Discussion related to commuter rail and rapid transit operations in the Chicago area including the South Shore Line, Metra Rail, and Chicago Transit Authority.

Moderators: metraRI, JamesT4

  by dinwitty
 
The CTC system may become operative on a portion of the line fairly soon and also New catenary will be replaced in the same sections, different from the current setup.
New catenary will have only 1 contact wire with no secondary feeders on the wire, on the poles will be the secondary power run feeding to the catenary at regular intervals.
A lot of the catenary is getting aged, looks like it will be going thru replacement phases.

  by PRRGuy
 
The CTC between 115th st and Emerson is looking at a Mid to late July cutover date.
Also, the new catenary (which is taking bids soon) will be a tension system similiar to what's on the N.E. corridor, or so I'm told.
  by MikeF
 
dinwitty wrote:New catenary will have only 1 contact wire with no secondary feeders on the wire, on the poles will be the secondary power run feeding to the catenary at regular intervals.
Can you clarify this? The present catenary system has only one contact wire with primary and secondary messenger wires. (Some portions have only one messenger wire.) I'm not familiar with the catenary out East, but I would imagine the South Shore's new stuff will be the single-messenger type. Feeders currently exist at regular intervals. The new catenary will, as PRRGuy wrote, be a constant-tension system, which should help eliminate a lot of the wire breaks that have been problematic on the South Shore in the past.

  by Tadman
 
I want NHRR-style triangular catenary. Pick up a copy of one of Don Ball's color books and check out his pics of E60's and Cosmos running under the NH catenary - neat stuff.
  by dinwitty
 
MikeF wrote:
dinwitty wrote:New catenary will have only 1 contact wire with no secondary feeders on the wire, on the poles will be the secondary power run feeding to the catenary at regular intervals.
Can you clarify this? The present catenary system has only one contact wire with primary and secondary messenger wires. (Some portions have only one messenger wire.) I'm not familiar with the catenary out East, but I would imagine the South Shore's new stuff will be the single-messenger type. Feeders currently exist at regular intervals. The new catenary will, as PRRGuy wrote, be a constant-tension system, which should help eliminate a lot of the wire breaks that have been problematic on the South Shore in the past.
I am hedging information that came from the meeting they just had.
I wasnt there but my father was.

  by Nasadowsk
 
Constant tension systems are all basically the same - either they have weghts at one end of the run and the wires fixed at the other, or they have weights at both ends and the wire fixed in the middle.

I'm guessing whatever support hardware that can be reused will be, but you'll see a few new poles go up.

I wouldn't be surprised if the final result looks somewhat like a cross between the NEC and a light rail line - the voltages are lower so insulation's no biggie, but you've got the heavy hardware holding things up for high speed operation.

I'd expect a slight uprate in wires sizes - that'd drop resistive losses.

Properly done, these systems work really nicely.

  by Tadman
 
I once traveled on some interurbans in spain, and they used a constant tension system that had a large wheel/ratchet at either end of each wire - the catenary was wrapped around that wheel and the ratchet was used to tighten/loosen the tension depending on seasons.