Why do Cleveland L.R.Vs have steps?

General discussion of passenger rail proposals and systems not otherwise covered in the specific forums in this category, including high speed rail.

Moderators: gprimr1, mtuandrew

Re: Why do Cleveland L.R.Vs have steps?

Postby electricron » Tue Sep 06, 2016 3:19 am

Myrtone wrote:Consider the amount of floor space, not just seating capacity, in case of low floor vehicles, wheel-box intrusions do eat into the floor space. Even on part high floor vehicles, this can be seen where the articulations are. The issue is the capacity relative to length, not absolute capacity. While the S70s may have the same number of seats as the high floor LA fleet, is the latter slightly shorter than 81 ft. This is one of the unavoidable trade-offs with low floor vehicles. Reduced capacity relative to train length is one. Some have part high floor, while most other have reduced bogie movement. Building high platforms, if they are possible in all locations, avoids the trade-offs in designing each new generation of rolling stock.


There's almost as many low floor intercity, commuter, and light rail railcars in America as high floor trains. There is no trade off, there's advantages and disadvantages to both. America isn't the only country in the world that uses low floor trains and low platforms. Every transit agency, sometimes different for different lines, makes a choice which type platform they want.

The only real advantage I've read for trains having higher floors (and therefore stations with higher platforms) is a higher maximum speed. There are TGV double deck trains with low floor heights and maximum speeds of these trains is still 186 mph. Light rail vehicles, in dedicated lanes or not, in dedicated right-of-way or not, do not travel fast enough (186+ mph) for floor heights to matter.
electricron
 
Posts: 3924
Joined: Tue Aug 25, 2009 8:35 pm

Re: Why do Cleveland L.R.Vs have steps?

Postby Myrtone » Tue Sep 06, 2016 8:53 am

The TGV is heavy rail, which runs on open ballast trace and most certainly has larger wheels than even high floor L.R.Vs. If there is low floor over the bogies, there needs to be space to each side of the aisle for the wheels to protrude above the floor, there also needs to be room for primary suspension, and also motors if the bogie is powered. Also, the low floor between the wheels constrains bogie movement. Electrical control equipment has to go in the roof rather than under the floor.
With high platforms (and thus high floor), control equipment, motors, wheel-sets and primary suspension are all under the floor.
Also known as Myrtonos
Myrtone
 
Posts: 163
Joined: Sat Sep 25, 2010 6:11 pm

Re: Why do Cleveland L.R.Vs have steps?

Postby Arborwayfan » Tue Sep 06, 2016 2:43 pm

A Cleveland light rail station. Notice fairly narrow platform with cars parked on the left and the tracks on the right. Very convenient. Imagine trying to get a high platform into the same place, and then trying to use that platform. Many other stations on the lines appear to be in similar places.

https://en.wikipedia.org/wiki/Southington_(RTA_Blue_Line_Rapid_Transit_station)#/media/File:Southington_(Blue_Line)_Rapid_Station_October_2015.JPG

Yes, all-high platforms have advantages, but the traffic densities have to be pretty high to offset the costs and disadvantages.

Moderator's Note fixed broken link
Arborwayfan
 
Posts: 655
Joined: Thu Jul 15, 2004 11:27 am
Location: Terre Haute, Indiana

Re: Why do Cleveland L.R.Vs have steps?

Postby mtuandrew » Tue Sep 06, 2016 4:08 pm

electricron wrote:Seating and train capacities are no different on a level floor whether its high or low vs a split floor train. Need some examples? Here's a few:
Level Floor (High Floor)
LA Nippon Sharyo P865 87 ft (26.52 m), 76 seats
LA Siemens P2000 89.5 ft (27.28 m), 76 seats
LA AnsaldoBreda P2550 90 ft (27.4 m), 71 seats
LA Kinki Sharyo P3010 (Difficult finding its length), 68 seats

Mix Floors (High 30% and Low 70%)
Seattle Link Kinki Sharyo 95 ft (29.0 m), 74 seats
Minneapolis Flexity Swift Type 1 94 ft (28.65 m), 66 seats
Houston Siemens S70 96 ft (29 m), 72 seats
San Diego and Salt Lake Siemens S70 81 ft (24.7 m), 68 seats

I do not necessarily see a drop in seating capacity, take a second look at the 68 seats of the low floor Salt Lake Siemens S70s and high floor LA Kinki Sharyo light rail vehicles, having the exact same seating capacity!

