Propeller shaft stopping for motorsailer

[Alik]

Interested in details and links on propeller shaft stopper for motorsailer. Need effectve and unexpensive method to prevent propeller shaft rotations when under sail for 27m LOA boat with twin 280 h.p. diesels. Anyone have experience of such system? Also interested in comparison between CPP, feathering or folding props for this case. Thanks in advance.

[FAST FRED]

There are various companies that mfg such shaft locking gear.

The unit "should" index the prop so a 2 blade will always align behind the deadwood , for minimum drag.

Biggest difference is in how the units release.
The cable pulls will frequently have a starter cut out built in , so the engine can not be started with the unit locked.

Others use engine oil pressure to release after engine start up.

The concern is always for a MOB situation where procedure may not be followed.

Folding props that trail blades aft seldome have enough area to do anything but move for a racing rule.

Adjustable pitch props can feather either automatically or with a controll.

These if cont adjustable can assist in motorsailing with a low rpm and a bunch of pitch cranked in.

Install a pyrometer if used to avoid overtemping the engine..

The early props that feather (Hyde and todays Luke) do work well and have the added advantage of having EXcellent power in reverse , as the blade leading edge switches.

Cheapest would be a HD geared marine tranny (Twin Disc or similar) that does not use hyd clutches.

A lump of epoxy in the right spots on the shaft , and a microswitch would allow EZ indexing of your prop. Almost no cost , 'cept selecting a good tranny in advance..

FAST FRED