Overview
ISO 4864:2023 - Ships and marine technology - Jacking system appliances on self-elevating unit - General requirements defines general design, testing and marking requirements for jacking systems used on self-elevating units (jack‑up rigs and similar marine platforms). The standard focuses on the two common types of jacking systems: rack-and-pinion and hydraulic yoke-and-pin, and covers acceptance tests, nameplate information, and packing, transport and storage provisions.
Key topics and technical requirements
- Scope and terminology
- Defines terms such as jacking system, hull jacking speed, leg jacking speed, pre‑load, normal holding and storm holding conditions.
- Design and safety
- Requires a failure mode and effects analysis (FMEA) so single-component failure will not compromise hull safety.
- Systems must maintain leg elevation in the event of loss of electrical, hydraulic or pneumatic power.
- Monitors, alarms and control devices are required (incl. inclination indication, hydraulic pressure, oil level, motor status, overload alarms).
- Remote and local controls with two‑way communication and conspicuously marked emergency cut‑out switches are mandatory.
- Strength and safety factors
- Calibrated safety factors for main structures are specified (e.g., axial/bending: static 1.67, combined 1.25; shear: static 2.50, combined 1.88; equivalent and yield values provided).
- Rack-and-pinion specifics
- Fail‑safe brakes that engage on power loss, brake sizing relative to pre‑load/storm conditions, pinion tooth safety factors and prototype testing (pinion test load requirement).
- Hydraulic yoke-and-pin specifics
- Locking/holding mechanisms sized to carry specified loads with the safety factors required by the standard.
- Hydraulic power units to have redundancy (at least two separate oil pumps).
- Acceptance tests (factory and post‑shipment)
- Includes hydraulic power unit tests (pressure tests at ≥1.5× design pressure, rated flow checks, valve calibration, sensor and alarm checks, emergency handling demonstrations).
- Electrical control unit testing and functional tests such as security test, leg jacking test, pre‑load test, hull jacking test, pulling leg test and full‑stroke jacking test.
- Identification and logistics
- Requirements for nameplate information and for packing, transport and storage.
Applications and who uses this standard
- Intended for: naval architects, marine equipment designers, jacking system manufacturers, rig owners/operators, shipyards, classification societies and inspectors.
- Practical use:
- Design and verification of jacking systems on jack‑up rigs and self‑elevating units.
- Factory acceptance testing and on‑site commissioning protocols.
- Contractual and regulatory compliance for equipment supply, transport and storage.
Related standards
- ISO 3828 - Shipbuilding and marine structures: deck machinery vocabulary and symbols (referenced by ISO 4864).
- Other marine and classification society rules may apply in conjunction with ISO 4864:2023 for specific projects.
Keywords: ISO 4864:2023, jacking system appliances, self-elevating unit, rack and pinion, hydraulic yoke and pin, acceptance tests, marine technology, ships.
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