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Old June 14th, 2007, 12:57 AM   #781
BoulderGrad
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Thank you Greg, great sum up of the two systems, but I was more referring to what distinguishes the DC metro as being a Heavy Rail metro system, and Seattle's new system as being light rail? Whenever I've heard "heavy rail", I've always assumed it to be something like the Sounder in Seattle or MARC and VRE trains in DC: A commuter train with an independently powered locomotive that runs on the same track system as freight trains. But I've also seen heavy rail refer to DC's metro and Chicago's EL on these forums.

Is the DC metro considered part of that same group, or is it a 3rd kind of animal all together? DC metro seems to have many things in common with the new Seattle line; Grade separated for the most part, runs along its own unique rail system, powered from an external electric source (overhead in Seattle, third rail in DC), etc.

I see a number of the differences; Seattle's crosses streets at parts, DC uses smaller cars but more of them and they run faster, DC's is automated to a point, etc.

What distinguishes Seattle's as Light Rail, and DC's as heavy rail?
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Old June 14th, 2007, 01:23 AM   #782
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Originally Posted by BoulderGrad View Post
Thank you Greg, great sum up of the two systems, but I was more referring to what distinguishes the DC metro as being a Heavy Rail metro system, and Seattle's new system as being light rail? Whenever I've heard "heavy rail", I've always assumed it to be something like the Sounder in Seattle or MARC and VRE trains in DC: A commuter train with an independently powered locomotive that runs on the same track system as freight trains. But I've also seen heavy rail refer to DC's metro and Chicago's EL on these forums.

Is the DC metro considered part of that same group, or is it a 3rd kind of animal all together? DC metro seems to have many things in common with the new Seattle line; Grade separated for the most part, runs along its own unique rail system, powered from an external electric source (overhead in Seattle, third rail in DC), etc.

I see a number of the differences; Seattle's crosses streets at parts, DC uses smaller cars but more of them and they run faster, DC's is automated to a point, etc.

What distinguishes Seattle's as Light Rail, and DC's as heavy rail?
I would call Sounder, MARC, and VRE "Commuter Rail".

The word "light" in the term "light rail" refers to the level of engineering of the line. Simply put, light rail is generally built cheap. Heavy rail metros are generally designed for capacities in excess of 20,000 passengers per hour per direction whereas light rail is usually designed for no more than 10,000 passengers per hour per direction, but system capacity alone does not define whether a system is light rail or a heavy rail metro.

Compared to heavy rail metros, light rail generally features only limited use of bridges and tunnels to achieve grade separation and light rail vehicles are designed for tighter radius curves than heavy rail metro cars. Recently constructed metro lines generally feature some degree of automation whereas there are only limited examples of automation on light rail lines such as the downtown tunnel segments of the systems in San Francisco and Philadelphia. Heavy rail metros that serve suburban areas with widely spaced stations are generally designed for higher speeds than light rail.

Seattle Central Link presents an awkward situation in which the system capacity and the engineering of much of the track system are consistent with a heavy rail metro but the trains and the low platform stations are strictly light rail. This is the reason for the high cost.

Last edited by greg_christine; June 14th, 2007 at 01:31 AM.
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Old June 14th, 2007, 04:57 AM   #783
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Originally Posted by greg_christine View Post
I would call Sounder, MARC, and VRE "Commuter Rail".

The word "light" in the term "light rail" refers to the level of engineering of the line. Simply put, light rail is generally built cheap. Heavy rail metros are generally designed for capacities in excess of 20,000 passengers per hour per direction whereas light rail is usually designed for no more than 10,000 passengers per hour per direction, but system capacity alone does not define whether a system is light rail or a heavy rail metro.

Compared to heavy rail metros, light rail generally features only limited use of bridges and tunnels to achieve grade separation and light rail vehicles are designed for tighter radius curves than heavy rail metro cars. Recently constructed metro lines generally feature some degree of automation whereas there are only limited examples of automation on light rail lines such as the downtown tunnel segments of the systems in San Francisco and Philadelphia. Heavy rail metros that serve suburban areas with widely spaced stations are generally designed for higher speeds than light rail.

