Designing your own boat, A fool for a client?

Pierre:
I've a pretty similar mission, and initially looked a replica Dutch Barges (mostly Luxemotor styles) that could be modified to a higher RCD than normal for the coastal work. But I figured that oceans wouldn't be readily handled with the comfort and safety I wanted.

That got me looking again at Tad's PL series. Initially the 56, but more recently his 74 came to light and I think would be a pretty good fit to your (our?) mission. Take 1' off the beam to fit the 5m French canals, in aly the draft should be OK and I think a folding screen on top would meet the airdraft spec, but haven't checked in detail. And it seems to me that it should be capable of the fair-weather-preferred ocean work you describe, and meet a large proportion of your other items listed.

I'm a little way off buying plans - at present I'm dating a bit (cancer stole my wife a few years ago, and now its time for a new partner.....) and still mulling what to do re: boats. Its going to take a while to build, but despite the fabulous buyer's market (in NA, if not here) there's not much like the PL74 out there that I've been able to find. So a new build might have to be done.

And I think you are in general right with overall SOR and concepts, but as I think Daniel said -get someone else to do all the dirty work. Whatever they charge will be worth it.

Look forward to following your progress, good luck with it - Brian

 

More often than not, it is a wise decision to have a seasoned project manager involved, even before the NA is choosen!
This project is about the size where it makes sense to go that way.

And this one from Tad, maybe lengthened to 80ft and with just 15 in. breadth would fit the bill almost perfect. imho
I could build her at far lower cost than Windhorse.

http://www.boatdesign.net/forums/at...agemaker-style-within-genre-pl74blueprint.jpg

Regards
Richard

 

What can I say, Tad did what the Dashew should have done.
Efficiency and elegance are very compatible.

By the way, just a thought, that will be a perfect low volume production high end yacht.

Richard

Tad, I really like you style, you have the knack to deliver well proportioned vessel, with a touch of classicism and an actual touch.

Daniel

 

There are some activities in the background which would most probably not only meet the requirements, but would not restrict the boat to fair weather.

A bit patience, it is worth it.

Regards
Richard

 

The PL 74 is starting to come together....

 

I am already over the calculations..............

Thanks Tad.

 

And the low profile version of the same boat.......



LOA = 74’ 0” (22.55m)
LWL = 71’ 3” (21.7m)
Beam max = 16’ 0” (4.87m)
Beam waterline = 14’ 7” (4.44m)
Draft (half load) = 4’ 6” (1.37m)
Displacement (half load) = 90,000 pounds
Speed max = 15 knots
Speed cruising 10-12 knots
Fuel = 4000 usg
Fresh water = 1500 usg

Single or twin engines, both with propellers in pockets with heavy full depth skegs for excellent protection.

Round bottom aluminum hull with all integral tanks and three full height watertight bulkheads.

The ship is available in two exterior configurations, Flying Bridge and Low Profile. The Low Profile provides an air draft of less than 12’ 0” (3.65m) for access to many European canals. Interior arrangements will be semi-custom but configuration allows a huge completely private owner’s suite forward, with office, day head, and walk-in storage. Amidships under the pilothouse is space for twin guest cabins each with en-suite head. Galley and dining areas can be up or down.

Key areas of the arrangement are a full headroom engine room, and a huge storage garage accessed from the aft swim deck. There is also a large watertight storage room forward of the collision bulkhead, accessed from the foredeck. Storage for a 17’ hard outboard skiff is arranged on the aft deck, with easy launching and retrieval over rollers (no crane required). Additional kayak storage is available on the rooftop or in the garage.

Stabilization options include active fins, fixed bilge keels, towed paravanes, and steadying/get home sails.

 

A man who wants the job, you're probably gonna get it.

Who builds it will probably be critical.

 

Actually you can blame Richard....He was poking at me all weekend........

 

Well, I did yes,

sorry.

But I was already negotiating yard capacities for it during the weekend.
And I have found them in Holland. Where I went for this project.

So, building her in Aluminium to highest standards is not a problem. And due to the extremely high efficiency of the Dutch boatbuilding clusters, the price will be very competitive as well.

