The simplest girder bridges, for which the engineering departments specially procured logs, eventually replaced the collapsible timber-metal spans. By the end of the war, such structures were assembled in the rear, then transported by train to the front line, and were transferred to the installation site by cars. Disassembled bridges up to hundreds of meters long were loaded onto columns of trucks equipped, among other things, with a mass of auxiliary equipment. In the first period of the war, bridges on small rivers were installed in an extremely laborious way, with the help of hand-made wooden women. Diesel pile drivers significantly simplified this procedure, and now 700-meter bridges (width - 6 meters) were erected in just 3.5 days. A true masterpiece was the transfer of low-water bridges across the Dnieper in an average of 7 days. The art of military bridge builders of the Red Army was appreciated abroad, rightly comparing such work with a feat.
In the West, one of the most interesting developments was the collapsible metal bridge designed by Donald Bailey, with the help of which it was possible to organize a single-track traffic with a carriageway width of 3.75 meters. The spans of the bridge could immediately block 70 meters of a water barrier with a design load of 100 tons. The prefabricated unit of the bridge was a grid of 3, 5 m by 1, 45 m, which were bolted together during construction. To increase the carrying capacity of the Bailey bridge in one section, it was possible to install three elements at once in one or two tiers. The flooring on such bridges was usually constructed from 5-centimeter planks. With the help of the Bailey Bridge, a high-water crossing was built across the Rhine River with a central span of 45.6 meters, coastal ones of 45, 3 and 36.3 m and a height of 22.5 meters above the river's low water. The allies built the bridge in just 24 hours.
“Due to snow drifts and blizzards, the capacity of the roads was sharply reduced, movement outside the roads became almost impossible … fortified hard-to-reach points … It was a time of severe trials for the road workers. Experience has shown that they had the least to reckon with pre-existing roads. Extremely broken in the autumn thaw, they did not quite meet the requirements for a "snowy road". Open fields, even plowed ones, turned out to be more convenient. On them it is freer to choose the shortest direction, it is easier to apply the technique."
So the officers of the road service of the Red Army spoke about the construction of winter roads.
The Germans also suffered from the peculiarities of the winter roads in Russia
The key problem of winter roads at all times is the cleaning of freshly fallen snow. And in the conditions of a constant shortage of snow-removing equipment in the engineering parts, the problem was squared. A typical harvesting technique has become a trailed grader, which regularly breaks against protruding mounds of frozen soil. Therefore, I had to build home-made equipment from timber. There were no typical designs - everything was limited by the imagination and technical capabilities of the parts. However, general requirements have been developed: light weight, quick and easy disassembly, stability in motion, and the ability to change the width of the capture. The technique for clearing was weak, so after the formation of large snow banks on the sides of the road, the roads had to be abandoned. New ones were laid next to the old ones, which, having turned into deep trenches, contributed to the snow protection of the fresh road. If the road was located in the rear, then it was possible to install stationary snow protection. Of course, slat shields, widely used in peacetime, were not mounted, but were limited only to brushwood, spruce branches, straw, which were fastened to a frame made of poles.
"The road of life"
It is worth noting that on the fronts of the northern part of the country, road workers were looking forward to winter. Swamps and numerous lakes froze over, becoming an excellent springboard for maneuvering troops. In the summer and even more so in the autumn and spring, the combat units were forced to gravitate towards the narrow arteries of wooden roads laid between the swampy swamps. Often it was necessary to go to the tricks in the operation of winter roads - for example, to organize traffic on frozen lakes only at night during the period of minimum temperatures. Also on icy roads, wooden flooring was widely used, as well as freezing of reinforcing layers of brushwood.
The legendary "Road of Life", laid across the ice of Lake Ladoga to besieged Leningrad, has become a real symbol of the feat of Soviet road builders and drivers. The total amount of cargo transported on the ice is more than 1,000,000 tons, and the number of people evacuated exceeds 600,000. Difficulties in the operation of the road arose with the uneven freezing of ice and a large amplitude of fluctuations in the water level during the winter. This led to the formation of dangerous cracks, into which more than one hundred cars fell. The Road of Life has become a real testing ground for studying the behavior of ice in such conditions. First, under constant traffic loads, the ice stratum passed from an isotropic homogeneous state to a columnar, much more fragile state.
Broken Ring Monument
Monument to the Unknown Driver in Dus'ev
For this reason, any road on the Ladoga ice could not be used for more than three weeks. As a result, traffic lanes were changed more than 60 times in the winter of 1941-42. Secondly, the static load on the ice caused deflection, resulting in the formation of cracks and breaks. That is, the most loaded trucks should only move on the ice, in no case stop for a long time. Therefore, all the broken cars were immediately towed away without waiting for repairs. Thirdly, empirically, they found out about the existence of safe speeds for traffic on ice. The thing is that under the ice, during the movement of equipment, a "wake wave" is formed, which must be either behind the car or in front. In the case of synchronization of the speeds of the machine and the wave, resonant vibrations are formed, leading to cracks and catastrophes. So, with a lake depth of 6 meters, the dangerous speed was 21.5 km / h, and at 10 m - already 27.7 km / h. Calculations are given for ice thickness close to the minimum for a truck.
The experience of the military road services of the Red Army during the war years is invaluable, since it was the engineering units that ensured the mobility of troops in seemingly hopeless conditions. We can only hope that the modern mobilization potential of the Russian military road workers is just as high and effective.