Tsunami Roof Barges

[Airbrush]

I got this idea after the Indonesian tsunami disaster. Since these people cannot find high ground, they should build their house with a simple wooden barge on the roof. The barge would be enclosed like a submarine and have a hatch. When the tsunami alert sounds, everybody climbs up a ladder onto their roofs and get inside the barge and seal the hatch. When the wave comes and it tears down their house they will be safe inside their barge to float around like Noah's Ark.

[tomgwyther]

Good idea. Although you'd have to weigh up the cost of a 'roof-raft' against the likelihood of a tsunami hitting your house.

maybe a sealed, self-righting boat like this one.

[Airbrush]

I like your self-righting boat, but I was thinking of something dirt cheap. Make it out of plywood. It only needs to float a few days or weeks, until they get rescued.

[Cap'n Refsmmat]

Would plywood withstand a tsunami?

[Mr Skeptic]

I think a simple raised platform would be much cheaper and more reliable. A tsunami may be strong, but a pole will give very little surface area for it to hit. Whereas a boat would be much more expensive, especially if it is supposed to withstand rough waters.

[tomgwyther]

I'm not sure if i'd trust a home-made plywood raft against a tsunami.

For one thing, it would probably get battered, flipped over and tossed around in the water along with you and your family, who would have the added problem of fighting off an unwieldy wooden raft whilst thrashng around in the water.

Maybe a self inflating life raft, like you see on the side of ships. they're about the size of an oil drum when packaged. Another risk which might present itself is that, what washes in from the ocean, can also wash back out again. You might find yourself a few miles off-shore in your boat/raft/dingy.

A young student at my local college was caught in the boxing day Asian tsunami, her parents died but she survived by seeking refuge in a tree.

Maybe a tall sturdy pole (Like a cell-phone mast) with a seat on top. you could keep some food, a few beers and maybe some gentlemen's literature up there in case of emergency.

[Sisyphus]

Or you could simply construct the house in such a way that it would float, and is resting on (but not attached to) the ground. Tie it down with a sturdy anchor chain with lots of slack, so it can't be washed away.

 

However, I figure this can't be as simple as it sounds, because AFAIK nobody does it that way. There are a lot of buildings on stilts in flood-prone areas, though, like Mr Skeptic suggests.

[Rickdog]

In a Tsunami, besides the mass of water, the other thing that produces a great part of damage its all the debris and materials drifted by the waters, which also have the power to destroy anything that gets in its pass, so if you are thinking in somekind of barge or boat, it also must be very resistant to high impact, or else you´ll end up preciselly where you better not be in a tsunami, in the water that is. Now if you really are thinking to live in a place that is in risk of suffering by one, I`d suggest you to build your house next to a hill, where you can seek for shelter in case of one. Most of the people that lived through a tsunami in the past episode back at my country, saved themselves by doing this. Those who remained are the ones who are now dead or "missing". A great part, among all the debris, where parts of boats and marine equipment, another thing you should not stop to consider in the case if you are thinking in a roof barge for this kind of events.

[Mr Skeptic]

Ah, debris might be a problem with a house/platform on stilts. The water itself would not do damage but if it is carrying a log, bye bye stilts.

[Airbrush]

Some islands and coastal areas have no high ground. For those areas I prescribe the tsunami survival barge.

 

You can build yourself an enclosed barge of 2x4 lumber and 1" plywood. Build it like a giant coffin about 3 feet high and 8 feet by 8 feet. Reinforce the sides with 2x4 lumber as appropriate, especially the sides that must withstand battering. You may even have additional 2x4 lumbers bracing the central axes. If you have a large family, it should be wider and longer, but not higher. The most dangerous thing in a tsunami is the debis that the water propels which is like battering rams that will tear everything down, including pole refuge platforms. Your barge will set freely on top of your house and you have a ladder up to the roof. It should be water proofed and painted bright red on the outside so you will be found easily days later. Inside will be straps to strap down the kids and pets, and/or handles to grip. Since it is only 3 feet tall, and much wider and longer, it will not get turned upside down very much. After the initial impact you may be flipped over, but after seconds, or less than a minute, you will probably settle down either right-side-up, or up-side-down. That is why there should be water-tight hatches on the floor and roof, because they can switch places. You will smash into lots of things during the first few minutes, but soon you will flow WITH the debris and not much battering after that.

 

Inside you keep gallons of fresh water, dry food, and fishing hooks, tools to cut your way out, and a deck of cards, and anything you want to have.

Edited March 4, 2010 by Airbrush

[InigoMontoya]

Sounds great until you realize the resources these folks have to work with aren't the same as your's.

