As the start of the 20^th century approached, the submarine was just coming to be an effective weapon system. However, it was still plagued by right mix of single or combination of propulsion units. It would be efficient if there was only one form of propulsion for the boat. Electric propulsion in the form of battery powered electric motors worked fine for propelling the boat submerged but it was slow with the small electric motors available and batteries were quickly exhausted and had to be recharged. The only practical solution required two forms of propulsion, electric for submerged use and another type for faster surface propulsion and to recharge the batteries for the electrical system. The only question remained as to the type of system for surface propulsion.

Early designs by John Holland and Simon Lake used gasoline-powered engines for surface use. However, leaky gasoline engines and gasoline fumes concentrated in the enclosed cylinder of the submarine’s hull created a very dangerous environment. The Royal Navy tried steam power with their infamous K class submarines and the result was a disaster. The diesel engine was the perfect choice for surface component of the submarine propulsion system. Through two world wars, even as the submarine transformed from a weapon of curiosity to an extraordinary deadly weapon of war, the combined diesel-electric power plant propelled the submarines of every navy. However, that situation was about to change. Two blinding flashes over Hiroshima and Nagasaki not only ended World War Two but also singled a revolution in not only submarine propulsion but also submarine weaponry. It did not happen immediately but from the moment that it was realized that nuclear power would be perfect for submarine propulsion, it was only a matter of time before a workable nuclear power plant was developed. The USN was blessed to have Captain Hyman Rickover involved in the nuclear program. Brusque, rude but brilliant Rickover was slated for retirement as a Captain and had already been passed over for promotion more than once. He had been assigned to work in Oak Ridge Tennessee after the war in the various nuclear programs that continued after the development of the atomic bomb had universally impressed the military and civilian leadership of those programs. Congress held up the promotion of 39 admirals and threatened to put civilians on navy promotion boards if Rickover was not promoted to Rear Admiral. The navy decided to fold its tent and give in. In July 1953 President Eisenhower announced Rickover’s promotion to Rear Admiral.

The immediate result for the USN was the quick development of the USS Nautilus SS-571, the first nuclear powered submarine. Although the diesel-electric still had a future, it would be as an adjunct to nuclear powered boats. One of the very first decisions was that the nuclear plant for USN submarines would be a pressurized water-cooled plant. The second USN nuclear submarine, USS Seawolf SSN-575, used a liquid metal cooling system, based on sodium. Since sodium explodes upon contact with water, a coolant system based upon an element that explodes in contact with water, might not be the best selection for a submarine, or any other ship for that matter.  That liquid metal reactor was tested but then replaced with the much safer water-cooled plant pioneered by the Nautilus. After the initial boats proved the safety of efficiency of nuclear power, plans were quickly put in hand to add nuclear weapons to a nuclear propelled boat. Initially an early form of cruise missile was tested with the Regulus II. These were air-breathing missiles and required the submarine to surface to prepare and fire the missile. During this launch time, the submarine would be very vulnerable to surface, sub-surface or aerial attack. It was decided to marry the nuclear powered submarine with nuclear tipped ballistic missiles that could be launched under water. This resulted in the Polaris missile, the George Washington class SSBM, and the birth of the “Boomer”.

The USN was not alone in developing both concepts. Hyman Rickover was born in 1898 in Makow, fifty miles from Warsaw Poland . His mother took him to the US in 1904. If she had stayed in Poland , which was part of the Russian Empire at the time, her son might have gone into a different navy. The Soviet Union also wished to have nuclear powered submarines and submarine carried nuclear tipped ballistic missiles. With the USN, the nuclear power plant was developed before the submarine launched ballistic missile, with the Soviet Navy, the ballistic missiles was developed first. The Soviet Union converted one Project 611 Zulu class diesel-electric submarine to carry one Scud missile based on V-2 technology. Five more were converted to carry two missiles housed in the sail. The first submarine class to enter operations designed from the start to carry ballistic missiles was the Soviet Project 629 Golf class. The Golf class was powered by a conventional diesel-electric propulsion system but carried three ballistic missiles in an enlarged sail. Introduced in 1958, twenty-three were built. The submarine had to be surfaced to fire the missiles.

A nuclear power plant for Soviet submarines developed very quickly. Between 1958 and 1960 three classes of nuclear powered submarines entered Soviet service. These were the Project 627 November class, Project 658 Hotel class and Project 659/675 Echo I/Echo II classes. Since all three designs were powered by the same power plants, which used two VI-A water coolant reactors, they were known collectively within NATO as the HENs. All three classes had comparatively short production runs because their nuclear plants were very dangerous. The Project 658 Hotel class was the first nuclear powered ballistic missile submarine, with the first one completed slightly ahead of the USS George Washington. Only eight were built and the very first one to commission was the K-19. You may have seen the movie K-19 Widowmaker, starring Harrison Ford. That was based on events that actually occurred on the K-19, which also was nicknamed by Soviet sailors, Hiroshima . On July 4, 1961 the K-19 was operating north of Iceland when a coolant line for the reactor burst and reactor temperature climbed to 1470 degrees F before a new coolant line could be rigged from the drinking water tank. Nine extraordinarily brave Russian sailors volunteered to make those repairs, knowing that they would receive a lethal dose of radiation. The K-19 was not scrapped. Instead the old power plant section was cut out and a new power plant section was installed. K-19 went back to sea in 1964 but her ill luck followed her. In 1968 she collided with the USS Gato, Thresher class attack boat, and in November 1972 twenty-eight crewmen of K-19 died as a result of a fire. The Hiroshima was not scrapped until 1991. The Hotel class was similar to the conventionally powered Golf class, with three missiles housed in an enlarged sail that had to be launched from the surface. As a design, it was far inferior to the George Washington design.

