Tuesday, May 9, 2017

Dropping the Big One

by Krzysztof Dabrowski

The Big One usually refers to a nuclear weapon, a nuclear bomb in particular. In case of the AN602 (AH602) this term is especially fitting for this thermonuclear weapon was indeed big both in terms of its yield as well as weight and dimensions. The bomb went under several other designations including RDS-202 (РДС-202), RN202 (PH202) and names such as Ivan (Иван). It was also called Kuzkina mat (Кузькина мать) literally meaning the mother of Kuzma which was a reference to the Soviet Union’s leader of that time Nikita Sergeyevich Khrushchev ( Ники́та Серге́евич Хрущёв) exclamation "Мы вам покажем Кузькину мать!" – phonetically “My vam pokazhem Kuzkinu mat!” – which literally means we will show you Kuzma’s mother but colloquially expresses the intention to teach others a harsh lesson. However arguably the weapon is best known as the Tsar bomba (Царь-бомба) even if the Soviets themselves never actually used this term. Since it is pointless to “swim against the tide” Tsar bomba will henceforth be used in this piece as well. The said “doomsday device” was developed by a team of physicists headed by Yulii Borisovich Khariton (Ю́лий Бори́сович Харито́н) which also included many other distinguished Soviet scientists with Andrei Dmitrievich Sakharov (Андре́й Дми́триевич Са́харов) among them.
While considerable attention is usually devoted to the bomb itself and its test – that hardly being surprising – the aircraft which delivered it and the men who flew it usually stay in relative obscurity. Yet a nuclear bomb without a bomber remains useless for obvious reasons. Thus it begs to devote a few words to the Tu 95V bomber which was an aircraft devised specifically to carry and drop the Tsar bomba.

The bomb undergoes the necessary preparations

Before moving on a few explanatory remarks concerning the aircraft’s designation seem fitting. In the Russian language  it stands as Ту 95В which leaves one with the not so obvious question of how to transliterate the Cyrillic character B into the Latin alphabet. In the English language V seems to be the most obvious choice yet in many languages, including the author’s native Polish, the letter W would be more appropriate. However since this article is in English it shall be Tu 95V as it is indeed spelled in most publications written in that language.

Officially the task of creating a delivery aircraft for the new bomb was given to the Tupolev design bureau (опытно-конструкторское бюро Туполевa) by the Soviet council of ministers on 17 March 1956 though work on the project had already commenced before that. Two options were considered, namely the Tu 16 jet bomber and the Tu 95 turboprop one and it swiftly became obvious that the latter was suited best for the task at hand.

The anti flash white finish is being applied – also to the back sides of the propellers as can be seen

Early calculations gave the weight of the bomb as 36 298 kg which was unacceptable for the aircraft would hardly be able to get into the air with such a load and any prolong flight was out of the question. Thus a revised designed of the bomb with a calculated weight of “only” 18 149 kg was prepared which showed itself to be more feasible for practical purposes.
Having gotten a realistic starting point for the design of appropriate aircraft modifications work could commence. The project was headed by the Tupolev Design Bureau’s deputy chief for armament systems A. V. Nadashkevich (А.В.Надашкевич).  A standard production Tu 95 aircraft number 5800302 (in some sources just referred to as the 302) manufactured in 1955 was taken in. The most obvious changes which had to be made were the fitting of a bomb carrying and release mechanism capable of handling the mass of the Tsar bomba as well as the enlargement of the bomb bay for the unusual ordnance would not only be much heavier but also considerably larger than any piece previously carried.

The bomb bay was enlarged to a length of 7,15 meters with bulkheads at each end separating it from the rest of the fuselage’s interior while its width was 1,75 or 1,78 meters depending on the source. Thus the Tsar bomba could be carried. However there was a penalty for this since the internal volume taken up by the enlarged bomb bay meant that there was less space for fuselage tanks which effectively reduced the amount of fuel and thus the aircraft’s range.

