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Old December 23rd, 2004, 12:54 AM   #61
sequoias
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This is the image of the metro bus tunnel in downtown Seattle which runs for 1.3 miles, it carries about 140 buses during peak hours. They use dual mode buses which run on electricity in tunnel and running on diesel when it leaves the tunnel, much faster than going on the streets of downtown seattle. Currently, they're replacing the old dual mode buses with brand new hybrid buses which run on diesel-electric power. it doesn't need the overhead wires. You don't smell any diesel or any fumes from it, low emission standard! It will share with the light rail line opening in 2009.

http://transit.metrokc.gov/tops/tunn..._stations.html

Last edited by sequoias; December 23rd, 2004 at 01:39 AM.
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Old December 23rd, 2004, 01:38 AM   #62
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Below is a computer simulated image from the Sound Transit website showing a light rail vehicle sharing the tunnel with a bus:



The bus tunnel is 1.3 miles long and features 5 stations. It was originally built with a two-wire overhead electrical system for the operation of dual power buses equiped with both diesel engines and electric motors connected to trolley poles. The dual power buses are now being retired in favor of hybrid buses that can operate on either diesel engines or batteries. Part of the motivation for the change to the hybrid buses is that the tunnel is to be rebuilt for the Central Link light rail system, which will require a single-wire overhead electrical system for the pantograph equipped light rail vehicles.

The bus tunnel will be closed for up to two years starting in September 2005. The tunnel was originally built with tracks for light rail vehicles; however, those tracks are now judged to be inadequate. During the tunnel closure, the trackbed will be lowered and new tracks will be installed. Also, a stub tunnel extension will be built for the reversal of the light rail vehicles. Sound Transit has plans to extend the light rail line from the stub tunnel to the University of Washington and beyond.

For more information on the tunnel reconstruction, see the following website:

http://www.seattletunnel.org/default.asp

For more information on Sound Transit's Central Link light rail system, see the following website:

http://www.soundtransit.org/projects/svc/link/
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Old December 23rd, 2004, 05:02 PM   #63
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Quote:
Originally Posted by greg_christine

The bus tunnel is 1.3 miles long and features 5 stations. It was originally built with a two-wire overhead electrical system for the operation of dual power buses equiped with both diesel engines and electric motors connected to trolley poles. The dual power buses are now being retired in favor of hybrid buses that can operate on either diesel engines or batteries. Part of the motivation for the change to the hybrid buses is that the tunnel is to be rebuilt for the Central Link light rail system, which will require a single-wire overhead electrical system for the pantograph equipped light rail vehicles.
Hi All,

Whilst it is true that the Bredas were life-expired it does seem to be somewhat unfortunate that they are being replaced with diesels. Especially as Seattle has just bought a lot of new electric trolleybuses (ETB) too.

OK so the hybrid diesels might be "reduced pollution" (aka "less dirty") vehicles but I understand that the exhuast fumes situation is such that tunnels are now becoming unpleasant places to be.

As a contrast the Bredas, whilst powered via the overhead wires were "zero" pollution. (no air pollution at point of use - rather important in unventilated tunnels!) As are Seattles' other ETB's

Experience in Essen, Germany showed that twin-wire powered buses and single-wire powered LRV's can share tunnel systems with ease. Its a shame this is not being done for Seattle.


The pics below come from my website,





for more information and pics visit
http://www.garden.force9.co.uk/OBahn.htm

Simon
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Old December 23rd, 2004, 05:06 PM   #64
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Yes i suppose it would help if I showed something *from* within the tunnels too!


Simon

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Old December 23rd, 2004, 05:25 PM   #65
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AFAIK those buses in Essen don't use the Stadtbahn (=light rail) tunnels anymore... didn't see it anyway when I was there a couple of weeks ago.
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Old December 23rd, 2004, 06:46 PM   #66
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when the hybrids are in the tunnel they will be switched to a "tunnel mode" which only uses electricty
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Old December 23rd, 2004, 06:53 PM   #67
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Sharing of Routes between Trolley Buses and Light Rail

San Francisco has many trolley bus routes. Because the trolley buses are not grounded to rails, a two-wire electrical supply system is required:



San Francisco also has several light rail lines. Modern light rail cars are typically equipped with pantographs. Pantographs have the advantages that 1) the driver can raise and lower them without leaving his seat and 2) there is no risk of coming off the wire at speed. The pantograph equipped light rail cars require a single wire electrical supply:



