Phase 3

Phase 3 has now been built. The following criteria were applied to the design:

• The extension had to go across the bottom of the garden, turn behind the summer house, then go back up towards the house. It must not cross the garden anywhere else or interfere with how the garden was used at the time. It was not required to reconnect with the existing layout.
• Because of the location of the garden shed, the track had to go through it. Alternatively the shed should be demolished, but it was and still is rather useful, especially for putting the controls in.
• At the end of the extension there should be a straight four- or maybe six-road fiddle-yard, with all the roads coming together in a single track, to enable locomotives to run round their trains, etc. The shortest track in this fiddle-yard should be at least the same length as the shortest track in Pant-y-fedwen Sidings (i.e. 26 feet). Each track in the fiddle-yard should be divided into two electrical sections.
• The fiddle-yard should be quite high, to enable the plants underneath to grow and to allow easy access by ducking under it (nobody is getting any younger!).

This gave rise to a problem to do with the slope of the garden. Given the height of the existing part of the layout and the slope of the garden, if the track were to stay level, it would finish about 2 feet 6 inches above the ground. It would be better for the layout to be higher than this, preferably 4 feet or more. There were several options that could be employed to attain this height:

1. Build at least 150 feet at 1 in 100 or 110 feet at 1 in 75.
2. Build most of the extension level, but put in a helix after the layout passed the garden shed. The approximate circumference of a 4-foot radius circle is (conveniently) 25 feet, so three loops at 1 in 75 should raise the layout by a foot, and four loops together with some extra track at the same gradient would raise the layout sufficiently to achieve the target 4 foot height.
3. As No. 2 but put the helix before the garden shed.

I eventually decided on a combination of options 1 and 2 and to make the helix oval (or rectangular) rather than circular. The track climbs away from the junction at somewhere between 1 in 100 and 1 in 200, until it comes to the garden shed, where it levels and stays level until it starts on the helix. This rises at 16mm. for every 4 feet of straight track (1 in 76¼), and 12mm. for every 45 degrees of turn (1 in 80 at 48-inch radius, 1 in 76½ at 46-inch radius).

This gave an out-and-back line with a total length of something like 1000 feet. At the same time the existing continuous runs are in use, which gives plenty of scope for interesting running.

Click on any of the following pictures to see a larger version.

This picture shows the trackbase coming from behind the summer house. The bricks are there to weigh down the roofing felt, which has been stuck to the wooden trackbase with PVA, until the glue has set.

This picture shows the trackbase coming out of the garden shed and into the helix. So far the trackbase has been constructed three-quarters of the way around the first loop of the helix, and it has not yet been covered with roofing felt.

This picture shows the completed helix. For more information and more pictures, go to the Helix page.