with media separators, or bladder accumulators – a gas spring acting through oil, with media separators or bladder accumulators keeping gas and oil cleanly separated for stable, repeatable tension; a low-pressure accumulator on the low-pressure side completes the circuit.
- Low-friction for drilling – built for low breakout and running friction so tension stays steady at the low motions that matter in heave-compensated drilling, where stick-slip would otherwise feed into the string.
- Vertical or horizontal arrangement – packaged to fit the deck or the structure, vertical or horizontal, mobile and removable between vessels where required.
- Harsh-environment and subsea rated – specified for exposed deck duty or for subsea deployment as the application demands.
Protection built in
- Load-loss protection – a load-loss / anti-recoil protection valve prevents uncontrolled recoil if the load is suddenly lost, protecting the equipment and the people around it.
- Overload protection relief – relieves over-tension events so the line and the compensator are not over-stressed.
- Tension setting and lock-off – local tension-setting valve to dial the holding tension, with a lock-off function where the duty needs the compensator isolated.
- Instrumented where required – a load-sensing sheave in the reeving gives line-tension readout and feeds monitoring and the safety chain, the same way our overload protection systems do on active equipment.
Where we’ve applied it
Line tensioners are long-standing MintMech work. We have designed and supplied them for heave-compensated geotechnical drilling, where low friction and predictable tension protect the drill string and for seabed frame and subsea equipment deployment, where the tensioner holds the lift steady through the splash zone and on the seabed. We also upgrade and repair existing units: re-engineering bought-in compensators that don’t perform, correcting friction, sealing and protection so they hold tension as intended. Whether you need a new unit, a multiple-fall deployment compensator or a fix for one that isn’t working. We cover design through supply and commissioning under single-party accountability.
| Parameter | Typical scope |
|---|---|
| Type | Passive heave compensator (gas-over-oil), no external power required |
| Reeving | Inline or dead-end · single or multiple fall |
| Gas / oil circuit | Air-over-oil with media separators, or bladder accumulators; LP accumulator on LP side |
| Line | Wire rope or umbilical (swappable sheave); load pin in final sheave |
| Protection | Load-loss / anti-recoil valve · overload relief · tension-set · lock-off |
| Friction | Low-friction build for drilling duties |
| Rating / arrangement | Harsh-environment and subsea options · vertical or horizontal · mobile / multi-vessel |
| Availability | Supply or rental; new-build, upgrade or repair of existing units |