Because the pantograph would cause a short circuit between the two wires, it is not possible for a pantograph equipped light rail cars to operate under the trolley bus wires. As shown in a post above, this problem has been circumvented in Essen by placing the trolley bus wires off to the side. Another solution is to use trolley pole equipped streetcars with the trolley pole connected to just one wire of the trolley bus electrical supply system. This approach has been used in San Francisco with the heritage streetcars:

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Old December 23rd, 2004, 07:30 PM   #68
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Quote:
Originally Posted by spsmiler
Hi All,

Whilst it is true that the Bredas were life-expired it does seem to be somewhat unfortunate that they are being replaced with diesels. Especially as Seattle has just bought a lot of new electric trolleybuses (ETB) too.

OK so the hybrid diesels might be "reduced pollution" (aka "less dirty") vehicles but I understand that the exhuast fumes situation is such that tunnels are now becoming unpleasant places to be.

As a contrast the Bredas, whilst powered via the overhead wires were "zero" pollution. (no air pollution at point of use - rather important in unventilated tunnels!) As are Seattles' other ETB's

Experience in Essen, Germany showed that twin-wire powered buses and single-wire powered LRV's can share tunnel systems with ease. Its a shame this is not being done for Seattle.



Simon
That shared line (2 different overhead wires at the same line) will not fit in a tunnel in Seattle, so the only option is have hybrid buses running thru tunnel. When the light rail becomes so fequent, buses will not go thru tunnel anymore. It's time of evolution from bus to light rail, sort of.
Don't forget those hybrid buses use bio-diesel blend, too. They also have particulate trap filters to trap diesel fumes. Most of the bus on the Metro fleet in King county have particulate trap filters installed running on bio diesel blend. You can't see diesel exhaust coming out, except for a bit of fumes.
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Old December 23rd, 2004, 07:32 PM   #69
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New Metro Bus Way

On December 17th, Phase II of the new Silver Line project opened to the transit riding public. This is the first new "subway" line built in Boston in 90 years. Too bad it is a BRT line and not a rail system. Below is a map of the current Silver Line. There are three underground stations, South Station, Courthouse and the World Trade Center, where it then goes above ground. Low emission 40' electric and 60' dual-mode (electric/diesel electric) articulated vehicles will be used so that the buses can use city streets and go to the airport. The tunnel cost $680 Million to complete.



Only picture I could find of new underground busway/metro. Can anyone find some better ones?


Cut and cover construction at the Courthouse station.


Outside the WTC stop


The section from Dudley to Downtown (also known as Phase I) is on the surface with over half the route using a bus only lane (which is just the right lane of a two lane street). The route opened in 2002 and has about 14,000/day but cost over $200 Million to for this section of the line. It has been highly controversial project in Boston for a number of reasons. Bus service instead of a LRT to very densly populated and under served area around Dudley Station. The new underground busway to the South Boston Waterfront. This is a new development zone in Boston, so there are still massive areas of land undeveloped (you can see this in the picture above). There are many other areas of Boston that have been desperate for rail extension, such as the long delayed green line extension to somerville.

A picture of the Silver line on Washington Steet.



Phase III of the Silver Line is to connect the too sections with an underground tunnel in the heart of downtown Boston. This is projected to cost up to $950 Million and be completed in 2010. However it has not been given funding yet from the federal government, which gave the project a non-favorable rating for the small benefit to cost ratio.



While there will be four different destinations of Silverline buses, one of the main reason for this project is to provide a more direct route to the airport from downtown. By next summer, the Silver Line will travel from South Station, through the tunnel in South Boston, then enter the harbor tunnel to the airport and stop at all the terminals.


MBTA Subway System Map


I road the Silverline a few days ago, with only two other passengers on the bus. Big, modern stations, but the tunnels are too narrow and curvey leading the buses to go rather slow for underground travel. The good thing is that it looks like it can easily be converted to LRT in the future.
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Old December 23rd, 2004, 09:07 PM   #70
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Quote:
Originally Posted by sequoias
Don't forget those hybrid buses use bio-diesel blend, too. They also have particulate trap filters to trap diesel fumes. Most of the bus on the Metro fleet in King county have particulate trap filters installed running on bio diesel blend. You can't see diesel exhaust coming out, except for a bit of fumes.

