Keeping within 1st Radius

For some modellers the sight of a 600 mm x 1200 mm x 7 mm sheet of plywood isn't going to do much to excite the senses or go too far towards completing the benchwork in your walk around model railway plans. So when the sheet measured only 596 mm wide x 1208 mm long and I was already wondering how much I could trim the board down to and still keep within 1st Radius curves on my new OO9 layout, its fair to say that this series of posts isn't going to be about building a large model railway...

While my idea isn't to build the smallest layout possible, the space I have available to keep my little model railway on permanent display, is sitting atop a pair of IKEA 700 mm long x 350 mm deep x 800 mm tall EKET display cabinets. These inturn stand beneath the staging shelf portion of my HO Scale shelf layout. And the reason for me to construct this layout using OO9 Scale HOe 9 mm track, is to simply enjoy watching some trains running continual laps of the layout.

The success of any small layout utilizing a loop of track comes down to one thing... being able to accommodate the curvature within the width available. As you can see in the image to the right, to keep the OO9 layout sitting flush with the front of my HO Scale shelf layout, it would need to overhang from the rear of the IKEA display cabinets. With the framework of my shelf layout free-standing 10 mm off the wall behind it, that gave me an availble width of 550 mm to play with.

So, how much room do you really need for a 1st Radius, 228 mm curve in OO9 Scale?

Here is a 1st Radius curve centred between the minimum recommended layout width of 500 mm. (See pencil lines). This doesn't leave any room to accommodate the overhang from your longest carriage and would leave your models running right along the edge of the layout board.

Here is the same 1st Radius curve, only this time centred between a layout width of 550 mm, (see pencil lines). Note how this does accommodate the overhang from the longest carriage while still leaving a 30 mm buffer to the edge of the layout.

I outlined in my book Model Railway Trackside Tips the reasons why it is important to include a minimum 40 mm buffer from the outside of the track to edge of the layout. So being my first time modelling in OO9 Scale, it was a pleasant surprise to discover that the 9 mm HOe gauge track could actually yield a tighter radius (228 mm or 9" inch), than what I would recommend for today's N Scale 9 mm counterpart, (249 mm or 9 3/4" inch).

I find that incredible, given that I am able to model scenery and structures in OO 1:76 Scale, within the confines of what has traditionally been considered N 1:160 Scale track curvature.

The longest carriage that will see action on my OO9 layout, is a PECO 160 mm long Ffestiniog passenger coach. It is actually longer than my largest Double Fairlie steam locomotive. So a 40 mm buffer from the edge of the sleepers on the track to the edge of the layout, still provides a 30 mm gap as the passenger coach swings around the curve. I can live with that.

The next step was to draw the station scene and passing loop on a curve at one end of the layout.

While for this project I could have been happy to have just modelled a small oval of track running around a Christmas Village scene, I went as far as including a short passing loop as part of the station scene at one end of the layout. There are plenty of examples of these rail height island platforms on the Ffestiniog & Welsh Highland Railways, and it simply allows me to park a short train running in a clockwise direction and release a second train running in an anti-clockwise direction. The simple track plan calls only for a 1 x right hand PST405 set track turnout, 1 x left hand PST406 set track turnout, 2 x PST402 1st Radius Double Curve packs, (enough to make a full circle so that I can trace the track plan), while the missing sections will be modelled using 3 lengths of PSL400 Code 80 irregular flextrack.

The station building is the Bachmann Scenecraft Harbour Station Office and Gents building, which is one of three sections they released based on the Ffestiniog's Harbour Station at Porthmadog in Wales. I purchased the ready-made station building, the Ffestiniog passenger coach and both of my sound equipped locomotives along with a book directly online from the Festrail Shop at Harbour Station. It is my way of supporting a Welsh heritage railway from the other side of the world. All profits go towards the operation of the Ffestiniog & Welsh Highland Railways, and their service saw my parcel arrive in Australia within two weeks!

Once again, using the longest carriage I was able to pencil draw the platform clearances from both the centre of the passenger coach (for the inside clearance), and the end of the same coach (for the outside clearance).

With the curved platform, passing loop and station building positioned so that I had optimum viewing angles of the scene, I could then trace around the pencil lines with a fine tipped felt pen, and move onto playing with pencil sketches for the locations of houses, village lanes and rising hills. Not only will this make it easier to see the track plan in future blog posts, but I can use an eraser a thousand times for all my other sketchy ideas, without erasing any of my track plan.

There's no need to trace each sleeper with a felt-tip pen! I'm just doing this so that you can see the track outline better in my future blog posts.

And there you have it. You'll now be able to see my track configuration better across my next updates.

So there you have it. I'm up, up and away and now tasked with making this Christmas scene as interesting a story as possible, all while keeping within 1st Radius curves. 550 mm wide by.... umm, something long. I guess you'll have to tune in next time to find out.

If you like what you read, leave me a comment below. Or better still, click on the blue coffee cup to the right and buy me a coffee... https://www.buymeacoffee.com/phildenmodelrailway

Over the coming weeks I'm going to start transferring some premium model railway pictures over onto that platform as a way of helping put myself through full-time study next year, (it's either that or starting an OnlyFans channel...) So I sure appreciate any support, be it through purchasing one of my books or browsing my eBay fundraiser. Until next time...

See also; Narrowing my modelling projects