Jim Duncan mentioned having space on a siding to two trains.  I noticed when watching an operating session on the Tehachapi layout at the La Mesa Club in San Diego that some of their sidings are "lapped" sidings (I think that is the correct term).  Basically some where near the center of the siding, there is a cross over from the siding to the mainline.  That allows two trains running in opposite directions to use the passing siding while a superior train passes.  Once the superior train has passed, one of the trains can then take the cross over to get out of the passing siding and allow the other train to then get out and back on the mainline.  

It was especially interesting to watch one operating session when the "prototype railroad operators" (I think that was the name of the organization) were operating on Tehachapi, and one train operator made a mistake leaving Caliente just after the first section of the San Francisco Chief had passed, but before the second section arrived at Caliente.   It was interesting to watch the dispatcher use creative ways to put trains in various sidings to get this long freight that had needed to do a saw by at Caliente to allow the San Francisco Chief to get by in order to allow this long freight to clear everyone up the hill and allow traffic to move again.

Indeed, lap sidings are often much more helpful than a "double length" siding as was suggested in MRH and require about the same length of layout. This is thoroughly described in John Armstrong's Track Planning for Realistic Operation (Kalmbach)

The reason for this is utility -- depending on train length, three (or even four) trains might be able to meet and/or pass flexibly at a lap siding. It could happen at a double-length siding, but there is not as much flexibility in terms of the order in which trains arrive and depart. The Lap Siding provides more meeting points for about the same linear layout length.

I was going to vote pretty low on this one until the thing about the bread clips. That pushed me back up.

The 4 scale grid on plan reduction/expansion was nice...but there are other scales. How about some love for G or 1/2" scale?

I was a little bummed on the answer to the question on paints....not even close enough on a complete answer. If you are going to bring the question....bring the whole answer....

An orange peel finish is the result of the paint drying before it hits the surface.

Drying of paint before reaching the surface is commonly termed dry spray. If dry spray is painted over with a wetter coat of paint it does induce an orange peel like effect as stated in the article. However, the orange peel effect is not the same paint defect as what is commonly termed orange peel. Although dry spray and orange peel are closely related paint defects.

The specific defect orange peel is the wavy surface on a paint film caused by improper flow out of the paint as a result of application or environmental influences. It results from one or more of the following application errors:

1. Paint too cold during application
2. Wrong mixing ratio used in a 2 component paint
3. Atomization air pressure too low
4. Fluid nozzle too large for paint product
5. Thinner (reducer) choice too fast for application temperature or insufficient quantity in mixture
6. Airflow too high in spray environment
7. Inconsistent overlap in spray pattern during application
8. Insufficient amount of paint applied (film thickness too low)
9. Pot life of paint product has expired (2 component paints only)
10. Too much wetting agent in mixture

The defect dry spray is a dull appearance due to fine dry paint particles on or in the paint film. It results from one or more of the following application errors:

1. Thinner (reducer) choice too fast for application temperature
2. Atomizing air pressure too high
3. Fluid nozzle too small for paint product
4. Gun distance too great
5. Wrong gun angle (deviating too far from 90 degrees)
6. Poor airflow in spray environment
7. Improper routing of work piece

I make this post because there are two very critical airbrush related differences between orange peel and dry spray - atomizing air pressure and fluid nozzle size. One of the possible remedies for orange peel is to raise the air pressure and/or reduce the nozzle size. Conversely, one possible remedy for dry spray is to lower the air pressure and/or increase the fluid nozzle size. Direct opposite approaches depending on the defect. Hence why it is important to differentiate the defects before applying a solution.