The use of blended bio-diesel is not unique to hybrid buses. Tighter emission standards also are not unique to hybrid buses. Whether there is any environmental advantage to the hybrid buses buses is a point of controversy:


http://seattlepi.nwsource.com/transp...9_metro13.html

Monday, December 13, 2004

Hybrid buses' fuel economy promises don't materialize
Older models have gotten better mpg

By JANE HADLEY
SEATTLE POST-INTELLIGENCER REPORTER

Expensive new hybrid diesel-electric buses that were portrayed by King County Metro as "green" heroes that would use up to 40 percent less fuel than existing buses have fallen far short of that promise.

In fact, at times, the New Flyer hybrid articulated buses have gotten worse mileage than the often-maligned 1989 dual-mode Breda buses they are replacing. Yet the hybrid buses cost $200,000 more each than a conventional articulated diesel bus.

Gilbert W. Arias / P-I
Metro's articulated hybrid buses were getting 3.75 miles a gallon in September.

The disappointing results are a far cry from the rosy predictions made by officials.

In May of this year, when Metro held a public event to herald the arrival of the first of the new hybrid buses, County Executive Ron Sims said they would save 750,000 gallons of fuel a year over the Bredas.

Metro was the first agency in the country to buy a 60-foot articulated bus with a hybrid diesel-electric technology. It ordered 235 of them, 213 for itself for $152 million and 22 for Sound Transit. Metro now has the largest fleet of hybrid buses in the world.

Hybrid diesel-electric buses use a battery-powered electric engine to assist a diesel engine. The batteries, carried on top of the bus, are charged both by the diesel engine and by capturing energy from braking action. The electric engine is especially valuable during acceleration from 0 to 12 mph, when a diesel engine would otherwise be gulping fuel, said Michael Voris Metro's procurement supervisor.

Of Metro's active fleet of nearly 1,400 buses, 1,005 are conventional diesel buses, 210 are hybrid diesel-electric, 144 are trolley buses and 28 are Bredas.

Despite the significantly higher cost and the underwhelming fuel efficiency of its hybrid buses, Metro had little choice but to get them, said Jim Boon, Metro's vehicle maintenance manager. That's because they are the only feasible bus Metro can use when it begins sharing the downtown bus tunnel with Sound Transit's light rail line in 2009.

Besides, the hybrids have their good points, Boon said. The hybrid fleet as a whole is saving $3 million a year in maintenance costs over the Bredas. And they're quieter than regular diesel buses and faster than the Bredas on hills and the highway.

They also have very low emissions -- as do all the new buses Metro is buying these days, hybrid or not.

But the expected fuel efficiency has not been there. One apparent culprit is stricter federal emissions standards. Another could be that the hybrids are used on routes -- suburban express routes with more highway mileage -- where their advantages don't shine.

In July, Yaz Yambe, a Metro schedule planner, asked Dennis Pingeon, Metro's vehicle maintenance supervisor, whether the new hybrids could be assigned to 400-mile routes. Pingeon said he initially assumed it would be no problem, but when he checked, he found otherwise.

"Yaz, it does not appear we have very good news for you on hybrid miles per gallons," Pingeon e-mailed Yambe.

The hybrids were not getting much better than 3.6 miles per gallon, yet they needed to average better than 4 mpg to be put on 400-mile routes. Pingeon suggested the hybrids not be put on any routes of over 300 miles for September.

"This is an unanticipated development," Pingeon wrote. "We had expected the mileage figures to be much better -- these figures are below our current Breda and conventional diesel New Flyer."

Boon said that today, the hybrids sometimes get better mileage than the conventional diesels and the Bredas. But it's difficult to compare different models, he said.

"It's comparing apples and oranges and pears."

And mileage performance varies from bus to bus, from route to route, and season to season, he said.

When he checked recently, Boon was told that Bredas are running at about 3.8 miles per gallon, while the conventional diesel older New Flyer articulated buses are running about four miles per gallon. The hybrids were getting 3.75 miles per gallon in September, but that has improved as the engines are getting broken in, Boon said. He expects further improvements with software tweaks.

"I've got hybrids that are getting four," he said recently. And Boon said he was surprised when he was told that Bredas were getting 3.8, because they've more typically been below 3.5.

Overall, the hybrids are getting about equivalent mileage to the older buses, Boon agreed.

That's not what was expected of the bus. In an October 2002 e-mail, Boon said, "The vendor indicates that hybrid buses can achieve up to 60 percent in fuel savings, but I am only projecting 20 percent to 30 percent given our hills and traffic congestion."

A year later, as Metro ordered the buses, the agency said they could reduce fuel consumption by 20 percent to 40 percent.

