dix design cat?

[Matt Johnson]

Are these being fiberglassed skinned, or just epoxy sealed and painted? I would assume fiberglass on the outside, but a few things I've read make it sound like they are just coating in epoxy and only taping along the seams.

Matt

[Catmandu]

For Wild Vanilla DH550 Hull #1 Phil H. did not put on a fiber glass skin nor use tape along the seams. I believe that some of the other DH 550's have fiberglass skins, but I don't think that they were built with fiberglass tape along the seams.

I asked Phil H. about this and his feeling was that besides adding weight, a fiberglass outer skin could increase the damage of water intrusion especially with small punctures by masking the issue with water hiding behind the glass.

The seams were not taped. The skins were bonded and fillets were added for for the skin/fram/stringer joints and seams. One builder (who also builds carbon fiber airplanes) visited our boat and thought that it was odd that tape was not used; however, he noted with some surprise that it was working very well the way it was.

Everything on the boat has held together very nicely and there are no stress cracks or delaminations anywhere after 10 years in/on the water. "Good to go." was his comment and decided that he wanted to learn more about this build approach.

So not being a boatbuilder or boat designer I don't know if it would be better to add fiberglass:

- As an outer layer on the hulls?
- Under the waterline only?
- on the decks?
- To reinforce the epoxy filets on all of the seams?

I have nothing to compare it with but I would tend to think that adding the glass to the seams and outside hull skins would be a good thing.

Phil H/Dudley Dix must have felt that it was not worth the cost/effort.

In the end, the boat performs great and is holding up great without it.

[cwjohm]

So leaving aside the 12Kw electric motor issue is the general concensus that Cheetah is a suitable boat for ocean passaging.

[clockwork orange]

I was involved in the build of quite a few cold molded boats from 26' to 45' back in the 1970s and we always sheathed, typically with dynel or light glass. While it does not contribute anything in strength dynel in particular improves abrasion and impact from small dings and scrapes vs epoxy alone so I have never been a believer in just using unreinforced epoxy. However I had to rethink that opinion a bit a few years ago when I was called on to carry out repairs on a plywood Searunner 25 trimaran that had broken free of its mooring and was blown ashore. This was a very nicely built boat and was 28 years old and I believe was still in its original 2 pack paint. As I got into the repairs it became apparent that it had not been sheathed except for the chines, which on the Searunners is a structural fiberglass chine without the usual wood chine log. The plywood panels though were still in excellent condition with the exception of the inside faces of the amas which on the 25 are almost horizontal and exposed to direct sun attack when folded and on the trailer and they were weather checked. This would likely not have happened if sheathed with fabric and perhaps a higher elongation epoxy. however it also probably would not have happened had the builder used BS1088 marine plywood rather than Douglas fir plywood. Weather checking is very common to Douglas fir plywood but not to tighter grained species such as okoume. So, I would now consider not sheathing on a small lightweight dinghy but would still dynel sheath on a larger plywood build. Yes it does add some weight but usually you can find somewhere else to make up for it easily in non essential fit out items.

Steve.

[Catmandu]

Originally Posted by cwjohm

So leaving aside the 12Kw electric motor issue is the general concensus that Cheetah is a suitable boat for ocean passaging.

From my experience - ABSOLUTELY.

The DH550 was designed from the ground up to safely and quickly cross any ocean with a short-handed crew.

Phil Harvey put all of his experience of 150,000+ sailing miles into designing a boat that would carry he and his wife and his two small children (3 + 1 years old) around the world while comfortably living on the hook 98% of the time.

He wanted a "fast/safe world-cruising" boat that could handle any ocean and that could be managed with ease by a single person. He wanted a boat with minimal maintenance.

Folks can/will debate until hell freezes over about the pro's/con's of each of the following choices but the combination of the following list of features results in a design that meets these goals really well:

Performance:
- 240 nm / day with an easy to manage rig
- 10-12 kts sailing / 8-10 kts motoring
- 1,500+ nm motoring range

Boat handling:
- Center cockpit
- Dual mainsheet / self tacking jib
- All sails can be managed with just two electric winches

Structure:
- crash bulkheads front/rear
- 1meter bridgedeck clearance
- Slightly curved decks (to shed water/increase strength stiffness)
- Protected transom (not open to BIG following seas - greatly increases stiffness)

Great livability:
- 44mm of insulation in hulls, deck and salon roof (THIS IS IMPORTANT)
- Large Expansive Salon
- Great 360 degree views
- Great airflow through the cabin and salon
- Fresh water catchment built into salon roof

Mechanical:
- Decent feedback on the helm (for a cat) w/direct linkage to rudders
- 1400+W Solar Power
- 54hp diesels ( small for a 55' cat but still motors at 10+ kts)
- Shafts w/folding props
- Boat systems kept simple and mirrored on each side.

