Pop 25

[abh]

Hi all.

Pop 25

I'm quite interested in this design, it looks to be very affordable and easy build, and just about the size for me. I'm trying really hard to talk me out of building one and was hoping for your help.

What do you all think of this one?

 

[Stumble]

Off hand I think the designers should have build a boat with the money they spent on the 3d mockups and done some real world testing. The human model has impossible dimensions so nothing can be trusted to fit to scale. Sleeping 6 on a 25' boat is insanely tight, though doable, and the cockpit isn't nearly large enough to fit that many people anyway since all the space was scavenged for down below, which is at odds with how most people will use a boat like this.

I won't speak to its sea keeping, but I have real doubts about some of the design decisions, like the twin keels and rudders, the high freeboard to try and get more head room, ect.

 

[philSweet]

Please ignore all remarks about electric drive and power consideration. There is no usable info there imho. Redesign for outboard or small saildrive. Definitely not cheap or easy to build to the finish depicted in the virtual boat. Ditto Stumble regards to scale issues, double keel. There are some things I like about it, but trying to build versatility into the inside of a rather nonversatile hull doesn't make much sense to me. You'd be better off buying a MacGregor, and I never though I'd say that to anyone.

PS Is there anyone over 5'4" , 130# in you family?

 

[PAR]

With it's flat flanks, it'll be fairly ugly compared to other, similarly sized boats.

 

[rwatson]

A 25 footer that is too wide to pull around roads seems a waste. (9' 2")

I would prefer another 10 feet in length if I was stuck with it at a mooring so at least it would be comfortable to stay on for extended periods.

 

[abh]

I won't speak to its sea keeping, but I have real doubts about some of the design decisions, like the twin keels and rudders, the high freeboard to try and get more head room, ect.

Would you please talk about that Why not bilge keels and rudders? What's the downside to those?

The only downside to high freeboard must be the windage? The design seems to me to be quite streamlined so it could counteract that to some extend?

 

[abh]

With it's flat flanks, it'll be fairly ugly compared to other, similarly sized boats.

What is flanks? Sorry my english isn't the best.

 

[abh]

Please ignore all remarks about electric drive and power consideration. There is no usable info there imho. Redesign for outboard or small saildrive.

This is actually one aspect I really like. I know of course that I can put electric motor in any boat I decide to build, so it isn't actually a design feature

PS Is there anyone over 5'4" , 130# in you family?

Well, the largest beast in my family is 5'10" and 132#

 

[philSweet]

If you want a reasonable electric drive option, go visit an electric boat that the owner is happy with and who uses his boat the way you want to. You might track these folks down through one of the electric boat forums (such as Yahoo Groups). Electric drive in sizes between Torquedo and Cruise ship sizes still appears to be a bit of a cobble, and the costs are large. Several times the cost of an outboard and at least twice the cost of a small diesel sail drive. And most seem to have been built by engineers who worked with DC electrical systems for twenty years. The real difficulty with electrics is recharging the batts. This issue tends to drive the entire system. The actual drive line is not that big a deal.

With your modest head room requirements, there are a huge number of older designs available from the sixties and seventies. Why do you want to build new as opposed to rejuvenate and older boat. That is way cheaper in the US at the moment. Where are you, by the way?

 

[Stumble]

The justification for twin rudders is that on wide transformed sailboats as the hull heels even marginally a centerline rudder quickly looses bite in the water as the hull is lifted out. To counter act this loss of bite designers moved to twin rudders so at predictable heel angles the windward rudder is mostly removed from the water flow, and the leeward rudder is close to verticle. This allows racing boats to operate with the highest efficiency rudder angle, and minimize drag. But it also requires the boat to sail at a determined angle of heel as much as possible.

For a cruising boat this complexity is just silly. And what cruiser wants to have to sail around all the time at 15 degrees of heel to keep the second rudder out of the water?