TriMet, Portland's regional transit agency, has only two hybrid buses, both the more common 40-foot hybrids.

Spokeswoman Mary Fetsch said the agency has been testing them since 2002.

"We like them," she said. "The question is about the price and when they get into full production, will the price come down."

"What we see with the fuel economy is there is improvement, but it may not be as much as we like," Fetsch said. But the bus has exceeded expectations for emissions reductions.

TIAX, a Cambridge, Mass., consultant, said a year ago that many transit agencies appeared to be delaying purchases of hybrid buses to see whether they would become "less expensive and more reliable."

Metro may have been a victim of bad timing.

The agency began road testing its first hybrid bus -- Coach 2599 -- in October 2002. The bus was put through grueling paces. It was run 20 hours a day, seven days a week loaded with barrels of water weighing 130 percent of normal capacity, to try to accumulate a year's worth of wear and tear in a short time.

Metro technicians examined its transmission, its repair record, its use of oil and its fuel efficiency, among other things.

The early tests were very encouraging. In December, Boon reported to his bosses that the buses were at 15,000 miles and had experienced hardly any mechanical problems. The hybrid was achieving about 32 percent better fuel economy than the Breda -- 4.46 miles per gallon compared with the Breda's 3.37 miles per gallon, he reported.

In January 2003, Todd Gibbs, manager of the hybrids project, said on a posting on Metro's Web site that the hybrid bus was achieving 40 percent better fuel economy than the Breda, even though it was overloaded with the water barrels. "We expect the numbers to go even higher," he said.

As the tests continued, Metro staff members called the results "impressive" and "remarkable."

But in July 2003, almost at the end of its testing period for the hybrid buses, Metro suddenly announced that it needed to switch engines.

The federal government had imposed stricter exhaust emissions standards, and the Cummins engine was not federally certified. Metro sent the bus to the Winnipeg, Manitoba, manufacturer to have a certified Caterpillar engine installed in its place.

The fuel economy results were never the same after the switch to the Caterpillar engine. Boon said it wasn't just a switch in the engine but also a switch in the emissions control system.

Caterpillar spokesman Jim Dugan said it isn't fair to compare today's buses with 1989 buses like the Bredas, which were much dirtier.

"Emissions coming out of our engines today are dramatically better than for a bus of 1989," he said. "The tradeoff is your fuel economy is not as good."

Dugan said Caterpillar "optimized" the Metro hybrid engines for lower emissions rather than for better fuel economy.

"As the EPA tightens emission control requirements on truck and bus engines, fuel economy suffers," Boon said. "The trucking industry is just going crazy over this right now."

A week before the media event to announce the arrival of the hybrids in May of this year, Metro's spokeswoman, Linda Thielke, exchanged e-mail with Voris. She wanted to break the supposed 750,000-gallon savings down into a per-bus savings.

Voris replied: "We have no revenue service experience with a Caterpillar-powered hybrid (articulated bus), so I am reluctant to make fuel economy claims."

But a week later, a Metro statement said the hybrid fleet overall would save 750,000 gallons of fuel annually.

Despite that public claim of fuel savings, Boon said that when Metro prepared its budget for 2004, it projected no fuel savings.

The hybrid has allowed Metro to eliminate 14 technicians from its staff, but Boon agreed that comparing the hybrid bus' maintenance savings to the Bredas is setting the bar rather low.

The Italian-made Bredas are notorious for the expense of their repair. Metro initially ordered spare parts from the manufacturer until Metro technicians could become more familiar with the buses and learn how to substitute lower-cost American parts. That resulted in $258 oil filters that could be bought locally for $4 and radiators costing Metro $6,292 that could be bought in Seattle for $742.

In more recent years, Metro has complained that the Bredas are difficult to repair because their original European-made parts have become more difficult to locate and often entail a long wait. At other times, a local manufacturer custom-makes parts for the buses.

"They're a very unreliable bus," Boon said, "It's a bad marriage of many technologies."

The dual-mode Bredas carried both diesel and electric trolley-powered engines and were bought in 1989 to deal with Seattle's 1.3 mile-long downtown tunnel. Their rarity made them expensive.

The hybrids share some of that problem. Only one company, New Flyer, bid on the buses. But the only other alternative was even more unappealing, Boon said.

Boston recently bought a dual-mode trolley-diesel made in Germany for its tunnel. It cost $1.6 million per bus, compared with $645,000 per bus for Metro's hybrid, Boon said.

