Worker Protection System

Aldridge has released a portable Worker Protection System which automatically alerts track workers of an approaching train.

The alarm comprises three 110dB sirens and three strobe lights mounted on portable lightweight tripods. The master warning controller and alarm is located centrally in a work zone and only takes a couple of minutes to install and commission. 

 Train detection is achieved with a portable wheel flange sensor connected to a slave unit which utilises an encrypted radio transmitter that communicates with the controller/alarm unit.

The wheel flange sensors and slave units are installed at either end of the work zone at a location which offers strike-in and strike-out protection for workers up to 1000m away. Up to two tracks can be protected with a WPS slave strike-in/out unit and wheel flange sensor combination.  

The wheel flange sensor can be installed in less than five minutes per track. When an approaching train passes over the strike-in/out wheel flange sensor, the controller and its alarms will alert workers at the work site.

When the train departs the protection zone by passing over the second wheel flange sensor and slave unit at the strike-in/out point, the system automatically resets. This basic system comprising two slave/sensors and one master warning controller and alarm is ideal for typical work sites and offers sufficient warning for the track crew to vacate the track from an approaching train.

For larger worksites it is possible to have up to six slave units with their integrated alarms, scattered around the site. 

And for even bigger sites it is possible to extend the 1000m range with ‘repeaters’. If an extended warning period is required (greater than 35 seconds at a track speed of 80km/h), a tripod mounted repeater can be installed between the controller/alarm and the strike-in units, doubling the warning time of the train approaching.

An optional solar panel kit can be used to maintain the batteries indefinitely. The entire system is supplied in ruggedised cases, battery-operated, rechargeable, portable, compact, and lightweight. 

Personal Alert Devices

It is also possible to supplement this system with rechargeable Personal Alert Devices (PADs) which are worn on workers’ arms, that emit a loud audible warning and strong vibration to alert the worker of an approaching train even in the most unforgiving environments.

Up to 200 PADs can be activated from the PAD controller, which is connected to the controller/alarm unit. The PAD system has a typical operating range of 800m from the unit, which is located centrally in the protection zone. 

Redundancy and fail-safe operation

The Aldridge-ITS WPS utilises the WLX controller which has been specifically designed for safety applications. Safety features include redundant power supplies, radios, warning elements, wheel sensors, and processors for fail-safe operation. The warning system can be operated from any WPS unit. 

The WPS system counts the train wheels entering and exiting the protection zone and detects the direction of rail traffic allowing track-mounted maintenance vehicles to exit the protection zone without activating the warning system.  

Cloud-based monitoring  

The WPS can optionally be configured by an authorised user with the WLX system manager, a PC application running on a laptop.

It’s also possible for an authorised user to monitor the system via the WLX server web-based application running in the cloud.

From the WLX server, users can generate reports of activations over any monitored period, train statistics including speed and direction, length, wheel count and system status information.

The application requires an internet connection from the WPS site (4G/5G or Satellite) while the WLX system manager application requires a PC connection to the master warning controller on site. 

Watch the WPS in action below –