'Trackless' trolley bus economics?

[mgk920]

Just a quick thought that I had last night, but with the recent runup in petroleum fuel prices, might a 'tipping point' be near where it might be economical for some USA transit systems to start stringing and/or restringing 'trackless' trolley bus wire?

(Yes, I do know that five places in the USA now operate 'trackless' trolleys and that at least two of them (Dayton, OH and San Francisco, CA 'MUNI') are currently expanding their systems.)

Mike

[Luca]

By trackless trolleys do you mean something like a bus but with wires overhead? I think they have some major advantages to trolleys, mostly having to do with noise, cost of rails and flexibility in traffic.

You still need to string the wires (which are a bit of a safety hazard), but not lay tracks. They can swing around a misparked car/obstacle (tracks are fixed, I've seen trolleys srtuck/delayed by inconsiderate drivers). Trackes themselves are a ahzard toi bikes, etc. Also track vehicles are nosiy and they generate some very nasty iron filings fumes/dusk which pits surfaces all over the street in question (as I found out on my car's paint job in Milan). Lastly, a borken-down trackless torlley can be towed awy without having to the track space and block all the other trolleys behind it.

[mgk920]

By trackless trolleys do you mean something like a bus but with wires overhead? I think they ahve some major advantages to trolleys, mostly having to do with noise, cost of rails and flexibility in traffic.

You still need to string the wires (which are a bit of a safety hazard), but not lay tracks. They can swing around a misparked car/obstacle (tracks are fixed, I've seen trolleys srtuck/delayed by inconsiderate drivers). Trackes themselves are a ahzard toi bikes, etc. Also track vehicles are nosiy and they generate some very nasty iron filings fumes/dusk which pits surfaces all over the street in question (as I found out on my car's paint job in Milan). Lastly, a borken-down trackless torlley can be towed awy without having to the track space and block all the other trolleys behind it.

Yea, they look and operate pretty much like regular 'diesel' busses, except that they draw their tractive power from two overhead wires. I can see some advantages over diesel in that they are very clean and quiet in their operation and can draw that power from whatever source is most economical at any given time (not dependent on now expensive petroleum).

Newer 'trackless' trolley busses also have reserve batteries on board, allowing them to operate 'off wire' for short periods so they can easily detour around street blockages and make life much easier in the shop/barn area.

Nice image, BTW, thanx for posting it.

Mike

[ChevyChaseDC]

Trackless trolleys make the most sense where the noise and emissions of a diesel buses are not acceptable and where steep grades give an advantage to the greater tractive effort provided by electric motors for climbing hills; also the rubber tires work better on steep grades than steel on steel. San Francisco, Seattle, and other hilly cities are thus ideally suited to trolleybuses.

[jmello]

NIMBYs in Boston would never allow the stringing of new wire. The Silver Li[n]e Washington Street segment was originally supposed to use trackless trolleys, but the Chinatown and Bay Village residents freaked when they found out about the overhead wires.

[njm]

Trackless (electric) trolleys are an option, though ethanol, natural gas, biogas are other options that can be explored at a lower price than standard diesel.

I believe the biggest (technical) issues with electric is the switches for the wires (which are 16' in the air) and the requirement of 2 wires instead of one.

PS ChevyChaseDC-rubber being better than steel wheels on grades is a myth. The higher contact force and smaller area gives rail vehicles much higher traction (and astronomically higher efficiency) on hills. I won't venture to imagine how many rubber-tired trucks would be required to pull the same load as a 6-axle freight locomotive.

[SpringfieldMonorail]

Trackless (electric) trolleys are an option, though ethanol, natural gas, biogas are other options that can be explored at a lower price than standard diesel.

What what what? Cheaper than diesel? Really?

[njm]

Testament for proofreading:

What what what? Cheaper than diesel? Really?

Well maybe not. That was a goof. I meant less than electric.

Though once diesel is 4.50/gallon, pretty much any hybrid or non-petroleum alternative will be more cost effective (I assume that natural gas will quickly become obselete as a fuel source due to higher demand for power generation as more coal plants are converted to gas.)

[Big Green Scott]

Alot of Bus' across the country are converting to natural Gas. Lets also not forget to mention BioDiesel as a possible alternitive. it can cost as low as $.45/gallon for many municipalities (if they're willing to make an initial investment.)

Personally I think that tracks should be laid for mass transit (preferably on elevated rail or on a new right of way). Simply using the roadway neglects the added benefit of a transit system to navigate around, and keep a regular scheduele during high car traffic periods of the day.

[Luca]

Personally I think that tracks should be laid for mass transit (preferably on elevated rail or on a new right of way). Simply using the roadway neglects the added benefit of a transit system to navigate around, and keep a regular scheduele during high car traffic periods of the day.

You can cheaply/easily sequester one lane for the trackless trolleys to avoid congestion issues. Rails, as I've pointed out, have issues. Elevated rails are a bit of blight, are they not? Who wnats to be next to the 'el' ?