"We didn't buy this (hybrid) bus because of fuel economy," Boon said. It has other desirable attributes, such as being cleaner, quieter, and saving on oil consumption and operating costs, but the tunnel forced the choice of the hybrids.

Regular diesels can't be used in the tunnel because they are too noisy, Boon saids, and older diesels put out too many toxic, smelly fumes. A trolley would be difficult if not impossible in the tunnel now, because Sound Transit needs to use overhead power for light rail.

Ironically, when the new hybrids are booted out of the tunnel next September to make way for light rail construction, their fuel economy may well improve. They can then be put on the kinds of routes -- city routes with lots of stop-and-go -- where they might well show a fuel consumption advantage over other buses.

The buses will be removed from the tunnel for about two years for tunnel alterations. When the tunnel is reopened, the hybrids will share it with light rail until the time when the trains are running so frequently they will replace buses in the tunnel.

At the end of October, a statement appeared on Metro's Web site. The headline: "Hybrid performance exceeding expectations."

Prominently mentioned were the reliability, the lower operating costs, the noise reduction. Missing from the statement? Emissions and fuel economy.

P-I reporter Jane Hadley can be reached at 206-448-8362 or [email protected]
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Old December 23rd, 2004, 11:21 PM   #71
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[QUOTE=greg_christine]The use of blended bio-diesel is not unique to hybrid buses. Tighter emission standards also are not unique to hybrid buses. Whether there is any environmental advantage to the hybrid buses buses is a point of controversy:

I already know that news about the mpg...old news....the old breda bus ARE dirty diesels.. we will see in the long run, since breda has been around since 90's so averages have been since for a long time, hybrid bus only has been around since over 6 months. Thanks for correcting me on the biodiesel use on the hybrid bus was wrong. It was for most of the fleet except the hybrid buses and a few others, I guess.
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Old December 24th, 2004, 01:27 AM   #72
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Quote:
Originally Posted by Vertigo
AFAIK those buses in Essen don't use the Stadtbahn (=light rail) tunnels anymore... didn't see it anyway when I was there a couple of weeks ago.
Vertigo,

they used tunnels shared with the trams, not the light rail vehicles (Stadtbahn).

However you are right, the buses no longer travel through the tunnels - this is because the experimental track used by the buses needed replacing but the the "dual-mode-bus" project had ended when funds became tight after German re-unification.

The duo-bus technology however is also used in Esslingen, (near Stuttgart) plus several other cities have buses whcih can operate like this too.

Simon
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Old December 24th, 2004, 01:40 AM   #73
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I think this will be of interest...

I dont recall exactly where it came from - I *think* it was a Canadian pro-clean urban air website such as http://www.bettertransit.ab.ca/ - its been on my computer for a long time!

Simon

Can the latest “clean diesel” technology using Ultra Low Sulphur Diesel fuel (ULSD) and Continuously Regenerating particulate Traps (CRT) compete with electric buses in terms of emissions impacts?

Diesel exhaust has been found to contain over 41 different toxins, many of which form part of the particulate. The same toxins are present in clean diesel". Because "clean" diesel particulate is so much finer than that from
conventional diesel engines, these toxins have an easier time entering our
bodies. There is no safe level of exposure. German researchers insist the
toughest diesel emission standards are not tough enough.

Vehicle emissions have their greatest impacts on those directly exposed, i.e. pedestrians, transit users, those living in busy transportation corridors. Trolleybuses produce no in-street emissions. Unless all the emissions diesels release into the surrounding air can be completely eliminated, the diesel can never be competitive with an electric trolleybus n terms of emissions impacts. This should not imply that efforts to reduce diesel emissions are wasted. Since diesel engines will continue to be used for a variety of purposes, every effort should be made to make them as clean as possible. But one needs to realize that making an internal combustion engine cleaner does not make it a universal substitute for an electric vehicle. There are a number of factors to consider:

Greenhouse Gases: Currently available data from the British Freight Transport Association (FTA, 1999) indicates that the production of ULSD [at refineries] results in some 20 tonnes more CO2 equivalent than the production of regular diesel. Indications are that powering a vehicle with ULSD requires more fuel than with regular diesel, meaning that, while some emissions may be reduced, the amount of CO2 released by the vehicle is likely to be greater. Based on available data, one would conclude that the use of ULSD does nothing to reduce the greenhouse gases responsible for global warming.

