Catching A Rogue Train With Data

December 13, 2016 by Jenny List 16 Comments

If you have been a regular traveler on one of the world’s mass transit systems over the last few decades, you will have witnessed something of a technological revolution. Not necessarily in the trains themselves, though they have certainly changed, but in the signalling and system automation. Nineteenth and twentieth century human and electromechanical systems have been replaced by up-to-date computers, and in some cases the trains even operate autonomously without a driver. The position of every train is known exactly at all times, and with far less possibility for human error, the networks are both safer and more efficient.

As you might expect, the city-state of Singapore has a metro with every technological advance possible, recently built and with new equipment. It was thus rather unfortunate for the Singaporean metro operators that trains on their Circle Line started to experience disruption. Without warning, trains would lose their electronic signalling, and their safety systems would then apply the brakes and bring them to a halt. Engineers had laid the blame on electrical interference, but despite their best efforts no culprit could be found.

Eventually the problem found its way to the Singaporean government’s data team, and their story of how they identified the source of the interference makes for a fascinating read. It’s a minor departure from Hackaday’s usual hardware and open source fare, but there is still plenty to be learned from their techniques.

They started with the raw train incident data, and working in a Jupyter notebook imported, cleaned, and consolidated it before producing analyses for time, location, and train IDs. None of these graphs showed any pointers, as the incidents happened regardless of location, time, or train.

They then plotted each train on a Marey chart, a graph in which the vertical axis represents time and the horizontal axis represents stations along a line (Incidentally Étienne-Jules Marey’s Wikipedia entry is a fascinating read in itself). Since it represents the positions of multiple trains simultaneously they were able to see that the incidents happened when two trains were passing, hence their lack of correlation with location or time. The prospect of a rogue train as the source of the interference was raised, and analyzing video recordings from metro stations to spot the passing train’s number they were able to identify the unit in question. We hope that the repairs included a look at the susceptibility of the signalling system to interference as well as the faulty parts on one train.

We’ve been known to cover a few stories here with a railway flavor over the years. Mostly though they’ve been older ones, such as this film of a steam locomotive’s construction, or this tale of narrow gauge preservation.

[via Hacker News]

[Main image source: Singapore MRT Circle line trains image: 9V-SKA [CC BY 3.0], via Wikimedia Commons]

Retrotechtacular: Railroads In The Jet Age

September 16, 2016 by Jenny List 29 Comments

The front of the Soviet jet train on a monument in Tver, Russia. By Eskimozzz [PD], via Wikimedia Commons.

It started with one of those odd links that pop up from time to time on Hacker News: “The strange and now sadly abandoned Soviet Jet Train from the 1970s“. Pictures of a dilapidated railcar with a pair of jet engines in nacelles above its cab, forlorn in a rusty siding in the Russian winter. Reading a little further on the subject revealed a forgotten facet of the rivalry between Russians and Americans at the height of the Cold War, and became an engrossing trawl through Wikipedia entries, rail enthusiast websites, and YouTube videos.

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Retrotechtacular: 6207, A Study In Steel

June 7, 2016 by Jenny List 47 Comments

If you ever encounter railroad or railway enthusiasts, you may have heard the view that at some point in the past there was a golden age of rail transport that has somehow been lost. It’s something that’s up for debate as to when that age was or even whether with a selection of new super-high-speed trains snaking across our continents we’re in a golden age now, but it’s true to say that the rail business has had its fair share of decline in the last half-century.

It’s quite likely that when they talk of a golden age, they really mean a golden age of steam rail transport. At which point depending on where you live in the world it’s easier to put your finger on a decade. For UK residents a good candidate would be the 1930s; steam locomotive design had reached its peak, the rail network hadn’t been worn out by the demands of wartime, and private car ownership hadn’t eaten into their passenger numbers. The country was divided up into a set of regional rail monopolies, each of which had their own locomotive works and designers who were in fierce competition to show that their machines were the best and the fastest.

The LMS, the London Midland and Scottish railway company, served the northwestern segment of the country, North Wales, and the West of Scotland. Their high-speed express trains were in hot competition with those of the LNER, the London and North Eastern Railway, who served the eastern side of the country, to offer the fastest service from London to Scotland. It’s difficult to grasp through an 80-year lens, but this battle was one of national excitement, with the fastest locomotives becoming household names nationwide. The railway companies were justifiably proud of their engineering expertise, and so featured their locomotives as a key part of their marketing to the general public.

And so we come to the subject of today’s Retrotechtacular piece, a film below the break from 1935 following the construction of a high-speed express locomotive from start to finish in the LMS’s Crewe railway works. 6207 was one of a class of thirteen 4-6-2 Pacific locomotives designed by the company’s chief engineer [William Stanier], built between 1932 and 1935 and known as the Princess Royal class, all being named for princesses. In the film we see the various parts of the locomotive being cut, cast and forged from raw metal before being assembled in the Crewe plant. All the machinery is human controlled, and one of the surprises is sometimes the number of people involved in each task. The level of skill and experience in precision metalworking to be found in plants like Crewe was immense, and in some cases it is very difficult to find its equivalent in our own time.

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Hacklet 109 – Complex 3D Printed Projects

May 28, 2016 by Adam Fabio 13 Comments

If you can’t tell, we’re on a roll with 3D printers and printed projects this month. So far, we’ve covered printers, and simple functional 3D prints. This week we’re taking a look at some of the awesome complex 3D printed projects on Hackaday.io.

Complex 3D printed projects are things like robots, quadcopters, satellite tracking systems, and more. So let’s jump in and look at some of the best complex 3D printed projects on Hackaday.io!

