HomeCalculatorsRequired Subdivision Index R (Cargo)

Required Subdivision Index R (Cargo)

Required Subdivision Index for cargo ships per SOLAS II-1 Reg 6: R = 1 − 128 / (Ls + 152).

Damage stability

Subdivision length Lsm

Required subdivision index R

0.6364 -

Formula, assumptions, and limits

Applies to cargo ships ≥ 100 m under SOLAS II-1 Reg 6.2.3. Attained A must be ≥ R. R rises from ~0.65 at 100 m to ~0.78 at 300 m. Passenger ships use a more complex R formula also dependent on N persons.

Symbol legend

Symbol	Meaning	Unit	Source
	Subdivision length	m	SOLAS II-1 Reg 2
	Required subdivision index	-	result