Red Line cable replacement

https://www.washingtonpost.com/local/tr ... story.html

It's not clear what this article is talking about. If it is the cables from the transmitter/receiver cards to the WeeZee bonds, they are not 19,000 ft long. There will be many pairs, 2 per block.

Unplanned audit finds the failing cable could have caused a collision

https://wtop.com/tracking-metro-24-7/20 ... lem-crash/" onclick="window.open(this.href);return false;

Metro does not need to wait until they are 40 years old or failing to replace them.

farecard wrote:https://www.washingtonpost.com/local/tr ... story.html

It's not clear what this article is talking about. If it is the cables from the transmitter/receiver cards to the WeeZee bonds, they are not 19,000 ft long. There will be many pairs, 2 per block.

It's referring to the cabling running in between the TCRs.

srepetsk wrote:
It's referring to the cabling running in between the TCRs.

A) I would hope the system would fail safe when such happens.

B) 90% of the cost is labor. You'd a thunk they would put in glass instead/in addition to copper; the future benefits of which would be huge.

But it's Metro......

They can't put in fiber between the rooms if the equipment in the rooms isn't digital. The Silver Line has redundant fiber runs between those TCRs, but that's only because it's newer equipment that can handle multiple routes.

And yes, there should be data verification/parity bits to ensure the info is correct, but I don't know any specifics about that in between TCRs.

srepetsk wrote:They can't put in fiber between the rooms if the equipment in the rooms isn't digital.

Yes they can. As I said "in addition" as in: along with the immediately needed copper. Not only for not-far-in-the-future use in this application but also for others.

I don't have details but have heard they rent a metric truckload of circuits from VZ and others. Giving that on an ISO layers chart, the most important is 0 (right of way), and Metro has a lock on that aspect; they should be exploiting it to the nth.

@ srepetsk and farecard

My understanding from a conversation on reddit are the cables in question are vital circuit cables that connect adjacent train control rooms to one another that are used to carry the track circuit occupancy information at the ends of the territory controlled by adjacent train control room. In other words it tells train control room B06 that a train is occupying first and or second track circuit on track B2 at the south end of the B07 train control room territory. The cables are part of the block signing system.

The RTU to ROCC comm link uses T1 style channel banks carried on a SONET ring network over fiber along with most of the rest of the IP voice, video and data traffic (MetroNet) need to support the operation of the railroad.

I had been told many years ago that there was some fiber but it was since saturated with the DHS Big Brother cameras, and they'd rented other circuits to cope. But maybe they got a clue somewhere along the line and upgraded the backbone.

farecard wrote:I had been told many years ago that there was some fiber but it was since saturated with the DHS Big Brother cameras, and they'd rented other circuits to cope. But maybe they got a clue somewhere along the line and upgraded the backbone.

I hope they're adding a few more fiber lines then. I heard MTA had 16 fiber lines for their light rail system but after sacking someone for misconfiguring the signal network, only needed three of them lit.

One of many things Hogan cut from the Purple Line was the redundant fiber.

farecard wrote:One of many things Hogan cut from the Purple Line was the redundant fiber.

First canceling the Red Line, then BaltimoreLink, and now trimming the Purple Line's construction, which was in the works since... my college years? Wait, I did a web comic about it... November 24th, 1999?!?

Ooooh I'm glad we put in the Charger order when O'Malley was governor...

STrRedWolf wrote:

farecard wrote:One of many things Hogan cut from the Purple Line was the redundant fiber.

First canceling the Red Line, then BaltimoreLink, and now trimming the Purple Line's construction, which was in the works since... my college years? Wait, I did a web comic about it... November 24th, 1999?!?

Ooooh I'm glad we put in the Charger order when O'Malley was governor...

Well that's what happens when someone takes office that understands money doesn't grow on trees.

MCL1981 wrote:Well that's what happens when someone takes office that understands money doesn't grow on trees.

I can understand canceling the Red Line, but reworking how to build the Purple Line stinks of how the Light Rail got put in first -- as cheaply as the bond that was floated would allow.

Should of had a full subway built by now.