Shoebox skeg

Discussions related to the tiller and/or keel.
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Hamblesailor
Under way
Posts: 18
Joined: Tue Aug 14, 2012 2:17 pm

Shoebox skeg

Post by Hamblesailor » Mon Sep 16, 2013 5:36 pm

While broadly happy with my S 18, I feel somewhat distressed by the hydrodynamic shape, or lack of it, to the 'skeg'. It has a vertical leading and trailing edge and bottom, making it, in actuality, a box.
1) Are all these skegs the same shape, I know keel shapes varied? Has anybody got a better shaped one on their Swift?
1) Anybody know what's inside it before I take the grinder to it? Is it just hollow or is it foam filled? Is there a plywood stringer inside it as well?
2) I plan to replace it with something the same depth and height affording the same centre of lateral resistance but hopefully a little less drag (as it will be roughly foil shaped and much thinner)
3) I wonder though if it is not only a skeg to help combat rounding up in gusts, but also partly a support for the boat on the trailer roller and when drying out- to lift the stern so the boat dries more on the flat area in front of the keel.

I cannot imagine it featured on the original aluminium hulled prototype micro tonner

Can anybody shed any light on any of the above? Anyone got rid of the skeg completely to see what happens or know what's inside it?

For similar motives, has anybody had any success fitting a slot gasket for the keel slot. The shape of the exposed slot with keel down with that vertical aft end to the box is akin to towing a bucket.
I think any slot gasket would have to be a plate slid forward as the gap and keel are too wide for a dinghy type approach of flexible flaps, but if I'm making a new skeg the gasket plate can sit underneath it in a shallow garage... This is getting complicated already...
Jake

pancho
Under way
Posts: 21
Joined: Thu Jul 18, 2013 5:50 am
Location: Hamble

Shoebox skeg

Post by pancho » Mon Sep 16, 2013 8:25 pm

Hi Jake,
Where are you located ? As we have similar ideas to you having just bought Scoot it would be good to meet up and go through ideas.

John L WebbJustplanesailing@yahoo.com (Justplanesailing@yahoo.com)
Performance car instructor

07715 323 324


On 16 Sep 2013, at 18:36, "Hamblesailor" <forum-tillerkeel@swift18.org (forum-tillerkeel@swift18.org)> wrote:

While broadly happy with my S 18, I feel somewhat distressed by the hydrodynamic shape, or lack of it, to the 'skeg'. It has a vertical leading and trailing edge and bottom, making it, in actuality, a box.
1) Are all these skegs the same shape, I know keel shapes varied? Has anybody got a better shaped one on their Swift?
1) Anybody know what's inside it before I take the grinder to it? Is it just hollow or is it foam filled? Is there a plywood stringer inside it as well?
2) I plan to replace it with something the same depth and height affording the same centre of lateral resistance but hopefully a little less drag (as it will be roughly foil shaped and much thinner)
3) I wonder though if it is not only a skeg to help combat rounding up in gusts, but also partly a support for the boat on the trailer roller and when drying out- to lift the stern so the boat dries more on the flat area in front of the keel.

I cannot imagine it featured on the original aluminium hulled prototype micro tonner

Can anybody shed any light on any of the above? Anyone got rid of the skeg completely to see what happens or know what's inside it?

For similar motives, has anybody had any success fitting a slot gasket for the keel slot. The shape of the exposed slot with keel down with that vertical aft end to the box is akin to towing a bucket.
I think any slot gasket would have to be a plate slid forward as the gap and keel are too wide for a dinghy type approach of flexible flaps, but if I'm making a new skeg the gasket plate can sit underneath it in a shallow garage... This is getting complicated already...
Jake




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John Hainsworth
Cruising
Posts: 69
Joined: Fri Oct 09, 2009 8:07 am
Location: Poole Dorset

Shoebox skeg

Post by John Hainsworth » Tue Sep 17, 2013 6:42 pm

Hi Jake,

My Swift had two flaps which locked down at sole level to close off the outboard well.
I took those off and extended the slot from the well to the transom.. I also cut a semi circle in the bottom of the transome to allow water to flow through.
Finally I sealed the resulting holes into the lockers with marine ply and epoxy.

This gives a good flow of water and allows the outboard legto kick up if grounded and to be lifted clear of the water when sailing.
It works well and gives me an extra knot plus shallow water drive if needed. I can also leave the outboard attached for storage if necessary.

I have a 3hp yamaha malta fitted.

