Since the First World War in developed countries, the concept of the so-called. squadron submarine - a ship with torpedo and artillery weapons capable of conducting surface combat as part of a formation. In the thirties, the Soviet industry implemented this idea in the framework of the IV series of submarines ("Type" P "), but the results were far from desired.
From concept to project
At the end of the twenties, an employee of the Leningrad Ostekhbyuro of the OGPU at plant No. 189 (now the Baltic plant) Alexei Nikolaevich Asafov (1886-1933) proposed to develop and build a diesel-electric submarine with advanced artillery weapons capable of fighting as part of a squadron. Such a boat could complement the vanguard and attack the enemy at the initial stages of the battle or fire at him when retreating. It could also be used to hunt amphibious assault forces during their transfer.
Several interesting technical solutions were proposed to implement the unusual concept. In order to improve the running and maneuvering characteristics in surface combat, the hull contours were designed with an eye on the destroyers of that time. At the same time, the submarine received a high side, for which the buoyancy reserve had to be brought to the level of 80-90 percent. The project involved the use of torpedo tubes and cannons up to 130 mm in caliber.
In the fall of 1930, the draft design of the future IV series was reviewed and approved by the command of the fleet, after which the development of working documentation began. However, organizational problems arose almost immediately. It was proposed to use German-made diesel engines on the new boats, but Ostechbyuro was unable to quickly obtain the necessary data about them. Without waiting for them, the bureau in January 1931 began to develop the final version of the project.
Having saved time, shipyard # 189 already laid down the foundation of the lead ship in May. This boat received the number P-1 and the name Pravda. In December, construction began on the P-2 Zvezda and P-3 Iskra submarines. They decided to name the cases of the new series after the famous party newspapers.
Criticism
Against the background of the start of construction, disputes began about the real possibilities and prospects of submarines. Calculations showed that the sediment is approx. 3 m and a buoyancy margin of more than 90% make it difficult to dive, and a quick dive tank was not envisaged in the project. The robust hull allowed operation at depths of no more than 60 m, which was considered insufficient. There were also complaints about insufficient torpedo armament, etc. Later, new problems were identified.
Due to the identified shortcomings and the critical attitude of the Navy specialists, at the end of 1931 the construction of three submarines was suspended. By this time, "Ostekhbyuro" was transformed into a Special design and technical bureau No. 2, and the revision of the project was entrusted to the renewed organization. In October 1932, a new version of the "Type P" was approved, after which it was allowed to continue the construction of "Pravda". At the same time, Iskra and Zvezda should have been mothballed.
Early next year, a group of engineers led by A. N. Asafov visited Germany to organize the supply of the necessary imported components. Returning home, the chief designer fell seriously ill. On February 21, 1933, he passed away. Asafov's place was taken by P. I. Serdyuk. Under his leadership, the development of the "P" project was completed, and the development of the "Baby" series continued.
On January 30, 1934, the completed submarine P-1 was launched and transferred to sea trials. The main characteristics were confirmed, but the question of the strength of the case and the permissible immersion depth remained open. On September 12, "Pravda" without a crew, with ballast and measuring equipment, with the help of the "Kommuna" vessel, was lowered to a depth of 72.5 m. Based on the results of this event, the working depth of the boat was determined at 50 m, the maximum - 70 m.
After passing the tests, the P-1 "Pravda" went for the last revision before being put into service. The Navy also allowed the construction of the P-2 and P-3 submarines according to the modified design to continue. The Iskra was launched on December 4, and the Zvezda entered trials only in mid-February 1935. However, the submarines of the new IV series were no longer considered as warships. They were planned to be used as training ships, as well as to gain experience in new solutions and technologies.
Design features
Project "P" proposed the use of a two-body scheme. The robust hull was divided into seven compartments and for the first time in domestic practice was built using external frames. The light hull formed general contours designed to improve performance on the surface. A set of ballast tanks was placed between the two hulls. The filling and blowing valves were equipped with electric and pneumatic remote actuators.
For the IV series, diesel engines MAN M10V48 / 49 with a capacity of 2700 hp were purchased in Germany. At that time, these were the most powerful engines in Soviet submarine building. Also "Type" P "received two rechargeable batteries of the EK type in two groups of 112 pcs. and two propulsion electric motors PP84 / 95 with a capacity of 550 hp each. The normal supply of diesel fuel exceeded 28 tons, the full one was approx. 92 t.
During the tests, "Pravda" showed a maximum surface speed of 18.8 knots. At this speed, the normal fuel reserve provided a cruising range of 635 nautical miles. An economic surface course of 15, 3 knots gave a range of 1670 miles. The maximum speed under water reached 7, 9 knots, while the batteries were enough for 108 minutes of movement. It took almost 14 hours to recharge the batteries.
P-1/2/3 received navigation and other devices typical for domestic submarines of that time. In particular, they used the MARS-12 sound direction finder, several radio stations and receivers of different ranges, the Sirius sonar communication device, etc.