Seattle Central Link presents an awkward situation in which the system capacity and the engineering of much of the track system are consistent with a heavy rail metro but the trains and the low platform stations are strictly light rail. This is the reason for the high cost.
I still don't see why we didn't build the subway we could have in the 70s.
Anyway, i think that the light rail cars are a little more pleasing to the eye anyway, plus you don't have the danger of the third rail.
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Old June 14th, 2007, 08:54 AM   #784
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One thing to note there is a "smart card" planned for use on the light rail (and all other public transit in the region). There will still be traditional proof of payment system was well.

In other news, not directly related to Seattle's light rail: Dump the Pump Day
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Old June 14th, 2007, 11:06 PM   #785
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Greg,
what are the concrete curbs between the tracks for, as shown in this Seattle pic? Vancouver's Canada Line has the same feature on its elevated segments. Thanks!

BTW - the Canada Line will be automated and will not be rubber tired or linear induction - so we'll see what happens in the snow!

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Old June 15th, 2007, 03:49 AM   #786
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1. I see the concrete "curbs" often used on concrete rail beds and on segmented concrete viaducts. I have not been involved in the design of these systems, so anything I state is purely conjecture. Having the secondary concrete structure supporting the rail would bring the advantage of providing a means of adjusting the height of the rails to provide proper alignment between segments of the concrete rail bed. The raised lip on the inboard side of the rail would be useful in capturing the wheels on one side of the bogie in case of derailment.

2. There are several transit lines that ride on steel wheels, are powered by conventional rotary electric motors, and are advertised as "driverless". To the best of my knowledge, they all have staff onboard the trains riding in the passenger compartment. Examples include the Docklands Light Railway in London, the Copenhagen Metro, and the Singapore North East Line. On the Docklands Light Railway, the onboard staff are called "Passenger Service Agents". On the Copenhagen Metro, they are called "Stewards". The latter name conjures the image of a person who pushes a small cart and dispenses complimentary packets of peanuts and soft drinks. The reality is that these onboard staff are trained to intercede should problems occur with the automated control of the trains. The ice on the tracks scenario that resulted in the 1996 accident in Washington, DC is an obvious scenario in which onboard staff might be needed.

Rubber-tired VAL metros exist in Lille, Paris (Orlyval), Toulouse, Rennes, Taipei (Muzha Line), and Turin. Smaller scale VAL installations exist in several airports. Every one of them operates without onboard staff. Bombardier's LIM powered system is used on transit lines in Vancouver, Detroit, Kuala Lumpur (Putra), Toronto (Scarborough RT), and New York (JFK Airtrain). All operate without onboard staff except for Toronto's Scarborough RT. (I have seen several explanations for the use of staff onboard the Scarborough RT including concerns regarding public safety and pressure from the trade unions.) Rubber-tired and LIM powered systems bring the advantage that train control is not dependent on the adhesion between a steel wheel and a steel rail.

The RAV/Canada Line being built in Vancouver will be driverless and will feature steel-wheeled trains with conventional rotary electric motors. I have not seen any statement that it will have onboard staff, so it might become the first such line to operate without onboard staff. The trains for the RAV/Canada Line are being produced by Rotem of South Korea. In South Korea, a fully automated metro line is under construction that will use LIM powered trains produced by Bombardier of Canada. (Can the designers of both systems be right?) The ships carrying the trains might presently be passing each other in the middle of the Pacific.

VAL Metro in Taipei


Bombardier Advanced Rapid Transit Train at JFK Airport in New York

Last edited by greg_christine; June 15th, 2007 at 04:24 AM.
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Old June 15th, 2007, 04:04 AM   #787
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^ great post. finally we have those curbs explained to us, thx....lol, so true about the ships carrying different trains passing each other over the Pacific.