Particulate Size: Trap devices such as the CRT primarily focus on reducing the amount of particulate matter that diesels spew into the surrounding air; there is also some concurrent reduction in hydrocarbon emissions. Some traps claim to reduce particulate emissions by up to 90% in tests, although their performance in real-world conditions may vary considerably. In any case, some particulate is still released, and that particulate is very minute in size. It is so small that it is invisible to the naked eye, but it quickly and easily penetrates the linings of the lungs. (PM10 particles with mass less than 10 microgrammes). The Daily Mail of December 27, 2000 reported that such particulate was found deeply imbedded in the lungs of very young children, in particular children who lived in homes located along busy corridors. This particulate is believed responsible for an increase in lung disorders and asthma and has also been linked to heart disease. The incidence of asthma in children under five has doubled in Britain in the last ten years and is on the rise in many other countries. There is also strong evidence for a causal link to cancer. Diesel exhaust particulate contains a polycyclic aromatic hydrocarbon (PAH) called 3-nitrobenzathrone; this being one of the strongest carcinogenic substances identified to date.

NOx Emissions: In spite of trap devices, Oxides of Nitrogen (NOx) still form a major component of diesel exhaust and pose significant health risks in spite of the advent of ‘clean’ diesel technology and trap devices. Oxides of Nitrogen essentially comprise a mixture of Nitric Oxide (NO) and Nitrogen Dioxide (NO2). NOx is transportation’s principal contributor to urban smog and poor air quality. In combination with the moisture in the lungs, Nitric Oxide (NO) forms nitric acid. This acid results in inflammation, leading to chronic respiratory problems. Eventually, all Nitric Oxide emissions are converted to Nitrogen Dioxide (NO2) in the atmosphere. Nitrogen Dioxide is a corrosive and very poisonous gas. At concentrations above 150 ppm it leads to death. The CRT (Continuously Regenerating Trap) uses a catalyst to convert Nitric Oxide in the exhaust stream to NO2 because it needs the NO2 for a reaction that ‘burns off’ particulate matter and hydrocarbons. There is a strong likelihood that the proportion of NO2 in the NOx emitted by CRT equipped engines operating in real world conditions will be greater than is the case with non-CRT equipped diesels. If so, it would put a greater quantity of the more poisonous constituent of NOx emissions directly into the airways of pedestrians, transit users and area residents than would be the case with conventional diesels, where the a slower process of oxidation in the atmosphere would be required to yield the same quantity of NO2. In other words, there is every possibility that ULSD in combination with the CRT may actually intensify some of the health effects of diesel exhaust.

Negative Environmental Repercussions: The environmental benefits of exhaust after-treatment devices was recently called into question when researchers discovered heavy metals from catalytic converters embedded in the ice in remote regions of Greenland. A European Commission study found that vehicle exhausts actually erode the metals in these devices, ejecting microscopic particles into the air. Some of these metals have also been linked to asthma and lung conditions. Researchers noted that some of these particles are soluble, meaning that they can be readily absorbed by vegetation and enter the food chain.. Scientists say the release of heavy metals from exhaust treatment devices is a global problem that stands to threaten human health. New Scientist magazine concluded that this is already a problem is of global proportions.



One "clean" diesel bus produces more emissions in its average lifetime than over 110 automobiles. Additionally, no reduction in urban noise pollution is achieved with "clean" diesel.

There are no such things as 'clean' diesel vehicles.

There are only less dirty ones.
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Old December 24th, 2004, 01:55 AM   #74
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Quote:
Originally Posted by spsmiler
I think this will be of interest...

I dont recall exactly where it came from - I *think* it was a Canadian pro-clean urban air website such as http://www.bettertransit.ab.ca/ - its been on my computer for a long time!

Simon

Can the latest “clean diesel” technology using Ultra Low Sulphur Diesel fuel (ULSD) and Continuously Regenerating particulate Traps (CRT) compete with electric buses in terms of emissions impacts?

Diesel exhaust has been found to contain over 41 different toxins, many of which form part of the particulate. The same toxins are present in clean diesel". Because "clean" diesel particulate is so much finer than that from
conventional diesel engines, these toxins have an easier time entering our
bodies. There is no safe level of exposure. German researchers insist the
toughest diesel emission standards are not tough enough.

