I've been doing a lot of head-scratching lately, concerning the best way to continue developing the layout. To some extent, I've become greedy: back when I started modelling in N, I'd have been content just to have a continuous run, a couple of sidings to shunt, a passing loop and a few fiddle yard tracks. Over the years, though, the layout has grown and not inconsequentially so has my pile of kits and items of rolling stock. Encouragingly, I've found that N works fine for slow speed operation and switching - but the downside of that is that I want more of it, not less.
A year ago I decided I fancied adding a locomotive servicing terminal, and my Christmas present 12 months ago was the Walthers turntable, plus a roundhouse and some add-on stalls. I have since acquired a couple more kits that fit in with this theme, and continued researching the topic. At the time my thoughts were simple: the terminal (let's call it an MPD) was going to fit on the peninsula that would project out into the room. Failing that, there was more room along the as yet undeveloped lower wall. There didn't seem to be any lack of space, so what was the problem?
Too much knowledge, that was what. The more I dug into MPDs in an American context, the less likely it looked that a modest passing point, with a few industries, would warrant a facility as big as the one I had in mind - a full on transition-era terminal with steam and diesel both being served, and a 9-stall roundhouse equipped with a turntable large enough to handle a Big Boy! An MPD like that would be much more appropriate situated by a division point, classification yard and/or major junction - somewhere where it would make sense to change locos and their crews, basically. I didn't want to create anything that looked toy-trainlike (it is a toy train, but I'd worked hard to keep a sense of spaciousness on the existing bits and I didn't want to blow that now). The problem had now become one of fitting in not just an MPD, therefore, but also a yard - and the yard was likely to take up at least as much space, if not more, than the original terminal.
Still - plenty of space, right? I thought so, but the more I tried to square the circle, the more the pieces refused to fit nicely. There was room for the yard and terminal on the peninsula - but the yard would need a through-road; real classification yards aren't dead-ends, and the peninsula didn't allow this.
There appeared to be plenty of room along the lower wall - a clear eight feet, surely more than enough? That was my fallback option but there were (are) problems that no amount of head-bashing has resolved. Shillingstone, my 4mm layout, runs all the way around the room, above the GA&E. On three of those four walls, the Shillingstone boards are light and narrow enough that they're supported by L-shaped brackets with no diagonal brace piece. However, the boards along the lower wall are wider, and I decided to go for fully braced brackets along this side. The downside of that is that the diagonal bit intrudes on the space above any putative extension to the GA&E. There's still room for it, but the backscene boards would need to be much lower - unacceptably so, in my view. I've considered various options such as spacing the backscenes out from the wall by five or six inches, and running a track behind them (with suitable access) but that then intrudes on the room available for foreground scenery. That may still be the way to go, but ...
A more radical option would be to accept that the lower wall, while providing useful shelf space for the layout, is not suitable for scenic development. In which case, it might make more sense to move the storage yards there - basically, flipping them through ninety degrees from their current position. The downside is that the storage sidings won't be any longer than those currently in use (which have an option to be extended by 12", say three cars per road) but that would not be too unacceptable a trade-off. The plus side would be unobstructed access to the roads, since I wouldn't be trying to screen them behind foreground scenery.
Even more of a plus, I'd then claw back 10 - 11 feet of existing layout footprint which could then be almost exclusively dedicated to the yard and MPD. That would mean the elimination of some work already done - not just relocating the storage roads, but also removing a couple of grades and re-aligning the existing trackwork. But that would not be too painful since nothing that has been ballasted would need to be touched, and to some extent one end of the storage roads could be transplanted with only minimal effort. Almost all the work seen in photos would be preserved.
So anyway - that's where I am with my current thinking. Of course in model railway land nothing's quite that simple - to even begin to extend the layout, I need to remove a bookcase from one corner of the room, and apart from finding space for all those books and mags currently sitting on it, I'd need to remove a shelf as well.
Apologies for the blather - any thoughts welcome, of course.