ISM Code Element 10 · IACS UR Z20 & UR Z7 Rev.29 · 2011 ESP Code (A.1049(27)) · Critical Spares
Planned Maintenance System (PMS), Critical Equipment & Class Survey Preparation Guide
A ship’s Planned Maintenance System (PMS) sits at the centre of ISM Code Element 10, IACS Unified Requirement Z20 (Machinery PMS / CSM), IACS UR Z7 Rev.29 (Hull Classification Surveys), and vetting inspections under SIRE 2.0, RightShip RISQ 3.2, and Port State Control (IMO Res. A.1206(34)).
Complementing our ISM Internal Audit & DPA Guide and Flag & Class Survey Checklist, this guide explains how Chief Engineers and Chief Officers manage running-hour vs calendar schedules, Critical Equipment & Spares (`ISM § 10.3`), dispensations for deferred jobs, and ESP / PSPC structural files.
Updated · Written by SeaReady in our own words. Not affiliated with OCIMF, RightShip, CDI, any MoU or any administration — always check the current official documents.
1. Statutory & Classification Maintenance Frameworks (ISM Element 10, UR Z20 & ESP)
Inspectors evaluate onboard maintenance against four overlapping regulatory frameworks:
| Framework & Standard | Core Interval & Audit Rule | What Surveyors & Vetting Inspectors Check |
|---|---|---|
| ISM Code Element 10.1 & 10.2 (Maintenance of the Ship and Equipment) | Regular inspection intervals; reporting non-conformities; corrective action & records | Applies to all SOLAS ships (Res. A.741(18) & Res. A.1188(33)). Requires the Company to establish procedures ensuring the ship is maintained in conformity with convention rules, class rules, and Company SMS requirements, with documented inspection intervals and root-cause analysis. |
| ISM Code Element 10.3 & 10.4 (Critical Equipment and Technical Systems) | Specific measures for sudden operational failure; regular testing of standby equipment | Requires explicit identification of equipment/systems whose sudden failure may result in hazardous situations (steering gear, emergency generator, main propulsion remote control, emergency fire pump, OWS 15 ppm stop, fixed fire detection/CO₂, GMDSS reserve power) plus regular functional testing of non-continuous standby systems. |
| IACS UR Z20 & UR Z18 (Planned Maintenance Scheme — PMS / CSM & Boiler Surveys) | 5-year CSM cycle (~20%/year); Annual Class PMS audit; UR Z18 boiler survey intervals | Under IACS UR Z20, an approved computerised PMS credits machinery items toward the 5-year Continuous Survey of Machinery (CSM) cycle (requiring ~20% / one-fifth of machinery items to be overhauled or condition-monitored each year) when the Chief Engineer holds a Class PMS authorisation letter and passes an annual class PMS audit. Under IACS UR Z18 & SOLAS II-1/32, steam boilers require 2 external inspections in every 5-year Special Survey period (≤ 36m apart), 2.5-year water-tube/waste-heat internal examinations, and steam safety-valve easing tests. |
| IACS UR Z7 Rev.29 & 2011 ESP Code (IMO Res. A.1049(27) / SOLAS XI-1/2) | Annual (±3m), Intermediate (2nd/3rd annual), Special Renewal (5-yr) & Bottom (≤ 36m) | Governs hull structure, ballast tank coating ratings (GOOD, FAIR, POOR — POOR triggers annual internal examination under ESP Code § 2.3.1), ultrasonic thickness measurements (Substantial Corrosion > 75% of allowable diminution margin), and the onboard ESP Survey Report File (§ 6.2) & Coating Technical File (MSC.215(82)). |
2. Critical Equipment, Standby Systems & Minimum Critical Spares (ISM § 10.3)
Under ISM Code §§ 10.3 and 10.4, every vessel must maintain a controlled list of Critical Equipment and Technical Systems, functionally test standby units that are not in continuous use, and hold a verified Minimum Critical Spares Inventory:
| Critical System Category | Statutory Performance Baseline | Mandatory Functional Tests & PMS Evidence |
|---|---|---|
| Emergency Power & Blackout Recovery (SOLAS II-1/42–44) | Emergency generator auto-start (≤ 45 s), 2 independent starting modes, 18h/12h fuel tank | Weekly load/no-load test, monthly automatic blackout simulation, 3 consecutive start attempts + 3 further starts within 30 minutes (SOLAS II-1/44.2), and remote quick-closing valve test on the emergency generator fuel tank. |
