The design was sketched out so that a range of train movements could be planned. The track design is shown below.
A continuous run double track main line runs around the baseboard at varying altitude. Much of the run around the middle of the layout is hidden at low level (deliberately so at the front of the layout so as to make it accessible to humans in case of problems). A fiddle yard is a part of this track loop; the aim is for around 10 lines in total.
two reverse loops are available, they allow trains to change direction from one line to the other and vice versa. They also have a few storage tracks to allow trains to be delayed.
Some of the layout will not be visible:
- Some of the main track loop at the front of the layout will be below ground. This will be accessible to humans easily with some kind of cover.
- Part of the main track loop will run below and behind a major terminus. It will emerge part way along the back wall.
- A tunnel below the terminus will hold a reverse loop and storage tracks. The tunnel is intended to represent the channel Tunnel.
Several locations are included as part of the layout:
| Location | Description |
| Portsmouth Station | A large terminus station with several platforms and some kind of diesel engine shed. Serviced by loco and carriages, DMU/EMU and Eurostar (probably running on batteries due to lack of 3 rail or overhead). This is at a high level , with tracks under it. The whole station will be removable for access. |
| Clanfield Station | A smaller terminus, intended principally for DMU visits. 3 or 4 roads max. High level, but with no tracks underneath. |
| Petersfield Station | Main line junction station: servicing a main line with various traffic and that going to Portsmouth Hilltop. This is at an intermediate level (and may be on a slope) but has no track underneath. |
| Eastleigh Depot | An oil depot; visited by bogie oil wagons. Several roads where trains can be left, then picked up and brought back. At a high level. It is unlikely to have track underneath. However the oil tanks may be a removable feature covering the main track loop at the back. |
| Fiddle Yard | The fiddle yard will have several roads in each direction, and access for adding/removing trains. An interface to allow a railway "extension" is also planned. |
This was enough information to agree the basic concept. There is a more detailed plan, but that used a CAD program once I was sure there would be no (gross) changes.