Thoughts on a large twin keel for world cruising

[stubones99]

An interesting note... Deutz fell on hard times (financially) in the 1980's and laid off a bunch of engineers and others... John Deere hired loads of ex-Deutz engineers and now we have quite competitive fuel consumption on John Deere to what Deutz had... All because of the layoffs. Back in the 1970's, A Deutz engine would burn half what a John Deere would at the same power output level.

Deutz petitioned the german courts to stop them from stealing the Deutz technology by hiring the layed off engineers, but lost the case since they didn't have set plans to re-hire the engineers.

The rest is history.

[Muaddib1116]

That's pretty interesting. Looking at their website, it seems like they own the Torqueedo brand.

The engines on the Reinke that I've been talking about are 65hp, which is 48.5kw. Under their marine engine section, they don't have water cooled engines until you get up to 81kw. Maybe they've redone their marine engine lineup in the last 2 years, or maybe these engines are older than the age of the boat. Or maybe they are actually air cooled in an insulated engine bay and not using a custom water cooling system like I assumed, I don't know enough to tell from the pictures. Either way, impressive provenance or not, there is virtually zero use of them in the recreational boating world. Which is a problem for me, since I'm not a diesel mechanic. Maybe in the area where it was built, this poses no issue.

[stubones99]

There are lots of water-cooled Deutz engines. Many smaller construction dozers and bob-cats have Lombardini-Deutz engines which are oil cooled.

Air cooled is only on some industrial (pumps and gensets) or agriculture engines (tractors)

No one would build an air to water cooling system for an air-cooled engine, just blow more outside air over it. That's how the were designed and the last air-cooled one I worked on finally needed an overhaul at 50,000+ hours pulling an irrigation pump.

[boatman61]

Well I delivered a 64ft Aluminium bilge keeler designed by Laurent Giles.. from St Martin across to Spain via Gibralter, she could do 5kts in 10kts of wind, handled 4metre beam seas easily.. a great boat all round.
Don't let bilge keels put you off a boat.

[boatman61]

As for bilge keelers having flat bottoms..

[xarvia]

We have a aluminium Reinke 13m twin keel. We've done a fair bit with her over the last twenty years including a lap of the Pacific including the Aleutians and more recently Hobart to New Caledonia direct.

I don't have experience on other boats to compare to. But my experience with this one has been very good. Regarding the various points raised and a few observations of my own:

• Getting caught on debris has not been a notable problem. Once we got kelp caught on the prop, once got caught on a net.
• The rudder has a skeg and is completely solid, the skeg got caught in a fishing net off Kamchatka and we abruptly went from 7knots to stopped with no damage.
• The hull between the keels is difficult to clean on snorkel, while in the water, you need scuba to do it properly. On land it's a bit of a wet cave to work in but manageable.
• We have never used the twin keels to dry out, but it has made haul outs very simple as there is no need for a cradle or supports, also perfectly secure if it was ever on the hard during a cyclone. No way it will topple over.
• The primary reason my dad chose the twin keel version was for the lower draught (1.35m vs 1.6m), which has been highly advantageous for getting into lagoons etc.
• Upwind performance is not great but probably not that dissimilar to many single keel cruising yachts. Hard to work out how much is due to the rest of the design versus twin keel.
• I've had a little bit of a balance issues with this yacht. It has a fair bit of weather helm and a tendency to round up with a quartering sea if you push it too hard (it cruises comfortably up to 7-7.5knots, but the additional force required to go beyond this makes it a bit tetchy and I usually reduce sail). That's probably as much a rigging issue as it is a hull issue. Although the single keel version has the keel further back than the twin keel and I wonder if there's a bit of a design flaw (but not intrinsically an issue with twin keels).
• I recently converted from a Trekker balanced boomed foresail to a cutter rig, both on furlers. This has made it easier to balance the boat and has made sailing in 30+ knots much more manageable with lots of options for reducing sail easily.
• I've had it in 60 knots & 6m seas a few times and felt perfectly comfortable and safe. Would have been even better to put out a drogue to keep it more stable when surfing down waves but it wasn't necessary at the time and we were going in the right direction :-)
• I recently repowered and I collected a lot of data in the process, under engine with a light swell, cleanish bottom and minimal wind, we use about 28-30hp (6L/hr) to go 7 knots, or ~20hp for 6 knots (4.5L/hr) (LWL 11.4m 12t displacement). I'd be intrigued what the single keel numbers look like for the same design, my complete guess would be maybe a 10-15% penalty for twin keels? FWIW, we repowered with a Beta Marine 50 (single engine), continuing to use the original SS folding prop (23 years old, good as new).

