# Staility – I : Chapter 2

1. ###### Find the thrust exprienced by a flat keel plate 10m x 2m when the draft is 8m in SW.

Solution :  Area of the flat keel plate = (10 x 2)
= 20m2
Pressure = (depth x density)
=    (8 x 1.025)
=  8.2t /m2
Thrust = (pressure x area)
= 8.2 x 20 =164 t .

1. ###### A box-shaped vessel 150m x20m x 12m is floating in a dock of RD 1.010 at an even keel draft of 10m. Find the total water pressure experienced by the hull.

Solution: The total water pressure exerted on the hull to the water =  (Thrust of keel plate which acting   horizontally + Thrust of forward and aft  which act vertically +Thrust of  port and stbd side which act vertically)
Thrust of Keel plate = (pressure x area)
Pressure = (depth x density)
=10 x1.010 t/m2

Area = 150m x 20m = 3000m2
Thrust =(10 x1.010 x 3000) = 30, 300 t

Thrust of forward and Aft =(pressure x area)

Pressure = depth x density
=( 5 x1.010)t/m2

Area =L X B
=(20 x10)
= 200m2

Thrust = (P x A)
= (5×1.010 x200)
= 1010t

Thrust acting both forward and aft = (1010 x2)
= 2020 t

Thrust of port and stbd  side = (pressure x area)

Pressure  =( depth x density)
=( 5×1.010)

Area = (L X B)
= 150m x 10 = 1500m2

Thrust = ( P X A )
= 5 x 1.010 x1500
= 7575 t

Thrust acting on Both sides = 7575 x 2
=15150 t

Hence , Total pressure on the hull = (30300 +2020 + 15150)
=47,470 tonnes. • rasel says: