An odd question from an ex-sailor about boat design

[Reb Bacchus]

As my bio states, I'm a retired computer nerd who is playing at being a Sci Fi writer. My first book has cleared several hurdles and is currently sitting on the Ex. Publisher's desk waiting for him to read and...

I'm currently writing the second book of the series. The premise is that a piece of a maximum security prison has been instantly transported to an apparently deserted planet. They are stranded there will be no rescue. The landmasses are different, but think of it as a clone of Earth, nothing weird. They have built a very small society (72) and survived a Juneau, Alaska type winter. Now they need to build a boat/ship to cross the "Atlantic" for supplies and raw material like crude oil. They are located on a peninsula similar to Nova Scotia. The west cost, where the tides are twice what you see in the Bay of Fundy is 25 miles away, the east coast is about 60 miles. They have a parking lot full of cars and trucks, but don't want to render them useless. They still have a small quantity of diesel and gasoline. There is an old growth hardwood forest at hand, they've established a saw mill and kiln. They also have pine trees for naval stores. The planet has trade winds and they have navigation equipment.

Finally, they have discovered there are people on the other continent, and they may want to bring those people (stone age savages) to their location. Given the above, what sort of vessel would you design. Their manpower is very limited, and the crew must be small. I had decided on a Viking Knorr. When I visited a Catalina forum two day ago asking about a canting keel to offset the fluid motion of the crude oil a member suggested a junk. I'm at sea, does anyone have a map?

PS
I should point out that I'm a storyteller with a programmer's understanding of written grammar. The book I wrote would be unreadable if my wife wasn't a wonderful English teacher willing to 'fix' my ramblings.

[marshmat]

Well, that's quite a challenge you've set there. It's been done before; that's how the Vikings got over here back about a millennium ago.

It worked for the Vikings; no reason why a knorr-type ship wouldn't work here either. You'd need some way of obtaining fabric for a sail.... the actual construction, of whatever wood is handy, was done entirely by hand back then and so should still be possible now- especially with a sawmill. A good look at Viking construction techniques (or, rather, what little we know about them) would help you greatly.

As for junks, canting keels, etc.- your situation sounds like it needs an uber-low-tech approach; none of that fancy stuff can be built without some degree of existing infrastructure at the construction yard.

[Skippy]

If you want a design that sounds alien, you might consider a proa. It's not necessarily the best design for that purpose, but then again it is good for open water, and maybe sci fi readers would be intrigued by it.

[yokebutt]

Polynesian style catamaran?

Yokebutt.

[FAST FRED]

With no shopbuilding experience a powered raft would be easiest to construct.

An axe and some binding vines would do it.


With sawn wood a barge (Long box) would be possable.

Propulsion would have to be a padle wheel, again as its far easier to construct than a propeller.

A jeep or similar vehicle could be carried , using the vehicle tires to turn wheels with no tires mounted for power source , and use on the "Other side" to explore and collect stuff.

Sailing would be out with either vessel , as it would require knowledge to construct the necessary parts.

With only 60 miles to go , the 3 mph a raft should go would only be 20 hours , an easy enough weather window to watch for.

FAST FRED

[Reb Bacchus]

First let me thank you for your responses, I do understand what an off the wall question this is. I meant to explain that their own west coast is 60 miles from their location. I think their only choice is to build closer to home and add a 250 mile journey to the tip of their peninsula. The trip would include battling a tide that is twice as strong at the one at the Bay of Fundy. The roughly north-south Bay is narrow and shallow which would make tacking difficult. That's why I thought they'd need oars. I couldn’t come up with a way to mount a shaft through the hull or to have them design a propeller. I hadn't thought of something like a paddle wheel... which is easy to do amid-ship. I suppose I'd need one on each side.

Once they get to the open ocean they have a 2000+ mile voyage with Atlantic type storms. Because they have a shortage of containers (making barrels is a high tech job) they need to be able to transport crude oil in a hold. I was concerned that motion of the crude might set up a harmonic that would cause most designs to capsize I also neglected to mention they have one person who has some limited lake sailing experience on boat that was too big for the lake.

Some of the things I don't understand:

One person recommended that I make the masts from board rather than solid wood. Why would this be better?

Could the same mast be used for triangular sail and a large square sail.

Would a swing keel allow as ship that might be as long as 120 feet sail better and closer to the wind.

How difficult would it be to make the fittings needed to build something like a sloop.

How difficult would it be to train men to sail the designed boat.

I do like the idea of a proa, or at least the idea of an outrigger. How big would that have to be for a 120-foot long ship?

Thanks again for any suggestions.

[Reb Bacchus]

An important datum I forgot to add is that they do have everything that one would find if you were to make snapshot copy of the whole internet. Thus they could find plans and perhaps some simple how-to guides. They have experienced carpenters and welders, of course the gap between a blue print and a final product is huge.

