David Sexton

From the ground up

How a ground-based warning system improved outcomes for safety and the environment.

Traditionally, the sounding of a loud train horn has been an important part of moving trains safely around railway stabling yards and hubs. These sounds have played a crucial role in alerting workers and others to be careful as a large piece of machinery is about to be moving in their direction.

But the honking of a train horn can be unpopular with nearby residents and can be a significant environmental concern also. This conundrum has become increasingly apparent with more people living close to railway lines and stations.

It was these environmental concerns that led to a search for a solution that would be safe and minimise excess noise and disruption to surrounding residents. This is where the innovative Ground Based Warning Systems (GBWS) come into the picture. Two companies saw this opportunity, tm stagetec systems (TMS), a business focused on professional audio and visual equipment, and ITech Corporation, an integration and systems specialist. 

These businesses have worked to produce a ground-based warning system (GBWS) for rail hubs. The GBWS uses warning lights and directionally steered sound to alert all workers that a train is being moved.

General manager for TMS, Mark Lownds, took up the story. “There have been significant environmental concerns with the noise associated with safely moving trains around train yards and hubs,” Lownds told Rail Express. “Clearly something had to be done.”

ITech Corporation engineering director Joe Dwyer said they had worked on similar rail projects before, notably in south-west Sydney. The latest version with TMS was refined with a particular view towards projects in NSW. “In recent years we’ve engineered control systems for rail applications and that is how we came to work with TMS,” Dwyer said.

“We initially did a ground-based warning system about six years ago in the south-west of Sydney that was planned for future housing development.”

More recently, they worked on projects where there was a significant environmental requirement. “People had their nice, quiet country existence and weren’t happy about honking a loud horn in the middle of that,” Dwyer said. 

“We wanted some sort of warning system but we didn’t want the noise pollution outside of the stabling yards.

“Trains are parked in hubs while they are waiting to go into service but in such locations, with the new projects that we have done in recent years, you typically have a number of trains in standing rows. Moving them safely and efficiently is key.”

How does it all work?

The TMS system programmatically controls noise by way of Network Amplifier Modules. Each NAM has four 12-watt RMS class D amplifier channels, an Ethernet switch and built in DSP.

Each amplifier also has an individual Dante input allowing for simple zoning and future changes. Dante IP protocol is used in this system, developed by an Australian company called Audinate. This GBWS design has purposefully used Australian developed and manufactured technologies.

“We designed the TMS system to fulfil the need for a warning system; and also addressed the need for a PA system in the yard,” Dwyer said.

“We would effectively double up PA announcements by also using it as a warning system.”

Lownds said they worked with Dwyer and his team to ensure the NAMs were compatible.

“We also built some additional monitoring of the NAM unit itself and then gave physical status back to the IPEX ground-based warning system,” he said.

“It was not just telling the NAMs what to do but giving the NAMs feedback,” he said.

“It was also giving the NAMs feedback into the system and confirming there were no faults and providing a really robust system that was capable of being part of this GBWS.”

Lownds said the reaction was positive.

“The residents surrounding the hubs have been taken into consideration and environmental studies have been conducted in order to determine the appropriate audio levels,” he said.

Significant progress

Dwyer says the system designed by TMS and ITech represented significant progress in handling noise around rail hubs. 

“When we were going over the design of that – previously you could control the noise but it was a lot more ‘agricultural’,” he said.

“Within the shed there was a slightly different requirement and generating warning sounds within the sheds. Overall, it was about a system with greater flexibility and more control. “

Lownds said that in the past if one required two independent systems then it would involve separate amplifiers and speakers, and one would be paying for hardware and the extra labour. 

“With this solution, we were able to share the system and still have all the priorities go to the GBWS, over and above the paging and announcement system,” he said. “Fibre is used for all interconnections so only power and fibre connections are required.”

The TMS business has been in operation for a decade and Lownds said they were looking forward to an exciting next decade ahead.

“Some of our recent projects in rail show how much we can do and skill level involved,” he said. “As an audio and visual technology specialist, we believe we have a tremendous amount to contribute in the world of rail.”