Sailing with only one rudder

[Declan]

The metal bracket holding one of the rudders broke. I am waiting for a new one to be made. Meanwhile can I sail with just one rudder down? I would go out in winds under 10 knots. Is there any way with the sailing and rigging and use of the motor to ensure the other rudder will not break?

[bartmac]

I would say only on one tack....the side the rudder is down on!!!.....when heeling the upside rudder does not have much "bite" and in light winds I can't imagine it would make much difference?

[Russ]

Go for it. Enjoy your boat. If it doesn't steer well, who cares, you are on the water.

Break? Seriously doubt it under light conditions. I've lifted one rudder and sailed that way at times. No worries.

[mastreb]

Put your outboard motor down and use it as an additional rudder. It works surprisingly well. Keep it in neutral so the prop will spin.

[seahouse]

Put your outboard motor down and use it as an additional rudder. It works surprisingly well. Keep it in neutral so the prop will spin.

Hey Matt- as a side note, you might find that on your Beneteau that you want to put it into reverse gear while sailing. It will reduce vibration ( you'll be able to feel that) save wear and tear on the drivetrain, and reduce drag. So the sailing community seems to say. Obviously the design of the prop is a variable in this.

-B.

[mastreb]

Put your outboard motor down and use it as an additional rudder. It works surprisingly well. Keep it in neutral so the prop will spin.

Hey Matt- as a side note, you might find that on your Beneteau that you want to put it into reverse gear while sailing. It will reduce vibration ( you'll be able to feel that) save wear and tear on the drivetrain, and reduce drag. So the sailing community seems to say. Obviously the design of the prop is a variable in this.

-B.

Why reverse and not fwd?

I actually have a folding prop, so when I put it in gear while sailing, the prop folds back and the drag drops off. Can't really feel any difference, but the boat picks up about 1/3rd of a knot when I do it.

[Russ]

Why reverse and not fwd?

I actually have a folding prop, so when I put it in gear while sailing, the prop folds back and the drag drops off. Can't really feel any difference, but the boat picks up about 1/3rd of a knot when I do it.

Good question. With my Hunter I would simply put it in forward and the prop stopped rotating.

The idea is that a rotating prop causes the transmission gears to turn and without the engine running, there is no fluids pumping and cooling them. Besides for the extra wear on moving parts that aren't helping you move.

Folding props change everything. I never used one. I've never heard of problems. I just had trouble trusting it to unfold when fouled with junk, especially in reverse when docking.

[seahouse]

Probably other reasons, but when in reverse, there is no possibility of the engine starting inadvertently. Because the crankshaft on the motor is being pushed to run counter to its proper direction, which it can 't do. They do exist, but very few motors themselves are capable of running in reverse, so gearing commonly does that instead.

Note that a diesel can start and run without the ignition key turned on. Next time the engine is running, try turning the key to OFF. A lot of (boat) diesels, even some newer ones, will just keep on running because they don't need electricity for a spark.
They are turned OFF instead by cutting the fuel supply to them, rather than the ignition like a gasoline motor.

-B.

[Russ]

Probably other reasons, but when in reverse, there is no possibility of the engine starting inadvertently. Because the crankshaft on the motor is being pushed to run counter to its proper direction, which it can 't do. They do exist, but very few motors themselves are capable of running in reverse, so gearing commonly does that instead.

Note that a diesel can start and run without the ignition key turned on. Next time the engine is running, try turning the key to OFF. A lot of (boat) diesels, even some newer ones, will just keep on running because they don't need electricity for a spark.
They are turned OFF instead by cutting the fuel supply to them, rather than the ignition like a gasoline motor.

-B.

All good points and makes perfect sense now that you explain it that way.
My Yanmar diesel had nothing tied to the "ignition" switch except the panel. Turn the key off and nothing happens except the tach went off. To shut it down you had to pull the decompression lever.

It came with a hand crank to start it. You couldn't turn that thing until you pulled the decompression lever. The idea was to crank it without compression until you got some RPMs on the bad boy and then release the compression. Tried that once. No way. Pretty dangerous as I'm sure those old Model Ts were to hand crank.

[raycarlson]

Boy I'd really love to read the engineering on the cam system that will let a 4stroke diesel run in reverse, if you would please post which motors do this....thanx.

[seahouse]

Boy I'd really love to read the engineering on the cam system that will let a 4stroke diesel run in reverse, if you would please post which motors do this....thanx.

There are a number of ways to accomplish this, but they all involve a variety of mechanisms that vary the fuel and valve timing (links below). Of course, the fuel cam will have to be switchable so fuel is injected before top dead centre when the crankshaft is turning in either direction, and the intake and exhaust valve timing will have to be switchable to accommodate the combustion sequence too. Mechanically easier to do on a two-stroke diesel, but it's done on four-strokes as well.

One system has two sets of cam lobes on a cam shaft that slides axially, so that either the set for forward, or the set for reverse, is engaged on the followers. Another method uses a dual-position cam follower that can switch positions by off-setting for either forward or reverse.

In older ships it can actually take several minutes for the mechanics in the engine room to make these changes before reversing can happen. Some advance planning needed when in close quarters there!

While there is little reason to have an engine itself that is reversible today, (with gearing and prop pitching etc, even with the camless engine just around the corner), there are now dozens of different ways of changing the injection and valve timing in use; each manufacturer has their own technology. While accessory functions (alternator, all manner of pumps and fans) would have to be looked at separately, the precise computerized controls that are on modern engines would make this much easier to accomplish than it ever was before. By simply writing new lines of code you can have the fuel pulse and valve lift and timing wherever and whenever you would like it.

Of course there are also the engines built from scratch that run in what would normally be considered a reverse direction only (for twin-engine airplanes, boats, where one turns the opposite direction from the other).

http://www.brighthubengineering.com/mar ... e-engines/

http://www.machineryspaces.com/reversing.html

- B.

[Mac26Mpaul]

have sailed with one rudder down quite a few times in lighter winds. Give it a try, you will be fine.

[BOAT]

I have always wondered how those folding rudders work in reverse.

[mastreb]

They work in both directions the same way: When the shaft is powered, rotational inertia forces the prop blades directly out. They're geared together so they always move together. Same thing happens in forward or reverse, and the force imparted by the blades against the water is overwhelmed by the rotational inertia that keeps them spanned out. It was true that early designs backed against a stopper in forward and were inertial only in reverse and therefore had worse reverse performance, but that's largely been worked out.

When the shaft is locked from rotating (because the engine is off but in gear), the water flow over the blades pushes them in to the folded position.

Easy peasy.

[cptron]

We sail quite a bit with only one rudder in 10 to 15 knot winds. Just make sure its the lee rudder. Even forgot to switch once and didn't notice too much difference. (until it comes out of the water) but still you will only round up. So go out and enjoy.