Outboard Rudder

[Jaguar 25]

Just noticed that on some canal boats, the outboard includes a rudder aft of the prop. This apparently helps when steering, as usually, this is achieved by turning the outboard as on small motor boats. The rudder is fixed and turns with the outboard and not independently (I assume).

Has anyone any experience of this on a sailing boat?

 

[VicS]

Just noticed that on some canal boats, the outboard includes a rudder aft of the prop. This apparently helps when steering, as usually, this is achieved by turning the outboard as on small motor boats. The rudder is fixed and turns with the outboard and not independently (I assume).

Has anyone any experience of this on a sailing boat?

It is possible to link the outboard to the rudder. At least when they they are side by side on the transom.
The boat is steered with the tiller and rudder in the normal way and the outboard is turned through a similar angle.
The linkage has to be fairly easy to disconnect so that outboard can be raised and/or the rudder used independently

somewhere I have a design for such a system for the Sea Wych although I have never felt inclined to try it

 

[duncan99210]

It's a fairly common setup on outboard powered canal boats. The addition of the rudder to the outboard helps in steering the boat at slow speeds, often only just above tickover, when the engine is developing minimal thrust. Also helpful when the engine is put into neutral, as it still gives directional control, which disappears if using just the outboard. Most, if not all, boats fitted with these rudders will not have a separate rudder fitted at all, so no requirement for links between outboard and tiller.

 

[VicS]

It's a fairly common setup on outboard powered canal boats. The addition of the rudder to the outboard helps in steering the boat at slow speeds, often only just above tickover, when the engine is developing minimal thrust. Also helpful when the engine is put into neutral, as it still gives directional control, which disappears if using just the outboard. Most, if not all, boats fitted with these rudders will not have a separate rudder fitted at all, so no requirement for links between outboard and tiller.

The OP asks about using a similar system on a sailing boat, Under sail one would normally lift an outboard from the water so a normal rudder would have to be fitted

I assumed he was interested in fitting some such system on his own boat to link the rudder and outboard.

This is the general idea to which I referred earlier

 

[Boathook]

My 9m Cat has its outboard connected to the steering by some ropes and some 'snap' style clips. Very good in confined spaces but it open water I 'lock' the engine fore/aft and just use the rudders.

 

[Jaguar 25]

The OP asks about using a similar system on a sailing boat, Under sail one would normally lift an outboard from the water so a normal rudder would have to be fitted

I assumed he was interested in fitting some such system on his own boat to link the rudder and outboard.

This is the general idea to which I referred earlier

Thanks for the replies.
I wasn't thinking of the ability to link the boat's installed rudder to the outboard, which can be done. I was referring to the possibility of adding a small rudder directly onto the outboard aft of the prop. I was thinking that this may improve steering in reverse, which is difficult on my Jaguar with the outboard offset from the boat centreline.

 

[Fantasie 19]

Thanks for the replies.
I wasn't thinking of the ability to link the boat's installed rudder to the outboard, which can be done. I was referring to the possibility of adding a small rudder directly onto the outboard aft of the prop. I was thinking that this may improve steering in reverse, which is difficult on my Jaguar with the outboard offset from the boat centreline.

..but acting independently of the outboard or like this?

 

[VicS]

Thanks for the replies.
I wasn't thinking of the ability to link the boat's installed rudder to the outboard, which can be done. I was referring to the possibility of adding a small rudder directly onto the outboard aft of the prop. I was thinking that this may improve steering in reverse, which is difficult on my Jaguar with the outboard offset from the boat centreline.

I dont think it will help with that, not much anyway. The problem you have is that the thrust is offset to one side so the boat will turn in a tight circle one way but barely turn at all the other.

Best to plan so that whenever possible you turn in the direction in which it turns best but when its unavoidable to turn the other way the trick is to get the boat moving as quickly as possible then throttle right back and just use the rudder and way you have built up.

Practice, and learn before you stuff up.......... dont ask how I know this!

 

[Tranona]

Thanks for the replies.
I wasn't thinking of the ability to link the boat's installed rudder to the outboard, which can be done. I was referring to the possibility of adding a small rudder directly onto the outboard aft of the prop. I was thinking that this may improve steering in reverse, which is difficult on my Jaguar with the outboard offset from the boat centreline.

A rudder behind the prop will do little in reverse as there is no flow from the prop. You have to remember that in reverse your outboard is pulling the boat backwards which is why it steers to one side if your motor is offset. Trying to turn 25'+ of boat while pulling it slowly is almost impossible so as Vic says you can only work with what you have and use the offset pull to your advantage rather than fighting it.

As suggested those auxiliary rudders are to provide some low speed control on power boats that do not have a rudder at all and rely solely on turning the engine for steerage.

 

[William_H]

The rudder mounted on the outboard engine could have it's uses as an easy fix for boats with no rudder and particularly heavy boats where there is a lot of operation of the boats under inertia drift as with a heavy barge.
However the rudder has no balance and would not be as useful as say a proper deep well balanced rudder for steering. I love my deep transom mounted rudder with plenty of balance. (ie area (25%) forward of the pintle line small leverage distance pintle line to the trailing edge.
olewill

 

[LittleSister]

I was thinking that this may improve steering in reverse, which is difficult on my Jaguar with the outboard offset from the boat centreline.

Any fool can handle a boat that steers in reverse, it takes a true sailor/complete idiot* to handle an offset prop/prop behind rudder/long keeler*! (*Delete according to taste.)

Though I spend a fair bit of time dreaming up cunning devices to help steer our long keeler in reverse (none of which will ever be built), I like to think it's more about developing towards a zen-like ability to handle the uncertainty and fear involved. Hamlet cigars may help.

On a more immediately practical note, I found outboards which exhaust through the prop exacerbate matters, as in reverse the prop's effectiveness is compromised by the flow of exhaust over it. One seems to get all the prop walk but much reduced thrust (compared to forward). Realising this is half the battle, I found, but mounting the outboard on the other side of the boat, or finding one with a prop rotating the other way (so the prop walk and the offset counteract) might be worth a try.

 

[PhilCole]

I am considering the same, using an outboard instead of the inboard Penta and sail drive.
Mine is a 26 foot boat with a 40 year old engine, at some point it will fail hence desiring an external new unit and again with a deep keel and rudder.
How effective is an outboard when being used as a rudder centrally mounted?

 

[rogerthebodger]

Adding a rudder to a small outboard - Practical Boat Owner

outboard motor rudder - Bing

I had one when I lived in the UK and the canal boat I used on the BCN