If given the choice, I suspect I'd be tempted to go the twin keel again. There are so many great places where we've just snuck in (under some protest from my wife... admittedly we do bump the bottom occasionally...) where the extra 25cm of draught would have been prohibitive.

If buying a secondhand yacht, I suspect that the many other differences between the boats I was looking out would be more important than twin vs single keel.

If I had deep pockets, I'd choose a Boreal with a lifting keel. But that's not going to happen in this lifetime!

[HappyGuy]

Originally Posted by Pete7

I much time for Roger Taylor

who has repeatedly sailed north to the Arctic for nearly two decades. His choice? small twin keeled yachts. His reason, in bad weather they slide sideways down the waves rather than tripping on a deep keel. Perhaps he has something in this.

I have a 31ft twin keeled yacht. Under sail I doubt you could tell me whether it was a fin or twin keeled yacht. The boat achieves the same speed as its fin keeled cousins, the pointing ability to windward if any; only a couple of degrees less. The condition of sails, hull bottom and crew sailing ability will have a much greater effect.

This assumes we are discussing the later aero foiled keels which tend to be splayed and toe'd in to assist with lift to windward. The yachts behaviour will therefore be similar to a fin keeled yacht. This will be different from a long keeled yacht loved by US sailors. That isn't to say its a problem or not the right choice, just different. Heeled of course, one keel will be vertical straight down the other to windward with a huge righting moment. Ours are 820 kgs each.

There is a slight risk to picking up a lobster pot since a long keel or fin may help divert the line away from the prop. However, thankfully despite 12 years of coastal sailing including running over a few pot markers it hasn't been a problem. The rope cutter adds extra insurance. We don't seem to pick up any weed or if we do it is quickly washed away with the angle on the leading edges of the keels.

If you are going "off piste" the ability to dry out on a beach or be lifted without the need for stands and frames could be useful to you in remote areas. Will she tip over if ashore in a Hurricane? I don't know, interesting question.

As you say they tend to be 36ft or less, but manufacturers build what the market demands and therefore what sells. Today that is deep fins or cats. Interestingly there weren't any long keeled yachts either on display at the Southampton Boatshow last September.

So I certainly wouldn't rule it out. Do you have a link to the yacht?

Oh and as HighAndDry pointed out there are those super RM yachts which I would have in a flash if I could afford one.

I agree with your comment entirely.
Years ago I owned a 22'6" twin keel yacht. (Alan Wright "Variant" - NZ)
These boats were designed both in twin and fin keel versions - as are a number of his designs.

Did some 6000 nautical miles of sailing in her.
Cleaning the bottom was easy as I just parked it up on a calm beach at high tide - no hauling out.
Being relatively shallow draft meant being able to anchor further into shelter in bad weather

The twin keel version made slightly more leeway hard on the wind than the fin keel version - but boat speed was pretty much the same on all points of sail.
It was noticed that running downwind the fin keel version rolled significantly more than the twin keel version - esp under spinnaker.
The top twin keel sailor of those that raced often came in well up in the fleet, beating some of the fin keel boats so the performance difference is not hugely significant

Never ever had any issue with collecting weed. The forward slope of the keel and skeg shed weed easily.

If you hit the putty when heeled the boat will float again when sheets are eased and the boat come upright - unlike a fin keel boat
But if you ground upright you can't heel the boat to get off and probably will stay here till the tide floats you off, But at least you won't fall over on your side like a fin keel boat.

I had one occasion in the outer Hauraki Gulf of being hit by a squall of 40 knots from the SW that lasted about half an hour while bashing back to Auckland. Not an issue.
Another time running in a northerly of 30 knots from the outer Gulf to Auckland, No issues..
Have bashed against 30 gusting 40 knots for passages of 20 nautical miles or more on many occasions without issue.