Maybe there will be a bit more poking from my side.................
Poor Tad.

I hope my comment above answers this doubt!

Regards
Richard

 

Air draft

You really need a max of 3.50m if you want to cross France. Even then, you might have problems with some bridges after heavy rain - the levels are not guaranteed all year round.

VNF (Voies Navigable de France) has a website with detailed maps, showing max. draft and air-draft:

http://www.vnf.fr/vnf/content.vnf?action=content&occ_id=31740

Perhaps you could take down the top screen to go through France, or add a (very large) water-ballast tank somewhere?

Sounds useful for passage-making, but (imo) you'd want the aft deck clear when on canals (reserved for dining - so galley up). Kayak/PWC garage would be cool, though.

Fins risk getting ripped off in shallower parts, especially if you're forced to the edge of a narrow canal when passing - they're not full depth across the whole width. Same goes for anything else sticking out. Most of the commercial barges in France and Belgium are single prop for this reason.

The boat looks interesting! If only I could persuade my wife to let me sell the house ...

 

Thanks for your comments Euro......

In my first iteration of this concept I've been struggling (erring on the conservative side) to get the height needed to double deck in the pilothouse area. I now have a plan to reduce overall height by over 6", getting us below the critical 3.5m.....and the difference between half load and full load is 5.25".....this will be sorted out as we work through the detail design.

So when in canal mode perhaps the small boat moves to the foredeck, obscuring visibility from the pilothouse but you still have the upper control station........

My other thought was that with that great small boat, why take the big one into the tiny canals? The big dinghy can have a full weather enclosure, heat, full electronics, two outboards, even an electric outboard....she could easily support week long trips away from the mothership....you sleep in local B&B's beside the canal, eat in local restaurants, you minimize the disturbance of your passing in a small open boat....you gain many more local acquaintances while traveling in a humble open boat.......

On fins.....See http://setsail.com/naiad-stabilizer-fin-replacement-and-questions/
Your comments on the shallow banks lead one to suggest that paravanes are the solution....except that some object to the possible work involved in deploying and recovering these. So what about retractable bilge boards?

 

I've spent some time on the canals,and IMO you are right on about the small boat idea.


Having spent time on fishing boats, paravanes are so simple with nothing hydraulic or electrical to break.
Using steel rod instead of cables stops the fish from flying when they break out of the water.

However on the 74' with the outriggers sticking up they would likely ruin the sleek look of it and stop any canal work.

I have some ideas for a solution to the outriggers and wonder if they're marketable.


Which reminds me-a few years ago seeing a ~55 pleasure craft a few hundred yards off,listing heavily yet making headway.
No response from my hails & worried about them,I hopped on the PWC and blasted over to see if they needed any help.

Turns out one stabilizer was stuck in the down position...

 

I would not go too far down that way.
The narrowest French canals with the lowest bridges, must not be on the list.
There are quite enough years left to explore the deeper and easier to navigate rivers and canals in Europe.

I therefore see no sense in going below 3,50 meter (and not even that is required).

One could have horizontal outriggers for the paravanes, but they don´t look good. My guess, the average boater will vote for stabilizers on such vessel. And sure enough, you will not break them! Same is valid for twin rudders (engines), half of the river fleet in Europe has twin engines / rudders, they don´t break every season!

Regards
Richard

 

I agree. Tad's idea of using the small boat for a few days away will allow you to explore, say, Burgandy, with its low bridges and tunnels.

Not sure about going above 3m50. If it were me, I would want a boat that can get from the Channel to the Med, and that requires 3m50.

Again, it depends where you want to go. Here's a picture of two barges passing on the Canal de la Marne a la Saone - the barges are not fully loaded, but they are both rubbing against the bed/bank and each other.



Rest of the picture story is on:
http://www.picaro.nl/marnealasaone/index.html

Even if you don't have such an incident, there's a lot of debris in the canals. I've seen cars, shopping trolleys, animal carcasses, rope, tires, etc. all of which could damage a fin or a propeller.