HomeCalculatorsAuxiliary Engines - N-1 Redundancy Check

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
Total online capacity
4,500kW
Capacity with N-1
3,000kW
N-1 compliance
Compliant - covers essentials plus transient

Formula, assumptions, and limits

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