Scheel Keels

[jimi]

Are these any good, if one is not normally constained by draught should they be avoided and preference given to a proper fin?

 

[boguing]

Can't remember his name off the top of my head, but one of the Profs at Delft worked on these and Australia II's winged keel. Not a stupid man! More subtle than a simple bulb.

 

[aluijten]

Running aground with these kind of keels can be quite an experience, so I've been told. The large horizontal surface sucks itself tight in muddy seabeds. So freeing yourself can be an issue.
Then again, because of the smaller draught, the risk of grounding may be smaller as well.

just my 2 cents....

 

[photodog]

I had a good conversation in Newton Ferrars a year or so ago with a bloke who had a particularly stunning blue hulled Starlight 35....

He had the Scheel keel on her when purchased... then swapped for a deep fin after he took up racing.. He felt they were at a odvious though very slight disadvantage racing with the scheel... but that for cruising it was a better bet due to the shoal draft....

So I guess it just depends on how preformance oriented you are.... I suspect that it also depends what boat you are purchasing... Ie if its a Sadler then there is a ready market for the boats with that keel... its a known quantity... but possibly at a disadvantage on others?.......

I would have one without hesitation... if I was looking for a Starlight 35 or Sadler 34 it would be miy prefered choice.... I doubt you would notice the difference in preformance...

 

[Twister_Ken]

Very useful for avoiding marina charges.

 

[Tranona]

I had a good conversation in Newton Ferrars a year or so ago with a bloke who had a particularly stunning blue hulled Starlight 35....

He had the Scheel keel on her when purchased... then swapped for a deep fin after he took up racing.. He felt they were at a odvious though very slight disadvantage racing with the scheel... but that for cruising it was a better bet due to the shoal draft....

So I guess it just depends on how preformance oriented you are.... I suspect that it also depends what boat you are purchasing... Ie if its a Sadler then there is a ready market for the boats with that keel... its a known quantity... but possibly at a disadvantage on others?.......

I would have one without hesitation... if I was looking for a Starlight 35 or Sadler 34 it would be miy prefered choice.... I doubt you would notice the difference in preformance...

Think you will find that keel is a Stephen Jones designed wing keel, not a Scheel. The latter are a very specific shape of bulb designed by (you've guessed it) a Mr Scheel. They were quite popular on Moodys in the 80's as they gave shallow draft without going the then popular route of twin keels.

 

[E39mad]

They are a compromise trading stiffness and sailing speed against shallow draft. Not the best compromise imho as the best lifting/swing keels or even the Warwick Collins wing keel (not seen these for a while) would be my preference for shallow draft.

 

[Seajet]

The main snag is probably lack of 'grip' below the surface drift layer, generally reckoned around 1 metre deep; important if racing, or trying to get off a lee shore.

Also the aforementioned problems with grounding, collecting flotsam, and dearer to manufacture.

 

[Bosun Higgs]

Very useful for avoiding marina charges.

That always looks to me like the fin keel version. The wing keel is much more shallow from hull to the start of the wings.

 

[Sans Bateau]

We had a Sheel keel on our last boat, an Etap 28i, on our first channel crossing we sailed in company with a Gibsea 33, a Maxi 34 and an Etap 30. We all left the same time, but we were the first to tie up in Cherbourg.

The boat pointed well, was pretty fast for a 28 ftr and the keel never fell off, what more can you ask for?

 

[dratsea]

Sara Jane is not a racing boat. For a Crealock 44: fin = 6ft 6ins and Scheel = 5ft 3ins. Huge difference in Pacific in terms of what we could enter. Closer to home much easier to dry out, enter later and almost sit on keel (love picture of yacht off St Malo but we would fall over, albeit with keel still inline with mast) not been to Cherbourg for years, go into Barfleur, dry out and make it to Alderney on next tide (or not = Omonville). Not sure if I would pay extra for the keel (no please.... no Bav comments) but we have been very happy with the Scheel keel on a boat with chainplates, 5.5 tons of lead, half a ton of water, the same of fuel, 660 AH batteries, a breadmaker, iron and enough tools to mend a tank. And if I have to, I can still go to windward.

Does that help?

 

[photodog]

Think you will find that keel is a Stephen Jones designed wing keel, not a Scheel. The latter are a very specific shape of bulb designed by (you've guessed it) a Mr Scheel. They were quite popular on Moodys in the 80's as they gave shallow draft without going the then popular route of twin keels.

I think you are totally correct! I am talking out of my arse! Please ignore me....

OTOH that Wing keel thing is pretty good by all reports!

