A few months ago I headed out to Epping to see something a little different – a new High Capacity Metro Train testing out the even newer High Capacity Signalling system.
So what is High Capacity Signalling anyway?
‘High Capacity Signalling‘ is a new technology that is about to be rolled out to Melbourne’s rail network as part of the upcoming Metro Tunnel.
Next-generation High Capacity Signalling technology will be installed on the Metro Tunnel and on the Cranbourne, Pakenham and Sunbury lines to deliver more trains, more often during peak times. The technology will also be rolled out on the new Melbourne Airport Rail when it is built.
High Capacity Signalling is a new hi-tech ‘moving block’ signalling system that enables trains to automatically adjust their speed to maintain a safe distance from the train in front.
This replaces the current conventional ‘fixed block’ system, which uses coloured signals to indicate when it is safe for a train to proceed.
High Capacity Signalling allows trains to run closer together and delivers more trains, more often.
With this nifty diagram indicating how it works.
Initially the scope of the High Capacity Signalling rollout was between Dandenong and Watergardens stations via the Metro Tunnel (54 km), but it appears this has been cut back – HCS equipment was only been installed between Westall and West Footscray stations (30 km).
High Capacity Signalling equipment
There isn’t much visible trackside to show that High Capacity Signalling has been installed. The first are new signal equipment rooms, used to house all of the new gear.
The second are ‘Trackside Radio Assemblies’.
Just a fancy name for 2.4 Ghz radio antennas pointed along the railway tracks, to transmit signals between trains and the signal control centres.
Some are located on new posts, others have been added to existing signal masts.
Making them hard to spot.
And finally – ‘norming points’.
Located between the running rails, they are passive RFID tags that provides precise location data to the HCS system onboard a train, so they know exactly where along the platform they are.
And testing it
The High Capacity Signalling system chosen for use in Melbourne is a Bombardier’s Cityflo 650 communications-based train control (CBTC) system – an off-the-shelf product used elsewhere, but it needs to be integrated with the existing signalling systems and trains used in Melbourne.
For this reason, a multi-stage test program has been conceived.
First up – February 2020 was system integrations testing in the lab.
From a Rail Projects Victoria video
Then off to the ‘Initial Test Site’ on the Mernda line between Epping and South Morang stations in June 2020.
From a Rail Projects Victoria video
Using a single X’Trapolis train retrofitted with High Capacity Signalling equipment.
From a Rail Projects Victoria video
And a suite of test equipment on board.
From a Rail Projects Victoria video
March 2021 saw the degree of difficulty increased – introducing a second X’Trapolis train fitted with High Capacity Signalling into the mix.
From a Rail Projects Victoria video
The two trains taking to each other, to ensure they kept a safe distance from each other.
From a Rail Projects Victoria video
Including out on the mainline.
From a Rail Projects Victoria video
And with the technology now proven, in August 2021 a HCS fitted High Capacity Metro Train was despatched to the test site to see how it performed.
Let’s pay a visit
After Melbourne’s Covid-19 curfew was finally lifted in October 2021, I took the opportunity to head over to Epping to see the High Capacity Signalling testing for myself.
HCMT set 18 was allocated to testing that night, departing Epping Workshops once the Mernda line had been replaced by buses.
Dust covers protected the seats.
The equipment cabinets were hanging open.
And the testing staff had set up desks in the saloon to hold their laptop computers and other test equipment.
A STOP board was erected over the tracks back towards the city, giving the testing staff free reign over the the line.
With a flagman standing guard.
The first task was a ‘sweep’ of the line as far as South Morang.
Followed by a second sweep move back to Epping – proving that the line was clear of all other trains.
It was now time to throw the changeover switch, deactivating the existing fixed-block signalling system, and activating the new High Capacity Signalling system equipment.
From a Rail Projects Victoria video
Once the system detected a HCS fitted train was in position at Epping, the lineside signal extinguished, indicating to the driver they could proceed according to the cab signalling equipment.
Heading along the line to the ‘Virtual Station’.
One end marked by a conventional lineside signal, the other by a CBTC ‘Block Marker’ sign.
And configured in the signalling system as a ‘real’ station, so that stopping and starting of trains at stations could be tested.
From a Rail Projects Victoria video
Once the test train stopped at ‘Virtual Station’, the signal extinguished, indicating that it could proceed again.
And by that point it was past midnight, and I’d seen all the testing there was to see, so called it a night.
So why X’Trapolis trains and the Mernda line?
High Capacity Signalling is intended for the new HCMT fleet of trains that use the Metro Tunnel – so why test it on completely different trains on a different line?
