Wednesday, October 25, 2023

How to Avoid a Train Wreck

A very simple chart designed by a French railway engineer in the 19th Century has helped save millions of lives. Charles Ibry's train schedule, originally developed to timetable and schedule trains on the Paris - Le Havre line, is an extremely effective tool for timetabling and visualizing train traffic on a railway line. Perhaps most importantly it provides railway companies with a powerful visual aid to avoid potential crashes between trains traveling on the same line.

Chemins de Fer de Paris à Rouen et au Havre is a small scrollytelling presentation of how Charles Ibry's chart for timetabling trains is used and how it helps to avoid train companies scheduling potential train wrecks. As you scroll through the presentation the map sidebar and image annotations provide a walk-through of Ibry's chart and explain how the chart is used by railway companies to schedule trains.

Chemins de Fer de Paris à Rouen et au Havre uses a IIIF image of Ibry's chart from the Bibliothèque nationale de France. I have been able to use this image with the Leaflet.js mapping library thanks to Jack Reed's Leaflet-IIIF plug-in. I created the annotations using my own Leaflet-IIIF-GeoJSON tool. The annotation arrows used in the presentation use Webkid's leaflet-swoopy plug-in.

The Chemins de Fer can also be viewed in detail on the Bibliothèque nationale de France website. If you are interested then you can also view a completed chart of the Paris to Boulogne line on the bibliothèque's website. 

Charles Ibry's timetabling graph is also discussed on Hannah Fry's BBC Podcast This Train has Been Delayed (Part of Hannah Fry's Uncharted series). This Train is Delayed discusses how Ibry's graph recently helped Singapore's transit network finally discover a glitch which was causing their driver-less trains to seemingly stop at random between stations (when they weren't meant to be stopping).


DMBY said...

So interesting! An an excellent mention of the fat controller.

Simon said...

Nice page showing the original Ibry chart which I had trouble imagining from Hannah Fry's Uncharted podcast episode and was desperate to see.

One criticism is that the head on collision is not shown on the example - this would occur with trains coming in the opposite direction - from Le Havre to Paris. The trains I think operated on one track only so had to make sure they did not meet going in opposite directions.

A train going into the back of another is not impossible but less likely as the rear train driver would hopefully have the gumption to apply the brakes before it happened!