let there be wires- Chard junction signal panel

Published: 08/07/2026

Credit: RH

As many of you will already know, the Chard Junction signal panel at Yeovil Railway Centre has been built up over time to demonstrate a range of different signalling control systems, all working side by side on the same layout. Visitors can already see relay interlocking in action alongside a computer-based system built around JMRI and Arduino, giving a real feel for how signalling technology has moved on over the decades.

The latest project to join the panel is the addition of a PLC (Programmable Logic Controller) to control part of the line. Rather than replacing what's already there, this is being added as a further string to the panel's bow, giving visitors and volunteers alike the chance to compare a third distinct approach to controlling points and signals - one that's widely used in modern industrial and railway applications.

Work on the PLC section is still very much in progress, with our volunteers currently getting to grips with the programming and wiring involved. As with everything on the panel, it's being developed steadily and thoroughly, so that once it's up and running it'll sit comfortably alongside the relay and JMRI/Arduino systems as another working example of how a signalling control system can be built.

We'll keep you posted as the project develops - there's always something new happening behind the scenes at Chard Junction, and this latest addition is a great example of the variety on offer for anyone interested in how signalling really works.

More updates to follow as the PLC work progresses.