Feeds

How two failed capacitors stranded Sydney rail commuters

Stalled by a LAN switch

  • alert
  • submit to reddit

Secure remote control for conventional and virtual desktops

The railway signaling failure which crippled Sydney on April 12 (some commuters reported trips of more than three hours) was caused by a failing LAN switch and software that couldn’t cope, an engineering report has found.

The switch, probably a Cisco device given that the Borg is Railcorp’s dominant LAN kit supplier, was part of the network in the Sydenham signaling station. That facility governs signaling for a large chunk of the Sydney rail network.

The guilty switch suffered partial failure of two electrolytic capacitors, the report found. The switch is part of a dual redundant LAN which is supposed to be resilient to failure; however, the configuration didn’t account for an intermittent breakdown.

With the caps failing, the switch would shut down and try to re-start itself. This, the engineer’s report says, meant the Sydenham LAN was “caught in a cycle where it was continually trying to reconfigure itself to address the changing state of the network.”

It only took a little over ten minutes for technical staff to initiate a disaster recovery plan, but the procedure took more than an hour to complete. In that time, The software that governs the rail network, known as ATRICS, was unable to cope with the flaky network. This led to a knock-on effect, taking out a system called Microloc at another station, Revesby.

With ATRICS and Revesby’s Microloc system both failing, the network failed to a “safe state”, the report says – in which trains were halted where they were. Because of the hugely interdependent state of the Sydney rail network, 847 trains were delayed and 240 were cancelled, and it took the rest of April 12th for the system to recover.

One of the key recommendations of the report is that “The resilience of the ATRICS software to automatically recover from network disturbances without the need for manual intervention should be addressed as a matter of urgency.”

Amen to that. ®

The essential guide to IT transformation

More from The Register

next story
Hello, police, El Reg here. Are we a bunch of terrorists now?
Do Brits risk arrest for watching beheading video nasty? We asked the fuzz
UK fuzz want PINCODES on ALL mobile phones
Met Police calls for mandatory passwords on all new mobes
Munich considers dumping Linux for ... GULP ... Windows!
Give a penguinista a hug, the Outlook's not good for open source's poster child
Detroit losing MILLIONS because it buys CHEAP BATTERIES – report
Man at hardware store was right: name brands DO last longer
Snowden on NSA's MonsterMind TERROR: It may trigger cyberwar
Plus: Syria's internet going down? That was a US cock-up
UK government accused of hiding TRUTH about Universal Credit fiasco
'Reset rating keeps secrets on one-dole-to-rule-them-all plan', say MPs
Caught red-handed: UK cops, PCSOs, specials behaving badly… on social media
No Mr Fuzz, don't ask a crime victim to be your pal on Facebook
e-Borders fiasco: Brits stung for £224m after US IT giant sues UK govt
Defeat to Raytheon branded 'catastrophic result'
Yes, but what are your plans if a DRAGON attacks?
Local UK gov outs most ridiculous FoI requests...
EU justice chief blasts Google on 'right to be forgotten'
Don't pretend it's a freedom of speech issue – interim commish
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.