Passenger Trains > Questions about catenary

I was wondering if there was any optimal height above the rails for HSR catenary, and for lower speed freight do you have a greater practical range of the clearance between the base of the pantograph and the height of the catenary. What I'm getting at is whether a electrified railroad could handled both doublestacks and HSR equipment? I think the answer may have some implications for policy alternatives in California.

Doesn't conventional wisdom say that freight and HSR don't mix? Not even on the same right of way, let alone the same tracks?

i don't know the exact optimum height but the railroad really doesn't want their pantographs raised to the point where they're unstable at high speed ... the higher the pan is raised the less stability it has ... and constant tension catenary weaves right to left instead of a straight line so as not to wear the pan shoes in one area unlike the NEC NH/PRR style



Edited 1 time(s). Last edit at 01/15/12 11:00 by Out_Of_Service.

The contact wire height of all the world's HS lines is around 5 meters (~16 feet), so the answer is no.

Ray

Ray_Murphy Wrote:
-------------------------------------------------------
> The contact wire height of all the world's HS
> lines is around 5 meters (~16 feet), so the answer
> is no.
>
> Ray

Thanks. Could I assume that you need a couple of feet clearance above the highest car? If so, for BNSF to run doublestacks on an electrified Soaquin Valley line, the catenary would be way too high (over 24') for the HSR equipment except at very low speeds.

ts1457 Wrote:
-------------------------------------------------------
> Ray_Murphy Wrote:
> --------------------------------------------------
> -----
> > The contact wire height of all the world's HS
> > lines is around 5 meters (~16 feet), so the
> answer
> > is no.
> >
> > Ray
>
> Thanks. Could I assume that you need a couple of
> feet clearance above the highest car? If so, for
> BNSF to run doublestacks on an electrified Soaquin
> Valley line, the catenary would be way too high
> (over 24') for the HSR equipment except at very
> low speeds.

double stacks run under wire on Septa's/CSX Trenton Line between West Trenton and Woodbourne

Out_Of_Service Wrote:
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> double stacks run under wire on Septa's/CSX
> Trenton Line between West Trenton and Woodbourne

Appreciate it!

There are doublestacks and then there are doublestacks (depending on the maximum height of the containers). Any ideas on the maximum height allowed or the height of the catenary? I wonder what the maximum passenger train speed is?

Ray_Murphy Wrote:
-------------------------------------------------------
> The contact wire height of all the world's HS
> lines is around 5 meters (~16 feet), so the answer
> is no.
>
> Ray

On the former PRR portion of the NEC, the standard height of the contact wire is 22 feet above top-of-rail. Physical constraints result in less clearance in some locations.

The double stacks CSX runs on the West Trenton line have to fit through several low-clearance tunnels south of PHL (including the Howard Street tunnel in Baltimore and the Virginia Avenue Tunnel in DC), and are therefore limited to two regular size (8 foot) containers, for a total height ATOR of just under 18 feet. Therefore, wire height must be about 19.5 or 20 feet ATOR.

As far as I know, SEPTA operates at 79 MPH on the West Trenton line. But clearly, wire 22.5 or 23 feet ATOR (for two stacked hi-cube containers) would be a major "stretch" for pantographs on HSR equipment, and would probably require a slow order.

Amtrak and NS were negotiating to clear one of the three tracks between Perryville and Baltimore for double-stacks by raising the wire, but of course that would mean raising the wire on three two-track bridges plus the two-track stetch between "Gunpow" and "Bush" on at least one of the two tracks. I don't know the implications for operating speeds.

Back in PRR and PC days, in some freight yards and a few other places there used to be little yellow diamonds on the catenary stencilled "high wire". Anybody know what the PRR considered to be "high wire", and what operating restrictions resulted?

Thanks for the additional comments.

