I know it's been a while since the last update. Modeling time is coming in very short periods right now. But with a few minutes here and there I've managed to complete a full loop. The Berlin Line is in and fully operational, both helixes work, as does the wye at the bottom of the east helix.
Until I get some more feeders installed, I can run a train from Elm Street going east on the Berlin Line and down the helix, all the way through staging, and up the west helix to Main Street.
Testing has commenced, including running a train forward and backward through the entire layout. That works fine. What has found a handful of trouble spots is running the I-4 with two Osgood Bradley cars. Particularly backwards. Fortunately, these trains won't need to run reverse, but it helps determine trouble spots. They even make it up the Berlin Line, which will never see passenger service once the mainline completes the final revolution on the helix.
I have found that the I-4 is a better test than the L-1 due to the 4 wheel pilot truck which can short on the cylinders. I also found that with the J-1 tender I have to use the longer drawbar connection because the cab roof can short on the top of the coal bunker otherwise.
Overall I'm pleasantly surprised at how well the layout runs, particularly with steam.
While I work on completing trackwork, feeders, etc. I will continue to test heavily. The goal is to be able to run every locomotive, with an appropriate train in forward and reverse on the entire mainline and major passing sidings. The industrial areas will be off limits to large steam (as they were on the prototype), but I'll still probably test them to identify the limitations.
The biggest trouble spot, not surprisingly, is the turnout for the exit of the east helix. It wasn't intended, but after I had to rotate the helix I had no other option. After quite a bit of tweaking today it's better, but not 100%. Well, I guess that cars are no longer derailing but I can still tell that the risk is higher there so I'm working to alleviate that.
The biggest issue with this is that I have to work in the tight confines of the helix, with about 3 1/4- 3 1/2" clearance. Had the wye and turnout been planned, it would have been installed before continuing with the next level of the helix.
Once I complete the last revolution of the helix and the remaining small section of the mainline (including feeders), I can also test all of the trackwork in New Britain Yard and the east side of town. Testing can also include small operating sessions with two throttles. I'm hoping to complete the trackwork portion of that by next week.