NetLogo User Community Models
by Robert Allen, Brian Coffey, Dante Montgomery, Ashley Rawson, and Brian Stebar II (Submitted: 07/25/2013)
## WHAT IS IT?
This is a model to analyze and compare the logistical support of the German armies in World War I. Specifically, this model compares the performance of the rail-based logistical support in the originally-planned (1905) Schlieffen Plan and the actually-executed (1914) Schlieffen Plan during the opening weeks and months of the War. In the model, trains navigate the rail network from Germany and transport supplies to the Western Front as the German troops advance across Belgium, across Luxembourg, into France and around Paris. Each train will move to train hubs in order to supply the German front lines as they advance toward Paris.
## HOW IT WORKS
When the simulation begins, all army corps are fully supplied. With a full supply, a corps can advance for 5 days without a resupply. When the corps becomes low, the corps requests a supply from the supply depot and is added to the cue. Each train is populated at three German train hubs, which are located along the Germany-France border. The train is then assigned a destination of a trainhead that is nearest to that corps whose request the train was assigned. When the train reaches its destination and the corps receives its supplies, the train will travel back to the supply depot. The train will then wait until the supply cue assigns it another request and destination.
## HOW TO USE IT
First, select the path-of-advance under “Simulation Modes” to select the Original Plan (1905) or the Executed Plan (1914).
Second, in the “Look and Feel” section of the interface: the background image of the plan can be switched on or off; the train targets (the assigned destinations of the train from the global cue) can be switched on or off; and the corps’ supply levels can be visually altered by the size (increase if fully supplied, decreased if not fully supplied) or color (green – high, orange – medium, red – low) or both.
Third, the supply and consumption rates can be changed in the “Supply Capacities and Consumption Rates” section of the interface. The defaults are automatically set: infantry supply capacity – 60 lbs, cavalry supply capacity – 250 lbs, artillery supply capacity – 10,000 lbs, infantry consumption rate – 10 lbs/day, cavalry consumption rate – 25 lbs/day, artillery burn rate – 1,200 lbs/day.
Fourth, the train characteristics can be altered, as well. The default number of trains in the simulation is 1,000. Average train speed is 15mph, the number of trains allowed over each segment of track per day is 60, and each train's capacity is 200,000 lbs by default. All of these values can be adjusted using the sliders.
Fifth, the attrition rate of both the trains and troops can be altered, both defaulted to 0% per 30 days.
Finally, the rate of advance of the front line can be altered in the “Troop Speed Adjustment” section of the interface.
After the adjustments made to the default settings, click on the "Set Up" button, then the "Go" button, and watch the simulation unfold. Settings can be returned to their defaults by clicking "Reset Settings".
## THINGS TO NOTICE
On the left side of the interface, notice that you can observe the number of trains idle, delayed, or en route in the simulation. Also, observe the force supply level as you change different aspects and factors (sliders) in the model.
Glance at the Delayed monitor under "Supply Overview". The monitor tells how many trains with supplies that are stuck waiting for an open track, which gives an indication that the supply rate was not the limiting factor, but rather the tracks.
## EXTENDING THE MODEL
In terms of extending the model, it would be interesting to stage supplies at other stations along the movement of the corps, as our simulation only stages supplies at three supply depots. Also, it would be interesting to cue supplies at individual stations instead of a global cue, which is what this model currently does. Finally, if a train breaks down, a track’s effectiveness should be altered because all tracks should not be in working condition all the time since historically there were a lot of mechanical train failures that would essentially block the track.
Sumner, Ian. The First Battle on the Marne 1914: the French "miracle" halts the Germans. 1. publ. in Great Britain. ed. Oxford [u.a.: Osprey Publ., 2010.
Creveld, Martin. Supplying war: logistics from Wallenstein to Patton. 2nd ed. Cambridge: Cambridge University Press, 2004.
Military Logistics of the Schlieffen Plan: Supply and Transport for the Western Front, Model, NetLogo, Group 1, Professor Salomone, 2006.