I wanted to take advantage of the size of N gauge and be able to run near to scale length trains in a busy mainline setting while also allowing for the appearance of a branchline. I struck on the idea of a double track figure of eight with junctions set to allow it to run as a regular circuit as well. This would allow me to design in the branch junction which in reality would just be the return loop on the figure eight.
The basic trackplan I settled on.
The layout was designed to sit on two baseboards, the main board being 7'6" and consisting of the high level station and low level goods yard linked by a severe 1:35 gradient on a 11.5 inch radius 180 degree curve. The second board would be the middle level loop, mostly hidden by a town scene with only the front running lines visible to give me the beginning my branch line illusion with enough room for an engine shed/turntable if I want it. The gradients between high and low levels on this board are less severe; 1:40 on 24" radius reverse curves down to the low level on the visible section and 1:50 on 11.5" curves up to the high level in the hidden section (greyed out on the plan).
High and Low-level overview
The site of the engine shed in Mid-level.
The station is actually a mirror image of a plan of Llandudno Junction, condensed a bit to fit the space, and altered a lot to allow me to use Peco Finescale without having to cut anything about too severely...so not really Llandudno anymore, but thats the basis hehe
The pointwork, slips and crossings at the station throat is an absolute nightmare to wire. Even me being a Telecomms engineer doesn't help matters! It's still not complete, only the through lines work!
A wiring nightmare! It will be nice to see it work fully...one day
The biggest concern I had when the boards were constructed and main running lines laid was how would lengthy freight trains cope with the horrendous gradient and tight curve. I couldn't even test it until the second board was built and track laid, so all through the construction I had a big weight on my mind as to whether it would all prove to be a waste of time. Either the trains would derail on the tight bend under the weight of gravity pulling them back, or the engines wouldn't be capable of hauling what I wanted up the long 1:35 stretch. After a week of long nights I had the boards built and enough track laid to test the "big one" using a Black 5 and all of the coaches I owned at the time. I must say I was impressed when she crested the gradient with 8 mark 1's in tow with little trouble, so I started adding wagons until the engine started to slip a bit. I've since found that the comfortable limit for a Farish Black 5 is 10 coaches. Freight trains are a different matter all together! I didn't have enough wagons to test it properly for some time...
Stanier 8F number 48045 negotiates the 1:40 gradient and junctions between Mid-level and Low-level with a lengthy coal train.
The 8F reaches High-level at a crawl, slipping slightly towards the end, it's train of 28 plus brake van fully on the 1:35 gradient. This is about the limit of a single Farish engines capability on the line.
And lastly why Canon Street for a name? Well, I do also have a soft spot for amateur photography and when I was struggling for a name, I noticed a lens box I'd left on the station area...
I look forward to seeing more 
Ratio brick sheets topped with plastruct which will eventually be faced with strips of Ratio stone sheet. Between the brick parapets I'll run phone wire wrapped around track pins to look like metal railings...I hope.
