Engine Room Bilge & Oily Water Capacity Tool

Bilge Generation • Holding Capacity • OWS Throughput • 15 ppm Readiness • Sludge Interaction • N-1 Redundancy • Port / Polar Retention • Reception Planning

Engine Room Bilge & Oily Water Capacity Tool

Model engine-room oily bilge water as an inventory-and-treatment problem instead of a single separator rating. Simple mode checks generation, holding-tank endurance and planned OWS capacity. Advanced adds source-by-source bilge and sludge generation, multiple tanks, multiple oily-water separators, 15 ppm alarm/automatic-stop readiness, N-1 capacity, voyage operating legs, shore reception and separated-oil residue into the sludge system.

↑

Capacity screen, not a discharge authorization.Select OWS overboard use only when the vessel has independently confirmed that the planned discharge is permitted and all MARPOL, flag, coastal-State, equipment and operating conditions are satisfied.

GenerationDaily oily bilge inflow

TreatmentOWS effective m³/day

EnduranceTime to planning ceiling

Bilge Holding & Generation

Average oily bilge generationm³/day.

Usable bilge holding capacitym³.

Current bilge holding inventorym³.

Planning horizondays.

Maximum planned fill% of usable holding capacity.

OWS Capacity Basis

OWS rated throughputm³/h.

Operational derate / availability% of rated throughput.

Planned OWS operating timeh/day.

Handling plan

Planning Limits

Maximum planned bilge-tank fill% of usable capacity.

Maximum planned sludge-tank fill% of usable capacity.

N-1 OWS coverage target% of baseline oily-bilge generation.

Separated OWS residue yieldL of separated oil/residue per m³ bilge processed. User-entered planning factor.

Oily Bilge Water Source Register

Use	Source	Generation m³/day	Duty %

Oil Residue / Sludge Source Register

Sludge is kept separate from oily bilge water. OWS-separated oil is added automatically from the entered residue-yield factor.

Use	Source	Generation m³/day	Duty %

Oily Bilge Water Holding Tanks

Use	Available?	Capacity m³	Current fill %	Usable %

Oil Residue / Sludge Tanks

Use	Available?	Capacity m³	Current fill %	Usable %

15 ppm Oily Water Separator Register

A unit contributes overboard-treatment capacity only when it is marked available and its 15 ppm alarm / automatic-stop or recirculation readiness is marked ready.

Use	Available?	Rated flow m³/h	Derate %	Max planned h/day	15 ppm alarm + auto-stop ready?

Voyage / Operating Leg Register

“OWS planned” means the user has independently verified discharge conditions for that leg. Polar mode always sets overboard OWS handling to zero. Shore quantities are removed at the start of the leg, limited by onboard inventory.

Use	Phase	Days	Bilge factor %	Sludge factor %	Handling mode	OWS h/day	Bilge shore reception m³	Sludge shore reception m³

Pollution-Prevention / Record Checks

15 ppm separator approval / readiness checkedSeparator, alarm and automatic stopping/recirculation arrangements are operational. OWS discharge conditions independently verifiedRoute, ship status, local requirements and MARPOL conditions are checked outside this tool. Oil Record Book Part I procedure checkedTransfers, processing and disposal are recorded under the vessel’s approved procedure. Sludge segregated from OWS feedSludge disposal follows approved means and is not routed as ordinary oily bilge-water feed. Reception-facility connection / plan checkedShore disposal capacity and standard discharge connection arrangements are available where relied upon. Detergent / emulsion effects consideredCleaning agents or emulsifiers that can impair separation have been minimized or accounted for. Bilge and sludge tank level indication checkedStarting inventories and available volumes are based on credible tank levels. Polar / local no-discharge restrictions reviewedAny zero-discharge area is represented as retain-onboard / shore-reception capacity.

Regulatory boundary: this tool never decides that an overboard discharge is lawful. MARPOL Annex I conditions, the ship’s approved equipment/certificates, flag-State requirements, coastal/port-State rules and the actual 15 ppm alarm/automatic-stop system control. Sludge is modeled as a separate retention/disposal stream and is not credited as OWS overboard throughput.

Technical basis: MARPOL Annex I defines oily bilge water as water that may be contaminated by oil from machinery-space leakage or maintenance and defines oil residue (sludge) separately. MEPC.107(49) specifies 15 ppm bilge-separator/alarm performance and an automatic stopping device that prevents overboard discharge above 15 ppm. MARPOL regulation 12 requires sludge to be retained and disposed through the standard discharge connection or another approved means rather than being connected into the OWS discharge system. Polar operations have additional zero-discharge requirements. Draft 2026 work on forced evaporation / IBTS is not modeled as an available disposal route here because adoption and ship-specific approval remain separate.

Generated by ShipUniverse.com

By the ShipUniverse Editorial Team — About Us | Contact