Dry Dock Preparation Checklist for Ship Managers

A well-managed dry docking begins months before the vessel enters the yard. For ship managers and marine superintendents, the objective is not simply to complete statutory surveys. The docking period must convert limited yard time into reliable repairs, verified machinery condition and predictable vessel performance after departure.

This dry dock preparation checklist covers technical inspections, repair specifications, spare parts procurement, contractor coordination and testing. Early preparation is particularly important for long-lead marine spares and equipment that may otherwise delay critical-path jobs.

1. Build the Dry Dock Work Scope Early

Start with the previous docking report, class recommendations, statutory survey status, planned maintenance system records, defect history, machinery running hours and reports from the chief engineer. Temporary repairs and recurring defects should receive particular attention.

Divide the specification into hull, deck, engine, electrical, automation, safety and statutory work. Each job should define the equipment identity, observed condition, required work, measurements or tolerances, materials, acceptance criteria and responsibility for supplying parts.

Confirm Equipment Identification

Incorrect identification is a common procurement problem. Before requesting quotations, record maker, model, serial number, drawing or part number, nameplate data and required quantity. Photographs of the nameplate and existing component can help suppliers verify compatibility.

2. Inspect Underwater and Hull-Related Systems

Prepare a detailed scope for hull cleaning, coating, sea chests, gratings, draft marks, sacrificial anodes and underwater fittings. Review coating history and expected surface preparation requirements before tendering.

Include inspections and servicing for propeller, rope guard, stern tube seals, rudder, rudder clearances and anchors where applicable. For controllable-pitch propellers and thrusters, review seal leakage, hydraulic performance and maker maintenance recommendations.

Plan Sea Valve Overhaul Carefully

List every sea inlet, overboard and ship-side valve scheduled for inspection. Verify sizes, pressure ratings, flange standards, actuator arrangements and materials. Procure anticipated consumables such as packing, gaskets, O-rings, seals, studs and valve internals before docking. Corroded fasteners and damaged sealing surfaces can expand an apparently routine overhaul once dismantling begins.

3. Review Main and Auxiliary Machinery

The engine department should identify maintenance that benefits from yard facilities or shore support. Typical candidates include main engine components, auxiliary engines, turbochargers, heat exchangers, pumps, air compressors, purifiers, boilers and piping systems.

Use operating evidence rather than assumptions. Review exhaust temperatures, lubricating oil consumption, cooling-water trends, vibration, leakage, bearing temperatures and recent alarms. Abnormal trends should be investigated before docking so the required spares and specialist services can be arranged.

For pumps, inspect mechanical seals, bearings, shafts, sleeves and impellers. For heat exchangers, consider plate or tube condition, gasket availability and evidence of cross-contamination. For compressors, review valve condition, piston rings, oil carryover, cooling and safety devices.

4. Check Electrical, Automation and Safety Systems

Dry docking is an opportunity to address electrical and automation defects that are difficult to manage during normal operation. Review generators, motors, switchboards, emergency power, insulation resistance records, alarm systems, sensors and critical control equipment.

Confirm planned testing of emergency generator operation, blackout recovery and essential alarms where relevant to the vessel’s survey scope. Fire detection, fixed firefighting installations, lifeboats, davits and other safety equipment should be coordinated with approved service providers when certification or specialist work is required.

5. Create a Critical Spare Parts Plan

A dry dock preparation checklist should connect every major work item to its material requirement. Waiting until equipment is dismantled before sourcing predictable consumables creates unnecessary schedule risk.

Separate materials into confirmed requirements and contingency spares. Typical preparation may include bearings, seals, O-rings, gaskets, valve parts, pump components, filters, electrical components, sensors, fasteners and machinery overhaul kits. Confirm whether parts are genuine, OEM-compatible or alternative supply according to technical and commercial requirements.

Reduce Procurement Errors

Purchasing teams should request technical confirmation rather than comparing price alone. A lower-cost component has little value if its material, dimensions or interface do not match the installed equipment. Send clear equipment data and request dimensional or technical verification where part-number certainty is limited.

6. Coordinate Yard, Contractors and Vessel Staff

Before arrival, identify which jobs will be performed by the shipyard, vessel crew, manufacturer’s technicians and independent contractors. Establish access requirements, lifting arrangements, permits, isolation responsibilities and testing procedures.

Mark critical-path activities such as docking inspections, tail-shaft-related work, steel renewal, coating and major machinery repairs. Daily progress should be checked against the docking schedule. When additional defects are discovered, document the finding, technical recommendation, cost impact and schedule impact before authorizing substantial extra work whenever circumstances permit.

7. Control Inspection and Testing After Repairs

Completion of physical work is not the same as technical acceptance. Establish inspection points before equipment is closed or returned to service. Record clearances, pressure tests, alignment readings and other relevant measurements.

Following overhaul, check for leakage, abnormal vibration, temperature, pressure and noise. Test alarms, trips and remote controls associated with repaired systems. Retain service reports, measurement records, certificates and photographs for the vessel’s technical file.

8. Prepare for Docking Completion and Sea Trials

Before departure, reconcile outstanding jobs and confirm that temporary blanks, isolations and protective arrangements have been removed or correctly restored. Verify valve line-ups and confirm that equipment opened during docking is operational.

Sea trials or operational tests should focus on systems affected by docking work. Monitor propulsion, steering, machinery temperatures, pressures, vibration and alarms. Any unresolved item should have a clearly assigned responsibility and completion deadline.

How UNICO Vietnam Supports Dry Dock Preparation

Effective dry dock planning depends on timely technical sourcing as much as accurate inspection. UNICO Vietnam supports shipowners, ship managers, marine superintendents, chief engineers and purchasing teams with marine spare parts, marine equipment, ship chandler services, ship repair support and technical supply assistance.

For faster RFQ handling, provide vessel name, equipment maker and model, serial number, part number where available, quantity, photographs and required delivery location and date. Early enquiries allow more time for technical verification and sourcing alternatives before the vessel reaches the yard.

Planning an upcoming dry docking? Contact UNICO Vietnam for marine spare parts and technical supply support. Website: unicovietnam.com | Email: sales@unicovietnam.com | WhatsApp/Zalo: +84 93 662 8883. UNICO Vietnam is located at No. 58/384 Lach Tray Street, Gia Vien Ward, Hai Phong City, Vietnam.