The world's first underwater mine layer "Crab". Part 3. The fourth, last version of the protector Naletova M.P.

The fourth, latest version of the mine layer Naletova MP, which was adopted for construction, was a submarine with a displacement of 500 tons. The length of the vessel was 51,2 meter, midsection width - 4,6 meters, depth - 45,7 meters. Transition time from surface to submerged position - 4 min. The speed in the surface position was 15 nodes with a total power 4-x engines 1200 hp, in the underwater - 7,5 node with a total power 2-x electric motors 300 hp The number of battery cells - 120 pcs. Navigation range at a speed of 15 nodes is 1,5 thousand miles, while underwater at 7,5 nodes 22,5 miles. In the superstructure was installed two mine tubes. The number of mines - 60 system Naletova having zero buoyancy. The number of torpedo tubes - 2 with 4 torpedoes.

The body of the minelayer consisted of a solid, cigar-shaped body with a waterproof superstructure for the entire body length. Attached to the robust hull, surrounded by a bridge. The extremities were performed light.
The main ballast tank was located in the middle of a strong hull, which was limited to two transverse flat bulkheads and a hull of a solid hull. Bulkheads interconnected horizontally placed anchors and pipes. There were a total of seven pipes connecting the bulkheads. The largest radius tube (1000 mm) was in the upper compartment, its axis coincided with the axis of symmetry of the submarine. This pipe was used for passage to the engine room from the residential compartment. The remaining pipes had a smaller diameter: 2 pipes in 170 mm, 2 - in 400 mm, 2 - in 700 mm. The 170-mm pipes served to supply fresh air from the main ventilation pipe to the dwelling, and the other four pipes were high-pressure ballast tanks. Fodder and bow ballast tanks were also provided.

In addition to tanks of the main ballast, there were feed and bow differential tanks, torpedo replacement tanks and leveling tanks. 60 mines were located in two mine tubes. Mines on rails that were laid in mine tubes, had to move with the help of a cable or chain device, which was set in motion by an electric motor. Mina and the anchor constituted a single system; four rollers served for her movement. By adjusting the engine speed and changing the speed of the minelayer, the distance between the mines to be set was changed.
Details of the mine tubes, according to the specification, should have been developed after the construction of the mines was completed and tested for specials. polygon.

The drawings and specifications submitted by 2 on October 1907 by the plant were reviewed in the mechanical and shipbuilding departments of the MTC, and then at the general meeting of the MTC (November 10) chaired by Rear Admiral Virenius A.A. and with the participation of a representative of the Marine General Staff. 30 November at the meeting of the ITC addressed the issue of mines, hydraulic testing of the hull and the engines of the minelayer.

The requirements of the shipbuilding department of the Maritime Committee were as follows:
Draft mine layer in the surface position should not exceed 4,02 meters.
In the surface position, the metacentric height of the minelayer with mines is at least 254 mm.
Transition time of horizontal rudders 20 seconds, vertical - 30 seconds.
When the scuppers are closed, the superstructure add-on should be waterproof.
The transition time from the surface position to the position position is no more than 3,5 minutes.
The performance of air compressors is 25 thousand feet 3 (708 m3) of compressed air for 9 hours, that is, during this time a full reserve of air should be resumed.
The barrier in a submerged position should lay mines, moving at a speed of 5 nodes.
In the surface position, the speed of the haul should be 15 nodes. If this speed is less than 14 nodes, then the Marine Ministry has the right to refuse to accept the minelayer. In the positional position, the speed (under the kerosene engine) is 13 nodes.
The final selection of the battery system must be made within 3 months after signing the contract.
The body of the minelayer, its kerosene and ballast tanks should be tested with an appropriate hydraulic pressure, and the water leakage should not exceed 0,1 percent.
All tests of the underwater mine layer should be carried out with full armament, supplies, as well as with a fully equipped team.
According to the requirements of the Mechanical Department of the Marine Technical Committee, four kerosene engines should be installed on the mine layer, with a capacity of at least 300 hp. at 550 revolutions per minute each. The engine system had to choose the plant two months after the conclusion of the contract, and MTK had to approve the engine system proposed by the plant.
Naletov M.P. after launching the "Crab" into the water, he was forced to leave the factory, and the further construction of the minelayer was carried out without his participation. The construction was supervised by a special commission of the Maritime Ministry, which consisted of officers.

After Mikhail Petrovich was removed from the construction of the "Crab" and the plant and the Marine Ministry in every possible way tried to prove that the mine device and mines and even the underwater mine layer were not ... "Naletov's system." In the MTC about this 19 September 1912, the special took place. The meeting recorded the minutes: “The meeting made sure that Mr. Naletov had no priority in the proposal for submarines of mine barriers with a hollow anchor (with near-zero or zero buoyancy of the mine while it is in the submarine), since this issue was fundamentally It was developed at the mine department of the Marine Technical Committee before Mr. Naletov’s proposal, and therefore there is no reason to believe that not only the mines being developed, but also the whole barrier of the “Naletova system”.
Creator of the first underwater mine layer Naletov MP lived in Leningrad. He retired in 1934 year. In recent years, Mikhail Petrovich worked in the department of the chief mechanic of the Kirov Plant as a senior engineer.
In the last 10 years of his life, Naletov in his spare time worked on improving mine layers and filed several applications for new inventions in this field. Zalessky N.A. advised Naletova MP on hydrodynamics.
Mikhail Petrovich, in spite of his illness and old age, until the last days was engaged in the design and improvement of underwater mine layers.
Naletov M.P. died 30 March 1938 of the year. Unfortunately, during the Great Patriotic War and the blockade of Leningrad, all materials of Naletov died.

All parts:
Part of 1. New project of underwater mine layer
Part of 2. The second and third variants of the underwater layer
Part of 3. Fourth, the latest version of the minelayer Naletova MP.
Part of 4. How was arranged underwater mine layer "Crab"
Part of 5. The first military campaign of the underwater mine layer "Crab"
Part of 6. "Crab" becomes in repair
Part of 7. The end of the first underwater mine layer "Crab"