Page 198 - statbility for masters and mates

186 Ship Stability for Masters and Mates
Let P1 thrust on the SW side, and P2 ; P1 P1
P1 ; P2 P2
P2 Resultant thrust
thrust on the FW side Pressure on the SW side rSW A h1
1:025 15 8 82
492 tonnes
Pressure on the FW side rFW A h2
1:000 15 9 92
607:5 tonnes
P2 P1
607:5 492
Ans. Resultant thrust 115.5 tonnes on the FW side
Example 3
Find the pressure and total thrust on two deep tank lids, each 4m 2.5m, resting on coamings 30 cm high, when the tank is ®lled with salt water to a head of 9.3 m above the crown of the tank.
Fig. 18.3
Pressure at A Pressure at B (see Figure 18.3) w A h
1:025 1:0 m2 9:0 Pressure on lids 9:225 tonnes per sq m
Total thrust 2 thrust on one lid 2 (P A)
2 9:225 4 2:5 tonnes Total thrust 184:5 tonnes
Ans. Pressure 9:225 tonnes per sq m. Total thrust 184:5 tonnes.