When work is taking place on or near an operational railway, giving track workers timely warning of an approaching train is a critical part of the wider safe system of work.
Track warning systems are designed to provide workers with audible and/or visual warnings, giving them time to respond and move to a designated position of safety.
There isn’t one warning system that suits every application. Different systems are designed around different operating requirements, site conditions and methods of working.
At RSP, we design and manufacture a range of track warning system equipment, including Automatic Track Warning Systems (ATWS), Semi-Automatic Track Warning Systems (SATWS), Train Approaching Warning Systems (TAWS), Signal Controlled Warning Systems (SCWS), Lookout Operated Warning Systems (LOOWS) and associated warning equipment such as Yodalarms.
What is a track warning system?
A track warning system detects or receives information about an approaching train and provides a warning to people working on or near the track.
Depending on the system, this warning can be generated automatically, controlled manually or initiated through signalling information.
The aim is straightforward: provide an effective warning that allows track workers to take the appropriate action within the available warning time.
Track warning systems form part of a wider safe system of work. The equipment, its configuration and the way it is operated all need to be appropriate for the particular application.
Types of track warning systems
There are several types of track warning systems used across the railway. While they all have the same overall purpose of warning people of approaching trains, the way they detect, receive and communicate that warning differs.
Automatic Track Warning System (ATWS)
An Automatic Track Warning System (ATWS) provides an automated warning when an approaching train is detected.
The system is designed to remove the need for someone to manually initiate the warning when a train approaches, providing an automatic method of alerting track workers.
ATWS can incorporate train detection equipment, control equipment and audible and/or visual warning devices.
Read more: What is an Automatic Track Warning System (ATWS)?
Semi-Automatic Track Warning System (SATWS)
A Semi-Automatic Track Warning System (SATWS) combines automatic train detection with an element of manual control.
The system detects an approaching train, while the warning process can include a controlled action by the system operator.
This provides a different approach to a fully automatic warning system and can be used where the particular application requires it.
Read more: What is a Semi-Automatic Track Warning System (SATWS)?
Train Approaching Warning System (TAWS)
A Train Approaching Warning System (TAWS) provides a warning to track workers when a train is approaching the worksite.
The system uses information about the approaching train to initiate a warning, helping workers recognise that they need to respond to the warning and move to a position of safety.
Read more: What is a Train Approaching Warning System (TAWS)?
Signal Controlled Warning System (SCWS)
A Signal Controlled Warning System (SCWS) uses information from the railway signalling system to control the warning provided to track workers.
Rather than relying solely on local train detection, the warning system is connected to relevant signalling information.
This allows the warning provided to workers to be linked to the status of the railway signalling system.
Read more: What is a Signal Controlled Warning System (SCWS)?
Lookout Operated Warning System (LOOWS)
A Lookout Operated Warning System (LOOWS) is operated by a lookout responsible for monitoring the approach of trains and initiating the warning.
The system can provide an audible warning to workers when the lookout identifies an approaching train.
LOOWS therefore combines the role of the lookout with warning equipment to alert people working on the railway.
Read more: What is a Lookout Operated Warning System (LOOWS)?
Yodalarms and audible warnings
Audible warning equipment plays an important role in track warning systems.
Yodalarms are used to provide an audible warning to track workers. They can form part of a wider warning system, providing a clear warning signal when the system is activated.
For workers on or near the track, an audible warning needs to be clear and noticeable in the working environment.
Yodalarms can therefore be an important part of the warning infrastructure used alongside the relevant track warning system.
Read more: What is a Yodalarm and how is it used in track warning systems?
How do track warning systems keep people safe?
Track warning systems are one part of the wider arrangements used to protect people working on or near the railway.
Their role is to provide a warning of an approaching train, giving workers the opportunity to respond and move to a designated position of safety.
The type of system used, how it is configured and how it is operated will depend on the specific application.
Warning time is also an important consideration. Workers need enough time to recognise the warning, stop what they are doing and reach a position of safety before the train arrives.
This is why selecting and configuring the appropriate warning system is an important part of planning railway works.
Track warning system components
A warning system is more than just the equipment that produces the audible warning.
Depending on the system and application, track warning infrastructure can include:
- Control system housings
- Equipment cubicles
- Disconnection boxes
- Mounting posts
- Audible warning devices
- Other associated trackside equipment
The equipment needs to work together as part of the overall system.
At RSP, we design and manufacture equipment for track warning systems, including the associated cubicles, housings, disconnection boxes and mounting infrastructure.
Choosing the right track warning system
The right warning system depends on the specific requirements of the railway application.
Factors such as the method of working, site conditions, train movements, warning time and how the system needs to interact with other railway equipment all need to be considered.
Understanding the differences between ATWS, SATWS, TAWS, SCWS and LOOWS is therefore an important starting point when considering a track warning system.
There is no substitute for understanding the requirements of the particular worksite and selecting a system that is appropriate for those requirements.
RSP track warning systems
RSP designs and manufactures a range of equipment for track warning applications.
Our track warning system range includes:
- ATWS
- SATWS
- TAWS
- SCWS
- LOOWS
- Yodalarms
- Control system housings and equipment cubicles
- Disconnection boxes
- Mounting posts and associated warning infrastructure
From equipment design and manufacture through to factory acceptance testing, our focus is on providing reliable equipment that can be integrated into the requirements of the particular railway application.
[Explore RSP’s Track Warning Systems]
Explore our Track Safety & Warning Systems Knowledge Hub
Want to understand more about how the different systems work?
Explore our guides covering ATWS, SATWS, TAWS, SCWS, LOOWS and Yodalarm systems, as well as the components and considerations involved in track warning applications.
Whether you’re specifying equipment, working on a railway project or simply need to understand the differences between the available systems, our Knowledge Hub is designed to provide straightforward technical information without the jargon.