Comment by tetromino_ | Hacker News Reader

Comment by tetromino_ | Hacker News Reader

What I found most interesting from the article was that the effectiveness of Soviet scorched earth tactics was due to expert Soviet planning and the German military engineers' naivete about railroad operations.

The Soviet decision of precisely what to scorch was made by railroad logistics experts. They tore up some tracks here and there, but paid especial attention to wrecking all locomotive depots before retreating, and taking all operational locomotives back with the retreating forces, leaving no equipment for the enemy.

The German military engineers spent their efforts on repairing and regauging the tracks, but didn't pay as much attention to the condition of the depots, failing to realize that without a fully operational depot per every 80 km of track, the line's overall capacity was severely degraded. This left front units starved of supplies as soon as the length of captured and "repaired" railroad lines got long enough.

> failing to realize that without a fully operational depot per every 80 km of track, the line's overall capacity was severely degraded

I am failing to realize this too. To be fair I'm not a logistician or train guy.

Why are the depots necessary, and why at 80km intervals?

(From the article) Trains need sand, water, coolant, and other materials for normal operation. These need to be regularly resupplied (at depots). Hence, a typical system would be to dedicate each locomotive engine to a stretch of track (the length of which was constrained by how long the train could go without a resupply) between two depots. The train would stop at the depot, move the cars to another engine, send the new engine along, resupply the old engine, and have the old engine take new cars from yet another train along the track in the opposite direction (to the depot it originally came from).

Steam locomotives could only travel a fixed distance (limited by locomotive design at the time, which in turn was limited by physical constraints of the track) before running out of water and coal and needing to be turned around. The train would then be detached from one locomotive and passed on to the next one - very much like changing horses in a preindustrial mail dispatch relay.

Refueling, refilling water, turning around, and performing needed regular maintenance to keep the locomotive in running order was very difficult without a specially prepared site - the depot. Without depots, you could get a train 80 km down the line, but then you were stuck without the ability to immediately hand the train off to the next locomotive.

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