We start with [Alberto] and Dtto v1.0 Modular Robot. Dtto is [Alberto’s] entry in the 2016 Hackaday Prize. Inspired by Bruce Lee’s famous water quote, Dtto is a modular snake-like robot. Each section of Dtto is a double hinged joint. When two sections come together, magnets help them align. A servo controlled latch solidly docks the sections, which then work in unison. Dtto can connect and separate segments autonomously – no human required. [Alberto] sees applications for a robot like [Dtto] in search and rescue and space operations. Continue reading “Hacklet 109 – Complex 3D Printed Projects” →

Rescuing The World’s First Preserved Railway

March 4, 2016 by Jenny List 32 Comments

Preserved railways are now an established part of the tourist itinerary. It doesn’t matter if you call it a railroad, railway, chemin de fer, Eisenbahn or whatever, the chances are that somewhere near you there will be a line rescued from dereliction on which you can spend a Saturday afternoon in vintage rolling stock being hauled by a locomotive long ago withdrawn from regular service. They are established enough to have become an industry in their own right, with the full range of support services to maintain hundred-year-old machinery and even build entire new locomotives.

So we’ve become used to seeing preserved railways in a state of polished perfection. Sometimes a little too perfect, there was a wry observation in a recent BBC documentary on the subject that a typical British preserved railway represents an average day in the 1950s when the Queen was about to visit. Anyone who lived through that era will tell you the reality was a little different, how run down the system was after World War II and just how dirty everything became when exposed to decades of continuous coal smoke.

A particularly worn-out section of railway in those days could be found at Tywyn, on the Welsh coast. A 2’3″ narrow-gauge line built in the 1860s to serve a slate quarry and provide a passenger service to local communities, the Tal-y-Llyn Railway (Welsh pronunciation help) had been in continuous decline for decades and on the death of its owner in 1950 faced closure. With only one of its two locomotives operational and its track in a parlous state it attracted the attention of the author Tom Rolt, already famous for kick-starting the preservation of Britain’s inland waterway system. A preservation society was formed, and in a joint enterprise with the former owner’s estate the line was saved. The world’s first preserved railway had commenced operations.

"Lawnmower" Locomotive in 1952 [Source: talyllyn.co.uk] — “Lawnmower” Locomotive in 1952 [Source: talyllyn.co.uk]

In a country reeling from the economic effects of fighting a world war there was no infrastructure for a group of enthusiasts rescuing a near-derelict railway. Nobody had ever done this before, there was no body of expertise and certainly no handy suppliers to call when parts were required. To rebuild their line the Tal-y-Llyn volunteers had to reach into their own well of initiative gained over the “Make do and Mend” war years and build their own way out of any challenges they encountered. In case you were wondering what the relevance to Hackaday readers has been in the last few paragraphs there’s your answer: what would you do if you were handed seven and a quarter miles of run-down track and a single barely serviceable locomotive that is one of the oldest in the world still running?

We are fortunate that in 1953 an American film maker, Carson “Kit” Davidson, visited the line, and through his affectionate short film we have a portrayal of the railway’s state in the early stages of preservation. When the footage was shot they had secured a second serviceable locomotive courtesy of the nearby and recently closed Corris Railway, but had yet to replace the majority of the worn-out and overgrown track. It’s a treat to watch, and sets the stage very well for the home-made machinery that is to follow.

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Retrotechtacular: Upgrading Train Signaling Before The Information Age

November 12, 2013 by Mike Szczys 25 Comments

retrotechtacular-british-railway-signaling

What’s surprising about the subject of this week’s Retrotechtacular is that the subject is not from that long ago. But looking at the way in which the work was done makes it feel so far in the past. In 1974 the British Railways Board set out to modernize and interconnect the signaling system. What you see above is one of hundreds of old signal control houses slated to be replaced by an interconnected system.

These days we take this sort of thing for granted. But from the start of the project it’s clear how the technology available at the time limited the efficiency of the development process. We’re not talking about all of the electro-mechanical parts shown during the manufacturing part of the video. Nope, right off the bat the volumes of large-format paper schematics and logic diagrams seem daunting. Rooms full of engineers with stacks of bound planning documents feel alien to us since these days even having to print out a boarding pass seems antiquated.

With fantastic half-hour videos like this one available who needs television? We’d recommend adding this to your watch list so you can properly enjoy it. They show off everything; manufacturing the cables, stringing them between the signal towers, assembling the control panels, testing, and much more.

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Controlling A Railroad With An Mbed

August 14, 2013 by Brian Benchoff 21 Comments

The word hacking got its start with model railway clubs, and the state of the art belies the current advancements in computer control and very, very small microcontrollers. [Jim] put together a great tutorial for driving model locomotives with a microcontroller, in this case an ARM-powered mbed.

Low-end model locomotives are controlled with DC, so an H-bridge and a PWM out on the mbed makes sense to drive these trains. [Jim] wired up a Pololu H-bridge driver, connected it to his mbed, and everything ran great.

Rail switches are another matter entirely. These allow trains to move from one track to another, but having them go to the left or right requires powering a fairly high current solenoid with 15 to 24 volts. For this, [Jim] used a MOSFET power control board to switch the rails and came up with a pretty neat demo that shows a small locomotive going back and forth over a single rail switch.

There is another class of model locomotive – ones with Digital Command Control. This setup is just a small decoder chip that fits inside an engine and tells the locomotive to turn on a lamp or run a motor digitally, allowing the conductor to control multiple trains on the same track.

[Jim] goes through the basics of DCC using the mbed, allowing two trains to switch positions in a rail yard using computer control. It’s really cool stuff that leaves us wanting a little more room in the basement to start building a huge computer controlled model railway.

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