…I will start with building the site with the closest tolerances, the site with my minimums in curves in particular.
I was reading a nearby thread where comments are being offered on a prospective plan. My mind flashed back to where I was when I had all my splines done, and then had to cram in my final curves into my yard. Those two end curves, effectively the AD track and leads, and then the yard parallels themselves, were effectively the last things to be done, and I was using a figurative crowbar by then in an attempt to close the folded loop larger plan.
We soon learn to set minimums early and to abide by them…or else! Isn’t that where our tolerances for error are the least? Then why leave those tougher spots, places where things have to be just so, until the end when you have less elbow room? Why not deal with the tricky spots first, get them truly reliable and functional, and then use up the generous room elsewhere. Move out to the wider expanses and reduce 32" curves to 30" in order to close it all up. Don’t make all those expansive curves and find you have to use that crowbar at the end, often ending up with a 23" curve where you absolutely wanted/needed 24"!
The result for me was a truly wonderful mainline and grades, but the entrance on one side, the last set of curves I laid into the yard, are my most troublesome curves and turnouts. If a derailment happens with my Walthers heavyweights, it will be there. If a light tender lifts out of the rails, it will be there. Nowhere else.
Hopefully, i’ll spend less time shopping and more time building. Also, I’ll spend a lot less time experimenting and instead use tried and true methods and products.
May I politely suggest that proper advance planning and engineering, combined with reasonable standards and accurate construction to those plans would prevent any such problems.
But what do I know, I only design houses for a living.
Sounds to me like you have learned one of the essential lessons of layout planning and design: no matter how hard you try you are never going to be able to squeeze 19 gallons into an 18 gallon tank.
I had planned all my mainline to be 28" radius and was just starting my splines when I found out about Sunset Models Selkirk coming out and how it needed a 30" minimum radius. AAAAAAAHHHHH! All worked stopped as I did some more homework and found out that some other higher end engines required a larger radius. I did not own any, but hoped to in the future.
I was just back into the hobby and in HO for the first time. I had one tough decision to make about giving up my scale length Stoney Creek Bridge. It took a couple of days to mull this over but I decided Brass engines that required bigger curves were much more important than the bridge. After talking to Tom White about Brass Engines I redesigned the entire mainline to have a 32" radius. A little padding if you like.
I got lucky this time. I would have had a big job changing my splines. It would mean throwing them out and starting over. I also have learned less is more as I work on my pike. I don’t buy things until I’m ready for them to go on the layout.
How much homework does one do before we take the plunge and start construction? [:)]
Every layout has taught me something for the next one - some to keep and some to avoid. I hope to start my 8th (or maybe it’s my 9th) this fall after finishing the basement. This is the “big one” so I hope I’ve learned enough to do a reasonable job.
Reading Iain Rice’s books on layout design have taught me that good layout design looks at likely locomotive rosters, rolling stock, structures, and scenery concepts as well as track design, era, and prototype. I would further add that personal standards such as uncoupling methods, willingness to hand lay special configuration tracks, operational preferences (dispatching or display or switching), control preferences (seated central panel vs walkaround), appearance of longer cars on curves, etc., also should be looked at in designing the layout. Basically - a complete set of givens and druthers.
In government construction where design-build contracts have become the norm, construction starts at around the 85% design completion point. Start construction sooner, and rework costs go up because of design changes. Wait to start construction until design completion, and costs go up because of schedule lengthening - despite reduced rework. And you have to wait longer for the faciltiy to be built. Note that there is a