 

[GrahamM376]

Are these any good, if one is not normally constained by draught should they be avoided and preference given to a proper fin?

We have scheel keel on Moody 376, 4'6" draft. Very little difference in performance against the normal fin version with 5'6" draft, maybe a little bit more leeway. Seems to have less roll in beam seas due to less depth and we can go where deeper keels can't. Dries out alongside OK.

 

[boguing]

The large horizontal surface sucks itself tight in muddy seabeds. So freeing yourself can be an issue.

I've tried to put this 'suction' thing to bed before, so here's another go.

Take an 8 metre sailing boat with a winged keel, span 1 metre, average chord 1m. Horizontal area is 1 sqm. Waterplane area of the boat is 12 sqm. Keel draft 1m. Displacement 1,000Kg.

Park it above mud and let the tide go out. Total force pushing the keel into the mud is 1,000Kg. This must have been soft mud, but let the tide go out a long way, and some of the water content of the mud also run away to make it a bit more aggressive.

When the tide comes back in as far as the designed waterline, there is now 1,000Kg lifting the boat. But the mud's gone stiff. So the wing now needs to lift the cubic metre of mud above it. Being pessimistic, lets say another 1,000Kg. Waterplane area is 12sqm, so for 1,000Kg the rise of water needs to be a further 1/12m = 80mm.

Freeboard of this boat is likely to be 0.5m or more.

This would give a volume of 6 cubic metres, equivalent to 6,000Kg before downflooding occurs.

You'd need some pretty fancy mud for that not to overcome the suction.

 

[Twister_Ken]

The boat pointed well, was pretty fast for a 28 ftr and the keel never fell off, what more can you ask for?

Topless go-go dancers.

 

[Seajet]

I've tried to put this 'suction' thing to bed before, so here's another go.

Take an 8 metre sailing boat with a winged keel, span 1 metre, average chord 1m. Horizontal area is 1 sqm. Waterplane area of the boat is 12 sqm. Keel draft 1m. Displacement 1,000Kg.

Park it above mud and let the tide go out. Total force pushing the keel into the mud is 1,000Kg. This must have been soft mud, but let the tide go out a long way, and some of the water content of the mud also run away to make it a bit more aggressive.

When the tide comes back in as far as the designed waterline, there is now 1,000Kg lifting the boat. But the mud's gone stiff. So the wing now needs to lift the cubic metre of mud above it. Being pessimistic, lets say another 1,000Kg. Waterplane area is 12sqm, so for 1,000Kg the rise of water needs to be a further 1/12m = 80mm.

Freeboard of this boat is likely to be 0.5m or more.

This would give a volume of 6 cubic metres, equivalent to 6,000Kg before downflooding occurs.

You'd need some pretty fancy mud for that not to overcome the suction.

Yes,

but this is in the unlikely scenario of being aground in a flat calm on a billiard table - smooth seabed.

With a stiff breeze blowing the boat sideways ( which often happens when the tide turns ) - and tripping her over the keel wings - not confusing this with a true wing keel - I wouldn't be worried about her eventually floating off, but being pushed hard over may be a bit of a bother and dragging the keel more with the slightest heel - a problem with twin keelers too of course - would be a pain when trying to get off.

 

[GrahamM376]

Running aground with these kind of keels can be quite an experience, so I've been told. The large horizontal surface sucks itself tight in muddy seabeds. So freeing yourself can be an issue.
Then again, because of the smaller draught, the risk of grounding may be smaller as well.

just my 2 cents....

Scheel keels have little more ground area than a loing bulb so no problems when running aground or drying out alongside. I've also never heard of wing keels sticking.

 

[jamesjermain]

Think you will find that keel is a Stephen Jones designed wing keel, not a Scheel. The latter are a very specific shape of bulb designed by (you've guessed it) a Mr Scheel. They were quite popular on Moodys in the 80's as they gave shallow draft without going the then popular route of twin keels.'

Quite right in all respects except its Admiral Scheel...

 

[Sybarite]

We had a Sheel keel on our last boat, an Etap 28i, on our first channel crossing we sailed in company with a Gibsea 33, a Maxi 34 and an Etap 30. We all left the same time, but we were the first to tie up in Cherbourg.

The boat pointed well, was pretty fast for a 28 ftr and the keel never fell off, what more can you ask for?

I think we would need to know the angle of the wind to judge. After all, downwind you would raise a centre board.

 

[aluijten]

I've tried to put this 'suction' thing to bed before, so here's another go.

.....
You'd need some pretty fancy mud for that not to overcome the suction.

Yes that is all assuming there is a tide to set you free and you did not run aground during highttide of course.