How Does a Ship Move

We all wonder How Does a Ship Move in water ?

In this Article I will Discuss How Does a Ship move .

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Let us start,

We all wonder how enormous ships of such a huge mass move in water.

How Does a Ship Move

Do they have some special means fitted to them for the movement ? Or do they have any other non- conventional machineries employed for this?

If these type of questions are coming to your mind , don’t worry about that. All your confusions regarding the movement of ships will get clear.

As other transport the ships also run with the help Engines but yes as they don’t run on roads , there needs to have some other arrangements for them to move in that particular medium i.e water.

And this problem is solved by the use of propeller. In short we can say that the main engine runs the propeller and the propeller creates the necessary thrust which helps the ship to move.


The ship moves because of the reaction force of water on the ship’s Hull. When the propeller rotates the water particles around the blades also rotates because of the force of propeller.

As we know , according to Newton’s third law of motion every action has equal and opposite reaction. So in this case also there is a reaction force, also called the thrust, generated by water on the propeller . But we can’t use this thrust directly for the movement of the ships, we need to transfer this thrust from propeller to the ship’s Hull and this transfer operation of thrust is done by the Thrust block.

The thrust block transfers the thrust to the ship’s Hull and hence the ship moves in the specified direction.

Now you must be thinking how the thrust block helps in this case.

So let’s figure it out.

How does the thrust block transfers the thrust?

Thrust block of the shaft has a thrust collar in the middle of its length and pads on both sides of it i.e for ahead as well as astern movement.

When the propeller moves, it throws water away from the ship which has equal and opposite reaction on the propeller shaft.

Propeller shaft tends to this enter into the engine room. There is a microscopic movement of the entire shaft till the thrust collar hit the forward or backward pads as per the direction of the propeller.

And then the thrust collar transfers this thrust to the ship’s Hull. In this way the thrust get transmitted to the ship and the ship moves forward.