Folkboat Fuel tank

[Tasybear]

Hello all ... from Tasmania.
I own a Nordic Folkboat (Clinker; Mahogany on spotted gum, teak cabin and cockpit coamings).She was built by Beashel, Sydney, Australia circa 1967.
The boat is fitted with a 12HP diesel. The fuel tank (cap. about 8 gallons) is aft above cockpit floor and close to transom.
I am concerned that the weight distribution of the boat may be compromised by the engine and exacerbated by the fuel tank location.
Is anyone here familiar enough with the folkboat design, to offer comment on adviseability of re-location of the fuel tank?

[Tasybear]

I guess I am off topic ... and you are all too polite to tell me so?
Reading some more (very interesting and informative) posts here, I guess questions should be confined to timber construction issues?
Or perhaps folkboats are just not so well known to members here.
Well, in truth, this boat shouldnt have an engine anyway!

[capt jake]

Tasybear, somebody will come by soon. Things are a bit slow lately. There is one fellow that comes to mind, he has written many stories about his 'fun' in his Folkboat. Noah is his name. Hang in there, you will get an answer. smile.gif

[ 01-20-2003, 06:49 PM: Message edited by: capt jake ]

[Gary E]

I am not familiar with the boat at all, but even if this tank is full it weighs say 100 lbs? where else would you place the tank? move your seated position and you change the boats balance ... ohh, and when you place a cooler of beer in the boat it weighs that much.. then after you drink the beer, what dif does it make where the tank is?

Maybe I am missing something here, but a 100 lbs just dont sound like much to me. Maybe a pic ot the problem might help?

G

[Tasybear]

'...Maybe I am missing something here, but a 100 lbs just dont sound like much to me.'

Gary ..I guess I could be exagerating the trim prob ...if it is one...of accumulated weight aft; the engine and the fuel tank?
I thought that it may make good sense to move the tank forward ...but the question 'where would you put it? ' is certainly a pertinent one, hence the post.

Capt Jake...thanks

[capt jake]

Malcolm, I haven't seen Noah post in quite a while. He is a great writer and had some great stories of his adventures with his Folk Boat. I hope we can get the word to him to re-join us!! smile.gif smile.gif

[mmd]

Tasybear, sorry that you haven't had a flood of helpful responses to your post. I think that Capt Jake may be right - people are a little wary here right now. Hopefully it will get back to normal soon.

I read your question when you first posted and didn't reply because I know that there are a few Folkboat owner/fans that frequent this place, and felt that they would be better suited than I to address the question. However, in their absence, I will jump into the fray, and hope that they will join in later and refine my answer.

Within reason, it is always good to get weight out of the ends of a boat. One can go too far and centralize the mass so much that the boat hobby-horses too easily, but a Folkboat is somewhat moderate in her overhangs, so I don't suspect that this would be a problem. Your challenge will be to locate the tank(s) in a new location that will be accessable for installation (I assume that you are not about to rip up the deck to gain access for removal/installation of the tanks), will not take up space needed for other uses such as cockpit lockers, and will not allow spillage or odours to enter the accomodations. I would consider a fitted, welded aluminium tank tucked up under the side deck just aft of the cabin trunk, between the hull side and the cockpit well side, on the opposite side of the engine from the exhaust manifold. Locating the house battery or fresh water tank opposite will balance the mass of the tank.

I wish that I had specific information on the design. I know the general form and layout of the design, but I have no hard data. My profession dictates that I deal in specifics, not generalities, so I usually like to answer such questions with "if you move this weight to that location, the changes that you will get are, blah, blah, blah ...". I can't do that in this instance, so am forced to give you banal general answers. Sorry.

The bottom line, as I see it, is that, yes, moving the tank out of the lazarette will be a good thing. Whether you are able to is dependant upon too many variables that I don't know, so I can't give you solid advice.

Hope that this helps.

[Hughman]

Malcolm, you didn't say if the boat is off it's marks with a full fuel tank, or if it steers poorly, etc.

Try this: Add some lead ingots to the forepeak and go for a sail. Anylize the effect of varying the trim. This might make any handling issues tolerable enough to avoid the crowbar remedy.

Good sailing, Hugh

[Tasybear]

'I would consider a fitted, welded aluminium tank tucked up under the side deck just aft of the cabin trunk, between the hull side and the cockpit well side, on the opposite side of the engine from the exhaust manifold. Locating the house battery or fresh water tank opposite will balance the mass of the tank.'

Yes thankyou mmd, this does help as it is along the lines of my own thoughts.

[Peter Jacobs]

Malcolm: I understand the Folkboat was originally designed with no motor, and ballasted accordingly.
Putting a motor in would cause her to squat slightly, so I'd think the best place to re-locate a fuel tank would be forward a bit.

[Ken Baker]

Malcom,

There was an article a while back in Classic Boat magazine about fitting up a diesel in to a wood hulled Folkboat in England. It's a tight squeeze! They had a fuel tank that was shaped to fit between the floors which is probably a great place to put the extra weight if your going to have it onboard. It was located fwd in the cabin area which would help with the fore/aft trim. I think they had the battery between another set of floors up foreward on a bracket to keep it up and out of the bilge.

My Folkboat (US-4) was built in Denmark for the US market in 1955. It had a Kermath Seapup gas engine installed somewhere in her lifetime. It was long gone when I acquired her and I've just stayed with using an outboard when I need it.

A 2nd waterline was cut in about an inch higher in the stern from the design waterline which must be where the hull sat in the water with the Seapup installed. This WL tapered back to the original waterline at the bow.