The first Soviet ballistic submarine design that even approached the capabilities of USN designs was the 1967 Project 667 Yankee class. This class marked a quantum improvement over the rather sad-sack Hotel class. The boats were equipped with the D-5 missile system with sixteen R-27 missiles that could be launched while submerged up to a depth of 300-feet. The range of the missiles was 1,440 miles. Although the design made extensive use of rubber outside and inside, as well as isolating mechanical systems with rubber padding in an effort to reduce noise, the design was still noisy and easily tracked by the USN. Nonetheless, the Yankee was a very successful design and 34 of the class were built. Although 34 units is certainly a long production run, the numbers champion for Soviet ballistic missile submarines goes to the design that followed the Yankee and was introduced in 1972. This was the Project 667B Murena Delta class.

As can be seen from the project numbers, the Project 667B Delta class was derived from the Project 667 Yankee class. The Delta design used the same sections forward of the missile bay as found in the Yankee design but employed the D-9 missile system with twelve R-29 missiles. Although the number of missiles had decreased from the Yankee design, the R-29 missiles were a great improvement over the Yankee R-27 missiles. The R-29 had a range of 4,680-miles. This greatly increased range meant that the Deltas could cruise in Russian waters or far closer to Russia and still be within range of US targets, making it much more difficult for the USN to acquire and track Delta boats. The Delta class has been built in four successive variants, each increasing in size and capabilities. Eighteen boats were built to the original Project 667B Murena Delta I specifications. Delta I boats were 459-feet long and displaced 11,750 tons submerged. Propelled by two water-cooled reactors producing a total of 45,000shp, the boats were capable of 18-knots on the surface and 25.5-knots submerged. The Project 667BD Murena-M Delta II, introduced in 1974, expanded the size of the design to accommodate four additional missiles of the R-29D type with a range of 5,460 miles. The length jumped to 510 feet, displacement to 13,250 tons submerged. The propulsion stayed the same so the speed dropped to 24 knots submerged. Four Delta IIs were produced. The Delta III was introduced 1975. Known as Project 667BDR Kalmar , fourteen of the Delta III boats were built. This variant had the same dimensions but were equipped with new missiles, the type RSM-50/SS-N-18 Stingray missiles in the sixteen missile tubes.

The final design was Project 667BDRM Delfin of Delta IV class. The first of this variant, the K-51, was laid down February 23, 1981 and went into service December 29, 1985. The size jumped again to 538 feet with a displacement of 11,740 tons surfaced and 15,500 tons submerged. Seven Delta IV units were completed with two more cancelled on the slips by President Yeltsin. Besides the extra length, the Delta IV boats could be distinguished from the Delta III boats by fewer limber holes at the base of the missile deck and a dispenser tube for a passive towed sonar at the top of rudder. The Delta IV was equipped with a new missile, the RSM-54 Shtil, SS-N-23 Skiff, with MIRVed warheads.

OKB Grigorov Delta IV
Have you been waiting for a 1:700 scale Soviet Boomer, other than the Typhoon? Now your wait is over because the Bulgarian firm of OKB Grigorov has produced the Delfin Project 667 BDRM, NATO Codename Delta IV. You certainly won’t spend days and days in assembling the kit, as it has only seven pieces, eight resin and two brass. This is typical of 1:700 scale submarines, since they don’t seem many things sticking out from the hull. It has something to do with water resistance and the desire to have a stream lined hull for high speeds.

With any submarine model, everything revolves around the hull. Even in 1:700 scale a Delta IV has a big hull. With the hump back missile deck, no one will call the Delta IV elegant in appearance but it does add character. OKB Grigorov has provided plenty of hull detail. Some may say that the incised lines are over scale and they would be correct. However, I am more than satisfied with this approach, since they purely to scale, most details wouldn’t be seen in this scale, especially when the hull is painted black. There are panel lines from the bow to beyond the mid point on the hull. Limber holes are fewer than the earlier Delta III and the model correctly shows no limber holes below the missile deck on the humpback, which were present on the Delta III. Torpedo tube doors as well as access hatches are clearly defined. The sail has base plates for the separate trainable dive planes, observation windows, as well as many other details. The sixteen missile doors on the missile deck really pop out on the model. At the stern of the hull are streamlined sensor protrusion and typical Soviet twin propeller hull configuration with two vertical navigation planes/ rudders and two horizontal dive planes but with the towed passive sensor pod at the top of the upper rudder plane. The model has a moderately thick casting sprue, which will need to be removed. There are seven more resin parts. Two are the sail dive planes, two are the propeller hubs and three are for a mounting stand for the completed model. The two brass parts are the seven bladed propellers. Once removed from the fret, they need to be gently curved to replicate the actual curves of the propellers. The propellers are counter rotating to cancel torque, so pay very close attention to the instructions which propeller goes to port and which to starboard.

The OKB Grigorov Delta IV is must have for any modeler who is a 1:700 scale modern submarines devotee. The whole line of modern submarines produced by OKB Grigorov is carried by Bill Gruner of Pacific Front.

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