• MARC HHP-8

  • Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.
Discussion related to DC area passenger rail services from Northern Virginia to Baltimore, MD. Includes Light Rail and Baltimore Subway.

Moderators: mtuandrew, therock, Robert Paniagua

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  by gokeefe
 
What exactly are you referring to by "whole phase sync system"? News to me ...
  by farecard
 
gokeefe wrote:What exactly are you referring to by "whole phase sync system"? News to me ...
Also curious about that. AFAIK, the 60Hz trackage is fed by local-to-the-substation power (i.e. from local POCO) vs. the 25Hz which has the overhead 138kV transmission system.
  by ApproachMedium
 
The 25 hz system is phase synced, its provided by multiple utilities just like the stuff up north but they have it entirely set up to sync the phases between providers so there is no need to throttle off or have active phase breaks.
  by farecard
 
AFAIK there is one phase break near Perryville. That's possible because the 25Hz 138 kV transmission system feeds the same supply to all the substations.

On the 60Hz/25kV, I believe they buy power locally; making it nowhere near as easy.
  by ApproachMedium
 
That phase brake is not active. Its only active if there is a difference in phase sync between the systems, and if safe harbor has the backup online to feed the corridor.
  by dt_rt40
 
Some MARC miscellany since I was last here:

I have now seen ACS-64s pushing MARC trains 3 times. Interesting.

The Chargers are now fairly common on trains north of Baltimore, in fact might now be more common than the Wabtecs, but for some reason they often only run them at 110 mph.

The first 'express' to Perryville is still typically an HHP-8.
  by amtrakhogger
 
dt_rt40 wrote:Some MARC miscellany since I was last here:

I have now seen ACS-64s pushing MARC trains 3 times. Interesting.

The Chargers are now fairly common on trains north of Baltimore, in fact might now be more common than the Wabtecs, but for some reason they often only run them at 110 mph.

The first 'express' to Perryville is still typically an HHP-8.
Amtrak has been rotating ACS-64's in MARC service for over a month now.
  by STrRedWolf
 
amtrakhogger wrote:
dt_rt40 wrote:Some MARC miscellany since I was last here:

I have now seen ACS-64s pushing MARC trains 3 times. Interesting.

The Chargers are now fairly common on trains north of Baltimore, in fact might now be more common than the Wabtecs, but for some reason they often only run them at 110 mph.

The first 'express' to Perryville is still typically an HHP-8.
Amtrak has been rotating ACS-64's in MARC service for over a month now.
They're probably down one or two HHP-8's for repair/refurbishment, as well as some diesels.
  by ApproachMedium
 
Its for lack of ACSES equipt leaders
  by TheOneKEA
 
RRspatch wrote:
ApproachMedium wrote:Its very possible. the NEC subsations are good for 25 miles. Theres one pretty much a lot less than 25 miles between each. There used to be one down on the other side of CP Viriniga but instead of fixing the corroded wires in the tunnels they forced high speed trains to not be able to full throttle out of dc. Till they finally caved and installed one in Ivy City. There should be more than enough capacity down that way. The penn overbuilt their stuff. The Reading, not so much.
The Pennsy electrification was built for both passenger AND freight. Old farts like me remember electric freight trains running on the corridor pulled by GG1's, E33's and E44's. The Tropicana Juice train was the heaviest electric freight train on the corridor and it used three E44's. Back in my tower days I would watch the amp meter on the power board at Landover as a heavy freight train climbed Lanham hill. Conrail dropped electric freight operations in March of 1981. So yes, there's plenty of capacity for what Amtrak and MARC are running on the south end.

As for the power situation on the south-end, yes the substation at Virginia Avenue was decommissioned due to the rebuilding of the Virginia Avenue tunnel and the fact that CSXT wanted the high voltage cables out of the tunnel. Power for Union Station and the Ivy City yards was sent down the freight line from Landover to the sub station at Virginia Avenue. From there underground cables delivered the power to Union Station. To replace this setup Amtrak erected new poles carrying transmission lines between Landover and Union Station (Magruder Branch).
I remember reading in this online paper that one of the reasons for the construction of Ivy City Sub 25 was to eliminate the voltage sag and brownouts which were contributing to the HHP-8’s misbehavior; the paper states that the HHP-8’s main circuit breakers would spuriously trip and kill the locomotive. I had also read an anecdote on Wikipedia which stated that the 25MW cycloconverter installation at Jericho Park in Bowie was derated due to bad harmonics and other electrical misbehavior at the south end of the NEC. With Ivy City Sub installed and operational, I’ve always wanted to know if the electrical supplies south of Baltimore are stable enough to allow the HHP-8s to become more reliable and better behaved despite their well-known fragility.
  by gokeefe
 
That's really interesting. I never realized that the electrical problems with the HHP-8s were related to it's sensitivity to low voltage conditions and/or other power related issues from the overheard wire.
  by TheOneKEA
 
gokeefe wrote:That's really interesting. I never realized that the electrical problems with the HHP-8s were related to it's sensitivity to low voltage conditions and/or other power related issues from the overheard wire.
That’s why I still think the MTA’s inability to figure out how to roster some of their HHP-8s for the busier/heavier weekend Penn Line services is so puzzling. In theory the lower electrical load from Amtrak services combined with the increased reliability brought by the availability of Sub 25 in Ivy City should allow the MARC H-8s to be equally as reliable if they were rostered for a limited number of weekend services. I certainly understand the maintenance concerns, the lack of electrified yards, and the crew rostering permutations that would be needed to bring HHP-8s to weekend services, but every time I see a pair of MP36s running in multiple at the head of a double-decker formation I really do wonder.
  by STrRedWolf
 
I think it's that institutional memory of having those HHP-8's break down at any time. It's going to take some time for Bombardier to convince MARC management that the rebuilt HHP-8's are much better.
  by gokeefe
 
Give it a year or two of steady operation and see what happens.
  by SRich
 
STrRedWolf wrote: Thu Aug 16, 2018 6:08 pm
gokeefe wrote:An unanswered question that I keep wondering about with this issue ...

Could the NEC power grid handle all of MARC going electric?

Given the previous history of freight trains with electric power and high volume passenger service with GG-1s it seems likely but I don't honestly know.
Which means electrifying a small chunk of CSX lines (Camden/Brunswick MARC lines) which share freight... which may impose height restrictions on those lines that CSX doesn't want and kill double/triple stack ability... Additional power requirements at the odd frequency... Plus you might as well electrify the Howard Street Tunnel and reconnect to the NEC at Bayview, and we all know how problematic that tunnel is... And don't forget what some of the freight they're running on the lines (think "trash trains").

The NEC infrastructure may handle it, but given history of those lines, CSX is going to balk or go wild with demands (like pay for expanding the lines for more actual capacity).
Why not electrify with still double stack ability. ?
I see on many youtube clips that Amtraks NEC wires a pretty high so i wonder why not use double stack on the NEC.
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