Superliner Catenary question

[SRich]

If double stacktrain can be under wire then an autotrain can also be under wire.

[WhartonAndNorthern]

If double stacktrain can be under wire then an autotrain can also be under wire.

Agreed. The catenary needs to be high enough to clear double stacks and tri-level autoracks and not arc. Then the AC locomotive pantograph must be able to reach that height.

While double stacks and autoracks have slightly different clearance profiles (squared off vs. arched: the Howard Street Tunnel can handle autoracks but not double stacks), the peak heights are fairly close.

[east point]

What is this problem of CAT clearances?. That is just a straw dog. Amtrak already has clearances for double stacks. My understanding is that PANs can reliably contact CAT when it is 24 feet above top of rail. I would imagine that only class 1 track would rock the PANs so much to prevent good contact ?

[mtuandrew]

Moderator Note: Unlocked, but play nice! I also shuffled posts around from other threads.

[SRich]

If double stacktrain can be under wire then an autotrain can also be under wire.

Agreed. The catenary needs to be high enough to clear double stacks and tri-level autoracks and not arc. Then the AC locomotive pantograph must be able to reach that height.

While double stacks and autoracks have slightly different clearance profiles (squared off vs. arched: the Howard Street Tunnel can handle autoracks but not double stacks), the peak heights are fairly close.

The Amtrak ACS-64 pantograph can reach that height? I thought some parts of the Amtrak owned electrified portion of NEC has standard double stack clearance?

@mod/admin Can you chance the TT to a general title? Moderator Note: done

[Backshophoss]

The wire height vari' across the NEC,with the MN New Haven Line being the lowest,except for the Tubes built by PRR and NY Penn(retrofitted)

[east point]

The wire height vari' across the NEC,with the MN New Haven Line being the lowest,except for the Tubes built by PRR and NY Penn(retrofitted)

Yes as far we know the MNRR clearances are low. The support ironwork is solid and cannot be raised very easily. That alone will preclude any superliner type cars from ever transiting the MNRR.

[WhartonAndNorthern]

If double stacktrain can be under wire then an autotrain can also be under wire.

Agreed. The catenary needs to be high enough to clear double stacks and tri-level autoracks and not arc. Then the AC locomotive pantograph must be able to reach that height.

While double stacks and autoracks have slightly different clearance profiles (squared off vs. arched: the Howard Street Tunnel can handle autoracks but not double stacks), the peak heights are fairly close.

The Amtrak ACS-64 pantograph can reach that height? I thought some parts of the Amtrak owned electrified portion of NEC has standard double stack clearance?

@mod/admin Can you chance the TT to a general title? Moderator Note: done

I'm not sure about the Amtrak network. SEPTA shares part of the ex-Reading with Norfolk Southern (the Reading main line was Conrail's and now NS's main line east of Harrisburg, displacing the PRR's Atglen & Susquehanna [Enola Low Grade]) and double stacks do run on the shared trackage. However, this is an older 12 kV electrification system. Any new install is going to be 25 kV which requires more clearance. I'm not going to math out the separation distance now (I'm an EE but it's not a formula I routinely encounter), but AAR Plates H (double stack) and K (trilevel autoracks) both require 20' 3" above the rail clearance. So we have 20 feet 3 inches car height plus a separation distance, plus this is at the maximum catenary sag, so how high is the catenary at max height?

[SRich]

23 feet?

[WhartonAndNorthern]

23 feet?

Plausible. I still haven't looked up the formula (is it simple dielectric breakdown or more complicated? ,shrug>) but found CA HSR documentation. It's 18' 9" wire height for 17' freight cars (AAR Plate F) in shared use areas.

Edit: I should add that the issue of electrifying Virginia's RF&P Line is not whether freight cars can travel under catenary, but whether catenary can be installed at that required height through the existing overpasses and bridges without compromising the line's ability to handle excess height cars.