Are you mad? Elmer Lane 1 - Genesis

DB says:

When the idea of Fremo120 was floated, operational practicalities at a public exhibition would mean you either need to: 

1. Assemble a loopty-loop layout. This is easier to operate, but challenging given the freeform nature and sizes of the modules. Its not impossible with advance planning and some on-the-day bespoke construction of a basic-plain-join-module using a lump of wood, a saw, and some flex track. Rhys and I did this at our first Dynamic Duo NZ120 exhibition appearance, which used temporary flex laid on a 2x2 piece of MDF (for the end horseshoe curve) and a long stick of 4x2 for the track behind my Otago Central bit. A few screws and a staple gun, and Bob was our Uncle.
2. Have balloon loops at the terminus of each 'end' or 'branch' that you don't want to have to 'run around' trains at and take them out backwards (most of my wagons are different weights anyway so I'm not sure whether my coal train would run too well reversed). While these balloons are an operational necessity on layouts, the ones I've seen at exhibitions have always seemed a bit 'forced' as balloon loops are not common in the real world, and thus are obviously a challenge to scenic. 

So a couple of balloons probably need to be made for a Fremo120 exhibition layout. But what to put in the middle of one? 

While perusing the Kato Swiss RhB offerings on the website of my Japanese purveyor of such addictive substances, I saw that Kato make a clever little motorised turntable (I had no idea). A lightbulb went off. What about modelling the Elmer Lane turntable and roundhouse? With the 'mainline' to Hokitika running right in front (just like the real thing) circling around the roundhouse (not at all like the real thing! But potentially hideable with trees, or a highway overpass, or something.)  And then the track comes back around the back of the depot where the old workshops / yard is. 

Elmer Lane loco depot in 1969 just after the end of steam (Retrolens)

Elmer Lane loco depot  in 1988 after the roundhouse was surgically reduced in the 1970s. (Retrolens) 

Fortunately, the pricey Kato turntable was out of stock, but upon my next order, it wasn't, and one fell into my shopping cart. This was about nine months ago now, as there have been plenty of other things to worry about in the interim. 

During those months, a bit of pseudo-planning occurred in Photoshop. Of course this is very guesstimental, because in the real world, tracks and things are very different sizes and geometries than when drawn on paper, PowerPoint, Photoshop, or even the track planing software I've tried, all of which are coated in a sheen of optimism as to how much can fit in a given space. But here you go (my doodle used the Kato diagram, overlaid with the retrolens aerial pic, and with some tracks drawn over that) :

(Flipped to make it easier to compare to the prototype aerials above)

Here is the the Kato turntable by the way:

Unlike many N scale turntable offerings, it does have a shallow pit (yay), however the bridge girders are 'upside down' compared to NZ turntables (boo), but surely the sides can be flipped to look a little better? Its modelled on an electric one with a gantry in the middle, but I'm sure that can be removed, and there is a little red operators cabin at one end. The bridge length is a smidge short, as we are 1:120 and Japan is usually 1:150 rather than the usual N 1:160, but its not actually a million miles out. In fact according to my calculations it should fit a scaled down Ja wheelbase. The tracks are radially spaced a little bit wider than Elmer Lane, so there will have to be fewer stalls than the prototype's 18. I reckon about 15 or 16 might be doable to keep the same shape as our roundhouse. 

The really nice thing about it, is that it indexes and locks to the tracks, and has some power routing capabilities too. 

As for Elmer Lane's roundhouse, one of two 'proper' ones that NZ had (three if you count the little three track Lyttelton one), the prototype will house the length of an Ab inside, and that should be doable in NZ120. The workshop extension tracks housed another Ab in length (and even longer than that on one track which had a wheelset drop table, and one assumes from the aerial pic that length was added to each of the three tracks (presumably to house J/Ja locos), but I won't have that much room available.