A Palme d'or for time-chainage planning
For the laymen, a time-chainage diagram looks like a pick-up sticks painting. A multitude of lines of different colors. Some geometric shapes. A kind of abstract painting. Yet each line, each color and each shape has a precise meaning. Once we dive into their signification, the artistic side disappears. Hence it is unclear what interest could lead a film director to explain how to read such graphics in their masterpiece. That this film wins a Palme d'Or at the Cannes Film Festival seems even more unlikely. And yet, it happened!
Time-chainage planning got its name from its first use on railways which were measured in chains. A time-chainage diagram or time-chainage in short, is very practical to plan trains moving along a railway. Most often, the railway is represented on the horizontal axis and time going down on the vertical axis. A stationary train is represented by a vertical line, a moving train by an oblique line. Two lines crossing on the graphics signal an upcoming accident on the route.
Long reserved for planning train timetables, time-chainage diagram began to be used at the end of the 19th century in factories to optimize production line speeds. In addition to its use for repetitive activities, its use has also extended to the planning of linear construction projects. Thus it is perfectly suited to the planning of horizontal linear infrastructures such as roads and railways but also vertical ones such as skyscrapers. For about ten years, its use is no longer reserved for linear projects and it finds its place for the construction of ports, factories and hotels as well as for the exploitation of mines.
Time-chainage plannign has many advantages compared to other planning tools. Because it shows the speed for a train and the rate of construction, time-chainage planning permits to synchronise tasks. The trains follow each others at regular intervals. Construction works progress in concert. Synchronisation is not limited to tasks in the field. It is possible to synchronise design and construction work. This is what allowed to design and build the Empire State Building in only 18 months! The first floors were assembled before the last floors were designed.
In addition to helping to optimize planning, the time-chainage diagram also makes it possible to better identify delays and their impacts. By displaying speed or cadence, deviations from schedules are identified even before they impact subsequent trains or tasks. Many tools such as the Gantt chart focus on the single resource time. By also highlighting the location, the accesses, the machines and their movements, the railway schedule makes it easier to identify the impact that the delay of a task will have and which tasks are likely to catch up with this delay.
This extraordinary tool has another advantage. If it makes it possible to optimize a project, it can in the same way be used to delay it, or even to make its progress impossible. The setbacks that most often occur fortuitously on a project were thus used to win a battle in the Second World War. This is what prompted René Clément to devote a minute of his film to it about this crucial battle that was the Battle of the Rails.
The Battle of the Rails is a film released in 1946 and retracing the resistance of railway workers during the Second World War. Written from real facts of the resistance, René Clément first shoots a short film. He then completes it to make a feature film, including the famous scene of the derailment of a train transporting German armored vehicles.
The railroad schedule is presented from the first minutes of the film — at 8 minutes 45 seconds from the beginning —, preparing the audience for its recurring use in the timed preparation of resistance operations:
“You will see extremely precise mechanics working. From this command post, we regulate and follow the progress of the trains on a determined route. During the occupation, these trains were most often TCO trains, meaning transport during operation. […] The railway workers, as we can see, watched over the TCOs with particular concern and neglected nothing to inflict considerable delays on them, always with the greatest discretion. […] This graph establishes in advance the route of all the scheduled trains. That's the theory. The reality is this other graph where the operator traces as they pass the progress of the trains as they actually circulate on the network.”
We then follow the operator in charge of planning and monitoring the trains to organize the blocking of the trains supposed to bring German reinforcements following the Allied landings in Normandy. The trains are diverted by blowing up the track at strategic places. A runaway train endangers the lives of the workers working on the track. All these operations are followed on the time-distance diagram which is shown again after 1 hour 15 minutes of film when all the trains have been immobilized.
Among all these resistance operations, the most delicate is the timed intervention intended to derail a train carrying German tanks. The operator plans to blast the track just after the passage of an armored train. It takes into account the route of the line so that the speed of the train is sufficient to rush the tanks into the ravine while allowing the driver to jump from the train in a curve. The following scene, which sees the derailment of a train carrying around thirty armored vehicles, is all the more impressive since it was shot without special effects. A real train carrying real armored vehicles was rushed at full speed down the embankment under the gaze of three cameras.
The film wins the International Jury Prize at the first Cannes Film Festival. During this first edition of the Festival international du film in 1946, the first prize — the Grand prix which became the Palme d’or in 1955 — is awarded to all eleven participating countriesex æquo. Hence, the jury expresses its choice for by awarding the Prix du jury international — which became the second prize of the festival as Prix spécial du jury — as well as the Grand prix de la mise en scène to the Clément's film. La Bataille du rail also wins the 1946 Méliès prize. The trailer is available freely on the French National Audiovisual Institute website which also offers the complete film for 2,99 €.
The time-chainage diagram had its heyday on the big screen. Today, it is still a screen — a computer screen — that breathes new life into it. From the 1980s, the drawing board gave way to industrial design software. If they made it possible to draw time-chainage diagrams, the planning continued to be done on paper. The interest of the time-chainage diagram being to display all the constraints at the same time, the thought was limited by the reduced size of the VGA screens. Planning software was limited to the Gantt chart and its much simpler theories. Formalized in the 1950s, the critical path method and the PERT method were within reach of the first computers. It was therefore only at the turn of the 2000s that railway planning began to be entirely computer-based with the arrival of larger screens, more computing power and above all... DynaRoad, which became MAGNET Project in 2019.
Since the early 2000s, DynaRoad and now MAGNET Project have made it possible to plan directly by manipulating tasks on a time-chainage diagram but also on a Gantt chart and on a map, all being updated in real time. Each view offers extended zoom capabilities in order to find on screen as much information as displayed on a A0 paper sheet. The diagram made in DynaRoad Schedule is the theory. But DynRoad originated from a request by earthmoving companies to follow actual earth movements. Hence project monitoring is implemented at the heart of DynaRoad since its first versions. DynaRoad Control tracks progress as tasks are completed. The operator can manually enter the quantities hauled, as for the passage of trains. With the generalization of machine tracking software, it is even possible to import these quantities in real time from the lorry GPS.
Overlaying planning graphics for planned and actual works allows to identify unexpected events before they impact the whole project. On the diagram below, dash lines show that earth cuts in orange and corresponding fills in brown have been done earlier than planned. Base layer in blue has also started early. After a break of several weeks, the productivity rate is not as planned. The forecasts in discontinuous blue segments show that it is expected to complete five weeks behind schedule. Thus this is a task to monitor closely.
DynaRoad and MAGNET Project are available in English, French and many other languages. If you wish to plan your project with this tool, feel free to contact me. You can also download the trial version.
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