New Boat Design - help needed!

[woodie1000]

Hi, Mrs Woodie1000 here...

It's our 3 year old daughter's school regatta next week and I have to build her a winning boat this weekend. I've (rather stupidly) built us up as obvious winners given our boating interests...but the truth is that neither of us have a clue about building a winning boat!

The brief...

"The boat should be no longer than 15 inches in length and capable of sailing across the school swimming pool (a distance of about five meters) with the aid of nothing more than the wind! No outboard motors, please!"

The children all line up at one side of the pool and woosh the water with their hands and blow...the first boat to reach the other side is the winner.

After initial discussions with JFM (admittedly blurred after a few bottles of wine) we've got a good stock of polystyrene, but I'm not sure what to do with it!

Please HELP!

 

[mil1194]

....an old (or new for that matter) chip tray and a sort of mast-ie type-ie thing on a chip fork blu-tak'ed onto the middle of the tray...... ('Only trying to help' he mutters as he creeps towards the door)

 

[grumpy_o_g]

As light a displacement as possible, so polystyrene's a good start. Test it and make sure it's fully waterproof - if the winds are light it could be a war of attrition so nothing that can get swamped or water-logged.

As much sail area as you can manage and make the sail(s) light and flexible (I assume it won't have to into wind). Better still try and make a range of sails for different wind conditions.

I'd suggest a catamaran if you can make it strong enough but the bridge needs to be very strong, light and well attached. Don't fall into the trap of thinking the mast needs to be a stick in the middle of the boat - it just has to be light, strong and to support the biggest sail area possible. If you're going downwind a frame is fine.

Give it a keel (or two) to give it directional stability and maybe simple transom rudders to help.

Test it all thoroughly (not just by dipping it in the bath). This boat has to survive transport to school, lifting and carrying to the pool and launching, waiting amongst all the other boats (with "enthusiastic 3 year olds holding them I presume), then a multitude of excited 3 year olds splashing, wooshing, blowing and probably falling in on top of them too...

Test it early - it should be built by now and being tank-tested. If you struggle to make a multi-hull that works then a monohull with a fin keel and a fisherman's lead weight at the bottom would be my next best guess.


Prepare your excuses early, examples are below but if you nip over to Scuttlebutt the racing types on there should be able to give you loads of them.

I can't understand it, Robin and Ellen were so impressed.
I think we stretched the sails testing it during Weymouth Speed Week.
Of course, it's more of blue water cruiser really....
We're still waiting for the protest results.
etc...


Look for loopholes in the rules. Is a strategically placed fan allowed? Can you find some ringers who can blow really hard? Is there any way you can nobble the others? Flame throwers on your boat? Feed all the other kids so much Jelly and Cake that they feel sick and can't blow hard at all?

Get your daughter in training now - she's needs to practice blowing hard and wooshing as well. This will have the added advantage you'll no doubt get a good night's sleep.

You'll want your daughter to share the experience of building the model - make sure you carefully modify and rebuild everything she's done after she's gone to bed, this time to your standards. Better still build two boats but don't tell her. This gives you a back up when the dog runs off with your boat/Mr Woodie sits on it by accident/etc.

All this is assuming you don't have time to get a roll of carbon-fibre to jfm along with a set of scale drawings of B&Q before his next visit to Broom of course...

OK, what have I missed?

Remember it's the winning that counts, not the taking part.

 

[jfm]

Tricky. This is an important competition. I reckon a catamaran design, plus fancy aesthetics. Pic below. Hulls can be 2 orange squash bottles, or two blocks of polystyrene. Make the structure that connects the two hulls out of a square bent from coat hanger wire. Bend it neatly with pliers, and make a big overlap of the two ends of the wire and bind that overlap with tape (see little sketches, left, below). Then bind the square to the hulls/bottles with tape, wound around the circumference of the bottles. That's your basic cat, and it has no surfaces to hold water when it gets splashed. Next, make two sail supports out of triangles from coat hanger wires. Again, tape triangles to hulls. Finally make a rectangle from coat hanger wire the size of the sail (bit bigger than A4 paper mebbe), and fill this with a taped-on plastic bag to form a sail, the thin Tesco sort. Tape this sail structure onto the masts.

