-
Ahoy and Welcome to the New SSS Forums!!
As you can see, we have migrated our old forums to new software. All your old posts, threads, attachments, and messages should be here. If you see anything out of place or have any questions, please scroll to the very bottom of the page and click "Contact Us" and leave a note with as much detail as possible.
You should be able to login with your old credentials. If you have any issues, try resetting your password before clicking the Contact Us link.
Cheers - Bryan
Lock and Seal shaft/prop
- Thread starter saildutch
- Start date
I put two small vice grips on the shaft - one for each direction and braced them on opposite sides of the bilge. I also drilled two holes behind my shift in the cockpit coaming and wire tied the shift to the side of the cockpit. About day four I got worried that a sheet would snag the shift and move it into gear and I'd start the engine to charge the batteries and despite the vice grips and the wire tie I'd still break the seal so I cut a slot in a tupperware container and taped it over the shift so that a sheet would slide over it.
I've heard that the prop shaft seal was designed by the originators of the SHTP to provide hours of entertainment for the racers. In '06 the race committee even gave each racer a big roll of gorilla tape for this and other mad thoughts that pop up.
Bill Merrick
I've heard that the prop shaft seal was designed by the originators of the SHTP to provide hours of entertainment for the racers. In '06 the race committee even gave each racer a big roll of gorilla tape for this and other mad thoughts that pop up.
Bill Merrick
I don't know anything about saildrives, so I can't be of help. But I can ask a related question! I've noticed that when I run my engine in neutral while under way, the prop and shaft revolve. Is this normal for marine diesels? (Mine is a BMW M-7.) If so, how would you seal it for the SHTP?
- Tom Kirschbaum, Feral
- Tom Kirschbaum, Feral
The shaft should not revolve in neutral. Either 1) the gear shift is out of adjustment. 2) the prop hasn't folded closed because the engine was not momentarily put in reverse after shutting down. Or 3) This little eggbeater of an engine shakes so much at low revs that it results in the shaft slowly revolving.
For 1) disconnect the shift cable from the gear shift lever on the engine, and see if you can stop the shaft spinning by slightly moving the lever fore/aft. For 2) after stopping engine, put in gear in reverse. For 3) if the shaft is slowly revolving, grasp with your hand and see if you can stop it. If so, vice grips locking, as suggested by Bill, will do the trick.
~sleddog
Critter
Desert Ratfox
I sealed most of the shafts for the '04 Transpac. I don't recall whether I did any Saildrives, but the plan would have been to wire the shift lever - not the external control in the cockpit, but the doohickey on the Saildrive itself - so that it couldn't move without breaking the wire.
Max
Max
dilemma
Thanks for the feedback. The problem is that the folding prop might be turning when in neutral. So typically (recommended by manufacturer) the saildrive is set in reverse during sailing, except when one is charging the batteries.
Maybe I can leave it in neutral and rubber-band the prop itself or put something between the prop and saildrive shaft that prevents the prop from turning but will pop out when engaged during an emergency.
I need to investigate this more.
Dirk - Xpression
Thanks for the feedback. The problem is that the folding prop might be turning when in neutral. So typically (recommended by manufacturer) the saildrive is set in reverse during sailing, except when one is charging the batteries.
Maybe I can leave it in neutral and rubber-band the prop itself or put something between the prop and saildrive shaft that prevents the prop from turning but will pop out when engaged during an emergency.
I need to investigate this more.
Dirk - Xpression
Hi Dirk, My boat has a volvo saildrive with a folding prop. In the SHTP in 04 and 06 the shifter was sealed in neutral. I had no issues with the small amount of shaft rolling due to clutch drag with the engine running in neutral. It is insufficient to open the blades. It does not turn at all when the engine is not running. If the gearshaft is turning in neutral when the engine is not running but the boat is sailing I am tempted to think the prop is not folding properly. I hope this helps, Al
The only solution I have heard about for saildrives was to have a diver remove the prop the day before the race. The skipper then dove the boat in Hanalei and put it back on! I'm not quite sure how he convinced the inspectors that the prop was gone or how he met the 'alternative propulsion rule', but apparently it was acceptable at the time. On the other hand, this was before it was also allowable to seal the transmission shift lever, so that's probably the easier solution for a saildrive nowdays. So long as you don't have problems with the prop freewheeling in neutral....
