Auxiliary Engines - N-1 Redundancy Check

Verify electrical load coverage with the largest auxiliary generator out per SOLAS Chapter II-1 redundancy rule.

Auxiliary engineGeneratorN-1SOLAS II-1

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This calculator requires JavaScript to compute its result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, limits

P_{N-1} = (N-1) \cdot P_{each}

P_{N-1} \geq P_{essential} + P_{largest}

SOLAS Chapter II-1 Part D requires the main electrical source to cover essential services with the largest single generator out (the N-1 rule). The remaining generators must provide enough capacity for essential services plus the largest single motor starting transient (e.g. bow thruster start). Margin of 10 to 20 percent above N-1 minimum is typical industry practice.

Symbol legend

SymbolMeaningUnitSource

Number of generators onlineunitsoperations Capacity per generatorkWnameplate Essential ship services loadkWload schedule Largest single transient loadkWload schedule

In short

Verify electrical load coverage with largest generator out per SOLAS II-1.

Learn the theory Marine Auxiliary Engines and Generators