Alan Wright twin keel designs go up to over 40 feet in length.
I saw one on the hard that had been around the world without incident.

If my main use of the boat was for cruising I'd certainly be happy to own an Alan Wright twin keel yacht.
I think the advantages outweigh the disadvantages.

[uhu]

Originally Posted by boatman61

As for bilge keelers having flat bottoms..

Reinke TwinKeelers are no BilgeKeelers
and indeed do have a very flat bottom ...

http://rehberger-yacht.de/assets/img...9/image002.jpg

http://www.reinke-yacht.de/images/20...s-150227-5.jpg

[Tupaia]

Originally Posted by slug

It would be very unusual to find a place in the world were the water level doesn’t move from wave action
The boat I sail draws 4 meters
It’s a fact of life that many times each year , when tied alongside in port I ground out
If the bottom is hard , The pounding will be enough to dislodge headliners and cause hot light builds to fail

This is complete tosh, I owned a bilge keeler for years that lived on an open sea mooring over sand, it dried out at every tide calm or rough and never sustained any damage. As for dislodging headliners that is just absurd.


But to answer, they are great in areas where other yachts cannot go and for bottom maintenance in areas with sufficient tide range. They suffer a huge performance handicap to windward, so make sure it has a big enough engine, not just an auxiliary.


On the other hand world cruising on a boat with 4m keel is much more of a disadvantage excluding you for many harbours, atolls, passes and anchorages.

[Nicholson58]

If you are looking for a twin keel boat check with Power Boats in Trinidad. This one next to ROXY on the hard seems abandoned. We’ve summered over next to her for three storm seasons. Roxy is 58 feet. The twin keel vessel is around 50.

Sorry I don’t have a better image.

https://www.powerboats.co.tt/

[HappyGuy]

Nicholson58 - The twin keel in your photo looks like it might be an Alan Wright (NZ) design?
Without being able to see the rest of the boat I can't be certain - but the keel shape is exactly the same as on the Variant I owned years ago and the underwater hull shape looks right too.
Alan used that shape of keel on a few of his designs.

Alan Wright was one of the worlds foremost designers of twin keel yachts.
When I lived in NZ there were more of his design sailing there than any other design.
They had an annual Alan Wright Day in his honour.

[Nicholson58]

Originally Posted by HappyGuy

Nicholson58 - The twin keel in your photo looks like it might be an Alan Wright (NZ) design?
Without being able to see the rest of the boat I can't be certain - but the keel shape is exactly the same as on the Variant I owned years ago and the underwater hull shape looks right too.
Alan used that shape of keel on a few of his designs.

Alan Wright was one of the worlds foremost designers of twin keel yachts.
When I lived in NZ there were more of his design sailing there than any other design.
They had an annual Alan Wright Day in his honour.

I believe it might be a British boat. It has the same Hudestat variable pitch transmission as we have on Roxy. I suspect built in the 1980s.

[s/v Jedi]

Someone mentioned the sideways sliding off waves where deep keels capsize the boat. A very important feature of bilge keelers that is otherwise ignored in this thread. Upwind performance is hurt but not as bad as for a cruising catamaran so that ain’t too bad either.

The argument brought forward that it has no resell value: that does not matter because it is the OP who profits from that by paying market price.

If that boat is solid and her rig is as well, then I would not hesitate to buy it.

[heintje23]

Originally Posted by boatman61

Well I delivered a 64ft Aluminium bilge keeler designed by Laurent Giles.. from St Martin across to Spain via Gibralter, she could do 5kts in 10kts of wind, handled 4metre beam seas easily.. a great boat all round.
Don't let bilge keels put you off a boat.

Hey Boatie, where you talking about this boat?
The previous owner told me he sailed her from New Zealand to Panama straight, sort off...
Could be because of the 5500 litres of diesel she carries in her belly

For storm tactics he motored into the waves at an angle during 45 knots sustained in the the gulf of Biscay. It was uncomfortable he stated, but doable.