Wombat's Woes

tdw · #1 (**permalink**) 10-01-2007

So there we where. Complete new standing rig (oh those new rigging screws are soooo purty), rewired the mast, new nav lights, new main sheet assembly, new vang, all tuned up, furler serviced ready to rock and roll. Cast off from the dock, engage forward gear, open throttle, lots of revs but bugger all else.

Couple of the guys at the yard see we ain' goin' nowhere and come out in the work boat and tow us back in. Thank you , Thank you, Thank you.

Tie her back up and start checking. Engine goes vroom vroom, Engage gear, reassuring clunk, shaft is spinning but alas no forward motion.

Shite.

Any thoughts ? I can only presume that somehow I've lost my prop but how ?

Raven is due for a tub but her bottom doesn't look that dirty. I can't believe the prop is so full of crap that it's not doing it's job.

Wombat seriously confused. I'll get a diver down there this week to have a look (water too cold for me I'm afraid).

What a bugger, it was a seriously fine weekend (long weekend to boot) in Sydney this week.

ozsailer · #2 (**permalink**) 10-01-2007

Hello Wombat,
I had a very similar problem on a Tasman 26 I was involved with. Got on the boat one day and she just would not power up over a knot. Same thing motor engaging - revving out but no thrust. Only just got her back on her mooring. Spoke to the local mechanic who quoted things from bent shaft to prop about to fall off. It was the middle of winter but I decided to have a look underneath myself. To my surprise there was a large build up of growth on the prop. I really did not think this would have slowed us down that much but I got a scraper and removed all the growth. This solved the problem and we were motoring back at full power.
Something so simple yet it had a major effect on the boat. Funny thing was the mechanic never mentioned that this may be the problem.
I dont know it this will help but a dive under the boat may save a lot of time and money

Greg H
Lake Macquarie
Aus

TrueBlue · #3 (**permalink**) 10-01-2007

Wombat should gear up in his specially designed scuba outfit and take a look for himself - no need to hire a diver to do so.

sailingdog · #4 (**permalink**) 10-01-2007

TB-

Wombat legs are stumpier and their bodies tend to be wider... so I don't know how well that would work for TDW.

TrueBlue · #5 (**permalink**) 10-01-2007

Always the pragmatist SD . . .

Tartan34C · #6 (**permalink**) 10-01-2007

If the engine over revs you have lost the prop. If you can’t get up to the RPMs you had in the past the prop is overgrown with junk. How fast does the engine turn in gear now?
All the best,
Robert Gainer

robfinora · #7 (**permalink**) 10-01-2007

Check for growth on the prop....same thing happened to me one summer when I let her sit for 4 weeks. At best I was getting 1/2 knot.

Boasun · #8 (**permalink**) 10-01-2007

There are times when it will not be natural growth of sea-weed, mussels and barnacles.
But there could be old fishing net, neighbor's mooring lines, your mooring lines or old lines that an idiot tossed into the harbor or sea because he was to lazy to carry it to the trash bin.

TrueBlue · #9 (**permalink**) 10-01-2007

Even if the propnut is still in place, and something created rotation resistance (such as rope, net, hard obstruction, etc), there is a very remote possibility that the prop key had sheared off from the shaft's keyway - resulting in free spinning.

sailingdog · #10 (**permalink**) 10-01-2007

Quote:

Originally Posted by TrueBlue

Always the pragmatist SD . . .

besides TDW is rather buoyant....so he'd need quite a weight belt to be able to get to the prop's depth.

T34C's point about engine RPMs is a good one, and TB has another good point about the key getting sheared—which would result in over-revving the engine but still have the appearance of a prop attached.