Concerning the carrying of the bomb itself it was decided to install a beam-type bomb rack similar to the BD-206 (БД-206) used on the Tu95K (Ту 95K) for the Kh-20 (X 20 – X in the Cyrillic alphabet and not x as in ex) missile. The device fitted to the Tu95V was designated BD7-95-242 (БД7-95-242) or BD-242 (БД-242) for short; it incorporated three Der 5-6 (Дер5-6) bomb shackles, each capable of supporting a maximum load of 8 167 kg. Yet the really difficult part was not to build the bomb rack itself but to ensure simultaneous load separation from all of its attachment points. In order to facilitate this the release mechanism underwent bench tests on the ground till the desired synchronization was achieved. Once the problem of releasing the payload was solved the whole apparatus was fitted inside the Tu 95V’s bomb bay being attached to the load bearing beams of the aircraft’s structure. Apart from the bomb the aircraft also had a defensive armament of six 23 mm cannons in three twin mountings: a dorsal turret DT-V12 (ДТ-В12), a ventral turret DT-N12 (ДТ-Н12) and a tail mounting DK-12 (ДК-12) with the overall ammunitions supply being 2 500 rounds.
Other than the enlarge bomb bay with its special fittings and the reduced fuel capacity there were hardly any the differences between the Tu 95V and a standard production aircraft – after all the Tu 95V was modified from one. However the difference in the amount of fuel carried was not a minor one for it reduced range and thus negated the ability of the Tu 95V to operate as a true strategic bomber

The bomb slung underneath the Tupolev, it obviously only partially fits into the bomb bay

Having modified an aircraft for the purpose of delivering the Tsar bomba the next stage of the program was to conduct its tests which were carried out in September of the year 1959 at the Zhukovsky (Жуковский) airbase under the supervision of colonel S.M. Kulikov (С.М.Куликов). The said trails were successfully completed but the bomb was not to be dropped for the time being. Politics prevented a live test of the Tsar bomba for the Soviet Union’s leader Khrushchev visited the United States and it was deemed to be undiplomatic to detonate a powerful nuclear device while there was a thaw in relations between the world powers. As a result the Tu 95V was assigned to the Uzyn (Узи́н) airbase located near Belaya Tserkov (Бе́лая Це́рковь) in the Ukraine. Since its bomb bay and bomb rack were configured for one-off type of ordnance it was incapable of carrying a standard war load and hence its usefulness was limited to aircrew flight training. But the Tu 95V was not to be employed in that role indefinitely.

As soon as the relation between the Soviet Union and the United States took a turn for the worse the test of the Tsar bomba was again on the agenda. It was scheduled to take place on a nuclear testing area at cape Sukhoy Nos (Сухой Нос) in the Novaya Zemlya (Новая Земля) archipelago the date being 30 October 1961. The operation was conducted from Oleny airfield (аэродром Олений) on the Kola peninsula (Ко́льский полуо́стров) were the Tsar bomba was delivered by train – it had a weight of 24 tons to which 800 kg more had to  be added accounting for a retarding parachute system. This was considerably more than earlier optimistic calculations showed (see above) but the Tu 95V was still able to take off with this load. Another problem arose due to the bomb’s size for the piece of ordnance measured 8 meters in length and 2,1 in diameter which was too much to fit even into the enlarged bomb bay of the aircraft meant to carry it. This problem was solved by removing the bomb bay’s doors so that the bomb would be carried semi recessed in the fuselage rather than fully internally. As a final touch the aircraft was given a white anti flash paint job. For the mission the Tu 95V was crewed by the pilot lt. colonel Andrey Egorovich Durnovcev (Андрей Егорович Дурновцев) navigator major Ivan Nikiforovitch Kleshch (Иван Никифорович Клещ) and flight engineer Valenty Yakovlevitch Bruy (Валентин Яковлевич Бруй).

