They consisted, like tin pontoons, of a wooden frame sheathed on the sides and bottom with copper sheets. The weight of each pontoon reached 35 pounds; the lifting force of the largest of them, before being completely immersed in the water, was 211 pounds, so the bridge of 30 pontoons had a length of no more than 55 fathoms (the crossbars were 71/2 arches long) and could be used for crossing weights equal to 12 pounds. guns, and therefore, when transporting more significant weights, it was necessary to place the pontoons almost close to one another and, therefore, with such closeness of them, the length of the bridge decreased. Such a small lifting force of the bridge occurred both from the insufficient dimensions of the pontoons and their own significant weight, and from the disproportionately large weight of the parts that made up the deck and, in particular, the bridge ropes. Let us quote here the own words of the artillery lieutenant colonel N%mago, who at that time was one of the most useful workers in the pontoon part: “When I joined the pontoon team during the Prussian War in 5 1759, I found with it tarred longitudinal ropes, in a circumference of 9 or more inches. and ends 120 fathoms long, weight from 80 to 120 1p40., anchor ropes thick 5 6 inches. in circumference and anchors from ‘10 90 15 poods. The fact is that everything, and especially the immense weight of the ropes, caused unbearable difficulties on the way during the battles, because under such heavy gear, the carts had to be laid out of a marked size, half-height, and therefore heavy; 710why for the mentioned ropes 10 00 12 horses were harnessed to each end, and for tensioning they fumbled, and all this not only caused great aggravation 65 TTI, BUT 65 Jo’s use of drawbridges was so inconvenient that as long as such ropes. unwound from the carts, set up for repairing their cars and brought into the mouth of the heavy weight of the anchor, it is possible to build a perfect bridge from decent bridges of shells in an incomparably shortest time” 1).
From this it is clear that the pontoon fleet of that time did not fulfill the main conditions that are now being paid so much attention, namely: lightness, mobility and speed when building a bridge. To transport a pontoon park of 30 pontoons (for constructing a bridge 66 fathoms long) with all its accessories, 516 horses were required; but this is a very significant figure, at the time Prussian war, turned out to be insufficient and reached 600-800 horses.
To provide metal pontoons with greater lifting force, Lieutenant Colonel Nmoy proposed giving them the same dimensions that were subsequently adopted for canvas pontoons. He suggested giving the sides a vertical position and making them double
1) A guide to learning about the marching bridges of Nimogo, p. 25.
metal lining, with the purpose of making it possible, in the event of a break, the bottom of the pontoon, its bow and stern parts to still float on the surface of the water. However, these pontoons were not accepted!).
In 1759, the pontoon part in Russia received an important improvement thanks to the introduction of canvas pontoons, which are an original Russian invention.
The canvas pontoons were invented by captain Andrei N'mov, who was at that time serving in the Artillery Department.
Canvas pontoons, when they appeared, had the same design and the same dimensions that are accepted at the present time, namely: 9 arsh. side length, 7 arsh. bottom length, 1 arsh. height and 214 arsh. width. Of the parts that make up the flooring, the crossbars imZli 91/4 arsh. length, and in section 4-5 inches, and placed on the edge; flooring boards were 10 ft. length and 1!/.—11/> dm. thickness. The pontoon with a canvas tire weighed 14 pounds, the bridge deck over the length of one span weighed 273/41 pounds.
Canvas pontoons, which appeared in our country at the very height of the war, were immediately put to use, and here, with their lightness and mobility, they did not slow down, from the very first time, in fact, to show their advantages over the heavy and clumsy copper pontoons. Their continuous and useful use during the Seven Years' War strengthened their existence. During these same campaigns, the Russwe, cutting copper and canvas pontoons, also used tin ones taken from the Prussians, and when building bridges of considerable length, or, in the event of a shortage of pontoons of one kind, they made them from these dissimilar pontoons. For example, in the campaign of 1760, the bridge was 170 fathoms long. length, built near Kulm, across the Vistula branch, consisted of: 22 copper, 3 tin Prussian and 48 canvas pontoons. Its construction began on May 19, at 3 o’clock in the afternoon, and was completed on the 22nd of the same month at noon; 112 people were assigned daily from the engineering regiment to carry out the work).