Ships/marine vehicles are used to carrying large amount of goods/passengers. These vehicles required large area/volume ratio of vehicle, so that required magnitude of upward force by water can achieve (according to Archimedes’ principle) or we can say, if we want to carry large total weight, we have to increase size and strength (weight) of ship/marine vehicle also. Whereas, Total weight = self-weight + payload. Efficiency of marine transportation systems can increase if transformation of magnitude of payload into total weight of vehicle can be decrease without actually decreasing it.
There are vast applications that uses Pascal’s law. If we install two cylindrical vessels of smaller and larger diameters vertically on ship. Lower ends of both vessels connected to each other with help of horizontal pipe and upper ends of both vessels have sliding pistons. (Assumed, Pistons will carry weight vertically, there will not component of weight on side of cylinder’s wall). Two vessels and pipe integrated to each other and makes a single system (Pascal law system) and all system filled with incompressible fluid.
Loading distribution is as follows:
Smaller piston and larger piston will carry small and larger magnitude of weight respectively. The pressure intensity will equally distributed in whole system and maximum pressure pipe can sustain equals to its bursting strength.
Total weight does not depend on payload.
Total weight = weight of vehicle + weight of system (Pascal law system).
An example can make the above expression clear:
Tire tube is lying on weight scale, as we fill air inside tube its pressure will dramatically increase as compare to increase in its weight on weight scale; or
If we fill air inside tube, due to increase in pressure, air particles will closely pack to each other and density will increase, so weight scale magnitude reading will increase, because more particles add into same volume.
But when fluid is incompressible the density changes negligible, so weight scale magnitude reading will remain same or minute changes will occur. On the other hand pressure will increase inside the tube.
So if we have tons of weight to carry in ship, we will have Pascal’s based arrangement and ship will not sink into the sea, because payload will not transfer to ship. According to Pascal’s principle the intensity of pressure will distribute in all directions in same magnitude, so pressure intensity will directly bear by pipes longitudinal and circumferential stresses.
Reduction in surface area that touches with water surface for marine vehicles
According to Archimedes, the force exerted by fluid is equals to weight of volume displaced (fluid) by object. So that, in design of ships/objects/marine vehicles there is need of large ratios of surface area to volume.
Please see the attached images.