At Fontenoy-sur-Moselle, between Nancy and Toul, there was, for example, a bridge of seven arches, effective destruction of which would have made a very serious check in the communications along the principal line between Germany and Paris; but, instead of blowing up the bridge in the middle, the men entrusted with the work (in January, 1871) brought down two arches at the side of the bridge, causing a break which the Germans were able to fill in with stones and earth, restoring communication in about seventeen days. Then, although several of the tunnels in the Vosges mountains were mined, the mines had not been charged, and before instructions to blow up the tunnels had been received by those awaiting them, the Germans were on the spot and took possession.

On the other hand the absence on the side of the French of an organised corps for destruction as well as construction did not prevent the carrying out of some very bold and highly successful work by parties of franc tireurs, who showed alike their appreciation of the importance of rail communications and their skill in impeding them.

One especially striking feat in this direction was accomplished by a company known as the "Franc Tireurs of the Meuse."

Learning that a Prussian troop train was to pass through Lanois (on the line between Reims and Mons) on October 26, 1870, they resolved to effect its destruction. How they operated is told by Lieutenant Fraser, R. E.,[25] who arrived on the spot shortly afterwards, and heard the story from some of the men engaged on the work.

Any obstruction placed on the line would have been seen. Hence a different course had to be adopted. Selecting a spot where the line ran along a 12-ft. high embankment, to which a well-wooded slope came down on one side, the franc tireurs took up a pair of rails, removed the sleepers, cut a deep trench across the line, laid some pieces of iron at the bottom of the trench, placed on the iron a box containing thirty kilos (2 qrs. 10 lbs.) of powder, and fixed into the lid of the box a French field shell in such a way that, when the rail was replaced over the box, the head of the fuse would be just below the lower flange of the rail. In restoring the line again in order that there should be nothing to attract attention, the franc tireurs omitted one sleeper so that the weight of the locomotive should in passing press the rail down on to the head of the fuse. The party—some seventy-five strong—then withdrew to the shelter of the woods to await developments.

In due time the train of forty coaches approached at the ordinary speed, the driver not suspecting any danger. When the engine reached the spot where the "torpedo" had been placed, an explosion occurred which tore up a mass of earth, rails and sleepers, threw the engine and several carriages down the embankment, and wrecked the train. Those of the Prussian troops who got clear from the wreckage were shot down by the franc tireurs under the protection of their cover. The number of the enemy thus disposed of was said to be about 400.

Altogether the French, in their efforts to impede the rail movements of the invader, destroyed many miles of line, together with no fewer than seventy-eight large bridges and tunnels, apart from minor interruptions. The repairs and reconstruction thus rendered necessary threw a great amount of labour on the Prussian Railway Troops, and much trouble arose from time to time on account, not only of the inadequate supply of materials even for temporary constructions, but, also, by reason of the shortcomings of the workers themselves. The sections of Railway Troops had been so recently formed that the men were still without adequate training. In 1870-71, as in 1866, military members and civilian members of the Construction Corps were alike unfamiliar with the special class of work called for in the repair or the rebuilding of railways under the emergency conditions of actual warfare. This instruction had, in fact, to be completed at the theatre of war at a time when the Corps should have been prepared to show the greatest efficiency.

Difficulties arose, also, on the side of the Germans in operating the 2,500 miles of French railway lines of which they took possession.

There was, in the first place, a deficiency both of locomotives and of rolling stock. So far as circumstances would permit, the French, as they retreated, either took their railway rolling stock with them or destroyed it, in order that it should not be used by the enemy. Attempts were made to meet the difficulty by obtaining constant reinforcements of engines and wagons from Germany; but even then the organisation for controlling the use of rolling stock, among other transport details, was still so defective that commanders who wanted to ensure the movement of their own troops by rail did not hesitate to take possession of engines and carriages set aside for the regular services of the line. There were, in fact, occasions when, for this reason, the regular services had to be stopped altogether.