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NYC officials say they can't find EV garbage trucks powerful enough to plow snow

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Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#571

Post by jcrawfordor »

sh1mmer wrote: post #411
jcrawfordor wrote: post #386

Earlier quoted context omitted.

3MPG strikes me as pretty good for a garbage truck. Heavy diesel vehicles weigh a LOT more than passenger cars and 3-7MPG is pretty typical territory. Garbage trucks spend so much time idling and starting/stopping they're going to be about the worst case. They also run very heavy for their size.

The bases of garbage trucks seems to just be a truck platform. So I don’t think they are much different from other equivalent vehicles. Given these trucks almost never get highway speeds, I would assume it’s even as good as 3mpg because heavy idling uses less fuel than highway speeds, but stop and go is much worse. I assume EVs would have some of the same stop/go efficiency issues for stop/start but that would gain s…

It's more that the category of "equivalent vehicles" is somewhat narrow. Mack dominates for garbage trucks because platforms of that size (18'-ish WB) rated for the 32-ton-ish GVW class aren't that common. Garbage trucks and dump trucks are two major applications, because both handle material that is much denser than typical truck cargo (once compacted, in the case of garbage trucks). Dump trucks of course are typically conventional cab, with the step-up cabover being a lesser-used option. There are some interesting design constraints that result in garbage trucks, particularly with pressure to minimize engine volume since putting a step-up cab over a large diesel engine is always a difficult space use exercise (and one that is almost unique to garbage trucks). This ends up meaning that the cabover version needs a pretty distinct frame from the conventional cab version because of the engine placement, and there ends up being implications on the suspension design. Historically some garbage trucks have been step-through, which is convenient for the operator, but extremely difficult to implement on modern truck platforms because the engine ends up occupying most of the middle of the cab. You pretty much have to go to rear-engine, which is rare and not really done to my knowledge except by Oshkosh for their generally very interesting front-end cement mixers.

That was all sort of a tangent, the point is that most garbage trucks are built on a truck platform, the Mack LR, that is specifically a garbage truck platform. I believe I have seen cement mixers built on the LR platform too but Mack doesn't seem to advertise it for anything other than garbage trucks.

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#572

Post by heavyset_go »

SllX wrote: post #478
heavyset_go wrote: post #361

Earlier quoted context omitted.

In 1875, Philadelphia had electric street car lines going through every numbered street in the city, and through every cross street in central Philly[1]. [1] https://i.redd.it/zidqa2mbmav31.png

That's neat. Thanks for sharing!

No problem. If you visit there, you can still see some of the rail lines in the streets.

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#573

Post by dredmorbius »

LeifCarrotson wrote: post #341
akira2501 wrote: post #307

Earlier quoted context omitted.

> 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 t…

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…

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>

(I'm presuming LeifCarrotson knows much of this, others may not. I didn't myself until a few years ago.)

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#574

Post by dredmorbius »

walrus01 wrote: post #298
JumpCrisscross wrote: post #89

Earlier quoted context omitted.

> never ceases to amaze me that the self styled "Greatest City on Earth" can't come up with a reasonable solution for its garbage The status quo is sanitary and efficient. All things considered, New York’s garbage problem is on par with its snow problem. Well managed enough to work, but annoying enough around the edges to be fun to bicker about. If you live in low-density New York, your experience mirrors suburbia; h…

> The status quo is sanitary and efficient. Are we talking about the same NYC? Visit Manhattan in mid July/August. Bags of garbage leaking juices and oil out onto the street into a huge greasy spot where the designated collection spot is near the curb. The whole city smells like a toaster oven roasted ballsack. Then combine that with all the cumulative liters of urine per day from dogs and humans all throughout the c…

It could be worse, and was once:

https://99percentinvisible.org/article/cities-paved-dung-urb...>

Cleaning up after horses (including, often, the horses themselves) is a large part of why and how NYC's municipal waste system evolved to its present state.

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#575

Post by dredmorbius »

brnt wrote: post #434
simmonmt wrote: post #291

Earlier quoted context omitted.

By row house do you mean something like this? https://goo.gl/maps/XTDwyAZy6GoqPRXt7 That's 4-5 stories of ~4 apartments per floor, times however many of those buildings fit in the 900ft/247m length of a block. There's nowhere near enough space on the corner (here's the corner: https://goo.gl/maps/aszPHqrQVGftcqTCA ) to collect that much garbage, much less to do it three times a week. Yes they could build big undergro…

> Yes they could build big underground containers. Obviously. (What else?) Why would that be a massive project?

NYC's underground infrastructure, which is poorly mapped.

See: https://news.ycombinator.com/item?id=34253193>

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#576

Post by weberer »

heavyset_go wrote: post #572
SllX wrote: post #478

Earlier quoted context omitted.

That's neat. Thanks for sharing!

No problem. If you visit there, you can still see some of the rail lines in the streets.

They've paved over the rails in the 90's, but a few bus routes are still powered by the overhead lines. I forget the numbers, but one of them starts at the Frankford transportation center.

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#577

Post by chitowneats »

JumpCrisscross wrote: post #540
chitowneats wrote: post #483

Earlier quoted context omitted.

Have anything to say about Tokyo, Paris, or Seoul? Your silence in that part of the thread is conspicuous. I'm forced to consider the likelihood that you are a typically provincial New Yorker with no real perspective on global megacities.

I’ve never heard New Yorkers call New York the greatest city on earth in earnest. It’s a great city in a way no other city in America truly is. In a league with Tokyo, Delhi, Shanghai, Paris or London. Density and cosmopolitanism bring a unique combination of economic and cultural gifts that set these cities apart, and have for similar cities across history. New Yorkers also tend to be well travelled to those cities,…

> I’ve never heard New Yorkers call New York the greatest city on earth in earnest.

My Uber driver said that to me within the first ride of my landing, and I heard it again and again, from millenials, Gen X, Boomers, basically every type of person I met and from every walk of life, during the many years I lived there.

You guys play this game where you don't say what you mean, and you don't mean what you say, in any context where it's marginally convenient/inconvenient to do so. It's eat or be eaten in NYC. I would hope longtime residents like yourself are just BS'ing the HN community, and not actually delusional about the waters you swim in.

Re: NYC officials say they can't find EV garbage trucks powerful enough to plow snow

#578

Post by mojomark »

tee_0 wrote: post #487
mojomark wrote: post #480

Earlier quoted context omitted.

The author of the article doesn't know what they're talking about. The issue in question is concerned with energy density, not break power of the motors. Electric motors are capable of delivering far greater torque than a similarly sized (weight/volume) diesel engine. Electric batteries on the other hand have far less energy desnity compared to an equivalent volume/mass of diesel fuel.

It’s brake, not break. As in the amount of HP available at the brakes after all transmission/diff/etc losses are taken into account which doesn’t even really apply to electric vehicles. They aren’t looking hard at all. If you just had a super capacitor bank to capture regen, all the energy from the stop and go could be retained and they could probably run the truck on the batteries that they are currently saying last…

Ha, yup, I used the wrong "brake". Silly me. The point is that power delivery and energy capacity of an energy conversion system are two different things and the author's incorrect usage of power to refer to energy is pretty egregious and is spreading an idea that is false - that electric motor vehicles deliver less power than combustion engine vehicles. That's my issue.

One only need look at the volumetric and mass energy density of diesel fuel and electric energy storage options to see that electric vehicles CURRENTLY store significantly less than diesel fuel tanks. That's well known and not a shock to anyone. Energy desnity of electric power storage (batteries, or even H2 fuel cells) will improve over time.

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