Tonnes Per Centimetre immersion (TPC)
Abbreviation: TPC
The number of tonnes of weight that must be added or removed to change the ship's mean draft by 1 cm.
Regulatory detail & full definition
Tonnes Per Centimetre immersion is a ship stability + loading parameter — the tonnes of weight required to change mean draft by 1 cm at a given draft. TPC is tabulated in the ship's stability booklet against draft. Chief Officer uses TPC for cargo + ballast + bunkers planning + draft-survey cargo-quantity determination. TPC changes with waterplane area; larger for beamy ships, smaller when the hull is fine.
Authoritative source: IMO — Load Lines ↗
Source: Ship Stability for Masters + Mates
High confidence
Editorial confidence: how we grade.