Retrotechtacular: The Fell Locomotive

January 3, 2024 by Jenny List 20 Comments

If you were to visit a railway almost anywhere in the world, you would find that unless it was in some way running heritage trains, the locomotives would bear a similarity to each other. Electric traction is the norm, whether it comes from a trackside supply or from a diesel generator. In the middle of the last century, as the industry moved away from steam traction though, this was far from a certainty. Without much in the way of power electronics, it was a challenge to reliably and efficiently control a large traction motor, so there were competing traction schemes using mechanical gearboxes or hydraulic drives. One of these is the subject of an archive film released by the oil company Shell, and it’s a fascinating journey into a technology that might have been.

A model of a gearbox, in black and white. — The Fell differential gearbox.

All diesel locomotive designs struggle with the problem of transmitting the huge torque required to start a fully loaded train at low speeds, and because of the huge force required, it’s impossible to design a locomotive-sized conventional gearbox to do the job in the way it might be managed on a truck. Electric and hydraulic drives exploit the beneficial torque characteristics of electric and hydraulic motors, but the mechanical gearbox isn’t quite done for. The subject of the video is British Rail number 10100, otherwise commonly known as the Fell locomotive, and it was a one-off prototype that took to the rails at the start of the 1950s designed to test a very novel gearbox design.

At the heart of the Fell gearbox is a set of differential gears the same as you’d find in the axle of a car, and in the locomotive they are used to combine the output of more than one engine. The loco had four smaller-than-normal diesel traction motors that could be combined, but even then, it wasn’t done. To achieve variable torque, they employed superchargers driven by a set of even-smaller diesel engines, resulting in an ungainly multi-engined beast but with the desired characteristics for both starting heavy trains and for moving them at high speed. Continue reading “Retrotechtacular: The Fell Locomotive” →

Polish Railways Fall Victim To Cheap Radio Attack

August 29, 2023 by Zoe Skyforest 41 Comments

Poland’s railways have recently come under a form of electronic attack, as reported by Wired. The attack has widely been called a “cyber-attack” in the mainstream media, but the incident was altogether a more simple affair pursued via good old analog radio.

The attacks were simple in nature. As outlined in an EU technical document, Poland’s railways use a RADIOSTOP system based on analog radio signals at around 150 MHz. Transmitting a basic tone sequence will trigger any duly equipped trains receiving the signal to engage emergency braking. It’s implemented as part of the PKP radio system on the Polish railway network. Continue reading “Polish Railways Fall Victim To Cheap Radio Attack” →

Luxury Train Cars Used To Ride On Paper Wheels

June 27, 2023 by Zoe Skyforest 20 Comments

Early on, railways primarily used wheels made of wood or iron. The former were cheap and relatively easy to manufacture, while the latter had far superior wear qualities. It may surprise you to learn, however, that some railways once used wheels made out of paper, as [Train of Thought] explains.

The wheels were pioneered by a man known as Richard N. Allen, in the 19th century. The wheels were constructed by layering up hundreds of sheets of paper with glue, compacting them with a press, and allowing them to cure for a few weeks. The solid paper disks were then machined to size, and were drilled to accept bolts that attached metal plates for protection. The wheels were given a cast-iron hub and a steel rim for wear reasons.

The benefit of the wheels was that their composite paper construction helped damp vibrations and noise from the wheels and rails. The North American Pullman railway ended up using the wheels for sleeper and dining carriages for the more luxurious ride they provided.

The paper wheels were short lived, however. While the wheels were up to the task when new, they would fail much sooner than solid metal wheels. A series of derailments led to the wheels being declared unsafe for use in the US by 1915.

The wheels serve as a good example of wheels and tires acting as a tuned part of a whole suspension system. Experimental wheel designs come and go, but there are reasons why we landed on certain designs for certain applications, after all. Video after the break.

Continue reading “Luxury Train Cars Used To Ride On Paper Wheels” →

Machine Vision Automates Trainspotting With Unique Full-Length Portraits

May 2, 2023 by Dan Maloney 11 Comments

As hobbies go, trainspotting is just as valid a choice as any — we don’t judge. But it does present certain logistical challenges, such as having to be in visual range of a train to be able to spot it. There’s also the fact that trains are very large objects, and they tend to move very fast. What’s a railfan to do?

If you’re also technically minded, you might try building an automatic trainspotting bot like [jo-m] has. It looks like the hardware end of “Trainbot” is pretty simple since it has been tested on both x86 and Raspberry Pi, and supports both video4linux and Pi cam. The magic is in the software, which is able to detect a train entering the frame, record images, and then stitch them together into one long image. The whole thing is coded in Go and has some interesting bits, like a custom image patch mapping package.

Trainbot gives an unusual view of a train, one that most of us accustomed to watching a train pass at a crossing have never seen. By stitching small chunks of the train as it passes, Trainbot is able to show the entire train in a single image, which would be impossible to do except for being very, very far away from the track. [jo-m] also built a web interface for Trainbot where you can check out the comings and goings yourself. Each passing train’s image is accompanied by data like its velocity and acceleration, length of the train, and time of passage. There’s also a GIF of the original source video, which is pretty cool.

Here in the States, we don’t have a lot of passenger trains to spot, but we do have some really long freight trains. It’d be interesting to see how this works with a train that’s over a mile long; that would be quite an image. Looks like someone at least has the hardware in place to give it a try.

Feeling The Heat: Railway Defect Detection

March 28, 2023 by Dan Maloney 29 Comments

On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.

But that basic simplicity belies the true complexity of a railway, where even just keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.

Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.

Continue reading “Feeling The Heat: Railway Defect Detection” →

China’s New 100 MPH Train Runs On Hydrogen And Supercaps

February 2, 2023 by Zoe Skyforest 83 Comments

Electric cars are very much en vogue right now, as the world tries to clean up on emissions and transition to a more sustainable future. However, these vehicles require huge batteries as it is. For heavier-duty applications like trucks and trains, batteries simply won’t cut the mustard.

Normally, the solution for electrifying railways is to simply string up some wires and call it a day. China is trying an alternative solution, though, in the form of a hydrogen-powered train full of supercapacitors.

Continue reading “China’s New 100 MPH Train Runs On Hydrogen And Supercaps” →

A Rail Cart For The Space Conscious Passenger

October 8, 2022 by Jenny List 29 Comments

For those who live in countries where there are plenty of abandoned railways, a popular way to explore them has been by means of home made rail carts. These are usually rudimentary rail trolleys with a small internal combustion engine, and a host of fascinating videos of them can be found online. Such a trolley has one disadvantage though — it’s not the most compact of devices. [Cato] has come up with a rail cart that’s extremely portable by replacing the engine with the guts of a pair of hoverboards.

The chassis of the machine is made from aluminium extrusion, and its deck from plywood. The wheels are the stock hoverboard wheels with flat flanges applied, which while they don’t have the ideal flange profile of a rail wheel are good enough to keep the thing on track. Finally to control the thing a rather stylish little 3D printed single-axis joystick serves as a combined throttle and brake.

Those of us who hail from places where abandoned railways have their track speedily ripped up can only gaze in envy and imagine speeding along the rails on one of these. The build starts with a warning never to use one of these on an active track, but should you wish to drive a real train there are plenty of places to do that.