Posts Tagged ‘Trolleybus’

Trams, Buses & Trolleybuses Can Co-exist

June 4, 2010

On another blog, a long standing member of the SkyTrain/metro fraternity alluded to the fact that LRT and buses could not co-exist on the Granville Mall. Sorry to disappoint the purveyors of misinformation, but they can and do in many cities.

A photo essay from several cities proves the point.

Milan

 

Geneva

 

Essen
Riga

Ghent

Geneva

When Trolleybus and Streetcar Cross Paths

May 11, 2010

In answer to a query from a regular poster, ‘Zwei’ has found a picture of a Russian trolleybus and tram intersection showing the overhead.  I have included from Wikipedia, a short description of tram/trolleybus junctions, locations, and the electric overhead.

Tram – Trolleybus Crossings

From Wikipedia

Trams draw their power from a single overhead wire at about 500 to 750 V, while trolleybuses draw their power from two overhead wires, at a similar voltage. Because of that, at least one of the trolleybus wires must be insulated from tram wires. This is usually solved by the trolleybus wires running continuously through the crossing, with the tram conductors a few centimetres lower. Close to the junction on each side, the wire merges into a solid bar running parallel to the trolleybus wires for about half a metre. Another bar similarly angled at its ends is hung between the trolleybus wires. This is electrically connected above to the tram wire. The tram’s pantograph bridges the gap between the different conductors, providing it with a continuous pickup.

Where the tram wire crosses, the trolleybus wires are protected by an inverted trough of insulating material extending 20 or 30 mm below.

Until 1946, there was a level crossing in Stockholm, Sweden between the railway south of Stockholm Central Station and a tramway line. The tramway operated on 600-700 V DC and the railway on 15 kV AC. Some crossings between tramway/light rail and railways are still extant in Germany. In Zurich, Switzerland the VBZ trolleybus line 32 has a level crossing with the 1200 V DC railway to mount Uetliberg; at many places in the town trolleybus lines cross the tramway. In the Swiss village of Suhr the WSB tramway operating at 1200 V DC crosses the SBB line at 15 kV AC. In some cities, trolleybuses and trams have shared the same positive (feed) wire. In such cases a normal trolleybus frog can be used.

Another system that has been used is to coincide section breaks with the crossing point so that the crossing is electrically dead.

Australia

Many cities had trams and fishsticks both using trolley pole current collection. They used insulated crossovers which required tram drivers to put the controller into neutral and coast through. Trolleybus drivers had to either lift off the accelerator or switch to auxiliary power.

In Melbourne, Victoria, tram drivers put the controller into neutral and coast through section insulators, indicated by insulator markings between the rails.

Melbourne has four level crossings between electrified suburban railways and tram lines. They have complex switching arrangements to separate the 1500 V DC overhead of the railway and the 650 V DC of the trams, called an overhead square. Proposals have been put forward which would see these crossings grade separated or the tram routes diverted.

Greece

In Athens, there are two crossings between tram and trolleybus wires, at Vas. Amalias Avenue and Vas. Olgas Avenue, and at Ardittou Street and Athanasiou Diakou Street. They use the above-mentioned solution.

From the opening of the tram system in the summer of 2004, trams and trolleybuses in the direction of Pagrati shared the same exclusive lane, about 400m long, on the far right side of Vas. Olgas Avenue, with tram and trolleybus wires side-by-side above a narrow lane of road. The trolleybus wires were on the far right of the lane, away from the trams’ (very wide) pantographs. Trolleybus drivers were required to drive very slowly because the trolley poles were extended to their limits. A change of route for trolleybuses was implemented in mid-2005, ending this arrangement.

Italy

In Milan  most tramway lines cross the circular trolleybus line once or twice, so crossings between overhead tram and trolleybus wires are quite commonplace. Trolleybus and tram wires run parallel in some streets, like viale Stelvio and viale Tibaldi.

Close-up of a tram/trolleybus junction.

Adiós Seattle’s Trolley Buses?

May 10, 2010

It seems transit authorities are taking a hard look at Seattle’s trolley bus system, with an eye to abandon the service. The problem in Seattle, as in Vancouver, the trolley buses are only seen as a electric bus, not a different transit mode suited for a specific job. Trolley buses should be used on heavily used routes, especially hilly routes, with stops every 450 metres or more. Broadway is a prime example of their ill use as if a European style trolley bus service were to be used, there would not be any need for the diesel 99B-Line express buses.

The term ‘hybrid‘ tends to scare me as it is the term used with experimental operation and that translates into expensive operation.

In the real world, trolley buses are slowly becoming a thing of the past, being replaced by low-end streetcars or more glitzy proprietary GLT or guided bus.

Fate of trolleybuses hangs in balance

King County Metro Transit’s fleet of 159 trolleybuses need to be replaced soon, but what they should be replaced with is up for debate

By Mike Lindblom

Seattle Times transportation reporter

About one-fifth of all King County Metro Transit rides are made on an electric bus, powered by a nonpolluting trolley wire overhead.

