ARCHIVE Seadog Owners Association Forum

twotails

Administrator

Registered: Thu 20th Nov 2014

Posts: 271

Prop' Shaft

Hi John,
I think you are just trying to get us all worried :-)
As far as I know it is not normal for any inboard engine to have a 'sheer' arrangement.
Fouling the prop is a good way to test your engine mountings, if they ain't up to it then it will jump out!
Seriously though I wouldn't want to have the propshaft giving up too easily, need top give the rope cutter a chance to chomp through whatever is threatening to stop the forward motion.
On an outboard it is different, it is quite an easy matter to remove the obstruction and replace the sheer pin.
all the best
Graham

SeaDog Name (if owner or crew) Dougal
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Eric Richardson
Feb 20, 2009 - 11:29AM
Re: Prop' Shaft

Hi John

I like Grahams comments, No there is no shear device incorporated in the system, the only point that could slip would be the clutch but as the Borg Warner box is designed for much higher horse power than our engines develps it does not slip but stops the engine. It is rare to hit something with no give, ropes and nets always wrap and whilst it is a quick stop it is rare to cause damage. The worst I have had was a chain from a stern mooring in Tidemill Marina on the River Deben fortunately I was only on low revs but apart from a bit of damage to the tips of the prop blades nothing else suffered (apart from my nerves)
Eric