| Steering Gear & Emergency Steering (SOLAS II-1/29–30 & V/26) | 28 s hard-over to hard-over (35° to 30°); pre-departure test ≤ 12 hours; 3-monthly drill | Verify hydraulic oil tank low-level alarms, overload/phase-failure/power-failure alarms (IMO Res. A.1021(26)), rudder angle indicator accuracy, emergency power supply within 45 s (≥ 10,000 GT), and local emergency trick-wheel communication. |
| Fire Pumps, Emergency Fire Pump & Fixed Extinguishing (SOLAS II-2/10 & 14) | Two independent jets; positive suction under light ballast; MSC.1/Circ.1432 intervals | Weekly emergency fire pump run under pressure with isolation valve test, monthly hydrants/hoses/nozzles inspection, annual foam protein/AFFF/fluorine-free lab stability test (MSC.532(107) PFOS ban), and 2-yearly CO₂ cylinder level/weight verification. |
| Main Propulsion, Bridge Control & HP Jacketed Fuel Lines (SOLAS II-1/26–28, 31 & II-2/4.2.2.5.2) | Astern power & bridge transfer (II-1/26–28, 31); > 15 bar HP fuel jacketed pipes & alarm | Under SOLAS II-1/26–28 & 31, verify essential auxiliary redundancy, astern stopping power, and bridge-to-engine-room propulsion control transfer alarms. Under SOLAS II-2/4.2.2.5.2, all external high-pressure fuel delivery lines (> 15 bar) between high-pressure fuel pumps and fuel injectors must be protected by a jacketed piping system draining to a collection tank fitted with a functional high-level audible and visual alarm. |
| MARPOL Critical Environmental Equipment (MARPOL Annex I Reg. 14 & Annex VI) | OWS 15 ppm bilge alarm (MEPC.107(49)), 3-way auto-recirculation valve, ODME & EGCS/CEMS | Verify valid 5-year / IOPP renewal calibration certificate for the 15 ppm bilge alarm, test automatic stopping device without overboard discharge, check sealed overboard valve numbering against the Oil Record Book Part I, and verify critical spare sensor cell / coalescer elements. |
- Running-Hour Counter Reconciliation: Compare main engine, auxiliary generator, air compressor, purifier, and steering gear hour counters on local control panels against the PMS software weekly. Unexplained gaps or frozen counters invalidate `IACS UR Z20` crediting.
- Critical Spares Verification (Box-Open Audit): Physically verify critical spares (main engine cylinder cover/exhaust valve/fuel injector, auxiliary generator AVR/circuit breaker, steering gear hydraulic pump seal kit, OWS 15 ppm sensor cell, fire detection smoke/heat heads, SCBA spare cylinders) against the PMS inventory quantities and shelf-life expiry dates.
- Overdue Jobs & Formal Postponement / Dispensation: Never leave a Critical Equipment job overdue in the PMS without an approved Postponement Request / Risk Assessment signed by the Master, Chief Engineer, and Technical Superintendent / DPA (`ISM § 10.2`), and where a statutory or class condition is affected, a formal Flag Dispensation or Class Condition of Class / Memorandum (`SOLAS I/11(c)`).
3. Pre-Survey & Pre-Vetting PMS Audit Checklist (7-Point Walkaround)
- Zero Overdue Critical Jobs: Run the PMS "Overdue Critical Jobs" filter before port arrival; ensure every completed job includes measured clearances, test pressures, or insulation resistance (`MΩ`) readings rather than one-word `"Done"` entries.
- Cross-Check PMS vs Statutory Log Books: Ensure weekly/monthly LSA/FFA tests (`MSC.1/Circ.1432`), emergency generator load tests, 12-hour steering gear checks (`SOLAS V/26`), and 15 ppm OWS tests carry matching dates and times in both the PMS and the Official / Deck / Engine / Oil Record Books.
- ESP Survey Report File & PSPC Coating Technical File (`SOLAS XI-1/2` & `II-1/3-2`): Confirm that all ballast tank and cargo hold/tank periodic inspection reports signed by the Master/Chief Officer are filed with coating ratings (`GOOD / FAIR / POOR`) matching the ship’s latest Class Survey Status Report.