The single-articulated RTA Bredas seat 84 people in appx 77 feet (23.5m), rather shorter than the above cars. However, I don't know how many standee passengers they can hold - their floor space looks relatively limited. In comparison, the above Siemens S70 can hold 220 passengers seated and standing.

-----

I keep coming back to the funding problem. Used equipment is an option - I'm serious about RTA knocking on Metro Transit's door - but really, Cleveland just needs a combination of Federal, state, and local funds for modern new equipment. For instance, San Diego just ordered some short-length Siemens S70s that would fit nicely on the RTA system, only a few feet longer than the Bredas.

As for low-floor versus high, the vast majority of LRT vehicles now in production worldwide are 50/50, 70/30, or 100% low-floor cars. RTA would spend more custom-ordering a 100% high-level car than it would on equivalent low-floor equipment, even beyond the cost of raising platforms. The wheelboxes are really not an issue in my experience - low-floor cars tend to have wider aisles than the older high-floors anyway (and the boxes are usually hidden under seats, which have to be there anyway.)
User avatar
mtuandrew
 
Posts: 4122
Joined: Tue Feb 20, 2007 2:59 am
Location: the Manassas Gap Independent Line

Re: Why do Cleveland L.R.Vs have steps?

Postby Myrtone » Tue Sep 06, 2016 7:25 pm

Arborwayfan wrote:A Cleveland light rail station. Notice fairly narrow platform with cars parked on the left and the tracks on the right. Very convenient. Imagine trying to get a high platform into the same place, and then trying to use that platform. Many other stations on the lines appear to be in similar places.


Is it possible to relocate the car parks? Even if not, it might be possible to dip the tracks.

mtuandrew wrote:I keep coming back to the funding problem. Used equipment is an option - I'm serious about RTA knocking on Metro Transit's door - but really, Cleveland just needs a combination of Federal, state, and local funds for modern new equipment. For instance, San Diego just ordered some short-length Siemens S70s that would fit nicely on the RTA system, only a few feet longer than the Bredas.


Most used equipment would be high floor, while it may need to be refurbished, it may be a cheaper option.

mtuandrew wrote:As for low-floor versus high, the vast majority of LRT vehicles now in production worldwide are 50/50, 70/30, or 100% low-floor cars. RTA would spend more custom-ordering a 100% high-level car than it would on equivalent low-floor equipment, even beyond the cost of raising platforms. The wheelboxes are really not an issue in my experience - low-floor cars tend to have wider aisles than the older high-floors anyway (and the boxes are usually hidden under seats, which have to be there anyway.)


Until recently, nearly all tram and light rail rolling stock has been high floor, even today, there is still more high floor than low floor rolling stock in the world. There may even still be plenty of tooling for high floor vehicles lurking around places. Many low floor designs do have podiums which are too big to be hidden under seats, because of longitudinal motors on the outside.

Even when podiums can be hidden under seats, this constrains location of the seats, as well as bogie movement.
Also known as Myrtonos
Myrtone
 
Posts: 163
Joined: Sat Sep 25, 2010 6:11 pm

Re: Why do Cleveland L.R.Vs have steps?

Postby Myrtone » Wed Nov 02, 2016 12:02 am

Simple fact is that there are unavoidable trade offs with making the floor lower than the wheel-tops (see above), there are no trade-offs with making platforms at off street stops higher. Low floor transit vehicles, be it buses or trams are made for applications where a) there is a need for level boarding and b) where the trade-offs of making the platforms higher than the wheels outweigh the trade-offs of making the floor lower than the wheel diameter. This is not the case for a reserved based system with no street stops.
Also known as Myrtonos
Myrtone
 
Posts: 163
Joined: Sat Sep 25, 2010 6:11 pm

Re: Why do Cleveland L.R.Vs have steps?

Postby mtuandrew » Wed Nov 02, 2016 3:29 pm

*sigh*

Moderator's Note: we're going around in circles. Locked.
User avatar
mtuandrew
 
Posts: 4122
Joined: Tue Feb 20, 2007 2:59 am
Location: the Manassas Gap Independent Line

Previous

Return to General Discussion - Passenger Rail

Who is online

Users browsing this forum: No registered users and 2 guests