This design is slightly front heavy. It would be good to add a tiny bit of weight to the transoms of the hulls. Eg, glue on a lego brick or two. Also you must make the hulls 15inches long. Any shorter and you could lose the race by a nose. So glue lego bricks or similar to the transoms, to make the thing 15inches long

This next part isn't necessary, but it would track slightly straighter with a couple of fin keels aft. Suggest do this by gluing on credit cards with Gripfill glue, left to dry overnight. As per pic. For maximum kudos these should be Coutts/Hoare+Co/JP Morgan PB style credit cards, and current not expired obviously

When all done, it needs to be made to look nice. The kids must like the boat, becuase after half the fleet have crashed and burned you want them all to want YOUR boat to win. So, trip to B+Q to buy spraypaint. Spray it all in primer first, then top coat. Pick a theme? Spray it orange and then write "easyschool" in white tippex down the side or something? Whatever, it has the be the boat the other kids most like, so they all want it to win and blow it the hardest

All imho and not at all thought about carefully. If you are allowed 2 entries (one for G?) I'd buy a big balloon and inflate it to 15inch diameter. That might go fastest when the kids start blowing

 

[jfm]

As light a displacement as possible...nothing that can get swamped or water-logged... make the sail(s) light and flexible...I'd suggest a catamaran... Don't fall into the trap of thinking the mast needs to be a stick in the middle of the boat...a frame is fine... simple transom rudders ...Remember it's the winning that counts, not the taking part.

Tee hee. I typed my reply before I'd seen yours but I see we must have gone to the same naval architecture academy

 

[mil1194]

(Feeling a little in-adequate now.....sorry)

 

[jfm]

Its 6.30am and no reply from the Woodies. B+Q opens in an hour and a a half. They must have not heard the alarm clock
I think I'd better ring them

 

[petem]

Tesco? Nah you need a Rolex or Cartier plastic bag (or Waitrose at least) carefully cut to retain the logo.

Pete

 

[Mr Googler]

Where's Bruce Farr when you need him...

To save all the worry of superior design may I suggest a WCT (Wind Creation Tool) be employed.
Any decent race team will need shore support so perhaps a shoe box placed on the side of the pool decorated to look like team headquarters. Inside said box could house your WCT and I see no reason why 10 knots could not be achieved.

Obviously there will be lots of screaming, shouting and puffing so this could mask any noise made by said WCT. Some might say its cheating but I would say its thinking outside (or inside in this case) the Box

I miss my childhood!!!

 

[woodie1000]

(Feeling a little in-adequate now.....sorry)

That's ok - I enjoyed eating the chips whilst reading the others replies!

Thanks everyone. I'll get started on my (winning) creation today and will post photos along the way, which you can compare to JFM's 'in build photos'.

And don't worry about the winning philosophy - it's already well ingrained. Here's a photo from sports day's 3 legged race. I'm teaching her to say "I'm a Woodie and I'm a winner!".

 

[Nautibusiness]

Adding to the squash bottle catamaran idea...

Turn the sail around and have the bottle tops as the stern of the boat.
Fit your Couts Keels just forward of the point the bottle necks leave the water.

Next comes the secret weapon.
Half fill each bottle with some really fizzy cola or preferrably lemonade as it is clear.
Remove the bottle tops and drill small holes which can be tightly filled with any pen shaped object (nails may not be a good idea in case they "go off"). Put said objects into the holes and make sure they are very secure. Attach a single pull cord to each so that they can be yanked out at the appropriate time (Ideally make these out of clear fishing line for invisibility)

Next, very carefully add two teaspoons of baking powder to each bottle before screwing the tops on very tightly.

Assuming parents can go to the Regatta be very proud of your childs design and vigorously show it to all the other parents and children, shaking it in the air. Alternatively, a three year old dropping it a few times on the way to the pool will have the same effect.

As the race starts allow things to commense as normal, but once the pull cords become taught give one sharp pull releasing the bottle stops.
The enormously high pressure fizzy drink and baking powder mix will provide instant rocket power which should provide at least 20 knots of performance across the pool. Using clear liquid, fishing line and descreet bottle stops and nobody will ever know how you (err sorry, your child) did it.

Go Woodie, Go Woodie, Go Woodie

 

[jfm]

How's it going? Keel(s) laid yet?

Also, what was I thinking with my comment on the orange colour scheme? You should spray it navy and white and call it MiniAnassa. And hand out charter leaflets and stuff to the parents

Talking of catamarans, it seems they're not built too well sometimes and you're safer doing as you're doing which is to make it yourself. Gludy is having trouble again. He should have bought another Fairline - the only boat that hasn't gone wrong on him is his trusty Squadron 59

 

[rr_123]

Adding to the squash bottle catamaran idea...