- Megger (Insulation Resistance) & Thermography Records: File 6-monthly / annual 440V and 220V switchboard feeder insulation resistance logs, harmonic/earth-fault checks, and switchboard infrared thermography reports.
- Lifting Appliances & Loose Gear Register (`SOLAS II-1/3-13` / `MSC.532(107)`): Verify that engine-room overhead cranes, provision cranes, hose-handling cranes, and chain blocks have current annual thorough examination and 5-yearly load test certificates and clear SWL markings.
Track machinery running hours and class survey items offline in the SeaReady Running Hours Tracker, run pre-survey walks in the Flag & Class Survey Guide, verify PSC readiness in the PSC Inspection Checklist, and review Marvel Solutionz’s Spark-Gas Engine Knock & Ignition Diagnostics Guide (opens in a new tab) and Ship Chandling & Technical Stores Requisition Checklist (opens in a new tab).
Questions seafarers ask
What is the difference between routine Planned Maintenance (ISM Element 10.1) and Critical Equipment (ISM Element 10.3)?
Under ISM Code Element 10.1, all shipboard hull, deck, and machinery items must be inspected and maintained at appropriate intervals. Under Element 10.3, the Company SMS must separately designate "Critical Equipment and Technical Systems" whose sudden operational failure would create an immediate hazard to the ship, crew, or environment. Critical equipment jobs cannot be deferred without a formal documented Risk Assessment, temporary mitigating measures, and Designated Person Ashore (DPA) / Technical Superintendent dispensation, and must be backed by a verified Minimum Critical Spares Inventory.
How does a Chief Engineer credit machinery maintenance under IACS UR Z20 (Planned Maintenance Scheme)?
Under IACS Unified Requirement Z20, when a vessel is enrolled in an approved Planned Maintenance Scheme (PMS) with its Classification Society, the Chief Engineer (holding a valid Chief Engineer’s CoC and class PMS authorisation) may carry out open-up or condition-based inspections of qualifying auxiliary machinery items in accordance with the manufacturer’s running-hour schedule. Each report must record running hours, clearances/wear readings, replaced parts, and photographs, and is audited annually by the attending class surveyor to credit Continuous Survey of Machinery (CSM) items.
Why do overdue PMS jobs trigger ISM Code Action Code 30 detentions during Port State Control inspections?
Under IMO Resolution A.1206(34) (Procedures for Port State Control, 2025) Appendix 2, a single minor overdue maintenance job is normally recorded as an equipment deficiency (Code 17), but a pattern of overdue Critical Equipment jobs, uncalibrated running-hour counters, missing critical spares, or jobs marked "completed" in the PMS software when the physical equipment on deck or in the engine room is seized or corroded is objective evidence of a systemic failure of ISM Code Element 10 — justifying an ISM Major Non-Conformity and Action Code 30 detention.
What must be kept in the onboard Coating Technical File (CTF) and ESP Survey Report File?
Under SOLAS regulation II-1/3-2 and IMO Resolution MSC.215(82) (§ 3.4), ships subject to the Performance Standard for Protective Coatings (PSPC) must keep the Coating Technical File (CTF) on board for the life of the ship and log all crew in-service ballast tank coating inspections and maintenance. On bulk carriers and oil tankers ≥ 500 GT subject to the 2011 ESP Code (IMO Resolution A.1049(27), SOLAS XI-1/2), the ship must also keep the complete ESP Survey Report File (§ 6.2: Condition Evaluation Report / Executive Hull Summary, structural survey reports, and ultrasonic thickness measurement reports) and Supporting Documents (§ 6.3) on board.
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Related guides
- ISM internal audit & DPA checklistSOLAS Ch. IX & ISM Code Elements 1–16, DPA, Master’s annual review, 12-month audit window and avoiding PSC Code 30.
- Flag-state & Class survey checklistHSSC windows, IACS UR Z1/Z7/Z10 class surveys and Flag-state ASI preparation.
- LSA & FFA maintenance intervals checklistWeekly, monthly, annual and 5-yearly LSA/FFA maintenance intervals under SOLAS III/20 and MSC.1/Circ.1432.
- PSC action codes (code 30 detention)Code 30 detention vs codes 10, 16 and 17, the Paris MoU tick box, and how a detention is lifted.
- Steering gear & emergency generator checklistSOLAS II-1/29 & V/26 steering gear (28s/60s, 12h tests) and II-1/42–44 emergency generator 45s blackout tests.