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Pump-jet facts for kids

Kids Encyclopedia Facts

A pump-jet (also called a water jet) is a special system used on boats and ships. It helps them move through the water by shooting out a powerful stream of water. Think of it like a super-strong water gun pushing the boat forward!

Pump jet
Typical 'jet ski' pump jet

How Pump-Jets Work

Instead of using a regular propeller that spins openly in the water, a pump-jet pulls water into a special pump inside the boat. This pump then pushes the water out very fast through a nozzle at the back. This strong jet of water creates a force that moves the boat forward.

There are two main ways pump-jets can be built. One way uses a propeller that is enclosed inside a tube, like a tunnel. The other way uses a type of pump called a centrifugal pump, which spins water around very quickly before pushing it out.

Why Use a Pump-Jet?

Pump-jets have some cool benefits, especially for boats that need to go really fast. Here are a few reasons why they are used:

  • Speed: They are great for high-speed boats because they can push a lot of water very quickly.
  • Safety: Since the moving parts are inside the boat, there's less risk of people or marine animals getting hurt by a spinning propeller.
  • Shallow Water: Boats with pump-jets can often operate in shallower water because there's no propeller hanging down below the hull.
  • Maneuverability: It's easier to steer and control boats with pump-jets, especially when turning or moving sideways.

Where Are Pump-Jets Used?

You can find pump-jets on many different types of boats. They are very common on:

  • Personal watercraft: Like jet skis, which use pump-jets to zip across the water.
  • High-speed ferries: These large boats carry passengers and cars quickly across water.
  • Military ships: Some fast patrol boats and other naval vessels use pump-jets for speed and agility.
  • Recreational boats: Some smaller pleasure boats also use them for fun and speed.

Images for kids

  • Pump-jet on NatchanWorld 02

    A view of pump-jets operating

  • Waterjet on HSS Discovery

    Two of four KaMeWa waterjets on the high-speed ferry Discovery

  • Ship's Waterjet system (cut view) NT

    This image illustrates the workings of a reversing bucket. 1: Forward thrust, reversing bucket disengaged 2: Reverse thrust, reversing bucket pushes the thrust flow backwards

See also

Kids robot.svg In Spanish: Hidrojet para niños

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Pump-jet Facts for Kids. Kiddle Encyclopedia.