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About the timber harvester: I assume better here is meant from a economical perspective, because from a ecological perspective the walkers are superior, as they do not devestate the ground so much. But that is sadly not really a issue for most wood production, but I could imagine, with rising awareness for the forests, market demand for not so intrusive wood harvesting(along with advances in the field in general) could bring the walking timber harvester back.

I would very much welcome it. I really hate, having all the forests paths messed up in the wood cutting season.

Would 500 trips with a giant mech walker wouldn’t hurt the forest as much as a dirt trail and wheels? Both would seem pretty messy

Well, yes, I know horsetracks who already look very bad, after regular riding.

But most forest paths are not driven (or walked) 500 times back and forth. Sometimes just once to go in, cut down and take it out. Enough to cut open the soil with the conventional foresters - but much less intrusive with mechanic legs.

Totally. I want that walker for my woodland, because it looks a lot less damaging to the soil (less soil disruption / compaction). The other thing is it would be nice for climbing to spots that don’t have easy road access. This way you can pick a few trees without devastating a whole area just to reach them.

Draft horse logging; we had it done in a sensitive woodland. It's not particularly fast, and it would be expensive.

Oh yeah, there was a bit on a Discovery real-life soap once where one of the characters was a draft horse logger; that was pretty impressive.

For those of you into team[ster]work: https://www.youtube.com/watch?v=NthnHmZT0Go

(for those of you who aren't familiar with the english method: https://www.youtube.com/watch?v=soPp06vwwiI )

Most timber today isn't harvested in natural forest, they are effectively tree farms, they have a 10 to 20 year growth cycle and since all the trees planted are harvestable, they basically clear cut the land, burn it, off cycle growth as needed, and do it again.

In those instances, there is no ecological consideration as the whole area basically gets wiped out.

That's not really accurate. It depends on the tree type, but the growth cycle is somewhere between 50 to 100 years for optimal results.

It's true that most forests today are not old growth anymore. They have been cut (usually clear cut) and then either replanted or just naturally reseeded and are now essentially waiting for the next cut. There are some areas where they are monocultural tree farms with not much else growing, but forest industry starts to realize that that's not the most efficient anyway. Most forests today, even those used for lumber (which are almost all) are integrated ecosystems. That's a great benefit to nature.

Clear cutting is quite bad for the surrounding ecosystem. Habitat loss, soil erosion, it's a pretty traumatic event for a forest. (Some shrubs really thrive for a few years after a clear cut though. In Sweden that's when you get to pick tons of wild raspberries, for example.)

An alternative is selective cutting where you only cut the oldest trees and leave everything intact. For that, such a legged harvester would be much better. The traditional method is to use horses, but that's too slow for modern forest industry.

I'm guessing you aren't from the U.S. but in the southern U.S. growing newer species of Pine (variants of Loblolly Pine). A standard lease is 20 years from seedling to harvest, some older variants can go 30 to 50, but you don't see that being planted any longer and that's all leases maturing.

And here, I can assure you they are very much mono culture, evenly spaced, engineered species of trees, almost nothing else happens on the land in that time period. (generally it looks pretty similar to this https://a.rgbimg.com/users/p/pa/paparabbit/600/mwYGk8q.jpg) They do come and selectively thing at 5, 10, or 15 depending)

See the issue is, at least in the southern U.S. they clear cut nearly everything in the 1800s. There is very little old growth left.

Yes they used to do forestry like that in Northern Europe. They realised the methods described by the OP are more sustainable and more reliable (e.g. diseases will wipe out monocultures).

I agree with it being better for the world in a lot of ways. And I would like to see it change, but it isn't likely to, at least not for a really long time.

P.S. As for mono culture timber, there is a reason almost no one in the US knows what a curant is. They (are/were) illegal in the US, because they are for a vector for a fungus that can wipe out timber pines.

"See the issue is, at least in the southern U.S. they clear cut nearly everything in the 1800s. There is very little old growth left."

I pity them. Real forest is something very different, than a wood farm.

With the recent droughts and dying out of the monoculture spruce, more and more mixed forest is coming back to europe. Idealism brought a little change, but the big drive was the huge economical loss of the timber industry that forced them to rethink how to do things.

We lost every ash tree in Ohio in the last 10 years some places it was 40% of the entire Forest

Ok, but that's still not 10 years.

There is a middle ground between the monoculture you describe and old growth. You can have an intact ecosystem with something every biologist would call "forest" even if you now and then strategically harvest some trees. We are almost 8bn people on this planet and we can't make do without lumber. All alternatives are much worse. Want to use plastic for everything? Steel? Concrete? We need to find a sustainable middle ground.

> in the southern U.S. they clear cut nearly everything in the 1800s. There is very little old growth left.

Linville Gorge being a notable exception:

https://en.wikipedia.org/wiki/Linville_Gorge_Wilderness

Interesting. I've never seen anything like that in the Northwestern US.

> because from a ecological perspective the walkers are superior

You sure about that? Soil compaction is the most serious long-term damage caused by timber harvesting. It's why only tracked harvesters driven by highly-paid fellers are allowed off the gravel. The masses of everyday log-truck drivers (and their wheeled vehicles) are not allowed on the dirt.

You want the ground pressure spread out as much as possible, not concentrated on tiny "feet".

I am not sure about compaction compared to a tracked forester. Physics implies that tracked ones are better, for that, yes. But they rip up even more surface. I believe it is a question, how often the specific path has to be passed by by a forester.

