09-18-2019, 01:03 PM
|
#31 (permalink)
|
Master EcoModder
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,256
Thanks: 24,382
Thanked 7,359 Times in 4,759 Posts
|
heat
Quote:
Originally Posted by oil pan 4
Busses designed to be electric from the get go would be a better product.
One thing they didn't address was heat. An electric heater murders range. My leaf uses resistance heating and it kills the range when it's cold.
|
The school districts can modify their purchase agreements with all manufacturers to provide an insulated cabin and glazings.The students will generate enough metabolic heat to temper the inside of the bus.With cameras,all the driver needs is a defrosted windshield,with little power requirement.
The weight of the pack will improve CG issues, and overturned-bus injuries/ fatalities.Worth doing anyway.
Tesla packs are good for 20-years.And EV won't contribute to global warming from 'dumped' compressed natural gas and propane tanks,as a prerequisite to maintenance at the school district bus barns.As is the current practice.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
|
|
|
Today
|
|
|
Other popular topics in this forum...
|
|
|
09-18-2019, 01:16 PM
|
#32 (permalink)
|
Human Environmentalist
Join Date: Aug 2010
Location: Oregon
Posts: 12,742
Thanks: 4,316
Thanked 4,469 Times in 3,434 Posts
|
I've been saying that EVs should have started with things like school buses and garbage trucks. Insane that garbage companies would run big noisy machines that require extensive maintenance and waste a ton of energy constantly stopping when they could have been EV.
Wish I had vehicle engineering experience so I could build a garbage truck company.
|
|
|
The Following 3 Users Say Thank You to redpoint5 For This Useful Post:
|
|
09-18-2019, 01:19 PM
|
#33 (permalink)
|
Master EcoModder
Join Date: May 2008
Location: Maynard, MA Eaarth
Posts: 7,907
Thanks: 3,475
Thanked 2,950 Times in 1,844 Posts
|
School bus seats should have seat belts, so when the seats get replaced, seat heaters should be added, as well.
There are between 460K and 480K school buses in the US. 460,000 x 60kW = 27,600,000kW.
|
|
|
The Following User Says Thank You to NeilBlanchard For This Useful Post:
|
|
09-18-2019, 01:21 PM
|
#34 (permalink)
|
Human Environmentalist
Join Date: Aug 2010
Location: Oregon
Posts: 12,742
Thanks: 4,316
Thanked 4,469 Times in 3,434 Posts
|
Meh, kids can wear coats. The first kids in might have a colder cabin, but each person puts out about 100 watts of heat. Get 40 kids in there and you've got 4,000 watts.
|
|
|
The Following 2 Users Say Thank You to redpoint5 For This Useful Post:
|
|
09-18-2019, 01:52 PM
|
#35 (permalink)
|
Master EcoModder
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,256
Thanks: 24,382
Thanked 7,359 Times in 4,759 Posts
|
garbage trucks
Quote:
Originally Posted by redpoint5
I've been saying that EVs should have started with things like school buses and garbage trucks. Insane that garbage companies would run big noisy machines that require extensive maintenance and waste a ton of energy constantly stopping when they could have been EV.
Wish I had vehicle engineering experience so I could build a garbage truck company.
|
The City of Denton,Texas,went to hydraulic-hybrid garbage trucks,and it pushed efficiency from,1.3-mpg,to 1.6-mpg.
The Denton School District uses propane-powered school buses,which,when the in-tank fuel pump goes out,are just vented off,(Nearly the most potent greenhouse gases)and no-doubt a federal crime if I was caught doing it.
I suspect that the energy efficiency of electric regeneration,vs hydraulic would be at least an order of magnitude.
And if you'll GOOGLE 'fatal school bus rollover accidents',you'll get an idea of the superiority of an EV layout.Manslaughter-by-incompetence.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
|
|
|
09-18-2019, 01:55 PM
|
#36 (permalink)
|
Master EcoModder
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,256
Thanks: 24,382
Thanked 7,359 Times in 4,759 Posts
|
each person
Quote:
Originally Posted by redpoint5
Meh, kids can wear coats. The first kids in might have a colder cabin, but each person puts out about 100 watts of heat. Get 40 kids in there and you've got 4,000 watts.
|
Yeah,it's 300-Btu's per person.13,800-Btu for a 45-passenger bus.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
|
|
|
09-18-2019, 02:00 PM
|
#37 (permalink)
|
Human Environmentalist
Join Date: Aug 2010
Location: Oregon
Posts: 12,742
Thanks: 4,316
Thanked 4,469 Times in 3,434 Posts
|
I expect EV efficiency to be way more than an order of magnitude. Consider very little energy is lost due to aerodynamic drag. A garbage truck might hit 5 MPH before stopping at the next can. That momentum can be recaptured at something like 80% efficiency. I imagine it could be even higher if supercaps were used to capture braking energy.
