Estimate of construction time

[Royhunter]

Hello Everyone,

I need to get some estimate of man hours for the hull and deck construction of a 42-44 sailboat, like a Roberts or Van De Stadt design. I plan to build the hull structure out of multiple layers pf ply to create larger structural members and skin the structure with either thin ply, fiberglass strips, foam core ply (or open to other ideas) and then lay up woven glass cloth inside and out.

I would like to know what the typical amount of cloth layers that would be used on the outside of the hull and what weight of cloth, and also how many layers on the inside.

Keep in mind I would be classed as a master carpenter by profession so anything wood is second nature to me and I have built large live seafood holding tanks laying glass over ply in the past so I am up for the task I just have not built a boat before.

I have some other questions I wouldn’t mind knowing like what the total man hours estimate would be for a complete 44 foot boat, what materials custom fuel tanks can be built with (fiberglass??), what the advantage would be to using Kevlar on the hull instead of glass, and how strong is too strong when building the structure and determining the amount of layers of glass and epoxy? Can a hull be too stiff? I know creating structural members with multiple layers of epoxy-bonded marine ply can create some extremely impressive strengths but I also know a little flex is a good thing in some applications. (Mr. hip pocket engineer here)

In the end I want a boat that can take a serious pounding and be near bulletproof even if I need to sacrifice a bit of performance due to additional weight. Considering I live in Key West and plan to sail to places that have killer tidal waves... I think having a boat near indestructible wouldn’t be a bad thing.

I am very interested in your thoughts and comments.

[Raggi_Thor]

The manhours needed to build a boat off course depends on the type of boat, how complex the structure is, etc, etc.
2kg/hour seems to be a god bet, that is 500 hours per ton.

You can multiply with anything from 0.4 to 2 or 3 depending on complexity, detailing, installastions, finish, use of cnc etc, etc.

Larger (heavier) boats may consume (relatively) fewer manhours than smaller boats...

Regards,
Ragnar Thor Mikkelsen
www.MBOATS.no

[Dutch Peter]

Originally Posted by Royhunter

I would like to know what the typical amount of cloth layers that would be used on the outside of the hull and what weight of cloth, and also how many layers on the inside.

Roy,

Skin thickness depends largely on the size of the panel and it's location. If you have proper drawings it's surely mentioned. Otherwise search this forum and buy the books that are recommended, you can do the math yourself.

Originally Posted by Royhunter

the end I want a boat that can take a serious pounding and be near bulletproof even if I need to sacrifice a bit of performance due to additional weight. Considering I live in Key West and plan to sail to places that have killer tidal waves... I think having a boat near indestructible wouldn’t be a bad thing.

I recommend you switch to steel if this is really what you're after.


Regards,

[Royhunter]

Thanks Thor, I never looked at man hours/ton but that is a good way of estimating to at least give you a ball park figure and that is what I was after. It's simular to cost per sq foot building a house. The fancier the house the higher the sq foot price for estimating.


Peter,
I do plan to get the books before I take on this project, I am just trying to get some general ideas before I make the final decision to do it. (To see what I am up against) As far as steel goes... well asking a life long master carpenter to build anything out of steel when it can be built out of wood is unthinkable! :-). But I do agree that a steel hull, for strength, is fantastic. I want to build a boat as the ultimate test of my talents and it will be something that will be a great source of enjoyment when it is completed knowing I built it.

As far as a 42-44 foot sailboat is concerned, I have found the Roberts and Van De Stadt stock designs for sale, are there any other designers that have stock plans for sale for a modern design? I would love to have a custom boat designed but it is just a little out of my reach when I want top of the line hardware, sails, and a 5 star interior.

Thanks

[D'ARTOIS]

Thor comes quite close to a fair estmate, it depends also quite a bit on the grade of finish you require. However, something between 6 and 10.000 hrs could not be exaggerated.
You mention Van de Stadt, I know this company quite well, or used to know quite well, and next to the boatplans they sell they give you a host of information you require about the construction system and many tips to make building easier.
They have in their program a 44' round bilge, that you can build out of various materials, steel, alu, GRP and Woodcore.
Woodcore might be in your case the best solution as you are an expert carpenter. To combine carpentry and working with glass and resins is notb that particular difficult, you know that already.
To give in the blind particulars about sizes and weights, is not opportune. The particular architect/designer will give you full guidance in that respect.
Specifically, if you opt for the woodcore concept, I would advise you to check with Van de Stadt & Partners in Wormerveer, Holland about a design or a catalogue of their designs.
For the rest, well you have found your way to this forum, didn't you?

[Royhunter]

Hello D'Artois,

Thank you for the post.

I am very impressed with the Van de Stadt designs. I am very impressed with most of the European designs come to think of it. I just wish I had more options to look at. I do not like designs like the Island packets. They are.. Find nice words.. Ummm not a very attractive sailboat and I dont see why they are worth so much money. There seems to be hundreds of them for sale in Florida and 10 year old boats are listed for $350,000!

I have looked at thousands of links on boats and the only two designers I can find for stock plans I would consider is Roberts and Van de Stadt. Roberts because of price, Van de Stadt for their design.

