Dry Dock Theory

Question 1

What is happening when the water is pumped out of the dock?

Answer 1

• Start of critical period
• Da starts to reduce
• Df will generally increase as v/l pivots at stern
• At critical instant Df=Da
• As water is pumped out Bf is decreasing and Pf is increasing

Question 2

Why is vessel continuously losing stability whilst in dry dock?

Answer 2

• As vessels weight is being transferred from the water to the keel blocks. That weight is acting as a capsizing moment.
• Capsizing moment will eventually exceed righting moment ∴ is important that vessel is flat on blocks and shored up by this point.