I just built a fold down board that will hold an interchangable car float. Just used a door hinge and pine board topped with masonite (so I could paint water on top). It has magnets inserted into a removable leg and the board has a metal plate. Works perfectly.
I built a simple shelf, secured at the layout end by hinges and supported at the far end by a simple fold-down leg, also hinged. The shelf then supported a piece of two-inch foam with my carfloat attached. I could easily slide the carfloat section away from the carfloat apron, which was fixed. The shelf then folded down and out of the way as needed.
It takes an iron man to play with a toy iron horse.
The last comment could be very important. Your main module will have proper supports and probably some braces for stability. I routinely screw the back plate to the studs just on the other side of the drywall behind it.
However, any added surfaces, if they get stiffly and adequately anchored to the front plate, will act as levers when sufficient weight is placed on them. If a heavy hand holds onto the close edge in order to reach further with that steadying hand, there's a greater chance the whole will want to tilt toward you if it is not anchored to the wall at the back. A thought.
By the same reasoning, if you don't adequately brace/support that extra square footage, you could cause it to bend down, maybe break something, including the plate to which the brackets are affixed. You needn't worry about anything of the scale model, certainly not locomotives; they don't weigh anything like your elbow, your gut, or your steadying hand. Figure out how to secure and strengthen the main module, how to mount the new surface item, and how to ensure your new leverage doesn't cause catastrophic damage.
Somewhere on MRVP on on of their project layouts, they did an attachable piece that held a couple tracks. It had it's own support leg, it may even have just folded down off the end of the layout.
Henry
COB Potomac & Northern
Shenandoah Valley
If you can line up with an edge, use 1" angle iron to join the two using pins to hold in place. You could have the section on or off in seconds.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
This is been something I have been pondering for a while, can I add removable sections of track or "wings" to the ends of my layout using brackets strong enough to support the weight of a locomotive and a few cars? ( the brakets would be attatched to the layout base)
Heres my crude drawing of what I have in mind