My guess on the skeg is that it is structural and to remove it may cause damage when towing, but I have wondered whether it would be better if the rear end of the keel box was to be sloped to give a better flow.

Cheers John

On 16/09/2013 21:52, pancho wrote:
Hi Jake,
Where are you located ? As we have similar ideas to you having just bought Scoot it would be good to meet up and go through ideas.

John L WebbJustplanesailing@yahoo.com (WebbJustplanesailing@yahoo.com) (Justplanesailing@yahoo.com (Justplanesailing@yahoo.com))
Performance car instructor

07715 323 324


On 16 Sep 2013, at 18:36, "Hamblesailor" forum-tillerkeel@swift18.org (forum-tillerkeel@swift18.org))> wrote:


: While broadly happy with my S 18, I feel somewhat distressed by the hydrodynamic shape, or lack of it, to the 'skeg'. It has a vertical leading and trailing edge and bottom, making it, in actuality, a box.
1) Are all these skegs the same shape, I know keel shapes varied? Has anybody got a better shaped one on their Swift?
1) Anybody know what's inside it before I take the grinder to it? Is it just hollow or is it foam filled? Is there a plywood stringer inside it as well?
2) I plan to replace it with something the same depth and height affording the same centre of lateral resistance but hopefully a little less drag (as it will be roughly foil shaped and much thinner)
3) I wonder though if it is not only a skeg to help combat rounding up in gusts, but also partly a support for the boat on the trailer roller and when drying out- to lift the stern so the boat dries more on the flat area in front of the keel.

I cannot imagine it featured on the original aluminium hulled prototype micro tonner

Can anybody shed any light on any of the above? Anyone got rid of the skeg completely to see what happens or know what's inside it?

For similar motives, has anybody had any success fitting a slot gasket for the keel slot. The shape of the exposed slot with keel down with that vertical aft end to the box is akin to towing a bucket.
I think any slot gasket would have to be a plate slid forward as the gap and keel are too wide for a dinghy type approach of flexible flaps, but if I'm making a new skeg the gasket plate can sit underneath it in a shallow garage... This is getting complicated already...
Jake















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windsong
Under way
Posts: 18
Joined: Wed Nov 22, 2006 8:48 am
Location: Neath, Wales
Boat Name: Windsong
Sail Number: 133

Shoebox skeg

Post by windsong » Tue Sep 17, 2013 8:14 pm

Hello John,
Can you post some photos of your outboard well mod. It sounds like just the thing i would like to do to my boat?

Cheers
Steve (Windsong)

Hamblesailor
Under way
Posts: 18
Joined: Tue Aug 14, 2012 2:17 pm

Post by Hamblesailor » Thu Sep 19, 2013 1:54 pm

Hi John, I live in Hamble and work in Swanwick so if you are also in Hamble we could compare thoughts. I wonder if you are the other chap that is talking to Crusader sails about improving the sailing performance of their Swift? I am now in (sporadic) communication with Colin Silvester and through work I have occasional dealings with John Charnley. I'm not going near my skeg with a grinder until I find out from them what's inside it and why it was put there.
Re: the other John's outboard well. Sounds like a good idea. I have instead gone for a pair of outboard well plugs, one that plugs it off entirely for sailing and another that fairs around my engine for motorsailing/ motoring. A more elegant solution would have been to make a little door inside the sailing plug to accommodate the engine but it was quicker to just make 2 plugs and cut a hole in one of them for the engine. The sailing one is a very tight fit indeed. So much so the cockpit no longer self bails when it is in (I moulded the plug in situ so it's an exact fit). So I will be fitting a couple of dinghy self bailers to the plug over the winter. It's a pain lifting the motor onto the pushpit when sailing but our boat is either cruising in which case the shrouded engine remains in situ, or racing in which case the engine remains at home.
The motoring fuel economy with our 4 stroke Mariner 5 and the motoring plug is phenomenal. In a light headwind the other week we got from Southampton to Poole on under 5 litres of fuel, including motoring up to Keyhaven Quay and back on the way. It gets along nicely at half throttle.

pancho
Under way
Posts: 21
Joined: Thu Jul 18, 2013 5:50 am
Location: Hamble

Shoebox skeg

Post by pancho » Thu Sep 19, 2013 4:26 pm

Hi,
This is good news to meet up and chat Swifts, I co own the boat with another John he lives in the HAMBLE and we both work on and off at HAMBLE Point, the boat is in Deacons on c pontoon and at the moment with Caos and Swift Exit
We are talking to all the Sailmakers to improve the sail plan, making a well cover with a self bailer is in hand and we are looking to re profile the keel and re shape the rudder.
So getting together would be a A1 idea.
At present sailing an Arcona 340 up and down outside the Boat Show and short of crew for Fri Sat and Sunday if anyone out there would like some larger yacht sailing !!! Call 07715 323324.
John

