147 replies to this topic

[Frankie811]

Garris, on Oct 17 2005, 02:43 PM, said:

Yup, that was great.  It's a capsule summary of everything everyone here has been saying for years.

- Garris

Yes, unfortuneatly

[pdxstreetcar]

Recchia said:

That parcel (Station Park) is going to be redone with Transportation Enhancement funding through the DOT, as long as everything goes as planned...

will it be a park? any rough idea approximately when this might happen?

[Recchia]

pdxstreetcar, on Oct 17 2005, 06:29 PM, said:

will it be a park? any rough idea approximately when this might happen?

Yes it'll stil be a park.  All I can remember is some new walkways and plantings and bus/trolley pull in on Francis St. I think.  Probly a year or two before it happens, since its federally funded it has to go through a whole bunch of red tape.

[Garris]

Recchia, on Oct 17 2005, 06:34 PM, said:

Yes it'll stil be a park.  All I can remember is some new walkways and plantings and bus/trolley pull in on Francis St. I think.  Probly a year or two before it happens, since its federally funded it has to go through a whole bunch of red tape.

Interesting...  As to the original question of why something more substantial isn't there, I believe the reason previously discussed here is that there is a gaggle of utility lines and other elements (for example, the rail lines and tunnel) immediately under the park, so nothing can be built there.

Like much in Providence, it wouldn't be such a big deal if the area was well cared for, which it isn't.

- Garris

[Recchia]

Garris, on Oct 18 2005, 11:10 AM, said:

Interesting...  As to the original question of why something more substantial isn't there, I believe the reason previously discussed here is that there is a gaggle of utility lines and other elements (for example, the rail lines and tunnel) immediately under the park, so nothing can be built there.

Also there are major drainage issues there, which the project will hope to solve as well.

[Frankie811]

http://www.explorene...land.com/travel

[Frankie811]

Um, I think it's time UP adjusts the time here  

[Cotuit]

Frankie811, on Nov 1 2005, 04:42 PM, said:

Um, I think it's time UP adjusts the time here  

It's fine for me. You have to go into "My Controls" and under "Options" choose "Board Settings" and check "Adjust for DST." That's for those pesky Indianans and Arizonans who don't observe.

[Frankie811]

Cotuit, on Nov 1 2005, 05:46 PM, said:

It's fine for me. You have to go into "My Controls" and under "Options" choose "Board Settings" and check "Adjust for DST." That's for those pesky Indianans and Arizonans who don't observe.

I tried that but it's not working. I'm still showing an hour ahead. This might work if I choose Central time instead of Eastern time.

[Frankie811]

Damnit, I don't care about the added features of Urban Planet! I'm tired of the outtages and slowdowns which occur on an almost daily basis! But I have no reason or basis to complain since I pay no money to access this portal.

[Cotuit]

This is interesting:

Ramp creates power as cars pass

[brick]

Cotuit, on Dec 16 2005, 12:58 PM, said:

This is interesting:

Ramp creates power as cars pass

I'd like to know ho wmuch power is required of the cars to move the ramp.  I could see this being used as cars are slowing down anyway, as if at a traffic stop, when they are dispelling energy.  Otherwise my guess is that you will use about 30 kW of engine power to supply the 10kW of ramp power.

[Cotuit]

I don't know exactly how they work, but it would be good if they could be used as part of a raised intersection such as is used in traffic calming.

[basachs]

brick, on Dec 16 2005, 03:06 PM, said:

I'd like to know ho wmuch power is required of the cars to move the ramp.  I could see this being used as cars are slowing down anyway, as if at a traffic stop, when they are dispelling energy.  Otherwise my guess is that you will use about 30 kW of engine power to supply the 10kW of ramp power.

Would that matter though? I mean the cars would be driving anyway, may as well capture that. At least that was how I saw the reasoning behind the invention.

[brick]

basachs, on Dec 16 2005, 02:50 PM, said:

Would that matter though? I mean the cars would be driving anyway, may as well capture that. At least that was how I saw the reasoning behind the invention.