[Rickdog]

The idea after reading the last post, to me it "looks", O.K., but the problem of carrying it out also comes with its cost (maintainance) and how many times in life you are really going to be able to use it. Building such a device could probably save lives, but at the end you really don´t build a house where you are expecting to be hit by a natural disaster as a tsunami, only to "prove if it serves or not.

 

It actually is more likely that you`ll ever be able to use it on your lifetime period. So why build anything, that is ever going to be used ?. When you have all kinds of resources that can assure your way of life, maybe you can afford having an element as the one described, but if no Tsunami hits you, you`ll end up only wasting your money in something useless. The life barge will also only help you, when that tsunami is a low height one, but if you`re hit by a mega tsunami, as the ones presented in hollywood films, the weight of the water will crack your life barge as it was an egg shell, besides that if you ever have a chance to use it, it will only be used if you are near enough to not spend time in boarding it, with the required elements of survival.

 

Sincerely, I hope that you`ll never have a chance to prove if its worthy, because if its not, you will not be around here to tell your experience. If you are warned with enough time, its better to run away and go for highgrounds.

[CaptainPanic]

Whatever you come up with, you must realize that a tsunami is not ordinary water.

 

It is highly turbulent water, filled with construction material, cars, trees, waterfalls, waves and perhaps even rocks and structures that are not washed away (houses, hills, trees).

 

Your barge must withstand a high velocity (50 km/h) direct impact with such heavy materials. It will be tossed around and all sides (bottom, front, back and sides) will receive a heavy beating.

 

I would certainly NOT choose plywood for a construction material. I would go with a fibreglass reinforced material, or a strong plastic (polycarbonate for example).

 

If it has to be safe, it won't be cheap.

[Airbrush]

"...how many times in life you are really going to be able to use it.[?] Building such a device could probably save lives, but at the end you really don´t build a house where you are expecting to be hit by a natural disaster as a tsunami, only to "prove if it serves or not.

 

...The life barge will also only help you, when that tsunami is a low height one, but if you`re hit by a mega tsunami, as the ones presented in hollywood films, the weight of the water will crack your life barge as it was an egg shell, besides that if you ever have a chance to use it, it will only be used if you are near enough to not spend time in boarding it, with the required elements of survival.

 

Sincerely, I hope that you`ll never have a chance to prove if its worthy, because if its not, you will not be around here to tell your experience. If you are warned with enough time, its better to run away and go for highgrounds.

 

This is all assuming there is no nearby high ground. If I was living on an island, or next to the ocean in an area with no nearby high ground, I could build myself a barge for a few hundred dollars in plywood and 2x4 lumber and screws and caulk to water seal it. It would take the average handyman a few weekends to construct.

 

The vast majority of killer tsunamis, like the Indonesian tsunami of Dec 2004, have waves of modest height, like a 10 foot wind wave that has the whole ocean behind it so it just keeps coming like a river flowing up onto land. It is not very high. If it is not big enough to knock your house down, then at least you were sitting in your roof barge ready just in case. I would try to install plexiglass windows on each of the 4 sides.

 

Once in a thousand years will be a asteroid tsunami that could crush your barge, but that is unlikely.

[Mr Skeptic]

This is all assuming there is no nearby high ground. If I was living on an island, or next to the ocean in an area with no nearby high ground, I could build myself a barge for a few hundred dollars in plywood and 2x4 lumber and screws and caulk to water seal it. It would take the average handyman a few weekends to construct.

 

On the other hand, for people living below the poverty line, that "few hundred dollars" might be a year's worth of wages.

[Airbrush]

That is true. Lumber is costly for them to import IF they cut down all their forests. I wonder how much plywood and 2x4's cost in an Indonesian Home Depot? Maybe they can build a tsunami "bunker" of concrete with an exit that snakes around and a sliding-door hatch that cannot be blocked and tools inside to cut and dig thru debris covering the hatchway. After the water recedes they should be able to exit.

[Sisyphus]

That is true. Lumber is costly for them to import IF they cut down all their forests. I wonder how much plywood and 2x4's cost in an Indonesian Home Depot? Maybe they can build a tsunami "bunker" of concrete with an exit that snakes around and a sliding-door hatch that cannot be blocked and tools inside to cut and dig thru debris covering the hatchway. After the water recedes they should be able to exit.

 

You're talking about people whose homes are one room bamboo huts (or something equivalent - I don't know what kind of structures people that poor live in in that part of the world). You want everybody to have their own bunker? As something that might save them in a highly unusual natural disaster?

