Marine Main Engine Lubricating Oil Pressure, Bearing Temperature & System Capacity Tool

LO Supply Pressure • Filter ΔP • Oil Temperature • Main / Thrust Bearing Temperature • Bearing Trend • System Oil Inventory • Tank Capacity • Reserve Runway

Marine Main Engine Lubricating Oil Pressure, Bearing Temperature & System Capacity Tool

Screen main-engine lubricating-oil health from the engine inlet to individual bearings and the system-oil inventory. Simple mode checks pressure margin, hottest-bearing temperature and oil reserve runway. Advanced mode adds filter restriction, pump-flow and oil-temperature diagnostics, bearing-by-bearing reference/trend analysis, multi-tank capacity planning and a structured action board for localized versus engine-wide lubrication problems.

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Fast lubrication-system screen: 12 inputs.Enter the actual maker/SMS pressure and bearing-temperature limits for this engine. The demonstration values are not universal limits. Inventory runway is a planning calculation and does not replace the vessel's minimum operating level or alarm system.

PressureSupply margin & pressure trend

BearingsTemperature margin & ΔT

InventoryCapacity, usable reserve & runway

Main Engine LO Snapshot

Engine load% MCR or comparable operating basis.

LO pressure at engine inlet / after filterbar(g).

Maker low-pressure alarm / minimumbar(g), engine-specific.

Same-load healthy/reference LO pressurebar(g).

LO temperature at engine inlet°C.

Hottest bearing temperature°C; use the applicable bearing metal or outlet-oil measurement.

Healthy/reference bearing temperature°C at comparable load and measurement type.

Maker bearing high-temperature alarm°C, engine/sensor-specific.

Total LO system capacitym³ across the inventory being screened.

Current usable system inventorym³.

Minimum operating / retained inventorym³, vessel-specific.

Net LO loss / consumptionlitres/day. Enter 0 if runway is not to be calculated.

Engine / Lubrication Operating Point

Engine load% MCR or equivalent.

Engine speedrpm.

Pressure before LO filterbar(g).

Pressure after filter / engine inletbar(g).

Same-load reference inlet pressurebar(g).

Previous inlet pressurebar(g).

Hours since previous pressure reading

Current LO pump flow (optional)m³/h; set 0 if unavailable.

Reference / design LO flowm³/h; set 0 if not used.

LO temperature at engine inlet°C.

LO temperature after engine / return°C where measured.

Reference LO temperature rise°C inlet-to-return at comparable load.

User-Entered Maker / Fleet Thresholds

These limits are deliberately user-entered because acceptable pressure and bearing temperatures vary by engine design, sensor location and operating condition.

Low-pressure alarmbar(g).

Slowdown pressure (optional)bar(g); 0 disables.

Shutdown pressure (optional)bar(g); 0 disables.

Pressure review margin above low alarm% planning margin.

Filter ΔP review limitbar, enter maker/company value.

Flow reduction review% below reference flow.

LO inlet high-temperature limit°C; enter actual engine-specific alarm/limit.

Oil ΔT deviation review°C above the entered reference temperature rise.

Bearing reference-deviation review°C above same-load bearing reference.

Bearing trend review°C per 100 running hours.

Inventory runway reviewdays to minimum/retained inventory.

Bearing Temperature Register

Mixing bearing-metal and outlet-oil temperatures in one comparison is misleading. Select the measurement type for each row and enter that bearing's own reference and alarm/slowdown limits.

Use	Bearing	Type	Measurement	Current °C	Reference °C	Prior °C	Hours	High alarm °C	Slowdown / trip °C	Sensor

Lubricating-Oil Tank / Inventory Register

Use the register for circulating/system-oil tanks, wet sumps and storage oil that is actually available to the main engine. Minimum retained volume is excluded from usable reserve.

Use	Tank / sump	Role	Capacity m³	Current m³	Minimum retained m³	Available to ME

Inventory Consumption / Loss

Net LO loss / consumptionlitres/day after normal top-up/recovery assumptions.

Planned daily top-uplitres/day from oil not already counted in the tank register.

Lubrication / Bearing Verification Checks

Maker pressure / temperature setpoints verifiedLow pressure, bearing alarm/slowdown and oil-temperature limits are taken from the applicable engine documentation. Readings taken at stable comparable loadPressure, temperature and bearing references represent a comparable operating point. Standby / prelube pump readiness checkedAutomatic changeover/start logic and pump availability are confirmed where applicable. Filter differential / changeover condition checkedRestriction and bypass/changeover status are known before blaming the pump or bearings. LO cooler / thermostatic control checkedHigh inlet/return temperature is evaluated against cooler and temperature-control performance. Tank level, suction and leakage paths checkedSuction strainers, aeration, leaks and circulating-tank level are considered when pressure falls. Oil condition / water contamination reviewedRecent analysis, water-in-oil/contamination evidence and purifier performance are considered. Bearing sensor / trend follow-up plannedAbnormal temperature is verified by trend, redundant measurement or inspection rather than a single unconfirmed channel.

Engineering boundary: this is a condition-screening and capacity-planning tool, not an engine-protection system. Maker alarm, slowdown and shutdown logic, bearing-monitoring system alarms, oil-mist detection, water-in-oil monitoring, vessel SMS and the Chief Engineer's operating decision remain controlling. A rising bearing temperature can become critical even when system LO pressure still appears normal.

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