No offense, but that stretch of four tracks winding through the middle of the layout is PRR-ish only by virtue of being four tracks; the curves are way, waaaaay too tight to be believable as a PRR mainline, IMO. Now, if you want something that's more in keeping with the PRR, try something along these lines: The PRR main dominates the space--just as the real railroad did--and serves as something of a scenic divider. It could go under all of the other track instead, but then the loop becomes much more obvious. Now you have something that won't make an articulated look awkward. Would also be cool to electrify it. Edit: Further to the above, I might consider changing the setting to an urban area, with the PRR running through town on elevated track, and the loop/yard being an industrial shortline serving an industrial neighborhood. Then you have densely-packed buildings dividing the space, which would further disguise the loop and justify the tight turns; it would be more believable, I think, than trying to cram mountainous terrain around everything. Just a thought... I just tossed this together in a rush, so I'm not sure it uses your track inventory properly, but it ought to be doable with some tweaks.