By your definition, all accidental death is due to manslaughter. There's always another level of safety that can be built into a system, but at some point we have to say "good enough". That isn't to say we shouldn't strive to improve something, but death by school bus rollover is among the lowest causes of death in children.
|
|
|
The Following User Says Thank You to redpoint5 For This Useful Post:
|
|
09-18-2019, 02:25 PM
|
#38 (permalink)
|
Master EcoModder
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,256
Thanks: 24,382
Thanked 7,359 Times in 4,759 Posts
|
rollover
Quote:
Originally Posted by redpoint5
I expect EV efficiency to be way more than an order of magnitude. Consider very little energy is lost due to aerodynamic drag. A garbage truck might hit 5 MPH before stopping at the next can. That momentum can be recaptured at something like 80% efficiency. I imagine it could be even higher if supercaps were used to capture braking energy.
By your definition, all accidental death is due to manslaughter. There's always another level of safety that can be built into a system, but at some point we have to say "good enough". That isn't to say we shouldn't strive to improve something, but death by school bus rollover is among the lowest causes of death in children.
|
The statistics don't properly flavor the loss experience of parents and family survivors whom will have to go on without the deceased.
The four-foot-high floor of the bus necessarily raises the center-of-gravity,making them ripe for rollover.Greyhound and charter buses as well.I'd like to see a side-by-side comparisons from the National Transportation Research Center.
I do believe the USDOT,NTSA,Bluebird and the other bus-makers, and purchasing departments are all guilty of manslaughter when I see this.
Peter Principle all-around.
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
|
|
|
09-18-2019, 02:38 PM
|
#39 (permalink)
|
Human Environmentalist
Join Date: Aug 2010
Location: Oregon
Posts: 12,742
Thanks: 4,316
Thanked 4,469 Times in 3,434 Posts
|
Bus travel is orders of magnitude safer than other forms of transportation. By your own criteria, parents are guilty of manslaughter when their children are accidentally killed in regular vehicles since they could have put them on a bus, which is statistically way safer.
Again, I'm not arguing to accept the status quo, and I'm in favor of EV buses for many reasons, and among them are the lower center of gravity.
You don't seem to get the concept that "make it as safe as possible" is not actually possible. It reduces to the notion that we'd better all stay home and do nothing, for risk of injury. Every single thing is a compromise, and the balance of that compromise is up for debate, but the existence of injury and death is not proof of negligence.
The level of emotion felt does not shape truth, either. It's irrelevant to the facts of the matter.
|
|
|
The Following 2 Users Say Thank You to redpoint5 For This Useful Post:
|
|
09-18-2019, 03:24 PM
|
#40 (permalink)
|
Master EcoModder
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 16,256
Thanks: 24,382
Thanked 7,359 Times in 4,759 Posts
|
safety
Quote:
Originally Posted by redpoint5
Bus travel is orders of magnitude safer than other forms of transportation. By your own criteria, parents are guilty of manslaughter when their children are accidentally killed in regular vehicles since they could have put them on a bus, which is statistically way safer.
Again, I'm not arguing to accept the status quo, and I'm in favor of EV buses for many reasons, and among them are the lower center of gravity.
You don't seem to get the concept that "make it as safe as possible" is not actually possible. It reduces to the notion that we'd better all stay home and do nothing, for risk of injury. Every single thing is a compromise, and the balance of that compromise is up for debate, but the existence of injury and death is not proof of negligence.
The level of emotion felt does not shape truth, either. It's irrelevant to the facts of the matter.
|
There might be an implied trust on the part of the parents,that those in a position of authority in the school district have their back.
The recent reporting on school shootings carries the misconception that parents don't give a rat --- about their children's safety?
It's easier and cheaper to build a lower bus and pull a trailer for cargo.We've had this in the USA since 1951.
What is the argument for more expensive,less safe buses?
It's a simple engineering proposition.The safety would be by default.
If I can envision an inherent safety concern,why not those charged with student safety? Are any of them qualified to hold their jobs? What are the manufacturers thinking about? Let's only launch Space Shuttles when it's below freezing?
__________________
Photobucket album: http://s1271.photobucket.com/albums/jj622/aerohead2/
|
|
|
|