I found from making passages on Wild Vanilla that the boat would typically average 200 - 250 nm/day and that it will stand up to rough steep seas.

Point the boat towards your destination, set the sails and watch the scenery whoosh by ...

Funny thing: Friends of mine (Nordhavn owners) said that if we removed the mast and installed a flybridge, the DH 550 would make the perfect trawler/passage maker.

[cwjohm]

Of course like Schionnings the quality of the boat will depend on the builder. I have no doubt that any boat that Phil Harvey built would be a great boat. How does one ascertain the quality of the same design boats built by other builders?

[Catmandu]

cwjohn,

With respect to the first 4-5 DH 550's you could contact Phil Harvey. He was involved in most of those builds. Harvey Yachts.

If you are interested in Cheetah, that boat was professionally built in Trinidad. You could contact Thomas Pinion owner of Custom Fit Marine in St. Martin who helped manage Cheetah's build. Thomas and some of his shipwrights have built or helped build at least 3 DH 550's.

customfitmarine@gmail.com or try (434) 210-2616

PS: There is not a better person to know if your boat breaks in the Caribbean than Thomas.

[cwjohm]

Thank you, much appreciated.

[Catmandu]

Good luck. Good sailing ...

[sprince83]

https://dudleydix.blogspot.com/2018/...ran-video.html

walk through video and a bit of info

[Catmandu]

Here is some more background on the boat:

https://epoxyworks.com/index.php/building-the-dream/

[Mick C]

Originally (about 7 years ago) I boughtthe DH550 to build the boat. That never happened as I simply did not have the support I needed to make it happen. I still think it’s one of the nicest boats I have seen. At this stage I have bought into syndicates which allow my sailing fix in Multis in beautiful locations. However there is a syndicate that is looking at an upgrade to something a bit special. In the $1m to $1.3M aud range there is a nice field of boats and this boat built professionally falls into that range. So I want to prompt a discussion re say three options and the ups and downs of this. I’m going to. Fully discount a home built option.
The three options for comparison are ...
- A big brand production boat at around 1.3 ish...think Lagoon 50 standard;
- A professionally built DH550 in timber; and
- A professionally built DH550 in Epoxy/fibre.
Just for comparison the fitout of the DH would have to be upgraded to a very high level, modified to be more accessible island beds etc. remember this is a syndicate where comfort is a factor.

The first thing is that from my calls and some investigation it would be easy to spend Aud 1.3M on a professionally built DH550 when you try to match the fitout standard of the big brand boats.

The sailing abilities ... well I think the DH550 would be miles ahead of it’s big brand rivals. Even the new leapords are said to sail more like the condo cats.

The resale I think would be very much in favour of the big brands (speed of sale and price). Even more so for the timber version V epoxy;

The customisation of features would be well ahead with the budget with the DH550. Both mechanically and aesthetically.

Safety, hummm... not sure...probably a draw, with the brand reputation being countered by the safety inherent in faster passages.

Waiting time for boat delivery...I’m thinking it’s a 12-18 Month delivery which ever way you go.

I think that’s a start in my comparison... what do you think? Fair comparison given it’s going to be a small syndicate boat?

Mick

[Catmandu]

Mick C,

I think that this is a great discussion topic. But to start, it would help to know what the (real) mission of the boat is.

For the DH550 Phil Harvey wanted a comfortable boat that he could live aboard and safely sail around the world with his wife and two children. From this mission statement a number of high level requirements that drive the design process fall out:

Comfort for long-term live-aboards on the hook:
(Lots of stuff here)

Safety: "Safely Sail around world:
2-3,000 nm passages around the capes (Phil is a S. African Sailor and has BIG seas sailing experience)

He and his wife: short handed crew - boat has to be easy to manage and sail by just one crew.

The DH550 is based on Phil's experience as a sailor and a builder and the Dh550 design is very well balanced to meet this set of requirements, much more so than most all big brand production boats.

