Chainsaw-wielding Robotic Submarine

merryprankster writes "New Scientist is running a story about Sawfish, a chainsaw-wielding robotic submarine used as an underwater lumberjack. There are some 200 million trees thought to be standing on the floor of hydropower reservoirs worldwide. Sawfish attaches airbags to, and cuts around 9 trees an hour - the trees then float to the surface for collection. Cue the jokes about robotic high heels, suspenders and a bra."

Environmental Consideration

[phonex98]

Sure this situation sounds like a win - win situation, but considering that most of the hydropower reservoirs are a minumum of several years old, many underwater animals have built their habitats among those submerged trees, and what will they do if we chop them down ? .. we've already made this mistake on the surface... should we do in the ocean as well ?

Old Growth Lumber

[Anonymous Coward]

Up here in Vermont, some guys made news a couple of summers ago by building a homemade submarine out of welded-together propane tanks(!) with trolling motors for propulsion. They were actually making some good money by going into some of the deep ponds here, attaching cables to long-ago fallen trees and hoisting them to the surface. Since the deep water is so low in oxygen, the trees are well preserved, and after propper drying yield some excellent lumber.

Okay, I'll Admit It...

[bfg9000]

... I have NO IDEA what "Cue the jokes about robotic high heels, suspenders and a bra" is supposed to mean. I feel strangely inadequate; I'm usually way ahead of the rest of you with the references to Lumberjack Crossdressing Porn.

Return on Investment

[stecoop]

cuts around 9 trees an hour...
Sawfish submarines for sale $750,000...

I wonder what the buyers of expect to get per tree? If the pure profit is 1 dollar per tree minus other operating expense than it will take 83333 hours or 3472 days or 9 years to pay off the machine. Hmmm, I would rather be selling these guys for 750k than buying it and hopping for a return on investment.

One Question

[acherrington]

One question... Why does talking about a Chainsaw-wielding Robotic Submarine make you think about robotic high heels, suspenders and a bra?

Re:How good is the wood like that?

[hackman]

Be careful though, some of this plastic wood works very well but the expansion/contraction in cold/warm weather is significantly stronger than regular wood. My father-in-law had a large boardwalk developed out of this stuff in upstate NY and the first winter pretty close to destroyed the better part of it.

That said is petroleum a better material to make wood out of? Maybe if it's recycled plastic products, but otherwise I'd just prefer normal wood.

But robotic underwater lumberjacks is a great idea. Maybe I'll build one next. Really.

Re:Old growth lumber

[mr_infiniti]

Old growth forests around here are HUNDREDS of years old. Kind of hard to get that way due to 100 years of firefighting. Old growth trees are rotten inside. They are quite often hollow, yet still standing and still producing needles. When a forest fire burns through, these trees are the least able to resist stress. A forest fire 100 years ago would have finished them off. By preventing fires, we've produced "museum" forests, that rob the understory of light, thus preventing new growth. Granted, they could already have 100-200 years old, but most conifers only mature at around 100 years, again, depending on soils and site conditions. Those same trees you speak of, probably would not be here today, if we didn't suppress forest fires. Also, this wood is in great shape if it is under enough water. You go deep enough, and it's pretty lifeless I agree, to some extent. Cut a plant, put its stem in water and it will still survive and even grow - provided there is adequate oxygen in the water, etc. But as anyone who has tried this knows, it's a short-lived, fragile existance. The tree can no longer absorb micro-nutrients through its roots. As I said, the Japanese bought lots of Canadian logs in the 90's, stored them underwater, and found them infested with bugs when they brought them up. Can't argue with facts.

Hey!

[Anonymous Coward]

That's not old-growth forest; that's just "forest". Huge difference.

For all I know you went from 735 million acres of old-growth forest in 1920 to 749 million acres of the modern spongy fast-grown pine now.

My house (in Canada) is 75% old-growth pine. I cannot find any knots in the old stuff, and it's about as hard as granite, while the new stuff is like sponge. I've had to drill holes through the old-growth joists, and the the spade drill just about glows red by the time it's made its way through the old joists. I'm not exaggerating. The wood ends up scorched black and smoking from the ten minutes of fierce drilling that it takes to get through it.

Underwater Cypress

[Flashbck]

I work at an engineering company and one of the consultants we frequently hire has been surfacing old cypress logs from the bottom of deep lakes for years now. He has made quite a profit from this and even holds a few patents on ROV's that find and cut the trees, similar to this sawfish. It is actually a _very_ lucrative idea, not to mention envorinmentally friendly since it does not cut down any of the old growth trees in forests, which would be the only way to obtain wood of this quality.

Re:Old growth lumber

[Anonymous Coward]

A great example of why we need a "-1, WRONG" moderation choice.

If you read the article you will see that wood submerged in cold, anaerobic conditions does not rot. Even in relatively warm, aerobic conditions storage is possible - read about the medieval method of cutting and preparing timber for an English Yew longbow, to see just one example.

As others have said, you do not understand "old growth" at all.

Forest renewal in the absence of fire, is, depending on species, quite normal.

What Japanese? Who tried to store logs underwater? What bugs? Could those bugs live in anaerobic conditions? (you'll need to look up that big word!)

You are an ignoramus.

Useful for piling removal

[Animats]

Years ago, I realized that something like this was needed to remove the old pilings that clutter up the SF waterfront.

