4 ms·

> so EVs eliminate idling. The vehicle, when stopped, has other functions to perform. It has hydraulic lifters and compactors that need quite a bit of power

> so EVs eliminate idling. The vehicle, when stopped, has other functions to perform. It has hydraulic lifters and compactors that need quite a bit of power to operate. It's a working platform, not a simple garbage transportation mechanism. Even to the extent is isn't for transportation, see how far away the dump is from your home. That distance has to be covered twice at least once a day, and possibly as much as 3 times per day.. and during one of those legs the truck is fully loaded with possibly up to as much as 20,000lbs of trash. Finally, they have to operate in all conditions, in both very low and very high temperatures. The logistics of this aren't as simple as it would be for a standard vehicle.

lostlogin 4y ago
Somewhere as densely populated as NY is surely best served by those rubbish bins that empty into a trash vacuum tunnel. Massive upfront cost (infrastructure and NY seems to be a bit fraught) and also likely expensive to run, but with high population density it’s got to be better. However this would then have a fleet of snow trucks that weren’t used 99% of the time, as the rubbish was mostly sorted. https://en.m.wikipedia.org/wiki/Automated_vacuum_collection https://en.m.wikipedia.org/wiki/Automated_vacuum_collection
- StrictDabbler 4y ago
  "[A] bit fraught" is an understatement. Any excavation under the right of way in New York immediately runs into undocumented tunnels, steam conduits, sewers, and water pipelines from the past 400 years of development. They're trying to map these things out but it will probably take more than a decade. Until that happens you can't even begin to budget for a new city-wide underground infrastructure project. Any project has to be point to point and focused. Let alone the issue of the rats. https://www.bloomberg.com/news/features/2017-08-10/nobody-knows-what-lies-beneath-new-york-city https://www.bloomberg.com/news/features/2017-08-10/nobody-kn...
- TylerE 4y ago
  Between the subways, underground rail lines, etc, you’d probably have to put them 100ft underground to get clearance. That’s 100ft through solid rock. Great for building skyscrapers, not fun for digging. Ironically one of the largest vacuum trays system in the world IS in NYC… but it serves Roosevelt Island, not the “mainland”
Symbiote 4y ago
In New York City, do the garbage trucks drive a long distance to unload their waste? In much of London, they drive a relatively short distance to offload the waste. Some is handled locally (e.g. composting food and garden waste). The rest is taken the much longer distance by barge or rail. Barge: https://www.wandsworth.gov.uk/news/2019-news/june-2019/thames-barge-fleet-investment-keeps-100-000-juggernauts-off-london-s-roads/ https://www.wandsworth.gov.uk/news/2019-news/june-2019/thame... Rail: https://westlondonwaste.gov.uk/where-your-waste-goes https://westlondonwaste.gov.uk/where-your-waste-goes
LeifCarrotson 4y ago
As an industrial EE dealing with hydraulics of much larger scales than those on a garbage truck, those other functions do not require significant power to operate when compared to actually accelerating the vehicle and cargo up to speed (and then slamming on the brakes/regen again for the next stop). The engines in diesel garbage trucks often run at idle when those hydraulics are working, lifting a 100 kg residential can or a 1-ton dumpster through a few meters of motion is not noticeable to a 350 HP diesel, accelerating 30 tons of truck and trash in the same amount of time is why they're equipped with so much more engine power.
- postalrat 4y ago
  How about compacting the trash in the truck?
  - LeifCarrotson 4y ago
    Assuming a 100mm bore cylinder with a 1.5m stroke (~10L volume), operating at 150 bar, with a stroke time of 1 minute, the power required is: Power in kW = Pressure in bar * Flow in liters per minute / 600 2.5 kW = 150 bar * 10 l/min / 600 or a little more than 3 horsepower. That gives you about 15 tons of force. Maybe the trucks use two cylinders, one on each side, so double it? Plus 10% for pump inefficiencies, and 5% for electric motor inefficiencies (200% for diesel-to-kinetic losses)? Still negligible compared to accelerating a huge steel box plus dozens of tons of trash to roadway speeds 1000 times a day. Looking up some existing PTOs and pumps on munciepower.com, it looks like typical refuse systems are provisioned with PTOs and pumps rated for on the order of 10-50 kW, and diesel "prime movers" of 200-400 kW.
- dredmorbius 4y ago
  Nit: Hydraulics do require a great deal of power, but often delivered over a short time or distance, meaning the total energy demand is low. Which is what NYC's concerned with. EV's are great at delivering high power on demand, for short periods. A selling point of Tesla since the Roadster days was the astounding acceleration. Peak torque at a dead start is a key characteristic of electric motors. What's far more challenging is range, a problem Tesla has addressed quite capably for passenger vehicles, though which remains largely unmet for cargo and heavy-transport equipment (including snow ploughs). Interestingly, there was a period where a non-electrical power network was fairly frequently encountered at neighbourhood or city scale: hydraulic power networks. These often operated high-power loads, though typically for short periods or efforts as my first paragraph describes. Hydraulic accumulators lifted weights or water and provided on-demand power for moving lock gates, cargo hoists, and other typically industrial tasks. These were developed in the early 19th century and many remained operational well into the 20th, with the Wikipedia article below listing several operating into the 1970s. Smaller such networks exist in dentist's offices, auto repair shops, and in many Amish workshops, based on compressed air, and utilising similar principles. <https://en.wikipedia.org/wiki/Hydraulic_power_network https://en.wikipedia.org/wiki/Hydraulic_power_network> (I'm presuming LeifCarrotson knows much of this, others may not. I didn't myself until a few years ago.)
askvictor 4y ago
> Even to the extent is isn't for transportation, see how far away the dump is from your home. That distance has to be covered twice at least once a day, and possibly as much as 3 times per day.. and during one of those legs the truck is fully loaded with possibly up to as much as 20,000lbs of trash. Swappable batteries at the dump depot? There's a company in Australia doing swappable batteries for trucks (https://thedriven.io/2022/03/25/worlds-largest-electric-truck-to-trial-battery-swap-technology-in-australia/ https://thedriven.io/2022/03/25/worlds-largest-electric-truc...)
ilyt 4y ago
Wouldn't hybrid make a lot of sense here? Engine working at max efficiency for most time or turned off completely.
fencepost 4y ago
Even to the extent is isn't for transportation, see how far away the dump is from your home. I may be biased by my experiences. At home the transfer station is about 4 miles away, and at my parents' place that I've been cleaning out it's probably 1.5-2 miles by road - or less than half a mile if I could go up a couple hundred yards of steep forested hillside.