A great website is that site in Norway Njordforum. http://www.njordforum.no/ The work done on that wood boat was more than exceptional. I wish the site was in English. Just the photo's kept me there for hours. That boat, without a doubt, is an breath taking example of fine carpentry skills. Boats like that make boatbuilding a true art form. I would encourage everyone to look at that site and just go through all the links on the left. It is an amazing example of old world craftmanship. Truly to be admired.

The two best things I have found so far on the internet is that website and this forum!

[Raggi_Thor]

:-) Ragnar Steinhovden at www.Njordforum.no has collected a lot of knowledge on boutbuilding where he combines traditional and modern materials and methods. Maybe he should translate parts of the site to English?

If you want a modern, lightweight, fast cruiser, take a look at Dudley Dix' website, www.dixdesign.com. He has a very nice 40-footer built in ply and epoxy with a radius chine (so it doesn't look like a plywood boat): http://www.dixdesign.com/didi40cr.htm.
Some of his larger steel boats can also be built in plywood if you prefer.
I think plywood with most part precut in a cnc shop is the quickest way to build a "one off" lightweight boat today. If you want a heavy boat, steel is better than grp.

[Jan van Veen]

2kg/hour or 4pounds/hour

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The manhours needed to build a boat off course depends on the type of boat, how complex the structure is, etc, etc.
2kg/hour seems to be a god bet, that is 500 hours per ton.

You can multiply with anything from 0.4 to 2 or 3 depending on complexity, detailing, installastions, finish, use of cnc etc, etc.

Larger (heavier) boats may consume (relatively) fewer manhours than smaller boats...

Does this formula include the weight of the keel?
These hour can be considered to be needed tot start from scratch and finish with a boat ready to sail?

Does it make any sense to use this rough estimate rule for:
- 40 foot sailbout (beam 13 foot )
- displacement 4500 kg
- ballast in keel, 1800 kg
- built with SAN foam, biaxial glass and epoxy
- interior pretty simple (no heads, basic table en settee, no interior in front of mast

Would this be 200 hours per kg, 500 or rather 1000 hours per kg?

Thanks for your help.
Jan

[Raggi_Thor]

I think this can be compared with some of Dudley Dix' simple designs where 500 hours per ton of finnished boat seem to be normal.
That means more than 2000 hours for you :-)

[Royhunter]

You will find if you havent done this before it will take you twice as long as someone who has done it over and over again. It is called the learning curve.

What skills do you have? Are you good with fiberglass? Are you good installing motors and rigging etc etc. Are you lazy or do you work quickly?

I dont think it will take you 2000 hours to build a lock up sailboat which is basically what you are building (No interior) Building a hull is not that difficult if you posess the skill and proper attitude to do it.

To be safe it is always best to plan for the worst but also think about being realistic.

[cyclops]

Larger beer kegs take more manhours to complete.

[DavidJ]

I would look at getting a custom plan done. The smaller one man designers out there are often much cheaper than big firms. With a custom plan you get what you want with no compromizes. It would be a shame to pour so much time, effort and money into something only to say I like it but if it only had this...

I highly recommend Paul Gartside. His name pops up all over wooden boat magazine and for good reason. I know him and can say he is very helpful and extremely talented. He actually builds the boats he designs so he can answer any questions that come up in the building process based on real life experience. Doesn't hurt to give him a call.
http://www.gartsideboats.com/

[Raggi_Thor]

Estimated building time can easily be doubled or halfed depending on skill, level of finnish, working conditions etc, etc.

If you look at Paul Gartsides list of plans, you also find an estimate of building time for each boat. Very interesting!
A five tonner, http://www.gartsideboats.com/catsail4.php#26whyte,
takes 5000 hours,
a 15 tonner, http://www.gartsideboats.com/catsail5.php#40canoe,
takes 9000 hours
a 2 tonner, http://www.gartsideboats.com/catsail2.php#wright
takes 2000 hours

Of course, theese are different kinds off wooden boats, more ore less details.

[Jan van Veen]

Thanks guy,

I'm planning a boat which will be more simple in rigging and interiour.
At this moment I have good skilles on wood and epoxy, doing hull repairs and changing interiour. Also entirly refitted the rigging and decklayout.
Little experience in glassfiber, but I am planning to get some more before starting building.

For now I think I have enough info for some rough estimates. These will be further detailed and verified in the design-process.

Some lessons form your postings and other readings:
- KISS and make sure you stick to it (hull, interiour, rigging etc.)
- adjust design to building methode like DUDLEY DIX did with the Didi 38
- keep momentum in the project
- work on more than one sub-projects at a time, so no time is waisted while rethinking on issues.

Im consdidering to use a swing rig:
- easy handling for solo sailor
- probable more affordable than conventional racer/cruiser rig
(one sail, little deckgear, however carbon mast and extra reinforcements on hull)
- lower risk of breaking parts of rig or mast (no compression from tension of stay's and shrouds)

Swing rig designer
RoboSail Open 40 with Swing Rig

[lprimina]

I dont remember who said it above but they are right. The first boat will take two to three times longer, the second boat two times longer. the third boat right on time (hopefully). Something else that will speed you up is-
1) do not panick when you make a mistake, it can be fixed
2) DO NOT PAT YOURSELF ON THE BACK WHEN YOU DO SOMETHING RIGHT THE FIRST TIME
and #
3) After you do 5 to 10 feet of completed work do not stand back and admire it for 30 minutes, 10 to 15 minutes is enough time.
Good luck and enjoy
Ben