In the bow of the submarine there were 4 torpedo tubes of 533 mm caliber, two more devices were placed in the stern. Ammunition included 10 torpedoes - one each in the vehicles and 4 additional ones in the bow compartment. The torpedoes were loaded through the apparatus and through a separate hatch.
It was originally proposed to equip the squadron submarine with 130 and 37 mm cannons. In the final version of the project, two 100-mm B-24 guns were used in closed installations at the bow and stern of the wheelhouse enclosure. A 45-mm 21-K anti-aircraft gun was placed on top of the fence. Ammunition - 227 and 460 shells, respectively.
The crew of the submarine "P" consisted of 53 people, incl. 10 officers. The latter were located in separate cabins; an improved layout was envisaged for the commander, commissar and navigator. There was also an officers' mess and a wardroom. 44 berths for foremen and Red Navy men were divided into several compartments.
The design autonomy of Pravda and other boats reached 28 days, but the actual one was reduced to 15 days. An air regeneration system with 13 machines was envisaged. There were 17 oxygen cylinders with a total volume of more than 650 liters and 1438 RV-3 regeneration cartridges.
In the original project, the length of the boat "P" reached 90 m, then it was reduced to 87, 7 m. Width - 8 m. The average draft in the final version of the project remained at the level of 2, 9 m. Surface displacement was 955 tons, underwater - more than 1670 T.
Submarines in service
On June 9, 1936, all three boats of the IV series were taken over by the navy. A few weeks later they were included in the Baltic Fleet. Due to the limited tactical and technical characteristics and specific weapons, such ships were not of interest as combat units, and they were identified as training ones.
Until the end of 1937, Pravda, Zvezda and Iskra provided training for the Red Navy and submarine officers of the Baltic Fleet and proved to be quite good in their training capacity. In addition, they have repeatedly had occasion to receive various delegations of the country's military and political leadership.
In the fall of 1937, a "Type P" modernization program began, taking into account the operating experience. In dry dock conditions, individual components and assemblies were replaced due to resource depletion or obsolescence. Also, the lightweight hull and the wheelhouse guard were improved. In particular, the B-24 cannons were now located openly. By the end of 1938, Pravda was returned to service; two other boats followed her.
On June 22, 1941, all three submarines were in Oranienbaum. In early September, they were transferred to Kronstadt to solve various problems. So, the P-1 was to deliver ammunition, medicines, food, etc. our parts on about. Hanko. September 8 "Pravda" under the command of Lieutenant-Commander I. A. Loginova arrived in Kronstadt, where she received almost 20 tons of cargo. The next day she went to see Hanko. On September 11-12, the submarine was supposed to arrive at the point of unloading, but this did not happen. In October, the ship was expelled from the Navy as missing.
In 2011, a wrecked submarine was found 6 miles south of Kalbodagrund Lighthouse. The following year, the expedition "Bow to the ships of the Great Victory" established that it was the missing P-1. During the trip to Hanko, the ship was blown up by a German mine. A memorial plaque was installed on the deceased Pravda. The submarine is recognized as a mass grave.
The P-2 "Zvezda" was also supposed to participate in the transport operation, but after the loss of the P-1, this was abandoned. Until the end of October, the P-2 remained in Kronstadt, when it was sent to fire at enemy positions on the coast. Due to technical problems, the submarine had to return; during the combat exit, she came under fire several times. After repairs, in December, the P-2 was repeatedly used to deliver fuel to Leningrad.
P-3 "Iskra" in September fell under the fragments of an enemy bomb and required minor repairs. On October 29, she arrived in Leningrad and became part of the city air defense system. In May 1942, P-2 and P-3 were mothballed. At the beginning of the next year, they were transferred to the division of submarines under construction and overhaul.
In August 1944, the P-2 and P-3 submarines were withdrawn from the Navy. "Zvezda" was transferred to the Research Institute of Communications and Telemechanics as an experimental ship, and "Iskra" was transferred to the Higher Naval Engineering School. However, already in August and November 1945, the boats were returned to the fleet for use as training. In 1949, both pennants became large submarines. Soon P-2 received the number B-31, and P-3 - B-1.
In 1952, due to moral and physical obsolescence, the B-1 submarine was withdrawn from the Navy, disarmed and dismantled. The building was transferred to NII-11 for research. The B-31 remained in service until 1955. The next year it was handed over for cutting.
Useful experience
Project P was based on the original idea of a squadron submarine capable of conducting open artillery combat and secretly attacking targets with torpedoes. Its implementation in the form of series IV ships was unsuccessful. The authors of the project, due to the lack of the necessary experience, made a number of serious mistakes, as a result of which the three built submarines turned out to be unsuitable for full-fledged combat use.
However, with the help of Pravda and two other submarines, it was possible to test new ideas, solutions and components. The accumulated experience of creating the "Type" P "project was soon used in the development of cruising submarines" K ". They were built in a larger series, were actively used in the Great Patriotic War and showed acceptable performance.