I would imagine with the revised waterline they had that the relationship of the center of lateral plane on the hull and the sail center of effort shifted a bit and may have effected the sailing ability under some conditions. I'm not sure why they chose not to reballast and get the boat trimmed to float parallel to the designed waterline. Not the way I would have done it.

Interestingly, the fuel tank was located outboard on the port side in the cockpit just aft of the cabin bulkhead but sat up high at the top of the cockpit seat level. Seems like an odd location but maybe not at the time. I think the Seapup had a magneto for spark and was hand started so there probably wasn't a battery onboard.

Mr. Jacobs is correct in that the original 1940ish design did not account for any engine installation. It was intended to be a very simple sailboat. For a boat with 5000 lbs of dispacement, adding a couple hundred pounds of engine isn't a big deal if that's what one wants and the weight gets distributed properly so she sails well. It's certainly been done many times but like you said, a Folkboat really doesn't need it.

If you interested, I'll see if I can scan in the tank location image from the article I mentioned and post it here. I've not tried the image posting routine on this forum as yet but I've certainly read enough about so I might as well give it a try.

Regards,
Ken

[mmd]

Ken, again speaking from a position of enlightened ignorance, I would suspect that the fuel tank was placed high in the hull so that it would gravity-feed to the engine.

[Tasybear]

Ken, thankyou for that ... indeed between the floors is a good place from the trim point of view. (I actually made this modification to an english 'Contessa 26' some years ago) but the space in this little Nordic folkboat doesnt appear to be as user friendly.
MMD's point about gravity feed to the engine is one I have been taking into account too..(airlocks are not nice and tend to appear at the wrong moments).
I have not sailed this boat extensively yet, I am refurbishing her, so I take on board Hugh's suggestion that I should thoroughly test sail her, before getting radical.

It does appear that, under the cockpit seat just abaft the companion way, balanced by a water tank opposite may well be a good compromise.

Thanks all for the input

[Ken Baker]

I hadn't thought of the gravity feed situation on an older gasoline engine. Probably just had a float bowl style carburator and no fuel pump. Probably only a museum piece now! Thanks for your very non-ignorant enlightenment mdd.

Malcom,

Your right about the air leak. But by the same token with a high mounted tank, a fuel line leak could happen and the tank would gravity feed it's contents into the bilge. There is probably no perfect answer. Boats are full of compromises aren't they?!

Anyway, hopefully, here's the tank installation picture I mentioned for reference:

http://www.imagestation.com/album/?id=4290794225&p=4240381326&idx=4

[Ken Baker]

Wrong address (I think)

http://www.imagestation.com/picture/sraid48/p19bede78d6832e800d1a76d5fd30963b/fcbf158e.jpg.orig.jpg

[Noah]

Yep, I'm hear. I have been away in LA for the last couple of weeks, and just now getting back to the forum.

In my limited experiance the Folkboat squats pretty easily. Between the batteries that I have just aft of the Cabin, and the 7hp outboard hanging off the back of my boat it does tend to have a bit of what some might call ass-squat...

My Folkboat used to have a 1 cylinder diesel engine in it (westerbeke) but was removed just before I got the boat. I do still have the engine. The previous owner used a small 5 gallon plastic tank for fuel, and this was located back under the helmsman's seat. I would assume that such a small quantity of fuel didn't add too much to the squating of the boat.

I would assume that the diesel was actually less stern weight than my outboard. I don't think that it weighed more than 150-200 lbs, but it was placed under the companionway as opposed to the 80lb outboard hanging off the transome.

Good luck, and let me know if you have any more questions.

Pictures of my Folkboat are at:
www.morebutter.com/patience (http://www.morebutter.com/patience)

Noah

[Noah]

Here are a couple more thoughts on my Folkboat:

Strangly enough the saltwater/diesel engine waterline scribe was right on for my boat being in freshwater with the outboard on the back. It may also be soaking up more water into the wood than it previously did because of years of neglect and massive wood drying.

The old tank was gravity feed and worked well according to the previous owner.

Because there isn't any overhand in the transom I wouldn't worry too much about the added weight as a structural issue, just as a trim thing.

Good luck, and post some pictures if you can.

Noah

[Dan McCosh]

I'm also not sure what exactly is involved here, but locally Folkboats are often equipped with a 5-hp. or so outboard on a bracket on the transom. This is pretty standard, and would have a much greater effect on the weight distribution than any inboard tank/engine. There also was a slightly modified later version with an inboard. Bottom line here is that the fuel weight at 8 lbs. per gallon isn't much. As one post mentioned--about the same as a beer cooler.

[Hughman]

My experience with this is from my Cheoy Lee Frisco Flyer, which is a carvel planked (teak) folkboat with an inboard MD-1 diesel engine.

The tank is placed just aft the cabin bulkhead, port side, and under the cockpit seat. Battery is just aft of this. There is about 50 pounds of lead placed forward for trim. for lateral trim, I use ground tackle in the starboard locker.

If I need more, I will shift Plato's "Dialogs" from port to starboard bookshelf. smile.gif

[John B]

Doesn't it also depend a bit on how you plan to use the boat. I worried about my aft tank but then realised that I was probably carrying enough anchor and chain to counterbalance the boat to a reasonable compromise trim. If you're racing, then you'll get rid of your extra anchor and other gear anyway and then perhaps you might worry. . I agree, I think you should sail it in it's current configuration first. Stick your grog up by the mast.......