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[Norman Castle]

When viewed from astern, looking forward, which way should my prop shaft rotate when going ahead?  And do I need a right-hand or a left-hand prop for that?

[merseyferry]

hi hope this helps ive just googled it , i dont know much  about props.... my mistake thats a double

[inertia]

Norman
It helps if you fit a left-hand prop - that is where the prop rotates anticlockwise when viewed from the stern, going forwards. This has the effect of tightening the prop onto the shaft, whereas the opposite rotation can (and often has) result in the prop unscrewing and being lost if it's not doubly secured with a lock-nut and thread-locking compound.
DM

[TailUK]

Always default to a left handed single prop. A LH prop will have a tendency to "self tighten" when going forward.  It should be locked on really well nevertheless as it will want to unscrew when going backwards.  It should rotate anti-clockwise as viewed from the stern of the model.

[Martin (Admin)]

Yep, 'standard' for model boats is  Left hand Prop,  Anticlockwise.

[BarryM]

On the other hand, full-size European practice is usually to fit RH, i.e. clockwise, rotation screws on single-screw vessels. I've always followed that lead, used 'threadlok' and a locking nut and never lost a screw.

Barry M

[dougal99]

So there you have it, on the one hand Left and on the other Right    I've used both and never had a problem with losing a prop. I've only ever used a lock nut, however go with what you're comfortable with.

[Norman Castle]

Thanks gents.  Gosh, aeroplane propellors are much easier to get your head round!

[TailUK]

Thanks gents.  Gosh, aeroplane propellors are much easier to get your head round!

You could always build an Airboat.

[Brian60]

hi hope this helps ive just googled it , i dont know much  about props.... my mistake thats a double

This diagram is both correct and incorrect from what I have read in the past Incorrect on most twin prop ships they turn the opposite way to make the stern squat down under power.

However it is correct for ships with low freeboard at the stern like all anchor handling or offshore craft and tugs. They set up like that to lift the stern when under power, otherwise if it squats you get even more water sloshing over the workdeck.

[CGAux26]

If the majority of your head-in docking is on the starboard side of the boat, a left hand prop, going in reverse helps pull the stern into the dock. Port side docking, right hand prop.  This is due to "prop walk," where the bottom blade of the prop pushes water to the side.  Think of it as a tire rolling along on the road.


And as others have said above, tighten the prop as tight against the locknut as you can, then tighten it some more.  When you suddenly go from forward to reverse with a left hand prop, that's when it will back off if it can.