I imagine there has never been a need for such an arrangement, but I wonder anyone has ever designed a extendable column to mount a pantograph on so that you could maintain the optimal distance between the contact wire and the base of the pantograph? Such a device would take up room inside of the carbody, so it wouldn't be workable for regular MU cars, but a locomotive or cab/end of train MU car could be designed around it. Incorporating such a design would allow both HSR equipment and maximum doublestacks to share a San Joaquin Valley route.

shoretower Wrote:
-------------------------------------------------------
> The double stacks CSX runs on the West Trenton
> line have to fit through several low-clearance
> tunnels south of PHL (including the Howard Street
> tunnel in Baltimore and the Virginia Avenue Tunnel
> in DC), and are therefore limited to two regular
> size (8 foot) containers, for a total height ATOR
> of just under 18 feet. Therefore, wire height
> must be about 19.5 or 20 feet ATOR.
>
> As far as I know, SEPTA operates at 79 MPH on the
> West Trenton line. But clearly, wire 22.5 or 23
> feet ATOR (for two stacked hi-cube containers)
> would be a major "stretch" for pantographs on HSR
> equipment, and would probably require a slow
> order.
>
> Amtrak and NS were negotiating to clear one of the
> three tracks between Perryville and Baltimore for
> double-stacks by raising the wire, but of course
> that would mean raising the wire on three
> two-track bridges plus the two-track stetch
> between "Gunpow" and "Bush" on at least one of the
> two tracks. I don't know the implications for
> operating speeds.
>

you might be referring to trash container double stacks going through Howard St tunnel ... i'm referring to Q190/Q191 which are full container double stacks between North Jersey and Philadelphia which also roll under wire on Septa's Norristown Line ... not high speed territory but double stacks under wire

cpl examples below :

http://www.railpictures.net/viewphoto.php?id=133583&nseq=37

http://www.railpictures.net/viewphoto.php?id=119770&nseq=44

> Back in PRR and PC days, in some freight yards and
> a few other places there used to be little yellow
> diamonds on the catenary stencilled "high wire".
> Anybody know what the PRR considered to be "high
> wire", and what operating restrictions result

this was usually in engine terminal areas where personnel had to work on electric engines and not be in close proximity of the trolley(contact) wire altho still had to adhere to energized wire and pantograph clearances for class "B" employees

an example below :

http://www.rrpicturearchives.net/showPicture.aspx?id=2624702



Edited 2 time(s). Last edit at 01/15/12 13:02 by Out_Of_Service.

Out_Of_Service Wrote:
-------------------------------------------------------
> you might be referring to trash container double
> stacks going through Howard St tunnel ... i'm
> referring to Q190/Q191 which are full container
> double stacks between North Jersey and
> Philadelphia which also roll under wire on Septa's
> Norristown Line ... not high speed territory but
> double stacks under wire
>
> cpl examples below :
>
> http://www.railpictures.net/viewphoto.php?id=13358
> 3&nseq=37
>
> http://www.railpictures.net/viewphoto.php?id=11977
> 0&nseq=44

I think the extended height containers are in well cars, so I believe that buys you nearly two feet. I seem to remember some enclosed multilevel cars at about 22' clearance. Anyhow, if the state of California comes to BNSF and says we want to electrify your Valley route to handle HSR equipment, the railroad might say, "fine, we want the contact wire at 25' above the top of the rail."

Trolley wire height comes under the classification of clearances around tracks, which are state regulated, not FRA. In California, this applies:
http://www.cpuc.ca.gov/PUBLISHED/GENERAL_ORDER/52593.pdf (server appears to be down at the moment)
ISTR that GO 95 specifies wire height to be something like 21 feet minimum from the top of the rails, the idea being that a man riding on top of a boxcar wouldn't be able to touch the trolley wire by standing straight up and reaching over his head. For operations like the SF Muni (city streetcar service only), the wire can be as low as 17 feet. The Key system could use 19 feet on its trainsbay lines except for those lines on which the SN ran freight (mostly 40th St), where the wire had to be 21 feet. The wire had been 19 feet, but the CPUC ordered the Key to raise it shortly after WWII (the same standard applied to the SN, CCT, TS, and PE, BTW).

I'm fairly sure the only way an HSR operation could get around this requirement would be to dedicate its line(s) to passenger-only operation.