But the agency hasn’t purchased a new trolleybus since 1979.

Since then, Metro bought new bus bodies and fastened old electric motors onto them. They pulled out the diesel engines from a fleet of dual-mode buses, so they ran only on their electric motors. These minor miracles saved the public tens of millions of dollars.

Now the day of reckoning has arrived.

By 2014, the agency expects its fleet of 159 trolleybuses to wear out.

At the Sodo maintenance base, trolleybus-maintenance manager Mike Eeds pointed to a crack in a steel roof member, near the rear door of a bus. It’s not a safety hazard but could cause leaks — and cracks are expected to spread through the fleet. Worn-out teeth were being replaced on the same bus’s drive axle. Metro has been cannibalizing spare parts, but those will run out by 2016, he said.

County elected officials must decide by next year whether to retire the old trolleybuses, buy new-generation models or switch to some other technology.

An audit last year suggested tearing out the overhead wires and switching to hybrid buses, whose diesel engines are supplemented with onboard batteries. Doing so could ostensibly save $8 million a year compared to trolleybuses, by reducing electrical-maintenance costs and making route schedules more flexible, the audit says.

But many residents along the routes, and Seattle transportation director Peter Hahn, insist on preserving electric buses because they are quiet and nonpolluting. Seattle ranks third of only six cities in the U.S. and Canada that operate trolleybuses, behind San Francisco and Vancouver, B.C. Edmonton removed its trolleybus wires last year, but Laval, Quebec, is considering a brand-new system using local hydropower.

More than pollution

The debate here involves issues far beyond pollution and noise, with a major consideration being torque — electric motors have superior power to turn bus axles coming off a dead stop.

“San Francisco and Seattle have hills that are alike, up and down. There’s no way you can put diesel buses on the hills,” says Nathanael Chappelle, Metro’s 2007 co-operator of the year. Eeds agrees, saying a “straight hybrid” wouldn’t work.

Midway up Queen Anne Hill, a former cable-car route, the Number 3 and Number 13 buses stop for passengers on a 15 percent slope. When the wheels turn again, the acceleration pushes people firmly into their seat backs. The best drivers wait for all to find a seat, or feather the accelerator pedal, so as not to topple unstable riders in the aisle.

Larry Nelson, living in a fourth-floor hillside apartment, says sparks fly off the wire or the tires spin on damp pavement. Still, that’s better than smelling diesel, he says.

In the overhead network, there are dead spots where electricity is interrupted, so a bus must build momentum to coast through, but not faster than 10 mph.

Take a curve too fast, and the power poles fall off the charged wires — trolleybus driver Chai Kunjara compares the physics to a waterskiier who swings wide faster than the powerboat.

Despite the quirks, he says, the steering handles smoothly, the dashboard console is simple and one can navigate by following the wires, though sometimes drivers forget and stray off them.

The downside of trolleybuses is inflexibility. In the ice storm of December 2008, several trolleybuses on First Hill became stuck, paralyzing the central-city service as the following buses couldn’t pass. Diesel buses can go around stalls — Metro says it will “dieselize” its electric Number 70 route for three years because of the upcoming Mercer Street reconstruction.

Trolleybuses cost $1 million or more, compared with $720,000 for diesel-hybrids. Auditors also point out there’s only one North American trolleybus maker, exacerbating the risk of higher costs.

On the other hand, Vancouver is happy with its 2007 models by Winnipeg-based New Flyer, and expects them to last more than 20 years each. Dayton, Ohio, imported Czech buses for final assembly in the U.S. Hahn argues there’s no danger a robust international trolleybus industry will go extinct.

Exploring options

The County Council has ordered a technical study. Councilman Larry Phillips, D-Magnolia, argues electric buses support the fight against sprawl, by making busy city neighborhoods more pleasant.

The timing is awkward. Hydrogen vehicles or plug-in electric buses seem promising, but Metro can’t wait until those technologies mature. That leaves other options:

• Order a trolleybus with supplementary batteries charged through overhead power and regenerative braking — so the bus can sometimes detour off-wire.

• Combine overhead power with a supplementary diesel motor, for long or short stretches off-wire.

• Travel wire-free using electric batteries and high-torque motors, to be recharged by a diesel motor running at a steady, fuel-efficient rate. Metro General Manager Kevin Desmond also hopes to research whether there’s a bus available to use overhead power in-city, then continue off-wire several miles farther out.

Just last year, Metro published a paper describing a better “Rapid Trolley Network” that provided trips as frequent as every six minutes. There could be off-board payment and roomier vehicles, like a train. New wires over Denny Way, Yesler Way and East Madison Street would fill gaps in trolleybus routes.

When the county took over Seattle bus lines in 1973, the deal guaranteed “electric trolley service” shall continue, transportation Director Hahn’s letter emphasizes. The city is writing a new transit plan that likely would keep or even expand the lines, he said in an interview.

“We believe, in terms of climate change, greenhouse-gas goals, this is the most reliable technology.”

http://seattletimes.nwsource.com/html/localnews/2011818844_trolleybus09m.html