Back in 2012 High Capacity Signalling was a standalone project, and the Sandringham line was favoured as the test site – a situation reiterated in 2015.
The reason for the change – a desire to get it done fast, so in 2017 what was a $131 million signalling trial rolled into the Metro Tunnel Rail Systems Alliance contract – the Metro Tunnel website explains their choice.
A range of locations were considered for the testing site. The Mernda line was chosen because it does not share tracks with regional or freight services and has fewer timetabled night services than other rail lines.
But what about the HCS equipment installed for the testing along the Mernda line?
- 60,000m of cable
- 13 Wi-Fi masts
- 29 axle counters
- 56 norming points
It’s all going to go.
At the end of testing, all of the infrastructure installed by the Metro Tunnel Project for High Capacity Signalling testing will be removed from the Mernda line.
So we’ve gone from a trial that would be put into production, to a prototype that is going to be thrown away.
As for the decision for HCS testing to be completed using X’Trapolis trains – the first High Capacity Metro Trains weren’t even ready yet! The first HCMT didn’t leave the Pakenham East depot under it’s own power until November 2019, and they weren’t cleared to carry passengers until December 2020.
And not to mention testing a new technology on a ‘known’ train on the Melbourne rail network eliminates one possible variable in the test program.
Sources
- High Capacity Signalling testing to begin – Victorian Government, 6 Aug 2019
- High-capacity signalling takes metro tunnel to new heights – Infrastructure Magazine, 26 May 2021
- Advanced signalling tested on Melbourne HCMT – Rail Express, 5 August 2021
- High Capacity Signalling Initial Test Site – Metro Tunnel
Footnote: a timeline of testing on the Mernda line
Thank you for your patience as we prepare the Mernda line for testing of new High Capacity Signalling.
Buses will replace trains from Thornbury to Mernda from 3-15 December.
Further info: https://t.co/EyZpNb4bzZ
👉 Plan your journey at https://t.co/aRUf2lAatg pic.twitter.com/BmntERBwPV
— Metro Tunnel (@metrotunnelvic) December 1, 2019
The Metro Tunnel is using specially fitted out X’Trapolis test trains on the Mernda line to test Melbourne’s next-generation High Capacity Signalling. pic.twitter.com/KMGQygb2i1
— Metro Tunnel (@metrotunnelvic) June 22, 2020
Testing of next-generation High Capacity Signalling for the Metro Tunnel is underway along the Mernda line between Epping and South Morang. Works will include using trains at night, when services are not normally running. pic.twitter.com/b5ZkBGWj3t
— Metro Tunnel (@metrotunnelvic) September 2, 2020
We are revolutionising Melbourne’s train network by moving to High Capacity Signalling (HCS). It will mean more trains, more often.
We are now testing HCS for the first time ever in Melbourne, resulting in minor disruptions to the Mernda line. More info: https://t.co/84iYkDRDGD pic.twitter.com/KK2FllnYgr— Metro Tunnel (@metrotunnelvic) September 18, 2020
We're testing Melbourne’s new High Capacity Signalling technology on multiple trains for the first time. This technology will enable our more modern trains to talk to each other and keep a safe distance. It means we’re a step closer to turn-up-and-go train services in Melbourne. pic.twitter.com/CPazRpbUlJ
— Metro Tunnel (@metrotunnelvic) March 24, 2021
Meet the Metro Trains Melbourne drivers who are testing the next-generation High Capacity Signalling (HCS) technology. This team is pivotal in revolutionising the metropolitan rail network, towards a "turn-up-and-go" service. pic.twitter.com/4pqlfFNrsz
— Metro Tunnel (@metrotunnelvic) April 1, 2021
Put simply, moving block signalling is similar to the way cars move on roads, except that its controlled by computers rather than just relying on drivers. It’s equivalent to maintaining a “safe driving distance” between moving vehicles on a road.
Here is a New York City Subway video on how moving block signalling works.
Hi. What do you think that it means for future timetabling if HCS is only being installed between Westall and West Footscray. Will they run additional shuttles between these stations, or will HCS allow the Pakenham trains to run express through a few stations like Murrumbeena, Hughesdale and Carnegie, or will it allow for both of these things. Maybe 6 Pakenham, 6 Cranbourne, 3 shuttles, 3 VLine to start off with.
I suspect they’ll do something similar to what they do now, but with just more trains – shortworkings from Westall to West Footscray, with services beyond those points being limited to the headways already possible with fixed block signalling.
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