Chad,
That part is actually some of the older construction on the current layout.
Years ago, the club had a smaller layout in part of a warehouse somewhere in Kitchener (Boehmer Box factory). Eventually they were forced to move and settled in our present location.
As I understand it, the only parts of the old layout that were incorporated into the new one were a few pieces of Sudbury yard ladder (some of the switches were changes and a couple more tracks added, and the whole thing lengthened by at least 4 feet) and the helix used to go from Nairn to McKerrow (and to the lumber mill on the level below Nairn). There's also some pieces from an old scene at Levack from the old layout stored upstairs, but these aren't likely to be reused.
The earliest construction was building/re-arranging some walls to form the front lounge/office area, and installation of Sudbury yard. Early on, there was a single level, double-ended staging yard that connected both ends of Sudbury.
The branch line from Sudbury to Mckerrow was built just under 10 years ago from about 1998-2000. Also the maintenance facilities and the secondary yard behind the shops were probably started around this time frame as well. Although, finishing all the switches in the car shops area somehow lost priority in the following years, something we hope to get back to sometime, considering the central nature of Sudbury to the layout.
The levels below Nairn, with the lumber mill and nickel mine spurs were added a little later.
Following getting the branchline in service, the simple staging yard across the bottom was replaced by the current double level staging yard, which connects via helix to the east end of Sudbury. This was built over a few years. Based on construction photos at the club, I gather they only built the helix up high enough to connect directly to Sudbury at first, and later finished it off all the way up to Romford with the double track helix back down to Sudbury. This is what it basically looks like now:
http://www.wrmrc.ca/graphics/romford-helix1.jpg
To the casual viewer, this arrangement doesn't really seem to make sense, until you image that a complete scene with a full wye junction will be here, with one leg running down to the staging yard, one running down to Sudbury, and one continuing in the visible scene towards the camera, towards North Bay and Montreal. The track from the west end of Sudbury yard towards Cartier and western Canada wraps around the outside of the helix and just kindof stops, requiring us to use the hidden ramp as serial staging (fits 4 trains of 40-50 cars on two tracks) - not the most flexible operationally. The plan is to have this continue on and emerge into the scene next to and above west sudbury by next year, and eventually upstairs to a temporary full staging yard. This is next on our construction agenda for this summer.
All of the above was basically in place when I joined the club about 3-4 years ago. However a lot of work has been done in the staging yard to add a proper control panel, optical occupancy detectors, etc. There is a scary amount of electronic bits installed there, which took a long time to complete and will never be seen by vistors.
Over the last year or so, we have completely rewired the yard, adding feeders to eliminate dead spots and engine stalling, disconnecting feeders from existing feeder buses and adding new ones to completely isolate sections of the layout (the original wiring was all cross-connected, so the layout operated as a single block, which is bad when a minor derailment causing a minor short circuit shuts down _everything_) and we also started rewiring and blocking the mainline tracks for occupancy detectors and signalling. Also on the agenda: ABS signalling from Sudbury to Romford, the interlocked junction at Romford, and CTC on pretty much the rest of the mainline part of the layout. The branchline to Nairn, McKerrow, Sault Ste. Marie remains "dark territory." In the 1970s it would have been operated by timetable and train orders. We run it as OCS right now, as it's a little easier to manage, especially with hand-held or headset radios.
Also over the last year, we built all the stuff in the previously empty space in the middle of the layout. (New stairs, new walkway, new ceiling, new helix, new benchwork in the middle and down the staging yard side, new lighting) It used to store extra wood and miscellaneous junk. (And in a way still does, since we shoved everything in there out of the way for the tour) This is where we are doing the most construction work right now, and we are still finishing up the mainline wiring. (a few things were temporarily reconnected to work for the tour).
So, yeah, I think that pretty much provides a synopsis of the layout's history at the current location...
We've got a ways to go but it should be pretty cool as it takes shape. Looking at the plan drawings and some of the current construction can be a little confusing, but the overall plan actually make sense and is pretty neat. Starting in Sudbury, there are three directions you can take, each matching up to a line or direction from Sudbury on the real railway. One set of aisles go towards Sault Ste. Marie and Manitoulin Island. One set goes west towards Cartier, and one goes east towards North Bay. A no point other than Sudbury do these aisles ever reconnect. So if you're at the end of the aisle at Cartier (west end of the layout), to get to Sturgeon Falls (east end) you might actually be physically 5-10 feet away, but the only way to get there is to go all the way around through Sudbury.
Hidden trackage serves to lengthen the run between stations. The member who designed the plan estimates the mainline length will end up being almost 20 scale miles. With a 4:1 fast clock for operation, that's about 100 miles which is pretty close to the real thing. So schedules and times can be pretty realistic. With meets, it could end up taking up to or over an hour to get a train from one end to another. We'll probably need a lot more operators then, as crews will be tied up running a particular train for much longer than the current 10 minutes start to stop for a mainline train running from staging to staging.