Warming the engines. The bomb protruding from underneath the aircraft is clearly visible. So is the bomber’s whit anti flash finish

During the nuclear test the Tu 95V was to be accompanied by a chase plane which was a standard production Tu 16A (ТУ¬16А) number 3709. For this purpose the said aircraft was fitted with film recording equipment as well as measuring instruments and hence designated as a flying laboratory (literally aircraft laboratory – cамолёт ¬лаборатория), in addition it also received an anti-flash white finish. The aircraft was captained by lt. colonel Vladimir Fedorovitch Martinenko (Владимир Фёдорович Мартыненко).

As planned the Tu 95V accompanied by the Tu 16 took off from Oleny airfield in the morning hours of 30 October 1961 setting course for cape Sukhoy Nos. At 11 : 33 Moscow time the aircraft arrived over the test area at an altitude of 10 500 m (the Tu 16 at a somewhat different one to facilitate better filming of the bomb drop) and the Tu 95V released its load. After 188 seconds – the descent being slowed down by the breaking parachute – the bomb went off at an altitude of 4 200 meters (4 000 meter above ground) the coordinates of the detonation point being most frequently given as 730 51’N 540 30’E. Lead tampers dialed down in half the yield of the bomb’s calculated 100 megatons to 50 megatons (some sources put the actual yield at 58 megatons) but that was still enough to bring about a  gargantuan explosion with a humongous fireball and mushroom cloud – 64 km in height and with a diameter of almost 40 km – as well as a shock wave that was literally felt world wide, in fact it was registered by sensors to have went around the globe three times over!

The bomber with its load clearly visible takes to the air

 The Tu 16 chase aircraft follows

The Tu 95V was 39 km away from the point of detonation when it occurred and 115 km when the shock wave caught up with it, the figures for the Tu 16 being 53,5 km and 205 km respectively. Both aircraft were roughly shaken by the blast with the Tu 95 dropping some 800 meters before the pilot regained control and their white anti flash finish was scorched too. Yet despite this and a temporary communications failure caused by the nuclear  explosion they flew back without further incident and landed safely.

Sources differ concerning the use of the Tu 95V in the time period right after the event described above. While it is generally accepted that for considerable time following the test of the Tsar bomba the aircraft set idle it was also claimed that it was utilized to drop several less powerful nuclear bombs in subsequent tests of which a number were conducted in 1962. What is certain, is that later the Tu 95V was employed in the transport role ferrying elements of the Tu-144 (Ту-144) supersonic airliner colloquially referred to as the “Konkordski” due to its external similarity with the Anglo- French Concorde event though the design of both aircraft differed considerably. Subsequently the Tu 95V was assigned to the 1023 Heavy Bomber Aviation Regiment (1023 Тяжелый Бомбардировочный Авиационный Полк) based at Semipalatinsk (Семипалатинск) were it was used for training before being relegated to ground instruction airframe status and finally scrapped in the mid-1980s.

Last but not least the men who flew the Tu 95V on its historic mission deserve a few words. The pilot  A. E. Durnovcev  and navigator I. N. Kleshch were bestowed with the Hero of the Soviet Union (Герой Советского Союза) title receiving the Gold Star (Золотая Звезда) medals number 11127 and number 11132 respectively. In addition V. F. Martinenko who flew the Tu 16 chase plane was also awarded the title and the medal number 11131. All of these men have passed away since.

Andrey Egorovich Durnovcev    -     Ivan Nikiforovitch Kleshch   - Vladimir Fedorovitch Martinenko
Андрей Егорович Дурновцев   -  Иван Никифорович Клещ - Владимир Фёдорович Мартыненко

Closing it is worth to point out that while the bomb was certainly very powerful its practical value was limited. That is so because of the already mentioned facts – its size meant that it could only partially fit into an enlarged bomb bay of a modified Tu 95 with the said enlargement being made at the expense of internal fuel tanks which in turn cut the aircraft’s range thus  negating its ability to operate in a truly strategic role.

1 comment :

  1. Merci pour cet article (bien que la traduction anglais français soit parfois malheureuse). Je tacherais de le mettre en réf sur celui de la Tsar Bomba et de Andreï Dournovtsev du wiki :)