6 ms·

They do, and this is fairly common on vast machines like combine harvesters. However they are a lot more expensive to run and maintain - eg. just think about t

by adwww 4y ago

They do, and this is fairly common on vast machines like combine harvesters. However they are a lot more expensive to run and maintain - eg. just think about the additional moving parts and friction. Also it's possible they do different damage - the metal treads are not as forgiving as soft balloon tyres.

supermatt 4y ago
They are (usually) rubber tracks.
- throwaway0a5e 4y ago
  It's not the tracks that cost you. It's the idlers, sprockets, etc.
  - supermatt 4y ago
    My comment was is in response to metal treads causing damage...
    - thatcat 4y ago
      It's the pressurized air in the tire that reduces applied ground pressure from the vehicle not just the surface material.
      - supermatt 4y ago
        Not sure why you are responding to my comment either... but what you are saying makes no sense to me. Obviously the pressurised air itself has mass, but I think its more to do with tyre deformation modifying the contact surface area. The air inside is just to distribute the load across the contact area.
deleted 4y ago
[deleted]
usrusr 4y ago
With the impeding electrification we might eventually see walkers on skis-shaped feet, as a compromise between load distributed over a large area and a narrow tread not usable for growing. They'd also excel in the metric of total traction per peak surface load. Key technology of electrification would be tethered drone swarms that feed from the cable they carry, because I'd assume that you'd want to separate batteries from your actors so that they are flexible you work from grid infrastructure just as well as from some battery truck tagging along on an access road (which brings us back to surface load, you wouldn't want the battery loading soil you still want to grow in).
- adwww 4y ago
  I would have thought electrification might work well on very specialist machinery - perhaps around horticulture, vinyards, greenhouses, etc. But part of the appeal of a big powerful tractor is their huge versatility - you'd loose a lot of that if you needed additional infrastructure in place.
- bluGill 4y ago
  As a John Deere Employee I have to be careful what I say. I will say (because this is obvious from public information) that we are "looking" at electric tractors, but making them work is hard. 10 years ago we stuffed as many batteries as we could in a 100 horsepower tractor, and for 45 minutes it when head to head with a similar diesel tractor, then the batteries were dead. 100 horsepower just above a small tractor these days. Remember a Tesla might be able to produce 500 horsepower (I can't be bothered to look it up, but something very large like that seems reasonable), but to maintain speed on a freeway it only needs about 20 horsepower. A tractor is expected to produce the rated horsepower for 10 hours non stop. Your idea of a feed cable is something we have looked at (you can find an announcement, though it might be in German). There are a lot of issues with making it work in the real world, though it might be where things go if diesel gets a lot more expensive.
  - seltzered_ 4y ago
    There's also a chart explaining the issues of battery electric tractors by Jason Bradford in "The future is rural": https://twitter.com/vivekgani/status/1426017955398176770?t=01BSeyUK_HOjCWgjXvVfDQ&s=19 https://twitter.com/vivekgani/status/1426017955398176770?t=0... Basically when ya chart out gravimetric and volumetric density stuffing batteries doesnt seem to make sense. There may be some other options (feed cable, slower cycle, etc.)
floren 4y ago
I've seen some mighty big combine harvesters, but I've never seen one on tracks. Tractors on tracks, yes.
- bluGill 4y ago
  Tracks are an option when buying a combine. I'm not sure how popular, but they are a factory option.
- wolverine876 4y ago
  Why not on harvesters?
  - floren 4y ago
    I don't know. Googling, I was able to come up with some examples, but I've never seen them in real life despite growing up in a farming community. My speculation: you only harvest in dry weather (so traction differences don't matter), and harvesting goes faster than say tilling, so maybe tires are preferred. You'll also see big fleets of combines going down the road to the next field; I think tracked vehicles are frowned upon on public roads.

by adwww 4y ago

supermatt 4y ago

They are (usually) rubber tracks.

throwaway0a5e 4y ago
It's not the tracks that cost you. It's the idlers, sprockets, etc.
- supermatt 4y ago
  My comment was is in response to metal treads causing damage...
  - thatcat 4y ago
    It's the pressurized air in the tire that reduces applied ground pressure from the vehicle not just the surface material.
    - supermatt 4y ago
      Not sure why you are responding to my comment either... but what you are saying makes no sense to me. Obviously the pressurised air itself has mass, but I think its more to do with tyre deformation modifying the contact surface area. The air inside is just to distribute the load across the contact area.

deleted 4y ago

[deleted]

usrusr 4y ago

With the impeding electrification we might eventually see walkers on skis-shaped feet, as a compromise between load distributed over a large area and a narrow tread not usable for growing. They'd also excel in the metric of total traction per peak surface load. Key technology of electrification would be tethered drone swarms that feed from the cable they carry, because I'd assume that you'd want to separate batteries from your actors so that they are flexible you work from grid infrastructure just as well as from some battery truck tagging along on an access road (which brings us back to surface load, you wouldn't want the battery loading soil you still want to grow in).

adwww 4y ago
I would have thought electrification might work well on very specialist machinery - perhaps around horticulture, vinyards, greenhouses, etc. But part of the appeal of a big powerful tractor is their huge versatility - you'd loose a lot of that if you needed additional infrastructure in place.
bluGill 4y ago
As a John Deere Employee I have to be careful what I say. I will say (because this is obvious from public information) that we are "looking" at electric tractors, but making them work is hard. 10 years ago we stuffed as many batteries as we could in a 100 horsepower tractor, and for 45 minutes it when head to head with a similar diesel tractor, then the batteries were dead. 100 horsepower just above a small tractor these days. Remember a Tesla might be able to produce 500 horsepower (I can't be bothered to look it up, but something very large like that seems reasonable), but to maintain speed on a freeway it only needs about 20 horsepower. A tractor is expected to produce the rated horsepower for 10 hours non stop. Your idea of a feed cable is something we have looked at (you can find an announcement, though it might be in German). There are a lot of issues with making it work in the real world, though it might be where things go if diesel gets a lot more expensive.
- seltzered_ 4y ago
  There's also a chart explaining the issues of battery electric tractors by Jason Bradford in "The future is rural": https://twitter.com/vivekgani/status/1426017955398176770?t=01BSeyUK_HOjCWgjXvVfDQ&s=19 https://twitter.com/vivekgani/status/1426017955398176770?t=0... Basically when ya chart out gravimetric and volumetric density stuffing batteries doesnt seem to make sense. There may be some other options (feed cable, slower cycle, etc.)

floren 4y ago

I've seen some mighty big combine harvesters, but I've never seen one on tracks. Tractors on tracks, yes.

bluGill 4y ago
Tracks are an option when buying a combine. I'm not sure how popular, but they are a factory option.
wolverine876 4y ago
Why not on harvesters?
- floren 4y ago
  I don't know. Googling, I was able to come up with some examples, but I've never seen them in real life despite growing up in a farming community. My speculation: you only harvest in dry weather (so traction differences don't matter), and harvesting goes faster than say tilling, so maybe tires are preferred. You'll also see big fleets of combines going down the road to the next field; I think tracked vehicles are frowned upon on public roads.