Intact Stability for vessels with Timber Loadlines

Question 1

What Criteria must vessels that carry timber comply with?

Answer 1

• IS Code 2.2 Righting Lever
• IS Code 2.3 Secure Wind and Rolling Criteria
• Additional guidance is given in TDC Code and IS Code

Question 2

Why are timber vessels given reduced freeboards?

Answer 2

• Due to additional RB that the TDC offers
• Additional protection against the sea
• Efffective increase in the vessels freeboard (∴ θDEI is later)

Question 3

What is the max GM for a timber vessel and why?

Answer 3

• Initial GM to be no more then 3% of vessels beam
• A large GM would result in rapid and violent motion in heavy seas imposing large sliding and racking forces on the cargo causing high stresses on lashings

Question 4

What is the absorption allowance for TDC?

Answer 4

• Anything less ≤ 2% ignore
• Allow for max 10% additional weight

Question 5

What is the Alternative Criteria for timber vessels?

Answer 5

• Area under curve not <0.08mr, 0-40° or to angle of flooding
• Max GZ ≥ 0.25m
• GM not < 0.1m

Question 6

What percentage of the volume of TDC is considered RB

Answer 6

75% (∴ has a permeability of 0.25)

Question 7

How must the TDC be distributed so that these alternative criteria may be applied

Answer 7

• Cargo to extend longitudinally between superstructures with no gaps.
• The full beam width.
• Min height for stowage of timber is the height of one superstructure
• Max height in winter is 1/3 of the beam
• Max height in summer? BE SAFE!
• Gunwale not more then 4% of breath of ship