And here's the LIM line you were talking about, in Yongin South Korea, using only 1-car MK II trains, at least for now.
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Old June 15th, 2007, 07:32 AM   #788
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Bringing the discussion back to Seattle light rail, there is a monthly picture gallery taken by a local photographer. 10 of his pictures are put up per month on the Sound Transit website. You can view this gallery here. It is in black and white, but it still shows the construction well. If you click on the first 2005 month, it will cycle through all the months up to the latest set.
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Old June 15th, 2007, 06:17 PM   #789
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Quote:
Originally Posted by tmaxxfreak11 View Post
The expected ridership with just the initial segment and the UW extension would be over 150,000. That would rank it 2nd or 3rd among US light rail systems. With the ST2 extensions ridership is expected to shoot well past 300,000. This would leave any other US light rail system in the dust by well over 100,000 riders. This passengers/mile is similiar to that of the Washington DC subway. Could Seattle support heavy rail? Probably.
Ridership doesn't equate to tax dollars for construction. The problem is not in how many people will use it, but rather in how many are available to help pay for it. Washington State does not have an income tax, fuel excise taxes are required to be spent only on state highways, and motor vehicle excise taxes are prohibited as a funding source.

The reasons for this being light and not heavy rail are partly political. The Seattle monorail project failed spectacularly, and the average Seattle voter doesn't know the difference between that agency and Sound Transit (the agency building light rail). The state government also only provided for a certain number and amount (percentage) of funding sources available as financial tools for a local agency.

There is, quite simply, *no way* Sound Transit could have passed a heavy rail ballot measure. They did pass a light rail ballot measure, and our light rail system (if ST2 passes) will have higher capacity than any other system serving a comparable urban area in the US. That's what we've got, and the vote for ST2 is going to be extremely close, even just with light rail.
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Old June 16th, 2007, 12:36 AM   #790
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Originally Posted by greg_christine View Post
The raised lip on the inboard side of the rail would be useful in capturing the wheels on one side of the bogie in case of derailment.
That's what I though. Thanks for the info (btw, for the Canada Line, it appears that the rail is affixed directly to the guideway floor and the inboard curb is added after the rail footings are in place). http://www.canadaline.ca/gallery.asp...rPage=1#larger
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Old June 16th, 2007, 01:07 AM   #791
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Quote:
Originally Posted by UrbanBen View Post
Ridership doesn't equate to tax dollars for construction. The problem is not in how many people will use it, but rather in how many are available to help pay for it. Washington State does not have an income tax, fuel excise taxes are required to be spent only on state highways, and motor vehicle excise taxes are prohibited as a funding source.

The reasons for this being light and not heavy rail are partly political. The Seattle monorail project failed spectacularly, and the average Seattle voter doesn't know the difference between that agency and Sound Transit (the agency building light rail). The state government also only provided for a certain number and amount (percentage) of funding sources available as financial tools for a local agency.

There is, quite simply, *no way* Sound Transit could have passed a heavy rail ballot measure. They did pass a light rail ballot measure, and our light rail system (if ST2 passes) will have higher capacity than any other system serving a comparable urban area in the US. That's what we've got, and the vote for ST2 is going to be extremely close, even just with light rail.
Regarding the now defunct Seattle Monorail Project, the following was the cost for the construction portion of the proposed contract with Cascadia Monorail:

Seattle Monorail Project
Design/Build portion of Cascadia Contract:
$1.6 billion / 14 miles = $114 million/mile



The monorail was controversial; however, there is no denying that it was relatively inexpensive for a fully grade separated system. For comparison, the following are the costs for the construction of the various portions of the Central Link light rail system:

Cost of Earlier Segments of Central Link
Central Link Initial Segment - Low Version:
$2.1 billion / 14 miles = $150 million/mile
Central Link Initial Segment - High Version:
$2.44 billion / 13.9 miles = $176 million/mile
Central Link SeaTac Airport Extension:
($225 million light rail construction + $75 million road
realignment) / 1.7 miles = $176 million/mile
Central Link University of Washington Extension:
$1.7 billion / 3.15 miles = $540 million/mile

