Jack-up Offshore Platform Lifting Cylinder

Pushes the ring beam upward by one stroke (2,150 mm), raising the platform. Bore 700 mm provides the massive force required. The cylinder does the heavy lifting — but cannot hold the platform at height by itself (hydraulic lock is not considered safe for long-term load holding).

Inserts a steel pin through the ring beam to mechanically lock the platform at the current height. Once the pin is engaged, the lifting cylinder can safely retract without the platform dropping. The pin carries the platform weight, not the hydraulic pressure.

How many lifting cylinders does a jack-up platform use?

Each leg typically has 2–6 lifting cylinders, depending on the platform size. A 3-leg platform with 4 cylinders per leg uses 12 lifting cylinders. All must be matched for force output and synchronised during jacking.

Why is the bore 700 mm — the largest in the range?

The lifting cylinder must raise the entire platform weight (5,000–25,000 tonnes) distributed across 3–4 legs. At 32 MPa working pressure, a 700 mm bore generates approximately 12,300 KN of thrust per cylinder — the maximum force in the offshore hydraulic cylinder range.

How long does it take to jack up a platform?

Jacking speed is typically 0.3–1.0 metres per minute. Raising a platform 20 metres takes 20–60 minutes depending on the platform size, number of cylinders, and hydraulic flow rate. The process is continuous but step-wise (lift → lock → retract → lift).

What classification approvals are available?

BV, DNV, LR, ABS, CCS. Jack-up platforms are among the most heavily classified offshore structures — every lifting cylinder requires full material traceability, witnessed hydrostatic testing, and dimensional verification.

Can an external displacement sensor be retrofitted?

Yes — the sensor mounting bracket and cable routing can be designed into new cylinders or added to existing installations. The sensor provides position feedback for automated jacking control and is essential for synchronised multi-leg operation.

"We ordered 12 lifting cylinders (bore 650 mm) for a 3-leg jack-up barge. The dimensional consistency across all 12 cylinders was impressive — maximum force variation was under 1.5% across the set. Critical for synchronised jacking."

Eng. A. Al-Sayed — Structural Engineer, Saudi Arabia

"The displacement sensors integrated into the lifting cylinders feed directly into our Siemens jacking control system. Level accuracy across 3 legs is consistently within ±15 mm — well within our ±25 mm tolerance."

K. Vermeer — Automation Lead, Netherlands

"Solid lifting cylinders for our jack-up maintenance vessel. The 700 mm bore cylinders are heavy (each over 5 tonnes) and required careful handling during installation. Performance has been good through 4 jacking cycles so far."

R. Santoso — Marine Superintendent, Indonesia

"Korea Ever-Power provided the complete lifting cylinder set with ABS class documentation. The material certificates and witnessed test reports were accepted by ABS without comment. Very smooth classification process."

Capt. J. Harper — Operations Manager, US Gulf of Mexico

"Replacement lifting cylinders for a 20-year-old jack-up barge. The original manufacturer no longer exists. Korea Ever-Power reverse-engineered from our measurements and delivered cylinders that match the original ring beam interface perfectly."

M. Tran — Chief Engineer, Vietnamese offshore contractor