"It's why only tracked harvesters driven by highly-paid fellers are allowed off the gravel."

And this is sadly not true for germany or other parts of europe I know about. I think I never saw a tracked forester in europe. Are they mandatory in the US? That would surprise me, given they have much more lax regulations in general (fracking for example)

This is a good example of the range of equipment I have seen:

https://www.mainecustomwoodlands.com/maine-custom-woodlands-...

Only thing non-tracked that goes off the gravel logging roads would be the Skidder (it literally drags bunches, or 'hitches' of trees to the transport vehicles). And even that might be partially or fully-tracked.

The feller, slasher, excavator, bulldozer, etc. are all tracked from what I've seen.

Mandatory? Doubtful. But they are most practical in the rough terrain.

> Mandatory? Doubtful. But they are most practical in the rough terrain.

I didn't mean to imply there was a government mandate. It's the large forestland owners who demand it of their contractors.

> But they rip up even more surface.

Compaction is much, much worse. It takes a century or more to undo in temperate rainforests like the Olympic Peninsula.

Oh I want one of those "Timberjack" machines. (well without the timber cutting stuff). Based on some of the papers I found on the OSU project it seems like you could replace the entire computing infrastructure it was carrying around with about one pound (1/2 kg) of computers.

I don't suppose you have a pointer to an IK paper on the 4-bar linkages do you? Looks like something that might be fun to cons up with servos.

There are quite a few quadruped robots that use them for legs: https://youtu.be/2k5lOUGenkE

Now that's a more modern way to use a four-bar linkage. The ASV used it to simplify the kinematic problem, which is doing arithmetic with big steel connecting rods. That little quadruped is using it to get two degrees of freedom without the first actuator having to carry the mass of the second one.

Hey you might know this. Is there a term for using what effectively a differential gear arrangement to get two axes of motion as shown in the arm in this video (twice actually, for axes 2/3 and 4/5)?

https://youtu.be/ri8kwOCJnY8

There's an MIT Press book.[1] Chapter 6, "Leg Design by Four Bar Linkage Synthesis" covers the four-bar linkage. They were struggling to get enough working volume for the foot out of the four bar linkage without the mechanism becoming too bulky. They wanted to be able to move horizontally using only one actuator per leg, which allowed manual backup control.

It's an interesting piece of history, but there's no need to do it that way today.

[1] https://www.amazon.com/Machines-That-Walk-Adaptive-Suspensio...

Bah. That thing's got nothing on the Onceler's tree harvester:

https://youtu.be/5cXntJFWv5U

A modern timber harvester run by a skilled operator is beautifully terrifying.

I once camped wild with a friend in the middle of a forest. The next morning there was sawing in the distance, no worries. Got closer and closer ... so we hurried to pack our things .. just in time to have our camping place vanished as it was in the path of destruction. I was not aware before how fast they could be.

(and I don't know, if we just had bad luck, or he had fun messing us, but we were quite hidden)

That’s some nightmare fuel haha

Well, I think I actually had some dreams in that regard, because there was also a second encounter with unexcpected approaching foresters and this time in a dramatic setting, with a strong thunderstorm approaching and we generally were quite paranoid, because we were in the border area of germany and Czech and we were really scared of the high wildcamping fines that exist in theory and we did not know at that time, that usually you get away with a warning and mostly not even that.

So we felt a bit like hunted ...

(ah yeah, also because a hunter was shooting close to us, without noticing us)

Tangential but I find it interesting how the old ad shows the machine and explains why it is interesting while the new one has detail shots, buzzwords and epic music.

I guess it’s just to catch the eye and then one can find all the info later, but still.

Related: tracked APC vs 4-legged (+wheeled) construction vehicle

https://www.youtube.com/watch?v=FBgzkKqCXzw

(Menzi Mucks are available with forestry attachments)

Bonus clip: (multi-metre obstacle) https://www.youtube.com/watch?v=8Y85nfQuU0M

That timber harvester looks amazing. As I commented below, the weight distribution is a pretty appealing aspect for minimizing the impact on soil. Though, unclear how much better it is then the tank treads which also do a pretty good job distributing weight as far as I know?

Super cool though. Would be a nice way to selectively take out trees without tearing up a whole area for access, etc.

It isn't just about weight distribution.

My yard is a forest. I have a mini excavator with tracks and I can sneak in and out of places without disturbing things too much - as long as I don't have to turn sharp (and the ground isn't too wet). I think the walking machines might have an advantage there. The tracks can only slide sideways when you turn, that tears stuff up.

I know what you mean — we’re restoring an oak woodland and between the various springs and poorly drained soil, there’s a very small window where an excavator can actually get in there to work.

Our Douglas Fir stand is on good soil, but getting to it is a little tricky. Getting a bit easier though after 3 years of blackberry removal, and tree limbing (to reduce wildfire risk and improve trails etc).

> It could only walk on flat ground. It was supposed to be able to cross a ditch, but that was manual.

Well, now I'm wondering what they needed eleven onboard minicomputers for. How much route planning intelligence do you really need if you're operating over identical terrain every time?

That timber harvester is pretty unbelievable for 20+ years ago. I wonder what Boston Dynamics would be able to do with it today.

Why didn't they also put wheels under the harvester for road travel?

I'm guessing that'd massively complicate things...

Would have been a good idea for towing to a site though. They wouldn't need to be powered.

I have seen working walking Timberjack models in Ohio I have pics from early 2000s someplace of fresh painted unit standing in the woods getting ready to clear some dead forest to stop all the wildfires we where having.