as the topic says it will be 00 gauge and for shunting, but also allow for running stuff through, I am planning on having fiddle yards at both ends with a scenic section in the middle which is approximately 54 inches by 16 (maybe 17 cant stretch to 18 sadly) inches.
Here is a rough idea of what I am talking about

I am thinking that single car units like 128 and 121 can pass through, and maybe even get a coach or two shunted past just operational interest, other than that just an 03 shunting goods round ready for a 25 to come and take it away, that's actually all the locos I have and want to have at this time, all BR Blue. like a built up area behind it, very industrial, maybe think areas of manchester where industry would be right up against the tracks, one would have a wagon loaded and then be moved about.
Please let me know of ideas and ways to improve it, I am literally not great at designing plans, I may have overdone it with the amount in the space I have.
It would all be done with code 75 peco track.
Thanks in advance