Vehicle emissions have their greatest impacts on those directly exposed, i.e. pedestrians, transit users, those living in busy transportation corridors. Trolleybuses produce no in-street emissions. Unless all the emissions diesels release into the surrounding air can be completely eliminated, the diesel can never be competitive with an electric trolleybus n terms of emissions impacts. This should not imply that efforts to reduce diesel emissions are wasted. Since diesel engines will continue to be used for a variety of purposes, every effort should be made to make them as clean as possible. But one needs to realize that making an internal combustion engine cleaner does not make it a universal substitute for an electric vehicle. There are a number of factors to consider:

Greenhouse Gases: Currently available data from the British Freight Transport Association (FTA, 1999) indicates that the production of ULSD [at refineries] results in some 20 tonnes more CO2 equivalent than the production of regular diesel. Indications are that powering a vehicle with ULSD requires more fuel than with regular diesel, meaning that, while some emissions may be reduced, the amount of CO2 released by the vehicle is likely to be greater. Based on available data, one would conclude that the use of ULSD does nothing to reduce the greenhouse gases responsible for global warming.

Particulate Size: Trap devices such as the CRT primarily focus on reducing the amount of particulate matter that diesels spew into the surrounding air; there is also some concurrent reduction in hydrocarbon emissions. Some traps claim to reduce particulate emissions by up to 90% in tests, although their performance in real-world conditions may vary considerably. In any case, some particulate is still released, and that particulate is very minute in size. It is so small that it is invisible to the naked eye, but it quickly and easily penetrates the linings of the lungs. (PM10 particles with mass less than 10 microgrammes). The Daily Mail of December 27, 2000 reported that such particulate was found deeply imbedded in the lungs of very young children, in particular children who lived in homes located along busy corridors. This particulate is believed responsible for an increase in lung disorders and asthma and has also been linked to heart disease. The incidence of asthma in children under five has doubled in Britain in the last ten years and is on the rise in many other countries. There is also strong evidence for a causal link to cancer. Diesel exhaust particulate contains a polycyclic aromatic hydrocarbon (PAH) called 3-nitrobenzathrone; this being one of the strongest carcinogenic substances identified to date.

NOx Emissions: In spite of trap devices, Oxides of Nitrogen (NOx) still form a major component of diesel exhaust and pose significant health risks in spite of the advent of ‘clean’ diesel technology and trap devices. Oxides of Nitrogen essentially comprise a mixture of Nitric Oxide (NO) and Nitrogen Dioxide (NO2). NOx is transportation’s principal contributor to urban smog and poor air quality. In combination with the moisture in the lungs, Nitric Oxide (NO) forms nitric acid. This acid results in inflammation, leading to chronic respiratory problems. Eventually, all Nitric Oxide emissions are converted to Nitrogen Dioxide (NO2) in the atmosphere. Nitrogen Dioxide is a corrosive and very poisonous gas. At concentrations above 150 ppm it leads to death. The CRT (Continuously Regenerating Trap) uses a catalyst to convert Nitric Oxide in the exhaust stream to NO2 because it needs the NO2 for a reaction that ‘burns off’ particulate matter and hydrocarbons. There is a strong likelihood that the proportion of NO2 in the NOx emitted by CRT equipped engines operating in real world conditions will be greater than is the case with non-CRT equipped diesels. If so, it would put a greater quantity of the more poisonous constituent of NOx emissions directly into the airways of pedestrians, transit users and area residents than would be the case with conventional diesels, where the a slower process of oxidation in the atmosphere would be required to yield the same quantity of NO2. In other words, there is every possibility that ULSD in combination with the CRT may actually intensify some of the health effects of diesel exhaust.

Negative Environmental Repercussions: The environmental benefits of exhaust after-treatment devices was recently called into question when researchers discovered heavy metals from catalytic converters embedded in the ice in remote regions of Greenland. A European Commission study found that vehicle exhausts actually erode the metals in these devices, ejecting microscopic particles into the air. Some of these metals have also been linked to asthma and lung conditions. Researchers noted that some of these particles are soluble, meaning that they can be readily absorbed by vegetation and enter the food chain.. Scientists say the release of heavy metals from exhaust treatment devices is a global problem that stands to threaten human health. New Scientist magazine concluded that this is already a problem is of global proportions.



One "clean" diesel bus produces more emissions in its average lifetime than over 110 automobiles. Additionally, no reduction in urban noise pollution is achieved with "clean" diesel.

There are no such things as 'clean' diesel vehicles.

