Case Study:

Comeng Life Extension – Metro Trains Melbourne

We are proud to have worked closely with Metro Trains Melbourne to locally develop a suite of products to enhance the Comeng train safety and experience for both passengers and drivers.


Intelligent Marker Light Design & Manufacture

The Need

As part of the Comeng life extension project, it was identified that the original incandescent marker light was difficult to see in high ambient light conditions and was found to be well below the Australian and international standards defined for railway marker light lux levels. It was also identified that there was an additional operational risk as the lights were manually controlled, and could be left in the wrong state during operation due to human error. This posed a major safety concern for the operator.

Due to being incandescent globes, the reliability and lifetime in the rail environment was also not ideal requiring frequent replacement of globes.

Our Solution

To address the needs of our customer, an intelligent, custom, retrofit LED marker light was designed in house and locally manufactured.

Key Features
  • Dual Red/White LED indication within the same envelope and using the same fixing points,
  • FPGA controlled board to provide intelligent control, monitoring and brightness adjustment,
  • Automatic control of colour/direction based on train status,
  • Status indication on rear of marker light and on driver’s desk for drivers and maintainers,
  • Fault detection with driver feedback including failed LED detection, over-voltage, over-current and over-temperature monitoring,
  • Multiple redundant parallel LED strings ensuring minimal loss of lux in the event of an open circuit LED chip,
  • Retrofit design for existing envelope and mounting,
  • Brightness level adjustments and careful selection of LED angles to ensure suitable projection of beam,
  • Automatic emergency state detection (detects unintentional loss of power) and functionality (timed operation as per railway standards),
  • Automatic stabling mode with timer feedback for drivers,
  • Certified to EN50155 (including EN61373, EN50121 and EN61000).

The outcome has proven to be a highly successful design with a reliable unit that has met all the desired specifications. Over 350 cab sets were produced in our production facility inline with the customer’s project schedule and quality expectations.

Drivers Fault Panel & Desk Upgrade

The Need
  • Following the design of the LED marker light, the customer had a need to upgrade the fault panel to include additional controls, and fault/status indication from the marker lights,
  • The driver’s fault indication panel had frequently failing filament bulbs that could prevent the driver from being alerted to a train fault.
  • The brightness of the globes were causing visibility issues for drivers at night.
  • There was no simple method to add indicators or change the way a fault is displayed.
  • The customer wanted to explore the option of having multiple colours displayed from one indicator to provide further information to the drivers.
  • Existing Westinghouse analogue brake/ammeter gauge bulbs were not effective at illuminating the gauges at night.

Aesthetically the driver’s desk panels were aged and typically in poor condition.

Our Solution

Using a similar design philosophy as the marker light, TTM designed an intelligent fault panel to provide reliability and flexibility for the life of the fleet.

Key Features
  • Single programmable PCB board back mounted to the panel with surface mounted RGB LEDs, allowing complete control of colour selection, brightness and behaviour of each indicator.
  • FPGA controller which interfaces all the existing train line inputs and can provide more valuable driver feedback.
  • Fault panel interfaces with the marker light to provide driver feedback of the marker light status.
  • Retrofit and cost effective LED backlight to suit the analogue Westinghouse brake pressure and traction current gauges.
  • Gauge backlight LED upgrade with driver dimmable function
  • Certified to EN50155 and EN61373

LED Saloon Light Upgrade

TTM partnered with Crous LED to develop an LED saloon light that could handle the challenging electrical environment of the Comeng train.  This required a detailed analysis of an already certified EN50155 design.

Through this analysis, several upgrades were made to the electronic design and ultimately, an extremely robust outcome was achieved.

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