Let's start with the (real) mission statement for the syndicate and answer the following questions:

1.) Where will the boat sail?
2.) When will it sail?
3.) Who will sail it?
4.) How long are their passages in distance and duration?
5.) How much time will the boat spend: ( on the hook, on the hard, at dock or sailing )?
6.) What makes a boat, this boat "special"?

Answering these will help ...

[Mick C]

What a great reply...

That’s a great place to start... I’ll give voice to the answers here.

Where will it sail? The boat has a one to two year sail plan and normally they s will be a season of “local” Australian coastal sailing alternating with an overseas season where a month or two passage is built into a run to say Fiji, on NZ, or Indonesia, Thailand, Vietnam, etc. a season at that little action and then a return sail to Australia. There will be a big effort for a European/Med trip and I reckon that’s about the extent of it.

When will it sail? Sailing seasonally and transit between the “peak” seasons. IE fair weather sailing when in the hands of the “clients”, most weather sailing when in transit.

Who will sail it? The clients when sailing in season at a destination. What we call “tier 1” sailors and possibly a hired skipper when on major transits. Tier 1 means x years experience and “ocean skipper RYA level qual.

How long passages? Speaking by purely on transits they will be in the order of weeks long mostly and potentially up to the Aust Europe trip with a “safety flotilla” for company.

Time on the water? This one is easy. All syndicates I have been in like to”sweat the assets” so to speak so the plan is usually 40 weeks sailing (short, Day sails, o/n on the hook type secnario. And 8-10 weeks transiting. And 4 weeks maintenance/repairs/on the hard.

What makes it special? There are two main things that if you like are in fact the compromise. For the sailors a boat that sails beautifully, something I think the DH550 seems to be famous for. And for the clients and their partners it’s the luxury WOW factor, bringing friends aboard and making them go WOW. Let’s be honest clients have egos!!!

That was really good to do as it explains in writing a lot of the thoughts swirling around in my head.

Love to hear your views all.

Thanks

Mick

[szkutnik]

Originally Posted by Catmandu

I love the DH550 design. I love its layout and performance as well as all the thought that Phil Harvey put into it gained from his experience of sailing over 150,000 miles. I describe the DH550 as fast or faster than a Catana/Outremer but with the space of a Lagoon".

While owning one, I have often asked myself what would I do to make it better. Here is a list of things that I would consider:

- Build it out vacuum-bagged cored S-glass/carbon fiber. I spoke to Phil Harvey about this and he said that a build out of carbon would make the boat stiffer (e.g. faster) but not necessarily lighter due to the layup schedule requirements. The stiffness and strength of a carbon version would increase and could accommodate a larger rig. (Our boat was about 13.8-14.1T (loaded with stuff) which is really light for a boat of her size.) The biggest downside to a cored vacuum bagged boat is price. This build approach makes the boat A LOT more expensive to build in terms tooling/molds and material costs.

- I would extend the hulls and transoms at least a meter in order to move the engines out from under the rear berths and trade out the shafts for sail drives (even with the added maintenance) I think it would be worth it when you have to motor. From a maintenance point of view the shafts were easy and having the engine under the berths made it really nice to work on them in inclement weather or out on the ocean if needed. considering the trade-offs, I would still move them back into a separate compartment.

- I would increase the size of the rig - well maybe not. The boat averaged 200-250 nm/day with ease as it was. The one time we sailed her at 14-15kts everyone started whining and yelling to slow down to smooth out the ride. At 8-11kts the boat just whooshes along.

- I would set it up with a sprit for a screecher/asym and four winches (instead of two) to manage a wider range of fore sails to improve its performance off the wind.

If I could get a DH550 in carbon/s-glass/epoxy would I do it - Absolutely if I thought that I would not take a bath on the resale price. I would need $1-$2M extra over a epoxy/ply version but a carbon boat would get me closer to that elusive perfect boat.

In my opinion Catmandu has answered all of the pertinent questions in the above post.

I would also fully agree with these statements and considering that these opinions are those of someone who is currently sailing a plywood epoxy version of this boat, and has clearly more real world experience than most contributors, then the value of his opinion is obvious.

It is for all the above reasons that we decided to build our current AQUINUS57 which is a improved version of DH 550 from cored epoxy/carbon/glass fibre.

We have also opted for the extended transom and of course saildrive stern gear is an option for those that require it.

As for the question of “luxury” and “WOW”, then of course, the level of interior spec, rig size and deck gear is always going to be negotiated according to the requirements of the owner/owners and totally dependant on the money they want to spend and their intended use of the boat.