Turn the sail around and have the bottle tops as the stern of the boat.
Fit your Couts Keels just forward of the point the bottle necks leave the water.

Next comes the secret weapon.
Half fill each bottle with some really fizzy cola or preferrably lemonade as it is clear.
Remove the bottle tops and drill small holes which can be tightly filled with any pen shaped object (nails may not be a good idea in case they "go off"). Put said objects into the holes and make sure they are very secure. Attach a single pull cord to each so that they can be yanked out at the appropriate time (Ideally make these out of clear fishing line for invisibility)

Next, very carefully add two teaspoons of baking powder to each bottle before screwing the tops on very tightly.

Assuming parents can go to the Regatta be very proud of your childs design and vigorously show it to all the other parents and children, shaking it in the air. Alternatively, a three year old dropping it a few times on the way to the pool will have the same effect.

As the race starts allow things to commense as normal, but once the pull cords become taught give one sharp pull releasing the bottle stops.
The enormously high pressure fizzy drink and baking powder mix will provide instant rocket power which should provide at least 20 knots of performance across the pool. Using clear liquid, fishing line and descreet bottle stops and nobody will ever know how you (err sorry, your child) did it.

Go Woodie, Go Woodie, Go Woodie

is this your, ahem, wind powered boat

 

[rich]

Try somthing like this, by the way, we won the race,

You can't see it on the pic, but you need a keel, i made it with a fishing weight, like a bulb

And Yes I do take Gaffer tape on holiday

 

[jfm]

Fantastic job Rich!
I don't think the woodies need a keel in this particular case cos they're only sailing downwind

 

[woodie1000]

Right - I've been to B&Q (and spent a small fortune) I've gone for a silver glitter paint and a Dora Explorer Kite for the sail - that should get the kids blowing in our direction!

Keels are laid, but I'm worried the glue won't hold it. I've used a kind of sealant type adhesive. I'll test it before going to bed and if it hasn't worked I'll try something else. I was going to make a small slit in the plastic bottle to poke the credit cards in, but was worried it might then take on water and sink!

Hangers are all bent and ready to be taped on - I've made the sail as wide as possible to grab maximum kiddie puff.

Swimming lesson tomorrow so I'll take the boat along and report back after the maiden voyage!

 

[BrendanS]

Equip your child with one of these air blaster toys - you can buy them in most large toy shops. This will allow directional air directly to your boat

http://www.amazon.co.uk/Hamleys-Caboom-Air-Blaster/dp/B001KM7CY4

 

[jfm]

Right - I've been to B&Q (and spent a small fortune) I've gone for a silver glitter paint and a Dora Explorer Kite for the sail - that should get the kids blowing in our direction!

Keels are laid, but I'm worried the glue won't hold it. I've used a kind of sealant type adhesive. I'll test it before going to bed and if it hasn't worked I'll try something else. I was going to make a small slit in the plastic bottle to poke the credit cards in, but was worried it might then take on water and sink!

Hangers are all bent and ready to be taped on - I've made the sail as wide as possible to grab maximum kiddie puff.

Swimming lesson tomorrow so I'll take the boat along and report back after the maiden voyage!

Suggest use Gripfill glue, and dont slit the bottles for the cr cards. Just stick the cr cards on with a heavy bead (same size bead as sealant around a bath) of Gripfill both sides. Glitter paint sounds excellent!

 

[grumpy_o_g]

Bright pink glitter paint I hope.. Can you find some good stick on carbon-fibre look-alike? All helps psyche the opposition. Don't forget the good luck message from "Robin, Ben and Ellen".

If you're struggling to get the keels to stick see if you can get a bit of quarter round or similar and use that give a good glueing area. Alternatively if you have some more plastic you could possibly glue a couple of struts, one each side to brace it. You really want the keels well attached and unable to flop sideways. Think how much force there is on a credit card even moving slowly through the water any way except edge on.

This is the sort of thing I was thinking about (I guess Bruce Farr's job is safe at the moment). I will bow to jfm's superior engineering knowledge if he feels otherwise.

 

[grumpy_o_g]

Another thought if it's not too late. You may want to blue-tac the keels on at first and test the boat to see how it behaves with them in different positions. Don't under-estimate the keels - they're turning your craft from a li-lo into a boat.