Still, one of the problems I have with most Hollywood stories is that they underestimate human creativity. I can't believe that a group large enough to build a boat, and with plans, would be unable to do so. My problem is that they would spend much more time and study on what kind to build than I can. After all, their lives would be on the line.

[yipster]

"The premise is that a piece of a maximum security prison has been instantly transported to an apparently deserted planet.
They are stranded there will be no rescue."

how cruel, it may be a good idea to open another exclusive interplanetairy mountain lake boating resort

[Skippy]

"The trip would include battling a tide that is twice as strong at the one at the Bay of Fundy. The roughly north-south Bay is narrow and shallow which would make tacking difficult."
Sounds kinda like Salamis. Any chance of them dukin' it out with a bunch of waterborne natives?
A large proa would not be able to come about in a narrow waterway. It would need alternate propulsion or a favorable breeze. And of course a keelboat might get stuck in the shallow.

"One person recommended that I make the masts from board rather than solid wood. Why would this be better?"
If you make a hollow mast out of four long vertical boards, it's lighter and stronger than a solid one.

"Could the same mast be used for triangular sail and a large square sail."
You'll need a yard for the downwind sail. Maybe it could pivot into a gunter or a lateen? The lateen rig is common on proas.

"Would a swing keel allow as ship that might be as long as 120 feet sail better and closer to the wind."
Yes. Anything to get the ballast to windward. Even better is those CBTF designs.

"How difficult would it be to make the fittings needed to build something like a sloop."
I don't see why a sloop would be any harder than any other multi-sail design.
On a large ship, a single-sail rig would be inefficient and hard to deal with.

"How difficult would it be to train men to sail the designed boat."
Considering the stakes, I would expect them to be well motivated. There might be one or two ****** along just to make the trip interesting, but it's not a weekend cruise straight out of the showroom, so learning some knots and terminology shouldn't be too bad.

"I do like the idea of a proa, or at least the idea of an outrigger. How big would that have to be for a 120-foot long ship?"
An Atlantic proa keeps the outrigger on the leeward side. The outrigger is almost as long as the main hull, and is designed to take a significant portion of the boat's displacement.
A Pacific proa keeps the outrigger to weather. It can be much smaller, and ideally a good crew will keep it flying for max speed.

[FAST FRED]

Unless they have a loom and experience making fabric that doesnt stretch , conventional sails are out.

Simplest is the chinese junk rig where long battens tke most of the load fabric would on a modern boat.Woven palm fronds work OK as junk sail , with wooden battens

With huge tides , its a FREE ride IF you have a good anchor and a way to get it back aboard.
Shallow water is a big help , as the current usually runs slower in thin water , and the anchor easier to get back aboard. Steer down he middle for the fast ride , head towards shore to anchor

Go with the flow , anchor when the current is adverse.

For 2000 ocean miles the only way to go is WITH the wind , as the Chinese learned milenium ago .
Ride the seasonal winds DOWNWIND to your destination , await the seasonal wind reversal to get back. No big loads ,no fancy metalwork in rigging , no wires needed to be mfg and very little sailing experience needed to blow downwind.

Any tank that is FULL develops no harmonic from fluid free surface .

Barrels are hard to make , any animals to skin for bladder tanks?

Maybe the fish are big enough to gut & hollow out and could be used as big containers?

FAST FRED

[safewalrus]

Hey this is science fiction for heavens sake, it's your story tell it your way while we get on with ours! Any way you want to it ain't Earth, normal rules don't apply do they - they don't if it's all in your head

[gonzo]

Vikings didn't know the saw. Nordic construction uses split wood. Also, the planks were sewn to the frames.

[yipster]

how can smart ancient vikings be dropped on a yet un-named planet beyond pluto without knowing what a saw is?

[Rasman]

Handling large sails with a limited crew, raising a good anchor, dealing with low-wind situations. Stick a jeep or two on board, use them as drives for paddle wheels (rear tires could roll over logs to turn the paddle wheels) and winches.

I am thinking of a proa style boat, if you want it to sail through narrow channels, stick a hinge in the middle of the bits which hold the outrigger on, and lift them from the middle with a cable. = thin boat.

For sail power, what about a kite? Very manageable in a situation like that. Again, jeeps for winches. http://www.gizmag.co.uk/go/3692/

annimal skins would be a good way to transport oil, and you could re-distribute the thingos around the boat to balance it (high winds, move them to the outrigger... big storm, stick them as low as possible etc etc etc)

You could even build a primative steam engine if you wanted, with you welder dudes.

sounds like it good be an interesting read.

[gonzo]

To have oil the planet needs a history similar to Earth. That would include all the geological eras with the exact fauna and flora.