I'm coming back to this graphic
once again. It shows (with the larger green circle) the approximate rumoured range of Iskander precision-guided ballistic missiles launched from the Russian Kaliningrad Oblast (rumoured ~499 km).

A closer look at the geography shows that two of three major rivers that are between Western European allies' land forces and Lithuania (Vistula and Oder, not the more Western Elbe) are in range. The Oder is just barely in its rumoured range.

9M723 Iskander (SS-26 Stone) has enough claimed accuracy (CEP of few metres) to be capable of hitting a bridge WHERE you tell it to hit, not just hitting the bridge at all. The cruise missile that can be launched from the same system has most likely the same range, and as a cruise missile it could approach a bridge horizontally, to penetrate and blow up from the inside the abutment.*

Successful strikes against the railroad bridges would no doubt disrupt rail traffic for weeks. Successful strikes against the road bridges on the other hand could be compensated with military engineers, maybe even within a day. More about that later. First, I'd also like to add that there are railroad and road connections between Slovakia and Poland that circumvent the Oder, but their capacity is lesser, using them would be a great detour for Western forces, the terrain is mountainous and might be troublesome for some vehicles (I suppose tank transporters would have trouble, at least in icy conditions).

So how could military engineers (Pioniere) compensate for destroyed bridges? Grid-style steel bridges are rather unlikely to be erected within days, but pontoon bridges can be built real quick. There are certain limitations, though.
_ _ _ _ _

600 German and British engineers exercised such pontoon bridge-building this summer on the Vistula as part of the Anakonda 2016 exercise, with both armies using M3 Amphibian rig vehicles and (un)folding pontoons to quickly create a 350 m wide pontoon bridge under near-ideal conditions.
Nominally, they would need 8 vehicles per 100 m bridging, but they needed 30 for 350 m this time, slightly more per metre.

The pontoon bridge was created (after due preparations) within 34 minutes. An engineer tank tested the bridge's stability, then it was cleared with a capacity of 250 vehicles per hour. That's one fourth of a brigade per hour, minimum four hours per brigade (there need to be spacings between units to avoid bunching up, since bunching up attracts fires and provokes traffic jams).

Now about the near-ideal conditions:
- very shallow water
- slow stream (2 m/s) that required no anchoring of the amphibian vehicles
- plenty time for preparation
- units knew in advance of the exercise and were able to ensure high vehicle and personnel readiness 
- no hostile actions
- no river flood (really big ones happened in 2010 along the Oder)
- river shipping was stopped in time

Germany has 30 M3 Amphibian rigs in active service (and apparently some more in storage), the UK 38. Others were exported past NATO's borders, the production total was 110 apparently.

With normal readiness and normal river width in mind and with the French inventory of similar amphibious bridging vehicles in mind one could expect 3-6 such pontoon bridges to be created. I have no idea whatsoever about the Polish inventory and capability in this regard; I can only guess that they would have participated in the exercise if they had anything similar. Their PTS vehicles are nowhere close in capability.
Two or three routes with 4-6 such pontoon bridges might be established across Oder and Vistula approx. within 24 hrs after strikes on the normal bridges, but maybe it would take 48 hours - this depends on the readiness of the units.

The capacity of two such routes with 250 vehicles/hour might suffice for alliance purposes, but it sure wouldn't be luxurious. Even with every vehicle a lorry with an average of 10 tons cargo, this would only be 120,000 tons throughput per day on two routes maximum. Realistically, it would rather be close to 50,000 tons per day taking into account that not only supplies, but also reinforcements would cross those bridges. 50,000 tons supplanted by what crosses the mountain passes of Slovakia - enough for approx. 12 divisional equivalents, or ~36 brigades. That's plenty supply capacity compared to what could be in (arrive at) the region within a week or two, but not much if we consider the supply needs of non-divisional forces, the possibility of damage by hostile action, or the quantities of forces that we'd want to have by the NATO doctrine of "counter-concentration" in the event of crisis.
And of course this capacity is one-way only; to maintain this throughput in one direction no vehicle would be allowed to return.

One might arrive at the conclusion that reactivating whatever M3 Amphibian vehicles are in storage and adding a few more simple steel (un)folding pontoon elements to the inventory may easily be worth the expenses in terms of deterrence and defence. The current inventories look to be close to the minimum requirements, without any robust reserve capacity.
We should also think about how to defend such pontoon bridges against air attack.
Furthermore, the battalions (German, UK and French) that can build such pontoon bridges should be held at highest readiness, second to no other land forces elements.


*: I suspect this is what the "bunker penetration with cruise missiles" craze of the 1990's and 2000's was in part about.  Bunkers alone could not explain the quantity of such missiles purchased, even if we count hardened aircraft shelters (which would not require that very much dedicated ammunitions). Germany alone purchased 600 Taurus missiles!

edit October 2016: The French system


  1. There is also old Czechoslovak bridging system PMS, still active in the army of Czech Rep and Slovakia. http://www.army.cz/scripts/detail.php?id=6082

  2. What is the civilian capacity to rebuilt or repair the existing bridges?

    The military should of course have the resources for contingencies, but commercial firms have overwhelming capacity and knowledge to reconstitute the affected bridges.

    If it is worth activating military bridging units, it is also likely worth putting contingency repair and re-construction contracts in place for these bridges.


    1. I suppose a real repair with civilian means would take months even under wartime conditions unless one is fortunate enough that parts happened to be prepared for a new bridge. There should be relevant experiences from repairing Yugoslavian bridges '99/'00, but I'm not aware of details.

      This kind of bridges
      is not quickly repaired or replaced.
      TD described military bridging at length
      and save for the pontoon variety nothing seems to be able to create useful Oder or Vistula bridges in less than several weeks, even with today's technology.

    2. Point made!

      As an alternative, what about ferry services? It should be possible to prepare emergency ferry landings and lease commercial ferries in the event of hostilities to help move military traffic.

      Still, I hope that civil authorities responsible for disaster relief would at least have the plans and other details necessary to respond. After all, destruction of key bridges would represent a massive blow to the economy that needs to be addressed immediately even if the final corrective action takes place after the hostilities end.


    3. There are hardly any such capacities, and the M3 Amphibian rig actually is a ferry (2 coupled can carry a Leopard 2):

      It's doubtful whether amphibious units (LCUs; at least one in civilian hands at the North Sea) could manoeuvre well on a river.

      I think there is little hope to restore rail links quickly, and the road capacity after successful strikes against bridges looks like a troublesome bottleneck.

      The Polish economy would stall anyway if war breaks out; they would be glad if they could maintain food supply, tap water supply, hospital operations and emergency services.

  3. A very important topic as bridges really seem highly vulnerable to (very) long range precision guided munitions. Even with a lot more M3 supply would be considerably reduced in such cases.

    Obviously another reason to increase throughput by avoiding too many (light tonnage) vehicles.