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Old Posted Jan 24, 2018, 10:30 PM
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Standardize North American Platform Heights

I think it is time to standardize platform heights for all trains, at least in North America. Creating a standard track gauge has been extremely beneficial to the rail network, as it allowed any piece of railroad rolling stock to go anywhere in the system. I think similar gains are to be made by creating a standard platform height for passenger cars.

In the United States there are many platform heights used. The best height from a passenger's point of view is the 48-inch height, which allows for level boarding into a single-level passenger car:



The trouble is, this means the platforms have to be extremely close to the tracks in order to avoid having dangerous gaps between the platforms and the passenger car. This means there is little or no clearance for freight cars, which can be wider than passenger cars. Also, a faster moving train has a wider 'dynamic envelope,' which means it can bounce around more, increasing the likelihood of it scraping the platform as it rolls past.

These two considerations mean that outside of the Northeast Corridor, most platforms are much lower - usually either flat with the rail or 8 inches above the top of the rail, to avoid wide freight cars or fast-moving trains (freight and passenger). Lower platforms mean that passenger cars need to be equipped with their own stairwells:



Stairs have their own problems. They make loading and unloading passengers much slower, and for passengers with disabilities, it means special lifts need to be installed on either the train cars or the platforms in order to raise the person up to the car height:



To get around these problems, car designers outside the Northeast Corridor have changed the design of the passenger car to have a lower floor. Amtrak's Superliner cars, for example have a floor height of eighteen inches above the top of the rail, meaning for a platform height of eight inches there would be only one 10-inch step. For platforms flush with the tracks, an 8-inch stool can be used to create the same step increments:




Only one city I know of has an 18-inch tall platform to be level with the Superliner cars, and that is my home town of Salt Lake City, Utah:



... and the only reason they can do it is because those are dedicated tracks for Amtrak. No other trains use them except for an occasional UP Executives train - pulled by diesels - and they have a very awkward step down onto the first step of the passenger car's stairwells, which are designed for an 8-inch platform height. When Union Pacific's steam locomotives come to visit, they cannot use these platforms either because the driving rods of the locomotive would scrape against the 18-inch tall platform.

Other commuter rail cars with a similar strategy exist. Bombardier's Bi-level cars have a floor height 25 inches above the top of the rail, which requires two steps for passengers boarding from an eight-inch tall platform:



Of course, both of these heights - 25 inches and 18 inches - still don't do anything to help passengers with disabilities. Special 'high block' platforms must be constructed in addition to the regular 8-inch platforms in order to be fully accessible:



And, as you can see, these high-blocks are placed father back so that they don't interfere with fast trains or wide freight cars. The commuter train has to line up perfectly with the high-block as it stops (causing station stops to be done slower) and the conductor will need to lay down 'bridge plates' to make a flat surface for a wheelchair to roll onto the train, which also takes time.



Sidenote - my hometown provides another exception in the UTA FrontRunner, which uses a 25-inch tall platform for all doors in its bilevel fleet, which I think is also unique:



One serious problem all of these cars of non-standard floor heights face is that once a passenger with disabilities is on-board the train, they are restricted to that single car, since there are stairs within the train car that must be traversed in order to move between cars. A passenger with disabilities cannot go from a coach car to a dining car, for example. So this solution is really only viable for commuter trains, or trains designed for shorter journeys.

Another approach has been to keep the passenger cars standard, but to use a 'gauntlet track' to either move passenger trains closer to the tall platform, or to move freight trains away from the platform:



This solution is very effective, but is costly since it involves extra track infrastructure to construct and maintain. Also, trains entering the 'gauntlet' must slow down, which decreases efficiency.

A less-common way to have a high platform and no gauntlet track is to have deploy-able platform extensions. These extend when a passenger train is scheduled to arrive, and retract when a freight train or a fast train needs to pass:




But again, like the gauntlet tracks, this solution relies on fixed infrastructure. If a train is going to make 10 stops along its route it will need at least 10 gauntlet tracks - perhaps 20 if it travels on separate tracks in each direction. If that train has 4 doors that open at each station, then there will need to be a total of 40 platform extensions - 80 if it uses the separate track.

All of this adds cost to a system. If only there was a way to eliminate any need to improve the infrastructure and instead incorporate such an extender into the vehicle...

----*----*----*----*----*----*----*----
The Solution:

Siemens has developed a deployable gap-filler, which is now in service on Florida's BrightLine:


Video Link




These allow for high platforms to be built directly on the mainline without need for gauntlet tracks or platform extenders, and freight trains can roll through these stations at full speed:

(skip to 20 seconds into this video)
Video Link


This solution solves all the problems with platform heights. There don't need to be any infrastructure improvements. There don't need to be any special tracks for station platforms. There don't need to be wheelchair lifts, steps, or high-blocks. The only moving parts are contained within the train cars, so they can be actively maintained at the same schedule as the doors themselves.

I propose that every new passenger rail system be designed to use high-platforms, 48-51 inches tall, and use active gap-fillers to make every platform a level-boarding platform.

