Ultralight Hybrid Transit Bus Developed

Technocrat

Ultralight Hybrid Transit Bus Developed

zogger

Tue Jul 29 21:13:00 -0700 2008

Mechanics

manage

A new hybrid bus was shown this week, with production models slated for next year. The bus, which runs on electric power for the primary, not just as a limited adjunct, was built with Nitronic 30 stainless steel, which is very light compared to normal vehicle steel and is "greener" to make than aluminum. Despite a higher initial cost, they estimate useful service life will be greatly extended, and weight savings alone make the bus twice as efficient as earlier hybrid models.

"The benefits of improved strength-to-weight performance quickly compound to all other vehicles systems such as smaller tires, lighter brakes, batteries, motors and so on," Emmons said. "By optimizing the total vehicle we have been able to cut the weight almost in half, which has led to performance improvements, most notably fuel economy gains." If you follow the links over to the product development page, they indicate a big pdf with more tech details. And now I wonder how long before they have a rockstar millionaire level upscale RV version...

Ultralight Hybrid Transit Bus Developed

Simon Arthur

Wed Jul 30 10:29:47 -0700 2008
manage

The yield strength of this Nitronic 30 stuff is 48 ksi. The yield of aluminum 6061 (a common, readily available, weldable alloy) is 40 ksi. But the aluminum is nearly 1/3 the density. So the advantage of using this alloy is questionable.

Also, why does the website have a cartoon of the bus, instead of a real photo?

Ultralight Hybrid Transit Bus Developed

Charles E Hill

Wed Jul 30 11:56:11 -0700 2008
manage

I noticed that, too. That bus, if not the entire scene, is a 3D mock-up. I'm not 100% sure of the photos of the bus in various stages of development on their website, either. But, it may be that I've just seen too many "reflective silver metallic" objects in my CG lifetime to be biased.

Ultralight Hybrid Transit Bus Developed

duhavid

Wed Jul 30 14:20:55 -0700 2008
manage

My experience comes from bikes, so I pray forgiveness if I am wrong, but in the bike scene, you usually use larger diameter tubes of much greater wall thickness, resulting in a stronger bike than a traditional steel frame bike, and a small weight savings, due to the increase in the volume of material.

So, I imagine that if the bus were built with aluminum, they would do basically the same thing, increase the cross section of the frame members, increasing the amount of metal, obviating the density advantage to some degree.

Also, for framing type work, Aluminum is relatively brittle, making bending parts back into alignment more of an issue ( at the bike shops I worked, we would straighten frames and forks, retap threaded parts, resize press fit parts as needed. We would not touch aluminum or carbon fiber bikes if they were bent in a wreck, as there were too many workability and liability issues associated.

Ultralight Hybrid Transit Bus Developed

Michael Smith

Wed Jul 30 19:45:30 -0700 2008
manage

Yeah I actually googled around for this material to compare it with Reynolds tube. The thing about a bus is you can build a monocoque body, effectively a cage made out of tubes. That way it can be stonger in one extra dimension than a bike frame using similar materials.

I ride an alumium mountain bike for commuting because that was all I could find in the shops. I wouldn't mind if the energy cost of aluminum manufacture pushed bikes back to using good steel. Then I could trigger inductive vehicle detectors again.

Maybe I should try one of those magnesium frames. It would be handy for attracting attention if I get stranded anywhere.

Ultralight Hybrid Transit Bus Developed

duhavid

Wed Jul 30 21:45:07 -0700 2008
manage

"The thing about a bus is you can build a monocoque body, effectively a cage made out of tubes. That way it can be stonger in one extra dimension than a bike frame using similar materials"

Yes, but bike frames are generally very strong in all the dimensions they need to be strong in, and they are not that big ( so your bending leverage on any given tube is not all that much, compared to a bus ). In other words, per tube, I think my analysis holds.

All you could find was aluminum frames? I guess things have changed since I was "in". Maybe it was the shop.

On the magnesium frame, yes, it would attract attention. I understand magnesium is hard to get started igniting.

Ultralight Hybrid Transit Bus Developed

Charles E Hill

Thu Jul 31 07:48:24 -0700 2008
manage

One of the "extras" people buy when upgrading a Jeep or other 4x4 for rockcrawling are steel rims. The aluminum rims that come on most vehicles are pretty, but if they get dented or bent you're screwed. With a steel rim you can just whip out the hammer and knock out the dents.

Ultralight Hybrid Transit Bus Developed

clanger9

Thu Jul 31 01:41:14 -0700 2008
manage

Nice to see these hybrids finally getting into production.

Newcastle-upon-Tyne in the UK has a small fleet of really cool gas-turbine hybrid buses. They're clean and quiet and most people think they're pure electric...