Mekong River Catamaran Using 5,000 Plastic Bottles

[ozskipper]

[QUOTE=Isara;485288] snip

Here is a pic of a pontoon without bottles.


And one with bottles.


What the boat will eventually look like.

QUOTE]

I wish you well with your venture. I am a little concerned that the weight of the construction will create somewhat of a crushing effect on bottles near the centre of bouyancy. Particularly as the loads shift forwards and aft with waves etc. I understand that the load will be spread out, but as it constantly shifts it will but the bottles under various compression loads.

Although I did just read down and see the Dry Ice concept. Very Clever! Will you be doing that on every bottle. And at the risk of being a Nay-sayer, have you considered the impact of the CO2 vs enviro positives?

Good luck with it all the same.

OZ

[Isara]

Hi OZ. Some adjustments will need to be made to the design but we won't know what those adjustments will be until we get the boat in the water and actually see how the bottles (and boat) react. Our earlier tests were positive that the bottles could handle the load but I'd be lying if I said I wasn't a little concerned. The boat is much heavier than we had planned.

Plastiki, a much larger catamaran that sailed from San Francisco to Sydney, used 12,000 bottles and the dry ice technique. They were the inspiration for this project and they were very careful about the impact their boat had on the environment. The CO2 issue was never an issue with them since the pros out-weighed the cons.

In total we will only be using about 2-3 kg of dry ice (just a small slice in each bottle). When a car burns one gallon of gas it releases about 2.9 kg of CO2 into the air. Since I haven't owned a car for seven years, I think the environment will forgive me if I release a little CO2 in the name of an anti-trash campaign. lol Especially if the dry ice comes from a business (ice cream manufacturer) that tosses it out any way.

The goal of this project is to make people aware of the trash problem in their rivers and oceans and do it in an interesting and unusual way. We are not trying to make a carbon-neutral boat.

[ozskipper]

Originally Posted by Isara

Hi OZ. Snip

The goal of this project is to make people aware of the trash problem in their rivers and oceans and do it in an interesting and unusual way. We are not trying to make a carbon-neutral boat.

All points taken. Good luck with it. And congrats for how far you have gotten so far.

Oz

[Isara]

Almost done with the pontoons.









Just waiting for the "metal guy" to finish cutting all the braces. Then we'll take it apart and move it to the river's edge, where we'll paint it and put it all back together again. Hopefully.

[Event_Horizon]

What sort of propulsion are you considering?

Also, using the dry ice to increase the pressure inside the bottles is a neat trick. Seems like that will be quite useful for the high load bearing bottles.

[Atlantic42]

Love your project. I think it has legs well beyond your two month timeline. Thinking along the lines of a more long term educational project perhaps... it might be wise to cover the 'below waterline' bottles that are not visible to your intened audience with a sheet of thin plywood (coated on all sides with a sealant like epoxy). This would help reduce drag considerably, speed your trip, limit marine growth and give the project vessel the opportunity to live on and continue teaching with a new skipper/educator.

[Isara]

@Event Horizon - Thanks. We'll be using a 10hp DC motor (either a Mars or D&D) and a lot of donated 12v batteries. We will recharge them at each village where we stop. We have a local mechanic who repairs golf carts helping us wire everything.



@Atlantic42 - I agree and, if the boat performs well on the Mekong, we'd eventually like to take it to the Gulf of Thailand and sail it along the coastline. There are some areas that have an unbelievable amount of trash and very little education about fixing the problem. Here are some pics of Bang Saen.





Thanks for the suggestion, David. Covering the bottles would definitely speed up the boat. Unfortunately, if the bottles below the waterline are covered then they won't be utilized for buoyancy. The bottles need to be exposed, and touching the water, or else they serve no purpose.

Similar plastic bottle boats seem to all have the bottles exposed below the waterline.





Thanks for all the feedback CF members.

[FlopShop]

Great project Isara!!!

I'm working on a similar project here in Hawaii. As you've mentioned, the Plastiki helped pave the way for projects like ours by proving two important building concepts/methods:
1. dry ice can be used to make the bottles ridgid
2. leaving the bottles exposed below the water line will work just fine

Most of the people I've shared my project plans with were amazed at how much bouyancy plastic bottles provide. My project is based around the use of 2 Liter soda bottles. A bottle this size will neutrally float 4.5lbs of weight. My catamaran will be 24ft long and make use of approximately 1600 bottles. That's 7,200lbs of neautral bouyancy!!!

While our designs differ in intended use (mine will be built for ocean sailing), it's interesting to note that we've both chosen a similar Deep V hull profile. And kudos on the planned use of electric propulsion!!

Anyways, I just wanted to compliment you on your design and your continued progress on the project. I look forward to seeing and hearing more about it in the months to come.

Thanks ~Will

[Geminidawn]

Originally Posted by FlopShop

While our designs differ in intended use (mine will be built for ocean sailing),

Great to hear of such adventures! There was once a story not too long ago of a tribe of homeless in New York that had no previous boatbuilding or sailing skills sucessfully built a raft out of junk and sailed it to Cork, Ireland.
It was a great story and I'd of loved to hear more about it but both the powers that be and the media played the whole thing down very quick and said nothing more of it for immigration and safety issues, which is sad.

I can't help but admire their determination and spirit though

[Event_Horizon]

Originally Posted by Isara

@Event Horizon - Thanks. We'll be using a 10hp DC motor (either a Mars or D&D) and a lot of donated 12v batteries. We will recharge them at each village where we stop. We have a local mechanic who repairs golf carts helping us wire everything.

If there is space in your budget and on your boat do you plan to take a more powerful outboard with just a bit of fuel?

A 10 HP electric sounds like it might not cut it if you need to fight a current.

[Isara]

@FlopShop - Sounds like a great project you're working on. Please keep me informed of your progress.

@Geminidawn - Very interesting. I had never heard about that story before. Thanks for sharing.

@Event Horizon - We're looking into that now. We might be able to get a used gas powered outboard motor and keep it for emergencies. The electric motor will go up to 25hp peak so we're hoping that will be enough for most situations.

UPDATE:
Last week our volunteers erected the tent where we'll be building the boat. (It was loaned to us specifically for this project.)





On Saturday we received the frame pieces to one of the pontoons and our volunteers quickly got to work sanding it and putting on the first coats of paint. All the sandpaper, brushes, and paint were donated by local shops.



On Sunday morning some kids from the neighborhood came by and asked what we were building. A few hours later they came back and showed us some plastic bottled boats they had made.



And one kid showed us a dead scorpion he found nearby. :-)



Our goal is to have the bottles in this weekend and have both pontoons in the water sometime next week.

[Isara]

The first pontoon is nearly complete! Just waiting to get the parts for the second one.





Yesterday two shops donated the aluminum we'll be using to build the cage that will hold all the bottles. Still not sure what material we should use to enclose the bow of the boat. Plywood will fall apart. Metal is too heavy. Any suggestions?

[David M]

Marine plywood. It has more laminates and is water proof. Apply some epoxy over it and it should be good for at least the two month time period you have planned for.

[Isara]

Thanks, David. Unfortunately, there's no marine plywood in this area. We can't even get the materials needed to make a decent cheeseburger here. :-( I could head down to the Gulf of Thailand (12 hour train ride) but it would cost too much (time and money). Do you know of anything else that might work?

I'll go look around some more shops today and see what else is available.

[Isara]

Progress has been slow but steady. The two hulls are now ready to be connected with metal cross-supports and the bottles are almost ready to be inserted into the hulls.







If all goes as planned (which it never does) then we should be "pushing" her into the Mekong sometime this weekend. After that will start adding all the equipment.