As for the twin keels. There are some advantages to them, but as I understand them, the advantage is primarily the ability to safely ground the boat in areas of high tidal range. This can make mooring much easier. But they also come with some significant downsides. Including
1) fin keels sail better at all points of sail
2) particularly in light air where the twin keels extra wetted surface is a killer
3 or in chop where they have a tendency to roll much more.
4) there are also reports of them having problems tacking in heavy air and chop as compared to fin sister ships.

Finally for a home build, twin keels doubles the amount of work involved in making the keels, and adds to the complexity, since they should not by symmetrical. So you have a much more difficult fabrication process.

Reason also pointed out that it's beem is to wide to tailor in most countries. Which in my eyes is a deal Keller for a boat this size. If special permits and commercial drivers are involved, I would rather go to a 30' for not much more work but a lot more capability.


Finally on the electric drive.... There are threads aplenty on this forum detailing the problems with them, and I don't want to get into it here. But the short answer is for every gallon of diesel fuel or gas you replace, you have to add 600lbs of batteries to have the same range. At the moment it just isn't practical. Though if I was dead set on this boat, I would try and have the electric drives mounted in torpedoes on the bottom of the keels.

 

[philSweet]

One other point regarding twin keels- Yes, can be stable when grounding. Good if grounding is intentional. Bad if grounding is accidental. You can't just spin on the keel and go back the way you came with twin keels. Not that I've ever run aground, mind you. (when you keep a 7' draft boat in a "less that five foot" controlling depth area, you tend to think this way.)

 

[Stumble]

Abh,

i just reread my posts, and i think it came across as being somewhat confrontational. I just wanted to add, that is not my intent. I know you like the boat, but to me it borrows some of the more advanced racing ideas and applies them to a radically different boat, with radically different problems.

Beyond that I see a boat that does one thing well, that is sleep lots of people. But that is almost never the intended use of a 25' sailboat, and for good reason. There just isnt enough room for that many people on board a small boat to live comfortably, even for a weekend.

 

[abh]

Phil: I want to build a new boat mostly for just doing it. That being said, I'm not a rich man so money does matter, so does time, but I'm not under the illusion that self building will be cheaper and faster than buying. I want to build a boat I can afford, and finish, but I still will have to like the end result. I'm in Iceland.

Stumble: Please keep being confrontational, I want to hear all negative aspects to this design. I'm have no "feelings" towards this design.

I thought the main benefit from twin keels is that it allows for shallower draft without the complication of lift or swing keel. I also have read that twin keels dampens the roll. Is that wrong? Is it possible to estimate the most efficient level of heel for this design?

Phil: I never run aground unintentionally. I have used my keel as an anchor though, and two of them might hold too strong

I totally agree on the interior. I can't see any need for sleeping six in this boat. The v berth looks to me to be useless at all for anything but storage, and now I have worries that the aft berths might be too narrow for two, so it might be actually useless at all.

 

[abh]

The main reasons I like the design are:

Looks to be very fast to build. I haven't built a boat this size yet mostly because I really haven't had the time to do it, and I know that after 3 years of building I would get sick of it anyway and quit. This one seems to be doable in that time.

I like the insulation that is built into the hull. Looks clever to me.

I thought the interior was acceptable, but now I have doubts.

I thought the twin keels would give shallow draft, without complicated system for lifting or swinging the keel into some box.

There is no keel box, or mast post that messes up the interior. But maybe the bulkheads that come instead are even worse.

Maybe I should keep on researching for better design under 30 feet.

 

[Stumble]

Any instead of building I would really recommend buying. Assuming you live in a part of the world where sailboats are you can get a reasonable used boat for a fraction of what a new build would cost, and save the time in the build process.

The most efficient heel angle for a boat heading to windward is with the keel pointed strait down (as far as keel efficiency). So for this boat is would be when the leeward keel is at zero degrees to gravity.

As for shallower draft... That really has more to do with the design of the boat than the keel configuration. All a keel does is provide righting moment, and there are a lot of ways to acomplish that, go deeper, go heavier, move to a torpedo, reduce demand (smaller rig), ect... Twin keels are not necessarily better at limiting draft than other options.