The usual solution is to get a large barge-mounted crane and pull them up by brute force, but that's expensive. So it tends not to get done until somebody wants to build something and can convince the city to let them. The bayfront clutter of pilings and rotted piers makes open shoreline look less attractive, which encourages "development". A cheaper way to remove that junk, even if it's slow, would be a big win.

Great Lakes Logs

[Jodka]

Companies are salvaging lumber from the Great Lakes [popularwoodworking.com] also.

from the article:

"One area in the Great Lakes where a team of horses ... went through the ice with a load of logs ... the skeletal remains of the horse are still there, harness, logs and all."

I'd like to see it try a Cypress stump...

[dcigary]

At my parent's lake house in Marble Falls, Texas, there is a stump in the cove that usually sits about a foot under the surface, and has caused many a boater to lose props or get holes punched in their boats. Usually someone in the area will mark it with a floater, so it's easy to avoid, but that hasn't stopped the faithful from trying to get rid of the hazard alltogether.

One weekend while up there, I had friends of mine who are Scuba divers don their gear, and try to use a large hacksaw to try and remove it. They came back with 5 chewed up hacksaw blades, and low on air.

About every few years or so, the LCRA will let the lake level down (it's a constant level lake, a dam on each end) so that homeowners can go out and clear out their lakefront property where the lake usually would be. Over the years we've seen folks try chainsaws, winches, fire, and even explosives to get rid of that hard Cypress stump, to no avail.

So, to this day, that stump remains vigilant and intact.

Re:The tenth floor fallacy

[The One and Only]

Most people in civilized societies eat agriculturally cultivated meat, fish, dairy, and vegetable products. The animals that we get the meat, fish, and dairy products from are agriculturally cultivated. Right now, the food supply you and I eat from is cultivated entirely by humans for human purposes. Yes, nature, untouched by human hands, is big and complex, and nature, touched by human hands, is simpler in many respects. However, the part of nature untouched by human hands has very little effect on us, since we don't eat anything it produces (commercial fishing, pre-hatcheries, was an exception, as is hunting, but quasi-natural hunting grounds with good, thriving game populations can and are artificially maintained as well). As far as I can tell, it produces oxygen for us to breathe, and takes in the carbon dioxide we exhale. That's it. Well, green plants (especially trees) are the parts of nature that do that, and we have no problem keeping the tree count up. One argument you can make is genetic diversity. In that case, it would be in our interests to maintain a wide gene pool to naturally evolve. Then again, I don't see how that couldn't be done with managed preserves that are studied by geologists and that have the genetic strains best suited to our needs sampled and cultivated. Either way, I'm pro-human. If you can show me the steps that can be taken that are good for humans, I'm for it. But the value of nature should be defined as its value to humans, unless you are willing to concede that trees and snakes are somehow more important than we are.

Re:Old growth lumber - ARRRRRG

[TheProcrastinatorTM]

There are some pretty big misunderstandings there... First of all, very little of American forest is old growth, at least speaking from the perspective of someone from Indiana, where we have millions (around 4.5) of acres of forest, but only 2000 of those acres are old growth. And I know the situation is similar in most states, if not quite as bad as here. (And old growth is a misnomer anyway; it can mean different things to different people - there are several useful definitions for the term, and merely being old does not under all definitions automatically make a forest "old growth" - it has more to do with the condition of the forest and the type of trees, I think) Second of all, citing a number from 1920 doesn't really help. 1920 was within like 10 years of the minimum forestation (at least for Indiana, I am sure it is similar elsewhere) - they had in our case already ripped up the vast majority of forest in the state and almost all of the old growth forest (basically all old growth forest had been logged by 1930). Since then much land RELATIVELY had been reforested (often not intentionally, so the new forest is only due in part to that 7% "planted by man"), but the vast majority of the damage was already done, and NONE of the new forest by definition will be old growth. And in fact there was still considerable deforestation after that time, but so much forest was added that it hides alot of that. (By the way, most estimates are the Indiana used to be around 80% forest; a quick check on google gave me numbers of around 20% current forestation - which is UP from the 1920 number. And that 80% consisted of significant amounts of old growth - though note it was not exclusively what would be called "old growth" by most people - and now old growth is well less than 1%.)

Re:Oh, I'm a lumberjack and I'm okay...

[lommer]

It's good to all have a laugh, but I actually know two guys who made a small fortune doing this. I'm from B.C. (west coast of Canada) which has a HUGE forestry industry. A good portion of the logs are hauled down to Vancouver in giant log booms towed by tug-boats. Inevitably, things go wrong and booms get lost, logs sink, get ensnared in cables, or whatever. Just a few months ago I met two guys who set themselves up to do log recovery a few years back. They do all SCUBA work, and basically the go down in places where there's known to be lots of old-growth logs that have sunk. They cut the cables and free up the logs and float them to the surface. Since these logs have been down there for ages, they technically count as salvage. That means these guys now own the logs outright and can sell them directly back to the forestry company. At >$10,000 per tree for those huge old-growth trees, they've actually made some significant coin at it.

The only downside to the work is that it's really dangerous. About a year ago they had an employee who was killed when cables got tangled wrong and the logs unfolded unexpectedly when the airbags were inflated. The guy got crushed between two big logs, and despite rushing him to hospital he died. I guess this is just another industry where robots are taking over profitable jobs that are too dangerous to justify humans doing them.