lostlogin 4y ago

Somewhere as densely populated as NY is surely best served by those rubbish bins that empty into a trash vacuum tunnel. Massive upfront cost (infrastructure and NY seems to be a bit fraught) and also likely expensive to run, but with high population density it’s got to be better. However this would then have a fleet of snow trucks that weren’t used 99% of the time, as the rubbish was mostly sorted. https://en.m.wikipedia.org/wiki/Automated_vacuum_collection https://en.m.wikipedia.org/wiki/Automated_vacuum_collection

StrictDabbler 4y ago
"[A] bit fraught" is an understatement. Any excavation under the right of way in New York immediately runs into undocumented tunnels, steam conduits, sewers, and water pipelines from the past 400 years of development. They're trying to map these things out but it will probably take more than a decade. Until that happens you can't even begin to budget for a new city-wide underground infrastructure project. Any project has to be point to point and focused. Let alone the issue of the rats. https://www.bloomberg.com/news/features/2017-08-10/nobody-knows-what-lies-beneath-new-york-city https://www.bloomberg.com/news/features/2017-08-10/nobody-kn...
TylerE 4y ago
Between the subways, underground rail lines, etc, you’d probably have to put them 100ft underground to get clearance. That’s 100ft through solid rock. Great for building skyscrapers, not fun for digging. Ironically one of the largest vacuum trays system in the world IS in NYC… but it serves Roosevelt Island, not the “mainland”

