N Scale switching layout plan help needed PLZ

[FCIN]

I thought I would add a 1'x4' side peice to see what it would look like.

Auzze;
This is a really nice plan. If you can, I would certainly include the 4 foot extension - however, I'd eliminate the switchback access to the large industry (area outlined in red on the drawing).    
You'd be sorry if you did that. It may appear to add operating interest, but in reality it only adds a very unrealistic headache! That industry looks as though it could hold at least 4 cars - each of which would need to be spotted at a specific door or location - and the tail track appears to only hold an engine and one car. Imagine the ridiculous moves you'd have to make in order to get your cars pulled and placed.

I see this sort of thing in model railroad plans all the time and as a former railroader, can tell you would would never find this situation on a real railroad. In the very rare cases where a switchback type spur occurs, you'd have more than enough room to pull everything from the industry. I suggest you read this article on Byron Henderson's web site which explains why you wouldn't want to do this [http://www.layoutvision.com/id16.html].

Changing this to simply having a curved turnout lead to the industry, would also eliminate the need for the runaround track on the extension.

Just my thoughts - as I said, this is a nice plan with plenty of prototypical operating potential. Go for it!!!
Ed