About

Introduction

The openSignalBox Project is a suite of software and hardware designs currently in development which will drive authentic simulations of railway signalling for different applications. It is a free and open source effort and is intended to inspire a community of users and developers to contribute and improve the project. By contributing to a common simulator, we open the possibility of connecting different signalboxes together, both physical (in a preserved box) and virtual (on a computer).

The modular nature of the software means that it can cater for a variety of applications, not only supporting full signalbox simulations. These include, for example:

• Linking two restored block instruments on two mantle pieces far away from each other over the internet, accurately repeating bell codes and block indicators using small single board computers (e.g. Raspberry Pi Zero) and an interface board.
• Providing virtual interlocking between a physical or virtual lever frame and points and signals on a model railway control bus.
• Simulating route-relay interlocking for panel or IECC interfaces.
• Full signalbox simulator for any size of lever frame, including fringing to virtual lever frames across the internet for joint simulation sessions. Options for spatial sound of trains passing, physical rumbling of the floorboards or frame, and 3D simulation of nearby locations (e.g. level crossing CCTV). Connection to live train locations and timetables for signalboxes facing existing railway lines.

More details can be found on the simulator framework page.

Roadmap

• Design and test of hardware configuration for initial users. ✔️
• Development and test of hardware testing code. ✔️
• Production of Bell Interface Board to support multichannel high-speed tapping. ✔️
• Development of microservice framework. Mostly complete. ⌛
• Alpha testing with basic versions of fundamental modules on selected physical signal boxes. Winter 2024. ⌛
• Initial public release with basic versions of fundamental modules. Spring 2025. ⌛

Support

It is intended that once established, the openSignalBox community will self-support to an extent, but until then a small team of experts will be available to provide support on an ad-hoc basis. This support will be at the discretion of the available experts and they are free to charge for their work as they see fit (typically depending on the nature of the support and the person/entity requesting it - e.g. charity, individual or business). The source code for new modules written as a result of support will normally be required to be submitted to the openSignalBox project for others to use, but this requirement can be waived in special circumstances if it would reveal interfaces to sensitive IP.

Typical support requests might be:

• A new code module to interface to your custom software.
• Support for a new protocol, e.g. Loconet for model railways.
• Installation and commissioning of a full hardware interface and PC system for a preserved signal box or museum.
• Development of new hardware to interface with a custom piece of signalling equipment (e.g SSI modules).

It is important to note that the open source nature of the project means that users are never forced to pay for support and can source it from wherever they wish, including general software developers as the code follows standard practices.

Licensing

openSignalBox will always remain free and open source, so please check the license details for each component to ensure you are compliant. If no license is specified, code authored by the project (openSignalBox) is licensed by the GNU AGPL version 3 and hardware by the CERN-OHL-W version 2.

The designs are free to be used for commercial purposes, but as the licenses are reciprocal this means any modifications or improvements to the source must be made available for others to access free of charge. In addition, some components of openSignalBox (the more fundamental ones) will require you to include the phrase “powered by openSignalBox” in a user visible location. This requirement is detailed in the relevant components.

Due to the modular nature of the software, it is possible for users to create their own modules under a different license (or none at all), but we encourage copyleft licenses where possible and if you want the module to be hosted on the main repository then you’ll need to use a compatible license. Please get in touch for details or wait for more specific information to be given here when the software is released.

Team

The openSignalBox project was started by @elstanto (Laurence Stant), and features a growing team of dedicated volunteers who are working towards an initial release in 2025. If you would like to get involved with the project, either as a developer or a future user, please contact us at info@opensignalbox.org.