There are only less dirty ones.
ouch, that's gonna hurt....too bad we're vunerable with the environmental pollution and all that. Interesting information about it. They need to run on air powered engines (zero emission) or whatever, it's too bad diesel will be around for a long time, I'm sure.
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Old December 24th, 2004, 01:59 AM   #75
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Quote:
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On December 17th, Phase II of the new Silver Line project opened to the transit riding public. This is the first new "subway" line built in Boston in 90 years. Too bad it is a BRT line and not a rail system. Below is a map of the current Silver Line. There are three underground stations, South Station, Courthouse and the World Trade Center, where it then goes above ground. Low emission 40' electric and 60' dual-mode (electric/diesel electric) articulated vehicles will be used so that the buses can use city streets and go to the airport. The tunnel cost $680 Million to complete.

Only picture I could find of new underground busway/metro. Can anyone find some better ones?
There is a better pic on the Boston Globe (newspaper) webpage

I hope its OK to link to it here
.

the newspaper article can be found here

http://www.boston.com/news/local/art...boom_lags?pg=2

I freely admit that I would very much like to find an image or two I could use on my own website (with, I stress, the copyright holder's permission) but living in London that wont be easy - and it seems that going there wont help either - especially as many US transit systems have literally decalred war on amatuer photographers, with, according to reports here in Britain, theft of their cameras and / or film, memory sticks etc not uncommon in come cities.

I have also recently heard that Greyhound Buses have issued an edict banning photography of their buses - even in the street.

Sorry to say this but this paranoia makes me think of Soviet Russia and 1930's Germany. Not the "free" world.

Simon
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Old December 24th, 2004, 02:24 AM   #76
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ouch, that's gonna hurt....too bad we're vunerable with the environmental pollution and all that. Interesting information about it. They need to run on air powered engines (zero emission) or whatever, it's too bad diesel will be around for a long time, I'm sure.
ah but - in 1944 an Austrian named Viktor Shauberger was (for the Germans who made him do this or be shot) testing a discoid shaped aircraft which used energy sourced from some sort of vortex power. It seems that he had found a way to harness natural energies from water - I dont fully understand the technology (unfortunately) because otherwise I'd be working on it too!

Anyway, the Russians ransacked his apartment, took away all his notes, etc and blew it up. The Americans ransacked his workshop, took away his developmental prototypes, working models, his notes (etc) and put him under armed guard - to make sure the Russians did not get hold of him.

Before he died (in 1954) Viktor visited the USA and told the various authorities all his secrets.

So its my contention that zero point energies (free, non polluting, clean energy systems) already exist. Its just that there is no money to be made out of them, whilst oil creates wealth for shareholders, etc.

As this forum is about transport the only comments about Iraq I will make are to suggest that our troops are not there for oil. We dont need it! The only clues I can find comes from the ransacking of the musuems, which I know sounds bizarre but I think they were looking for information on some other, ancient energy and / or transport systems. Just cant prove it - yet.

Simon

Last edited by spsmiler; December 24th, 2004 at 02:38 AM.
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Old December 24th, 2004, 02:31 AM   #77
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Oh, I should add that whilst it is true that our (mankind's) continued use of fossil fuels is harming the global ecology it is my understanding that the cause of global warming is that the entire solar system is moving into an area of space with different energies which are (amogst other things) causing the Sun to increase its energies. According to reports I've seen from Pravda global warming is affecting many planets in our solar system.

That said, we should still be using the cleanest energy options available - and as someone pointed out earlier, the use of bio-diesel (providing it is sustainably sourced) is good. But only for rural bus routes - cities like Seattle should be looking to increase their use of ETB's, as it results in the cleanest possible urban air.

Simon
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Old December 24th, 2004, 03:05 AM   #78
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Transjakarta Busway
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Old December 24th, 2004, 09:51 AM   #79
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Transjakarta Busway
WTF are those formula one cars doing next to the buses? Are those street legal ones. I've never seen them drive next to buses, that's one unusual pictures.
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Old December 24th, 2004, 09:52 AM   #80
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Oh, I should add that whilst it is true that our (mankind's) continued use of fossil fuels is harming the global ecology it is my understanding that the cause of global warming is that the entire solar system is moving into an area of space with different energies which are (amogst other things) causing the Sun to increase its energies. According to reports I've seen from Pravda global warming is affecting many planets in our solar system.

That said, we should still be using the cleanest energy options available - and as someone pointed out earlier, the use of bio-diesel (providing it is sustainably sourced) is good. But only for rural bus routes - cities like Seattle should be looking to increase their use of ETB's, as it results in the cleanest possible urban air.

Simon
good point there, we try ways to keep air clean and govt keeps denying it (US govt). Don't u agree?
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