John L WebbJustplanesailing@yahoo.com (Justplanesailing@yahoo.com)
Performance car instructor

07715 323 324


On 19 Sep 2013, at 14:54, "Hamblesailor" <forum-tillerkeel@swift18.org (forum-tillerkeel@swift18.org)> wrote:

Hi John, I live in Hamble and work in Swanwick so if you are also in Hamble we could compare thoughts. I wonder if you are the other chap that is talking to Crusader sails about improving the sailing performance of their Swift? I am now in (sporadic) communication with Colin Silvester and through work I have occasional dealings with John Charnley. I'm not going near my skeg with a grinder until I find out from them what's inside it and why it was put there.
Re: the other John's outboard well. Sounds like a good idea. I have instead gone for a pair of outboard well plugs, one that plugs it off entirely for sailing and another that fairs around my engine for motorsailing/ motoring. A more elegant solution would have been to make a little door inside the sailing plug to accommodate the engine but it was quicker to just make 2 plugs and cut a hole in one of them for the engine. The sailing one is a very tight fit indeed. So much so the cockpit no longer self bails when it is in (I moulded the plug in situ so it's an exact fit). So I will be fitting a couple of dinghy self bailers to the plug over the winter. It's a pain lifting the motor onto the pushpit when sailing but our boat is either cruising in which case the shrouded engine remains in situ, or racing in which case the engine remains at home.
The motoring fuel economy with our 4 stroke Mariner 5 and the motoring plug is phenomenal. In a light headwind the other week we got from Southampton to Poole on under 5 litres of fuel, including motoring up to Keyhaven Quay and back on the way. It gets along nicely at half throttle.




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pancho
Under way
Posts: 21
Joined: Thu Jul 18, 2013 5:50 am
Location: Hamble

Post by pancho » Thu Sep 19, 2013 5:01 pm

Picture of Scoot and Chaos with Swift Exit out of shot at Deacons on the HAMBLE three Swifts does that make a Squadron of Swifts ? >:D<
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John Hainsworth
Cruising
Posts: 69
Joined: Fri Oct 09, 2009 8:07 am
Location: Poole Dorset

Shoebox skeg

Post by John Hainsworth » Sun Sep 22, 2013 9:35 am

My Swift had a door arrangement when I first got it but as I sail mainly in Poole harbour I needed the outboard to lift up easily when not in use. that is why I cut the tunnel through to the transome. I find that it works quite well but iit needs a bit of fine tuning and when I have worked it out I'll put a note on the forum. It's all a matter of compromise between the height of the outboard and the distance beteen the fitting and stern of the boat. I use a 3hp Yamaha Malta shorth shaft, a long shaft would not fit.

John. Taranaki. Poole.On 19/09/2013 14:54, Hamblesailor wrote:
Hi John, I live in Hamble and work in Swanwick so if you are also in Hamble we could compare thoughts. I wonder if you are the other chap that is talking to Crusader sails about improving the sailing performance of their Swift? I am now in (sporadic) communication with Colin Silvester and through work I have occasional dealings with John Charnley. I'm not going near my skeg with a grinder until I find out from them what's inside it and why it was put there.
Re: the other John's outboard well. Sounds like a good idea. I have instead gone for a pair of outboard well plugs, one that plugs it off entirely for sailing and another that fairs around my engine for motorsailing/ motoring. A more elegant solution would have been to make a little door inside the sailing plug to accommodate the engine but it was quicker to just make 2 plugs and cut a hole in one of them for the engine. The sailing one is a very tight fit indeed. So much so the cockpit no longer self bails when it is in (I moulded the plug in situ so it's an exact fit). So I will be fitting a couple of dinghy self bailers to the plug over the winter. It's a pain lifting the motor onto the pushpit when sailing but our boat is either cruising in which case the shrouded engine remains in situ, or racing in which case the engine remains at home.
The motoring fuel economy with our 4 stroke Mariner 5 and the motoring plug is phenomenal. In a light headwind the other week we got from Southampton to Poole on under 5 litres of fuel, including motoring up to Keyhaven Quay and back on the way. It gets along nicely at half throttle.





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