I agree with Steve, that you put the incline back in. I participated in the engineering for the Sounder commuter rail at Seattle, and we did a lot of conceptual engineering which I have always found fascinating, so here is my concept.
Put the incline back in, but move it east. The original incline track was perhaps 1,500 feet long maximum, and only about 1,100 feet of that was available to overcome almost 20' of elevation difference, so the grade had to approach 2%. And anyway, rebuilding the incline in the original location would be very disruptive to the road and parking east of the Transportation Center, not to mention the new underpass under the mainlines opposite the ATC.
I would move the Main 1 switch of the new incline back to Liberty Street or about MP 37. From this point there is plenty
of room between the mainlines and the Hill Yard to come down the side-hill and tie into the Hill Yard Main 2 just west of the westerly utility bridge where the commuter equipment is plugged in at night. This new track might be 1,700 feet long and would only need to overcome about 16' of elevation difference, so the grade would be more palatable. The new track might require retaining walls, but this is only money.
Signalize the new incline track with simple control points (1 turnout) at each end. Then reconstruct Main 3 from West Eola to Hurd's Island. Between Liberty Street (MP 37) and Spring Street, construct new platforms on the mainlines, with pedestrian ramps to the ATC (at a minimum construct a south side platform on the old spur track grade). At the west end of Hurd's Island, construct a new control point similar to present-day West Lisle, with both universal and
parallel crossovers as necessary to maximize simultaneous moves.
From an operational standpoint, I wouldn't initially try to build another layover facility west of Aurora. My thought would be that extension of service to Yorkville (or perhaps Plano) might start with only 3 or 4 trains, all rush-hour. During the morning rush, for example, trains would run equipment only from the Hill Yard to the new west end of the suburban service, change ends and make all stops to Aurora (new platforms, not ATC), where they would become existing zone service trains, perhaps Lisle, Belmont, Main Street Downers Grove, and then 'express' in to CUS. An operation similar to this would require minimal investment (other than stations, which are a given) west of Aurora, probably an additional set of universal crossovers somewhere between, and other than, Bristol and Somonauk, plus a
second crossover at Bristol.
At some point in the future, when service expansion dictated more expansion, then consider moving the Transportation Center to Montgomery, a second layover facility, and third main extension (Hurd's Island to Bristol would be fairly easy), the main obstacles being money and political will, not engineering constraints.
Glen Haug
To: CBQ@yahoogroups.com
From: sholding@sbcglobal.net
Date: Mon, 16 Sep 2013 20:14:33 -0700
Subject: Re: [CBQ] RE: Suburban service west
Just put the "Incline" back in and you fix the problem.
The RO to OA problem is the lack of third main which bottlenecks the area to begin with. A legacy of a former Railroad Man of the Year.
Former RO operator and retired DS
Steve in SC
From: "BM4110@verizon.net" <BM4110@verizon.net>
To: CBQ@yahoogroups.com
Sent: Monday, September 16, 2013 2:59 PM
Subject: [CBQ] RE: Suburban service west
The only way to go past Aurora would be to bypass the Hill Yard. If the third main was back, they could put another station on the upper level, with an escalator down to the present station.
Servicing the trains would be a problem if a second lay over yard was built. Double staff would be needed, as well as facilities. If only the Hill Yard was used, the deadheading would congest Aurora to Eola W. The reverse move to back down to the yard would be fastest if the conductor used a tail hose, or since the locomotive is on the west end, rode in the cab. He could pull the air if need be. It would still be a pain, and hold things up while waiting for the switch and signal.