Cost of Sound Transit 2 Central Link Extensions
ST2 Central Link Extensions - High Estimate:
$10.26 billion / 49.4 miles = $208 million/mile
ST2 Central Link Extensions - Low Estimate:
$8.97 billion / 49.4 miles = $182 million/mile
ST2 Central Link Extensions - Mid-Range Estimate:
$9.62 billion / 49.4 miles = $195 million/mile

Last edited by greg_christine; June 16th, 2007 at 01:17 AM.
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Old June 16th, 2007, 01:13 AM   #792
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Quote:
Originally Posted by officedweller View Post
That's what I though. Thanks for the info (btw, for the Canada Line, it appears that the rail is affixed directly to the guideway floor and the inboard curb is added after the rail footings are in place). http://www.canadaline.ca/gallery.asp...rPage=1#larger
I don't claim to be an expert on this; however, it appears to me that the inboard curbs and the rail footings are both built after the concrete rail bed is already in place. The following image from the construction of the RAV/Canada Line appears to show the rails being leveled before the rail footings and curbs are added. This makes a lot of sense as it provides an opportunity to adjust the height and alignment of the rail footings after the rail bed is constructed:

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Old June 17th, 2007, 12:05 AM   #793
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New photo of the week by Sound Transit

This what the Westlake station looks like, it looks pretty much the same as it was before. There's new lighting, rebuilt the curb to match the link light rail low floor trains, new rails, etc. I don't know if I have seen that artwork on the wall, though.

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Old June 17th, 2007, 05:31 AM   #794
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It seems Seattle is bascially paying for heavy rail infrastructure (except for a small section) and sticking light rail cars on it...

I remember when they announced long time ago that they were going to share the use of the transit tunnel with buses and the light rail cars I thought to myselft "another half-assed short term decision"...
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Old June 17th, 2007, 05:55 AM   #795
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It seems Seattle is bascially paying for heavy rail infrastructure (except for a small section) and sticking light rail cars on it...

I remember when they announced long time ago that they were going to share the use of the transit tunnel with buses and the light rail cars I thought to myselft "another half-assed short term decision"...
i don't think the transit tunnel can handle heavy rail, the tunnels are just too small, they were build for light rail and buses, that was the original plan when it was build in the 1990s
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Old June 17th, 2007, 09:53 AM   #796
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i don't think the transit tunnel can handle heavy rail, the tunnels are just too small, they were build for light rail and buses, that was the original plan when it was build in the 1990s
That's right. The tunnel is basically too small to handle heavy rail trains. The trains are taller than light rail trains and it will require a lot of retrofitting and a bigger tunnel for that. I think light rail is good enough for Seattle. Look at Dallas, Houston, Portland, etc. They have light rail and they're doing fine.

Heavy rail is better for cities like NYC, Chicago or whatever.
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Old June 17th, 2007, 10:37 AM   #797
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Downtown tunnel disappoints me. I was expecting they would modernizate this tunnel. I guess they didn't do that. It still look ugly 80's design. Sighs.
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Old June 17th, 2007, 11:08 AM   #798
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light rail testing at International district station.

Crazyaboutcities, yeah me too. I was dissappointed that it looks pretty much the same boring 1980's, but at least it's got function for transporting passengers in and out of downtown without the surface traffic like in Portland.
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Old June 17th, 2007, 11:10 AM   #799
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Looking good! Can't wait to ride it in 2009!
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Old June 17th, 2007, 07:52 PM   #800
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Crazyaboutcities, yeah me too. I was dissappointed that it looks pretty much the same boring 1980's, but at least it's got function for transporting passengers in and out of downtown without the surface traffic like in Portland.
I am so glad they did not run it on the surface streets. Also, if the East Link is approved then it will either be run in a tunnel or elevated through downtown belleuve, not on the surface there either.
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