Energy isn't free.

If you use the car as it is driving to power this device, then the car needs to make it up.  mostly, it will do this through extra gas in the throttle.  Thus, you are using four different energy transfers to create the 10 kW.

Energy 1:  Gas to combustion providing movement of the piston
Energy 2:  Movement of piston contributing to movement of crankshaft
Energy 3:  Energy of crankshaft converted through the transmission to the wheels
Energy 4:  Transfer of energy from the wheels to this device

Even this is simplified but each of these transfers has energy loss and there are imperfections with the delivery of the energy.  You would be better off spending whatever it costs to deliever 10 kW of electricity through the power grid than generating it this way.  The only difference is that you are transferring the cost of the energy to people driving cars through increased gas usage.  One way to think of this might be to think of the amount of energy it takes to ride a bike even on a small uphill grade compared to a flat surface.  The same principles are at work.  

If it were used when cars are slowing to a stop, then it would actually help a bit with stopping as well as re-using some of the energy, much in the same way that hybrid cars do when they brake.

[basachs]

okay. The article was scant on details. I dont purport to be well versed in energy transfer. My mental model of how it would work is that it would not cause the car to expel more energy to activate that mechanism.

I am sure a lot of people reading that article would also think of it that way. That a car going 35mph or whatever just goes right over it. The mechanism does not really have enough resistance to cause the car to slow down at all.

Thanks for the info.

[Cotuit]

Here's the related link from the BBC article to the manufacturer.

At a quick glance, it appears the weight of the car is what is transfering the energy, not the motion of the car.

I wonder how it does in snowy climes, especially ones with pisspoor snow removal.

Edited by Cotuit, 16 December 2005 - 02:56 PM.

[brick]

Cotuit, on Dec 16 2005, 03:53 PM, said:

Here's the related link from the BBC article to the manufacturer.

At a quick glance, it appears the weight of the car is what is transfering the energy, not the motion of the car.

I wonder how it does in snowy climes, especially ones with pisspoor snow removal.

doesn't matter.  The car's motion still has to make it rise.  and in fact this adds to the inefficiency of the system as the suspension will use a lot the energy loading and unloading.  In order to use the positive impact of lowering the cars gravitational potential, you have to expend energy getting up there in the first place.

I just don't buy that it's any more efficient than just supplying power.  What it does do that would be attractive to towns is transfer the burden of the energy cost to the drivers, in the form of increased gas usage.  And since gas is taxed, it's like a double dip for the government.  For each person, it would be a minute difference but that's not the same as no difference.

Again, if you use it during stopping, it's all good.  The energy is being transferred off of the vehicle anyway.  It save a minute portion of brake wear instead of costing extra gas.  What would actually be cool is if they could somehow make it so that there was little or no storage and therefore no power would be wasted lighting lights that aren't being used because there is no traffic around.  I'm not sure how traffic safety people would feel about that, though.

On a side note, one of the "hidden costs" of this system is the fact that it will likely need regular maintanence.  This seems like an ok idea but will need a lot of thought and good planning to be implemented correctly.  My fear is that town manager types will not see the downsides and think that it is an abundant free energy source or something.

Edited by brick, 16 December 2005 - 03:15 PM.

[Cotuit]

Well one of the applications where they showed it being used was a toll booth, so I think they're looking at using it at intersections and places where people slow or stop.

[markOne]

Since we live in New England...  I would like to see a big plow doing 50mph run over a set of these things.

Finding ways to harness the energy used in bringing cars to a halt would be much better than just heating up cars' brakes.  I like that folks are thinking about this kind of thing.  My real concern with ideas like this is that they be applied where their use is more efficient than delivering power in more traditional ways.  Like Brick said, they should not be used to just transfer a higher overall cost to the drivers.  Using them in remote areas thus removing the need to extend the power grid to that location could work.  I also like the Brick's idea of using them to turn on lights and signs as needed instead of having them on all of the time.

Edited by markOne, 16 December 2005 - 04:16 PM.