LNG Tanker Case Study- Questions and
Answers| Latest Update
What considerations in deisgn must be undertaken? Deformation absorbed by
contraction of cylinder-shaped support welded to tank at equator
How is the tank physically mounted in the ship based on the previous questioN? Tank
spherical and mounted to ship using cylinder shaped support
What is the reference of sloshing?
--> How is this addressed in LNG tanks? Liquid sloshing around side to side in tanks,
emphasising rocking in ship and tipping it over
--> Free Surface Effect - Sloshing is free surface effect
Solution: Gas tanks are held in balls (spheres have smallest free surface effect) , so there is less
room from sloshing as long as the tank is full or nearly empty
The water tanks are used for carrying ballast (water) on the way back, when the LNG tanker is
relieved of its cargo. The water tanks are located beneath the LNG tanks. The water tanks are
not spherical. (No room to accommodate spherical water tanks in the boat.)
The baffles (dividers) are used to prevent sloshing in the water tanks. Baffles are not used in the
gas tanks, because due to friction heating occurs during the motion and can accidentally turn
LNG into gas.)
What are water tnaks used for?
Do LNG tanks and water tanks hav ehte same shape? explain why No they do not have
the same shape
Answers| Latest Update
What considerations in deisgn must be undertaken? Deformation absorbed by
contraction of cylinder-shaped support welded to tank at equator
How is the tank physically mounted in the ship based on the previous questioN? Tank
spherical and mounted to ship using cylinder shaped support
What is the reference of sloshing?
--> How is this addressed in LNG tanks? Liquid sloshing around side to side in tanks,
emphasising rocking in ship and tipping it over
--> Free Surface Effect - Sloshing is free surface effect
Solution: Gas tanks are held in balls (spheres have smallest free surface effect) , so there is less
room from sloshing as long as the tank is full or nearly empty
The water tanks are used for carrying ballast (water) on the way back, when the LNG tanker is
relieved of its cargo. The water tanks are located beneath the LNG tanks. The water tanks are
not spherical. (No room to accommodate spherical water tanks in the boat.)
The baffles (dividers) are used to prevent sloshing in the water tanks. Baffles are not used in the
gas tanks, because due to friction heating occurs during the motion and can accidentally turn
LNG into gas.)
What are water tnaks used for?
Do LNG tanks and water tanks hav ehte same shape? explain why No they do not have
the same shape
