To add a mast to a motor boat?

Gents,
I have recently purchased a 45' degroot steel motor boat and with the tax changes on diesel in the UK I am considering the addition of a 40' mast. I am looking to add skegs/bilge keels to protect the props and allow level drying where I can add ballast. I do not expect to point but if to sail off the wind could save lots of ££££s. Any ideas on what quantity of ballast I should be adding?

 

With this little information, you don't honestly think anyone could offer even a reasonable guess at ballast requirement, do you?

In short, you'll have to hire a professional to do a full work up on your yacht, to determine the necessary things to make an endeavor like this successful.

If you'd like to guess, so you can price lead or what ever, then take the weight of your boat and multiply by .2 and this will give you an idea. So, if you have a 30 ton boat you'll need around 6 tons of ballast, which would give you a 20% ballast ratio and a typical figure for a motorsailor. You may not need any ballast, but not knowing what you have, makes any further guessing fruitless.

 

Also depends on what type of rig. By the link is an example of this kind of modification with chinese rig. http://katera.ru/forum/index.php?act=attach&type=post&id=64317

 

I do not agree with some of what has been posted here
I am at present near start of canal river, coastal boat
and considred a reaching , sail for the rivers of europe with a sail something like loose footed with tack on bow and the (foot) as luff the masts will need to be lowered, in our case, quickly But the fuel savings considerable Many commercial fishers have these sails, lifting the load off the diesel
Simple to do a stability (inclining test upon your boat and , from there you will be able to determine how much sail you can carry
You have a very good idea and point
good luck mate
www.*********************

 

Hi Berty,
Without looking at the characteristics of your boat in some detail and discussing what sort of rig you'd like to carry, no one would be able to better answer your question than yourself. You probably have a feel for how tender your boat is, how much sail area you'll need to achieve a benefit, and some idea how much the resistance of your boat may increase as you add weight to it. How much freeboard does your boat currently have? Where do you plan on putting the ballast?
There are a lot of considerations to address, and it wouldn't be prudent to make a ballast recommendation without knowing <a lot> more information.
Best regards,
Nate

 

You should estimate what the whole price of such a addition will be, as well as its maintenance costs (sails, rigging, etc) and compare it against your fuel bill. Perhaps it doesn't worthwhile.

Cheers.

 

Home Bio diesel operations are actually quite practical once you get your setup correct. You can produce fuel from used cooking oil picked up from restaurants. It does require a bit of chemistry but is not out of the question. I know some farmers that produce most of their own fuel for equipment and their truck as well. If you have the space it might be a viable option for you. Here in the States some states have discussed taxing the amount of cooking oil that you convert but they will have one hell of a time proving it. Some biodiesel firms are putting contracts on restaurants and making it illegal for consumers to get oil from their dedicated restaurants. But it might be something to look into. Have you considered a diesel generator with a smaller engine powering large electric motors much like a diesel locomotive. This would probably make your craft handle better than converting it depending on the shape of your hull and could probably be accomplished with mostly second-hand parts.

 

i tis just common sense that the design of a power boat hull is optimized for entirely different things than a sailing or motorsailing hull, with the assumption of an adequate and reliable supply of steady power. When using wind to power such a vessel you are likely to be disappointed with performance, or perhaps tempted to take risks. Certainly you should consider multiple masts to get more drive for less heeling moment.

What is your boat like at very slow speeds? Does it wallow and roll uncomfortably and steer like a bathtub? I suspect plodding along at a couple of knots will not make you happy for long, but if you can live with it then you might get the same overall cost/performance ratio at lower risk and effort with a small outboard.

Having said that, if I were planning to do the same thing I would start by taking a look at current practice for an idea of what can be done in the say of a sail, such as a steel fishing boat. Better still, trade it in for a motorsailor!

 

All those comments have been valuable and pretty polite, but just the last of Terry´s sentences hit the nail!
You have purchased the wrong boat.
None of the old De Groot motor boat designs will sail, not if you add a keel, ballast etc. (or if, you have a dog unable to perform in both worlds). And the expense will never be worth the effort.
And btw. they usually are very fuel efficient boats.

Regards
Richard

 

I've never seen a powerboat that couldn't enjoy the benefits of at least a steadying sail, if not a down wind rig to ease the load on the drive train. Considering the original poster hasn't returned to the thread, it's likely I "insulted" him off or possibly he's found some first person advise.

 

Well I agree, but we are talking about this boat.

I do´nt see a conversion into a sort of motorsailor sensible here.

Regards
Richard

 

I can see a mast just aft of the pilothouse, on the centerline, with a small "main" to use as a steadying sail or a fairly good size jib, tacked to the foredeck as a reaching and running sail. A high cut clew and you're good to go. My 40' billboat conversion came with such a rig. It was used to save fuel, while loafing along at a few knots with their gear hanging.

 

Thank you for all your input. My gut feeling is to go for type of gaff main and a low genoa that will give a low centre of effort. The boat I have is the same model as the picture and with only paying 10k any modifications can be justified. Also as being a welder/fabricator the work is not a problem...
Thanks to all...Berty

 

I wouldn't recommend a gaffer, but a small Bermudian main with a large jib. The main alone can be used as a riding or steadying sail and the jib alone or with the main can be used to improve your range. Your CE will not be especially high with this type of rig and it's a more handy rig to live with.

 

Cheers PAR