[njm]

Not to mention the gargantuan capital cost of trying to convert entire systems (ROW acquisition, construction, fleet). Furthermore, grade-separated ROW's for rail can be just as disruptive to neighborhoods as freeways (if proper connections are not made.

I agree, however, that transit does need some way to avoid congestion.

This is where trolleybusses can be at a distinct advantage.

[safege]

You can cheaply/easily sequester one lane for the trackless trolleys to avoid congestion issues. Rails, as I've pointed out, have issues. Elevated rails are a bit of blight, are they not? Who wnats to be next to the 'el' ?

Heavy rail has the largest footprint, so its not fair to single it out. Elevated LRT has a smaller footprint, and monorail has the smallest footprint of the three.

Noise also follows this progression.

[jordanb]

PS ChevyChaseDC-rubber being better than steel wheels on grades is a myth. The higher contact force and smaller area gives rail vehicles much higher traction (and astronomically higher efficiency) on hills. I won't venture to imagine how many rubber-tired trucks would be required to pull the same load as a 6-axle freight locomotive.

You're right that steel on steel is much more efficient on grade or on the level because there is much less rolling friction than with rubber.

But friction is exactly what you need to keep the vehicle from slipping on grade. Railroads generally can only be built on much more gradual grades than those of roads because otherwise, the vehicles will slip down it.

Railroads can only be built on steep grades using a furnicular ratcheting or cable system that pulls the car up the grade. Without something like that you're going to be able to handle a much steeper grade with a rubber system.

[njm]

You're right that steel on steel is much more efficient on grade or on the level because there is much less rolling friction than with rubber.

But friction is exactly what you need to keep the vehicle from slipping on grade. Railroads generally can only be built on much more gradual grades than those of roads because otherwise, the vehicles will slip down it.

Railroads can only be built on steep grades using a furnicular ratcheting or cable system that pulls the car up the grade. Without something like that you're going to be able to handle a much steeper grade with a rubber system.

I know that friction is required to keep them from sliding. I spent 5 years in school studying engineering. However, I've also seen trams in Oslo climb some pretty steep hills.

A 'route' that requires a funicular most likely is not going to have a rubber-tired bus on it. The mechanical stresses on the machinery and tire wear would be unbeleivable. Not to mention that going downhill in snow would be unbelievable dangerous. If a bus has to be used in such a case, the most likely solution would be to go around.

For lesser 'steep' slopes (~15% to ~10%) it gets down to calculations of angle, vehicle weight, and the varying friction coefficients for rolling and sliding . There are certainly some places where steel wheels would be impossible. However, saying that rubber will be better on these hills can even be dead wrong because rubber wheels are more susceptible to weather-related reductions in traction. Overall, steel wheels are more predictable and, if designed properly, will provide consistently good traction.

[abrowne]

http://www.translink.bc.ca/Transport...rolley_bus.asp

*shrug* I happen to like the overhead wires... makes the street more interesting.

[JNL]

From my city - thought this might be of interest. I'd be sad to see them go.

Trolley buses in doubt

Wellington could lose its iconic inner city trolley buses. The Greater Wellington regional council says that the future of Wellington's trolley bus network is in doubt following the refusal of Land Transport NZ to provide additional funding for the upgrade and maintenance of the system, and advice of increased costs from Vector.

"Land Transport NZ has advised us that they will provide funding for trolley buses to the equivalent of 50 percent of the cost of a diesel bus," says councillor Glen Evans, chairman of council's Passenger Transport Committee.

"Added to that, Vector, the owners of the substations that feed the lines system, recently advised Stagecoach that there are significant costs to bring the infrastructure back up to a reliable standard."

"Together these costs mean that running the trolley bus network would be $2.5 million more than the cost of running an equivalent diesel system.

"About $1.5 million of these costs have already been built into our LTCCP (10-year plan), so the further cost to ratepayers would be in the order of $1 million, which is equivalent to about two percent extra on total rates."

Mr Evans says it was necessary to refurbish the old trolley buses and do additional maintenance to the network to keep the system running.

"Like the rail network, that was allowed to run down through lack of investment, we are now catching up on deferred maintenance and much needed improvements.

"If we don't make this investment it is likely the trolley bus network will go."

Impasse
Mr Evans says that if the funding impasse with Land Transport NZ cannot be resolved Greater Wellington will have to consider its options.

"One option will be to undertake a full consultation with the public to provide them will all the information about the options available, and their costs. The regional council will consider this issue when it confirms its LTCCP on June 1."

The Green Party has indicated it plans to start a petition to save the trolley buses.

To give a bit of context, we have a relatively small population - about 175k - and our bus network is very well used. Trolley buses run right through the central city and out through key connecting routes to the suburbs and the airport. "Rates" are property taxes.

[metroboi]

Another option is the hybrid bus. They have most of the advantages of electric buses, but no need for the wires and can run on biodiesel if it is available.

Hybrid Bus Transit Now Available in Charlotte