Symbiote 4y ago

In New York City, do the garbage trucks drive a long distance to unload their waste? In much of London, they drive a relatively short distance to offload the waste. Some is handled locally (e.g. composting food and garden waste). The rest is taken the much longer distance by barge or rail. Barge: https://www.wandsworth.gov.uk/news/2019-news/june-2019/thames-barge-fleet-investment-keeps-100-000-juggernauts-off-london-s-roads/ https://www.wandsworth.gov.uk/news/2019-news/june-2019/thame... Rail: https://westlondonwaste.gov.uk/where-your-waste-goes https://westlondonwaste.gov.uk/where-your-waste-goes

LeifCarrotson 4y ago

As an industrial EE dealing with hydraulics of much larger scales than those on a garbage truck, those other functions do not require significant power to operate when compared to actually accelerating the vehicle and cargo up to speed (and then slamming on the brakes/regen again for the next stop). The engines in diesel garbage trucks often run at idle when those hydraulics are working, lifting a 100 kg residential can or a 1-ton dumpster through a few meters of motion is not noticeable to a 350 HP diesel, accelerating 30 tons of truck and trash in the same amount of time is why they're equipped with so much more engine power.

postalrat 4y ago
How about compacting the trash in the truck?
- LeifCarrotson 4y ago
  Assuming a 100mm bore cylinder with a 1.5m stroke (~10L volume), operating at 150 bar, with a stroke time of 1 minute, the power required is: Power in kW = Pressure in bar * Flow in liters per minute / 600 2.5 kW = 150 bar * 10 l/min / 600 or a little more than 3 horsepower. That gives you about 15 tons of force. Maybe the trucks use two cylinders, one on each side, so double it? Plus 10% for pump inefficiencies, and 5% for electric motor inefficiencies (200% for diesel-to-kinetic losses)? Still negligible compared to accelerating a huge steel box plus dozens of tons of trash to roadway speeds 1000 times a day. Looking up some existing PTOs and pumps on munciepower.com, it looks like typical refuse systems are provisioned with PTOs and pumps rated for on the order of 10-50 kW, and diesel "prime movers" of 200-400 kW.
dredmorbius 4y ago
Nit: Hydraulics do require a great deal of power, but often delivered over a short time or distance, meaning the total energy demand is low. Which is what NYC's concerned with. EV's are great at delivering high power on demand, for short periods. A selling point of Tesla since the Roadster days was the astounding acceleration. Peak torque at a dead start is a key characteristic of electric motors. What's far more challenging is range, a problem Tesla has addressed quite capably for passenger vehicles, though which remains largely unmet for cargo and heavy-transport equipment (including snow ploughs). Interestingly, there was a period where a non-electrical power network was fairly frequently encountered at neighbourhood or city scale: hydraulic power networks. These often operated high-power loads, though typically for short periods or efforts as my first paragraph describes. Hydraulic accumulators lifted weights or water and provided on-demand power for moving lock gates, cargo hoists, and other typically industrial tasks. These were developed in the early 19th century and many remained operational well into the 20th, with the Wikipedia article below listing several operating into the 1970s. Smaller such networks exist in dentist's offices, auto repair shops, and in many Amish workshops, based on compressed air, and utilising similar principles. <https://en.wikipedia.org/wiki/Hydraulic_power_network https://en.wikipedia.org/wiki/Hydraulic_power_network> (I'm presuming LeifCarrotson knows much of this, others may not. I didn't myself until a few years ago.)

askvictor 4y ago

> Even to the extent is isn't for transportation, see how far away the dump is from your home. That distance has to be covered twice at least once a day, and possibly as much as 3 times per day.. and during one of those legs the truck is fully loaded with possibly up to as much as 20,000lbs of trash. Swappable batteries at the dump depot? There's a company in Australia doing swappable batteries for trucks (https://thedriven.io/2022/03/25/worlds-largest-electric-truck-to-trial-battery-swap-technology-in-australia/ https://thedriven.io/2022/03/25/worlds-largest-electric-truc...)

ilyt 4y ago

Wouldn't hybrid make a lot of sense here? Engine working at max efficiency for most time or turned off completely.

fencepost 4y ago

Even to the extent is isn't for transportation, see how far away the dump is from your home. I may be biased by my experiences. At home the transfer station is about 4 miles away, and at my parents' place that I've been cleaning out it's probably 1.5-2 miles by road - or less than half a mile if I could go up a couple hundred yards of steep forested hillside.