Jacking systems

We design complete hydraulic jacking systems for jack-up barges, self-elevating platforms and heavy-lift applications, from deriving the load cases and sizing the cylinders through specifying the power unit, control system and class approval. The same capability upgrades existing systems: faster, safer, better-controlled jacking on barges held back by short-stroke or slow, manually-valved arrangements. Our jacking systems suit all heavy-lift applications, and we specialise in the control and performance features below.

Central jacking

Many jack-ups still run manually-operated valves at each leg, with an operator at every corner. We deliver centralised jacking, all legs driven and monitored from a single control point, synchronised across the corners, with electrically-controlled proportional valves and a manual lever backup retained. Moving from independent manual valves to centralised control is a significant safety and level-keeping improvement.

Automated jacking

We build instrumented, semi-automated jacking around position feedback on every axis, linear transducers on the jacking cylinders and LVDTs on the locking pins, so the system sequences pin engage and disengage, keeps the legs level and gives the operator real-time cylinder position, speed and per-leg load in tonnes. It turns a manual jacking operation into a monitored, repeatable one.

Regen system – jack up faster for less installed power

Our regenerative jacking circuit speeds up the light-load strokes without a bigger power unit: on the raise/reset and leg-lift strokes it routes the rod-side return flow back to supplement the bore-side input, increasing cylinder speed. A pressure-sensing control switches automatically between regen and normal modes depending on the load. The benefit is real, in one new-build design the target jacking speed was met with a 180 kW power unit with regen, where the same pumps would have needed 250 kW without it. That means a smaller, cheaper, lower-power HPU, less fuel and lower running cost, for the same performance.

Shock-absorption / suspension system

When a jack-up transitions from floating to jacked-up on location, wave action lifts and drops the hull and the legs can impact the seabed, driving a pressure spike in the jacking cylinders that, if not absorbed fast enough, can bend legs or balloon cylinders. Counterbalance valves alone can’t dissipate these bump loads quickly enough. To address this, we have developed a dedicated shock-absorption system: an accumulator-based, suspension-type arrangement that stores the transition shock-load energy and returns the leg towards its pre-impact position, absorbing the impact rather than transmitting it into the leg structure, alongside fast-acting direct relief for over-pressure protection. The system has been engineered as part of our jacking design package; it is offered as a developed capability for new-build and upgrade jacking scopes.

Preloading control system

Preloading proves each foundation by deliberately over-loading the leg before elevating to working height. We size the jacking system so the leg-preload case governs the design and configure the load-holding and relief settings to hold preload across wave cycles, with per-leg load read out to the operator, so the foundation is proven under control.

Load-holding & safety

Motion control and load-holding are handled at the cylinder by a close-coupled manifold combining counterbalance/load-hold valves with the regen circuit. Our preference for new build is dual counterbalance valves hard-piped to each cylinder, removing reliance on load-holding hoses, with parallel direct-acting relief for shock dissipation, meter-out braking on jack-down, dual-pump and dual-valve redundancy and instrumented locking-pin control. The system holds position and holds the load through a hose or system failure.

Gripping systems & gripper cans

A jacking system is only as good as the grip that holds the leg between strokes. We design and supply the full range of leg-gripping systems, and retrofit them to older jacking systems that have outgrown their original arrangement:

• Pin-and-hole – the proven positive-engagement method, with instrumented working and holding pins under controlled sequencing.
• Air-bladder grippers (DeLong-type) – a continuous-grip system that clamps the leg by inflating against it, spreading load along the leg rather than through discrete pin holes.
• Friction grippers (ILT-type) – continuous friction clamping for smooth, holeless legs, sharing the same gripping principle as our internal lifting tools.
• Jacking cans & gripper cans – we design the structural cans that house and react the jacking and gripping loads into the hull, for new build and conversion.

The same gripping technology runs through our wider tooling, the internal lifting tools for pile handling and our conductor / pile-top extension adapters all use the same controlled-grip engineering.