Do You Need A Gearbox To Operate MJP Waterjets?

In this video, you’ll hear if you need a gearbox to operate MJP Waterjets. Depending on your intended use and engine selection, you may or may not need a gearbox.

In this video, Adam Mills explains why a gearbox is recommended but not mandated.

With the recent supply-chain issues many shipyards have had their projects delayed by 6 months or more from waiting for gearboxes to arrive. While that is a long time to wait, depending on what engines you choose to install you may be able to connect your engine straight to a Marine Jet Power waterjet without a loss of power.

Triple Man Engines using Gearboxes and MJP Waterjets - Sanlorenzo SP110
Sanlorenzo SP110 – Triple MJP Waterjets Using Gearboxes paired to Triple Man Engines

The Benefit Of Using A Gearbox For Your Waterjets

If something were to become lodged in the waterjet, you would use the gearbox to backflush the waterjets. If something does get sucked you would never know because the duplex stainless steel impellers would make it disappear.

For vessels such as landing crafts whose primary mission is to beach itself, we recommend using gearboxes so that the operator has the maximum control in this scenario.

There are a number of engine manufacturers that have been commissioned to power MJP waterjets, and a gearbox facilitates a secure matchup between engine and waterjet.

Sanlorenzo SP110 Using 
MJP waterjets while Operating Gearboxes
Sanlorenzo SP110 – Triple MJP Waterjets Using Gearboxes paired to Triple Man Engines

Why Using A Gearbox May Not Be Necessary

Given the supply chain issues surrounding gearboxes, many manufacturers have considered not using gearboxes on their builds for the following reasons.

No Loss Of Power – when we can match the engine to our impellers properly we don’t get the same losses. This provides more power directly to the waterjet, while Reducing Weight, Cutting Costs, and Removing Lead Time Problems.

The Choice Is Yours

It is up to you to consider what is right for your vessel. If you have questions about selecting the right options for your vessel. Click here to contact our global support team today.


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