[Airbrush]

Not everyone can have their own barge or bunker, but in areas that are very vulnerable to tsunamis, a community bunker. Concrete is perhaps cheaper for them than lumber. Any wealthy people who choose to live in those areas can afford such things. The poor should plan smaller families. How often do those areas get hit?

[Sisyphus]

How often do those areas get hit?

 

I'm just looking it up myself, but the sources seem to say oceanwide tsunamis occur an average of every 15 years or so, and 80% of these are in the Pacific. That doesn't speak to severity, though - if 2004-sized tsunamis were happening every 15 years in the Pacific, it seems like all those low-lying Pacific islands would constantly be getting wiped out. So does just a couple feet, like that experienced after the Chilean earthquake, count?

[Rickdog]

Airbrush, my friend, you must be refering yourself to the same kind of concrete used by all those resorts for tourists that were turned to rubles after the Indonesian tsunami event. I think you still don`t understand the power against what you are dealing with, here in the topic.

 

If your house is at the border of the sea coast, it will probably be as you say, that is, a continued flow of water in a big river, but remember that once the water has stopped advancing into the mainland, it will go back to the ocean, and in this case it will not only be water but lots of debris, not only small pieces but also very big ones too, maybe even a ship, a boat or a car or anything with enough mass to destroy your so called bunker. Imho, you better stay with your original idea of a barge. At least, with it, you may have a more plausible idea to survive in that improbable event. But it is still restricted to wealthy families, since for the great majority of people round the world, it is highly expensive to afford it, specially when there are other basic needs that have to be satisfied first (health and famine, as a daily and mostly probable issue, comes to my mind).

Edited March 11, 2010 by Rickdog
Correcting and completing

[Airbrush]

Rickdog: "Airbrush, my friend, you must be refering yourself to the same kind of concrete used by all those resorts for tourists that were turned to rubles after the Indonesian tsunami event."

 

You mean the collapse of unreinforced concrete multi-storied buildings from the earthquake. A bunker is not multi-storied and unreinforced concrete bunkers will probably have the integrity to withstand a great earthquake IF it is not too big. If it is reinforced with rebar it can be bigger. The tsunamis usually don't have the kind of forces necessary to crush a single storied concrete bunker, especially if it is reinforced with steel rebar.

 

It will probably be buried in debris after the water recedes. That is why the exit should be designed to be easily opened with a sliding door well above ground level.

Edited March 13, 2010 by Airbrush

[Rickdog]

The tsunamis usually don't have the kind of forces necessary to crush a single storied concrete bunker, especially if it is reinforced with steel rebar.

It will probably be buried in debris after the water recedes. That is why the exit should be designed to be easily opened with a sliding door well above ground level.

 

You think that tsunamis don`t have that force, well take a look at what happened in India in 2004 ( Real life, not speculations my friend), in reference to reinforced concrete (RC) structures. Probably it will not crush it, but a single crack that allows water in it, will doom everybody who is in it.

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JPCFEV000021000002000128000001&idtype=cvips&gifs=yes&ref=no

 

Besides this topic you started, was originally about a life barge against Tsunamis, I don`t see the relation with a RC bunker to it.:confused:

[Airbrush]

Hello Rickdog. I appreciate the attention you have given to this subject. I prefer the roof barge solution for people living in a coastal area very vulnerable to tsunamis, with no high ground anywhere nearby. If most people living in these areas cannot hire a handiman to build such a roof barge, which would cost materials less than $500 US in Southern California, where I live. I would build my own, but a poor family could hire a hungry unemployed handiman to work for California minimum wage maybe 5 days x 8hrs/day = 40hrs x $8.00US = $320. Materials $500 + Labor $320 = $820.

 

The much cheaper alternative, which would save many more lives of otherwise helpless poor people, would be a BELOW ground-level community concrete bunker where they would wait out the high water for a few days at the most. The downward pressure on the bunker, which is BELOW ground level will be almost nothing since tsunami are almost never higher than 10 to 20 feet high, and that little water depth will not push downward very much. The tsunami force is forward as water carries debris as battering rams to knock down any ground-level buildings.

[Cap'n Refsmmat]

I think the trouble is that many of these poor families already work at minimum wage or below. They're not going to go around paying $820 for something that isn't an absolute necessity.

[InigoMontoya]

I think the trouble is that many of these poor families already work at minimum wage or below. They're not going to go around paying $820 for something that isn't an absolute necessity.

Yup. It's very possible that $820 represents a full year's pay.

 

 

As for the underground idea mentioned. Ummm... You're talking about a very low lying area near the ocean. Holes like that will flood unless your construction is VERY good. Not likely. And I'm not talking about the tsunami. I'm talking about plain ol' groundwater seepage.