For busy rail corridors, bi-level cars can still function at high-level platforms, such as New Jersey Transit currently uses:


Another way to do bi-level cars is to go straight up, where space allows it. This would mean that passengers with disabilities could still move between cars easily on the bottom floor, and the top floor could be used for observation areas, just like in the Colorado Rail Car Ultra Domes, which are 18-feet tall (meaning they can go anywhere a double-stack container train can):


Most importantly, Siemens - the manufactuer of the Brightline cars - is set to manufacture 137 cars for Illinois and California for corridor service, replacing an order for bi-level cars. These types of passenger cars are also well-situated to be the car-of-choice for Amtrak's next long-distance fleet, replacing older cars on their long-distance trains. If these cars become that ubiquitous, it would be extremely easy to include the same gap-fillers in all these new cars (or retrofit them into existing Siemens cars). This would create a national standard platform height and eliminate all of the complicated and less-effective solutions that have been deployed throughout the non-Northeast Corridor parts of the country.

For more reading on how complicated platform heights can be, read this post of the Caltrans HSR Compatibility Blog:
http://caltrain-hsr.blogspot.com/200...VN24vHSWVqM2VM

Let's standardize passenger equipment in the USA! It can be done, and the benefits will be worth the pain!
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Old Posted Jan 25, 2018, 1:40 AM
jd3189 jd3189 is offline
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I'm all for this, but it would a major undertaking that most places in the country may not be up for. These differing platform heights are also a contributor to the US having low transit ridership compared to other Western nations.
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  #3  
Old Posted Jan 25, 2018, 7:41 AM
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Quote:
Originally Posted by jd3189 View Post
I'm all for this, but it would a major undertaking that most places in the country may not be up for. These differing platform heights are also a contributor to the US having low transit ridership compared to other Western nations.
Really? Other nations have platforms with different heights. Keeping my argument as simple as possible to just one train manufacturer; Stadler Rail builds several types of railcars for both Europe and America. Each different type of train can have different floor heights. the reason why is because there are different platform heights throughout Europe.

GTW low floor height can be between 600 mm to 830 mm (23.5 in to 32.5 in) (NJT, DCTA), high floor height 1000 m (39 in)
FLIRT low floor heights can be 570 mm (22.5 in) or between 760 to 780 mm (30 in to 30.7 in). (FWTA) high floor height 780 mm (30.7 in)
KISS low floor heights can be 440 mm to 555 mm (17 in to 22 in) and later capable of 1280 mm (50.5 in) to accommodate CHSR (Caltrain)
EC250 low floor height 940 mm (37 in), high floor height 1200 mm (47 in) (Swiss Rail through Gotthard Tunnel)

As you can easily see, there's a lot of standard floor heights being used in Europe.

A read you might find interesting!
http://caltrain-hsr.blogspot.com/201...-boarding.html

"Europe, where "blended" high-speed rail is the rule rather than the exception, is gradually standardizing around two platform heights: 550 mm (21.7") and 760 mm (29.9"). Accessibility laws are becoming more stringent, forcing train floor heights to match the platforms for seamless level boarding. The traditional single-deck high-speed train designs now operating in Europe, including recent models designed in the last decade such as the AGV and Velaro-D, still don't allow level boarding. Two or three steps are necessary depending on platform height, to the increasing dismay of advocacy groups for persons with reduced mobility. The next generation of single-deck high-speed trains, of the sort that California might order later this decade, are designed for level boarding with entry floor heights of 760 mm; for example, the Talgo Avril. Accessibility requirements will eventually leave the big three manufacturers (Alstom, Bombardier and Siemens) with no choice but to follow suit and offer high-speed trains capable of level boarding, most likely at 760 mm."

If Europe is standardizing around 21.7 inches and 30 inches floors for future trains, why not America too? Why stubbornly pick 48-50 inches?
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Old Posted Jan 25, 2018, 3:24 PM
mfastx mfastx is offline
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I'd be happy with a platform of any height above the rail, even if it's just 8 inches for all the freight shared lines. Many stations have a platform below the rail, and some barely have a platform at all.
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Old Posted Jan 25, 2018, 5:14 PM
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  #6  
Old Posted Jan 25, 2018, 6:11 PM
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Quote:
Originally Posted by electricron View Post
If Europe is standardizing around 21.7 inches and 30 inches floors for future trains, why not America too? Why stubbornly pick 48-50 inches?
Because that height taller than the train wheels. This means the inside of the train can have a level floor going all the way through. Not only is every door accessible by level boarding, but the entire train is also accessible once on board. No stairs, no ramps.

That said, no matter what standard you choose it will be somewhat arbitrary. But we should standardize to something. We could argue that Spain has multiple gauges of track and that train service has evolved to function anyway (with variable gauge trains and transfers and whatever). But that would ignore the fact that it is obviously easier to have a rail system with a single standard gauge of track.

Standardizing platform heights means any type of train car can stop at any station. Different operators could exchange train cars with any other train operator.
I don't think every transit line needs to conform; light rail and interurban trains wouldn't need to adopt a new platform height to gain these advantages. But intercity rail ought to standardize.
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Old Posted Jan 30, 2018, 9:41 PM
jamesinclair jamesinclair is offline
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I thought this was very informative, thank you.

One example you might want to add is that the subway and light rail in Cleveland share stations. One end is low, one end is high
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Old Posted Jan 31, 2018, 6:55 AM
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Also worth noting that level platforms were, traditionally, a way to speed up boarding on busy urban rail systems. It had very little to do with accessibility for the disabled, which is why quieter commuter and intercity lines in the US never upgraded to high-level platforms.

Commuter services like Metra and MBTA may want to build high platforms to make their service more efficient, but they have already developed ways to provide accessibility for the disabled onto their trains.

I like Siemens' gap fillers on Brightline, but I'd like to see other manufacturers come forward with similar technology before we make a decision to redesign the entire US rail network.
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