Many props can open up when the transmission is in neutral. One blade may drop down, and dig in, causing the prop to open and turn. Once this happens, it will continue to rotate. Stopping the shaft from rotating while charging is a good idea, since a freewheeling prop causes quite a bit of drag. On Alchera, I notice anywhere from a quarter to a half knot of speed difference. I meet the requirement by having my gearshift sealed, but I still wedge in some thin wooden shives (available at building supply stores) where the shaft connects to the engine so that it won't freewheel in neutral when I'm charging. The shives will easily splinter if I have to start the engine in an emergency.
I also take care to secure the prop such that the blades open horizontally so that there is less likelihood that one blade will drop down and drag. If I'm really feeling anal, I'll adjust the angle depending on which tack I'm on.
- Mark/Alchera
Many props can open up when the transmission is in neutral. One blade may drop down, and dig in, causing the prop to open and turn. Once this happens, it will continue to rotate. Stopping the shaft from rotating while charging is a good idea, since a freewheeling prop causes quite a bit of drag. On Alchera, I notice anywhere from a quarter to a half knot of speed difference. I meet the requirement by having my gearshift sealed, but I still wedge in some thin wooden shives (available at building supply stores) where the shaft connects to the engine so that it won't freewheel in neutral when I'm charging. The shives will easily splinter if I have to start the engine in an emergency.
I also take care to secure the prop such that the blades open horizontally so that there is less likelihood that one blade will drop down and drag. If I'm really feeling anal, I'll adjust the angle depending on which tack I'm on.
- Mark/Alchera
That saildrive must have had a fixed prop. You must lock the transmission in reverse to prevent wear from freewheeling under sail. I hope the vessel's rating was adjusted for the prop removal.
With a geared folding prop, the blades cannot open individually. The prop does rotate slowly in neutral with the engine running. The only way the blades can open is with centrifugal force or vessel sternway (not a good thing when racing). If the shifter can be sealed to limit movement out of neutral you should have no problems. You don't need to resort to rubber bands or prop removal. I don't have any knowledge of non-geared folders for saildrives. Feathering props should have no issues either if functioning properly.
With a geared folding prop, the blades cannot open individually. The prop does rotate slowly in neutral with the engine running. The only way the blades can open is with centrifugal force or vessel sternway (not a good thing when racing). If the shifter can be sealed to limit movement out of neutral you should have no problems. You don't need to resort to rubber bands or prop removal. I don't have any knowledge of non-geared folders for saildrives. Feathering props should have no issues either if functioning properly.
Possibly there is less of a problem with geared type folding props opening up. I have a bread and butter Martec which is non-geared, and it will often open by itself and start freewheeling if the propshaft is not prevented from turning in some way.
Of course, if the last thing you do is reverse into your slip at the Corinthian before the race, the prop is going to be left open. Then if you seal your gearshift in neutral, you have no way to get it closed when you start racing!
As for feathering props, I know with dead certainty that the AutoProp will *always* immediately open by itself and start freewheeling when the transmission is in neutral. Furthermore, it provides a fair amount of turning force against the propshaft even in the closed position when the boat is moving. I had an AutoProp on my Ericson 38, and it was a constant problem.
- Mark / Alchera
Of course, if the last thing you do is reverse into your slip at the Corinthian before the race, the prop is going to be left open. Then if you seal your gearshift in neutral, you have no way to get it closed when you start racing!
As for feathering props, I know with dead certainty that the AutoProp will *always* immediately open by itself and start freewheeling when the transmission is in neutral. Furthermore, it provides a fair amount of turning force against the propshaft even in the closed position when the boat is moving. I had an AutoProp on my Ericson 38, and it was a constant problem.
- Mark / Alchera
tiger beetle
N/M 45 Tiger Beetle
I also have a standard Martec Elliptic 2 blade folding prop on a regular prop shaft connected to a Hurth transmission. When sailing I open up the engine compartment and manually rotate the prop shaft such that the propeller hub pin is oriented vertically, which means that neither Martec blade can fall 'down' and open up partially. Then I lock the transmission in reverse.
For TransPac, I control the shaft using a vice-grip chain plier clamped to the shaft hub, and attach the plier body to the motor box via thin cord. This locks the shaft and prevents it from rotating, now I can put the motor into neutral when charging and the shaft will not rotate. It also requires that the vice grip be removed before putting the motor in gear in Hanalei Bay - a large NOTE is attached to the engine start switch reminding me of this fact...
If the Martec is left just hanging in the water flow it will start to free wheel violently at 11-12 knots of boat speed - which doesn't happen very often. Makes a lot of noise and I definitely wake up.
- rob/beetle