HSR is nice, but only if you can pay for it without breaking the bank. So far, it doesn't look like that's the case anywhere in the US.

ts1457 Wrote:
-------------------------------------------------------
> I think the extended height containers are in well
> cars, so I believe that buys you nearly two feet.
> I seem to remember some enclosed multilevel cars
> at about 22' clearance.

The extra height autoracks are 20'2" tall. I believe this is the tallest standard height for full-cube doublestacks in North America as well.

toledopatch Wrote:
-------------------------------------------------------
> The extra height autoracks are 20'2" tall. I
> believe this is the tallest standard height for
> full-cube doublestacks in North America as well.

Yes, I believe you are right. Thanks for correcting me.

I'm still trying to find out how much clearance BNSF would want for the contact wire, if the San Joaquin Valley line were to be electrified.

shoretower Wrote:
-------------------------------------------------------
> The double stacks CSX runs on the West Trenton
> line have to fit through several low-clearance
> tunnels south of PHL (including the Howard Street
> tunnel in Baltimore and the Virginia Avenue Tunnel
> in DC), and are therefore limited to two regular
> size (8 foot) containers, for a total height ATOR
> of just under 18 feet. Therefore, wire height
> must be about 19.5 or 20 feet ATOR.
>
> As far as I know, SEPTA operates at 79 MPH on the
> West Trenton line. But clearly, wire 22.5 or 23
> feet ATOR (for two stacked hi-cube containers)
> would be a major "stretch" for pantographs on HSR
> equipment, and would probably require a slow
> order.
>
> Amtrak and NS were negotiating to clear one of the
> three tracks between Perryville and Baltimore for
> double-stacks by raising the wire, but of course
> that would mean raising the wire on three
> two-track bridges plus the two-track stetch
> between "Gunpow" and "Bush" on at least one of the
> two tracks. I don't know the implications for
> operating speeds.
>
> Back in PRR and PC days, in some freight yards and
> a few other places there used to be little yellow
> diamonds on the catenary stencilled "high wire".
> Anybody know what the PRR considered to be "high
> wire", and what operating restrictions resulted?

Does CSX have any electrified territory? ASAIK, the Howard Street tunnel is not electrified and has no bearing on this discussion. (If I'm wrong, I'm sorry.)

ProRail Wrote:
-------------------------------------------------------
> Does CSX have any electrified territory? ASAIK,
> the Howard Street tunnel is not electrified and
> has no bearing on this discussion. (If I'm wrong,
> I'm sorry.)

As mentioned previously, CSX operates on an electrified portion of the ex-Reading northeast of Philadelphia. It also operates over parts of the Northeast Corridor in Maryland, New York, Connecticut, and Massachusetts, but in those territories -- owned by Amtrak or commuter-train authorities -- double-stack cars are not operated.

Ray_Murphy Wrote:
-------------------------------------------------------
> The contact wire height of all the world's HS
> lines is around 5 meters (~16 feet), so the answer
> is no.

Amtrak uses a 22'-0" wire height for high speed service at 150+ mph. Amtrak also permits in Rhode Island double stack freight service which requires 21'-8" minimum wire height to include electrical clearance. NS would like similar service in Maryland and Delaware, but ishoping for someone else raise wires orl lower tracks at low clearance points like bridges.

But since the self proclaimed experts here are saying reality is impossible ...

wlankenau Wrote:
-------------------------------------------------------
> Doesn't conventional wisdom say that freight and
> HSR don't mix? Not even on the same right of way,
> let alone the same tracks?

The conventional wisdom is simply wrong. America runs 135-150 mph Acela's with 50 mph freights every day on the Northeast Corridor.

We've run 100+ mph passenger with freight for 100 years in the US.

But why let reality intrude when we can turn to conventional wisdom?

abyler Wrote:
-------------------------------------------------------
> Amtrak uses a 22'-0" wire height for high speed
> service at 150+ mph. Amtrak also permits in Rhode
> Island double stack freight service which requires
> 21'-8" minimum wire height to include electrical
> clearance...

Mr. Byler, thank you for the info. So does 21'8" minimum wire height allow for maximum clearance of 20'2" or is the max a bit lower?