The Soviet "Scud" missile family
  

R-11 (8A61)

       
8A61 (R-11)

R-11A (Sounding rocket)

R-11

             
R-11F (SLBM)
 

R-11M (8K11, Scud-A)

Engine: Single-chamber rocket engine S2.253 / 8D511 design OKB-2, chief designer Isayev (developed in 1952). The rocket R-11FM - S2.253A engine.
Starting method:  Self-ignition of the starting fuel and oxidizer
Fuel supply:  Displacing liquid accumulator pressure (on the first experimental missiles in 1953 with a powder-pressure accumulator).
Fuel:  Kerosene T-1 / TS-1
Oxidizer:  AK-20 (20% Nitrogen Tetroxide + 80% Nitric Acid)
Starting fuel:  TG-02 "Tonka-250" (a mixture of 50% Xylidine and 50% Triethylamine.
Thrust:   8,300 kg (s.l.)
Thrust: 10,300 kg (vac); 13,300 kg (R-11M)
Specific impulse:  219 sec (s.l.)

            R-11                       R-11 M

R-11M (Scud-A) on TEL (ISU-152)

     
R-11M

German Scud-A

Forward tank segment                                                         Intertank segment                                                                           Engine bay                    
 

R-11MU (8K12)

The R-11MU / 8K12 is an upgrading of the R-11M - a topic of research "Ural". Development began in SKB-385 (chief designer Makeyev)  in 1957 by project will upgrade missiles (duplicate circuits and components of equipment improve performance) without changing the composition of complex equipment. Due to changes in the mass range of equipment needed to maintain a more powerful engine with a turbo pump assembly for fuel (instead of the displacement system). The project is proposed to use engine EDB S3.42T-3 (chief designer  Sevruk) which range is estimated to be 150 km. With the new engine developers proposed the creation of a new missile modernization instead of the R-11M. By resolution 1958 were asked to develop on the basis of the R-11MU missiles R-17 (version 1).
Single-chamber rocket engine EDB S3.42T-3 (chief designer Sevruk). The engine is designed based on the engine S3.42A, used for V-300 La 217. The engine S3.42T-3 is similar to the later version Isayev S5.1 .
Starting method: Self-ignition of the starting fuel and oxidizer. Fuel supply - turbopump assembly running from the gas generator.
Thrust:  13,000 kg (approx.)
Fuel:  TM-185
Oxidizer:  AK-27
Starting fuel:  TG-02 "Samin"
  

R-11M  propulsion

Scud-A engine S2.253 (8D511)

Rear of a Scud-A with its special characteristics

R-17 (8K14, Scud-B)

One of the first's R-17 missiles on mod. Scud-A TEL

One of the first's R-17 missiles on mod. Scud-A TEL (ISU-152K)

Rear of a Scud-B  missile with jet vanes

               
Scud-B intertank section                                                                                  Tank bottom and engine bay

       
Guidance section

Warhead types

Vietnamese Scud-B

Scud-B missile in Afghanistan

An rare photo provided by the “Thai Irrawaddy News Magazine“
on June 24, 2009 shows a Hwasong missile in a factory allegedly
in Pyongyang which was photographedduring a visit by a Myanmar government delegation in 2008.

Soviet Scud-B in Germany

A rare photo of a confiscated North Korean AK-27 storage container

  
North-Koreas's Hwasong-5

Libyan Scud-B

   R-17  propulsion

     
Shahab-2 engine                                 S5.2 (9D21)         

 
Scud engine turbopump (4)

R-17 (version 1) - single-chamber rocket engine EDB S3.42T-3 (chief designer  Sevruk) - used in the design stage of R-11MU and in the first series of R-17. The engine is designed based on the engine S3.42A used for V-300 La217. The engine S3.42T-3 is similar to the later version Isayev S5.1 .
Starting method: Self-ignition of the starting fuel and oxidizer
Fuel supply: Turbo pump assembly running from the gas generator.
Dry mass:  160kg
Thrust:  13,000 kg (approx.)
Fuel:  TM-185
Oxidizer:  AK-27
Starting fuel:  TG-02 "Samin"

R-17 (version 2) - single-chamber rocket engine S5.2 / 9D21 DB-5 (chief designer Isayev), motor open circuit with TNA and gas generator, turbine drive gas out of the starting powder chamber. The engine was produced commercially from 1962 to 1985 Votkinsk Machine Building Plant. Design support LRE is the same Votkinsk plant.
Starting method: Self-ignition of the starting fuel and oxidizer
Fuel supply: Turbopump assembly running from the gas generator
Thrust: 13,310-13,380 kg (various sources)
Specific Impulse (s.l.):  226 sec
Specific Impulse (vac):  258 sec
Fuel consumption:  57.83 kg/sec
Length: 1,490 mm
Maximum diameter:  770 mm
The diameter of the combustion chamber:  380 mm
Nozzle throat diameter:  124.5 mm
Nozzle exit diameter: 400 mm
The pressure in the combustion chamber:  69.4 kg / cm
The pressure at the nozzle exit:  0.827 kg / cm

Refuelling of the Scud missile

Turbine of  Shahab-2 engine

Cutaway of a Shahab-2 engine

 
                  
Some Scud engines 9D21 (S5.2)
 

  Shahab-2 (Scud-B)

R-17 VTO (8K14-1F, Scud VTO)

The R-17 VTO / 8K14-1F "Aerofon" is a missile with a warhead that has the ability with optical instruments to locate the target. Experimental design tests of MS "Aerofon" began at Kapustin Yar from November 1977 to September 1979 with starts on 8K14-1 missiles. During state testing conducted 22 missile launches with MS "Aerofon."

Scud-B with optical warhead "Aerofon"

Scud-B on TEL with optical warhead "Aerofon"
 

  Qiam-1 (Scud-B)

  
Qiam-1 is a changed Shahab-2 without fins and a new design of guidance section and warhead

Comparison between Iranian Scud-B and Qiam-1

Source: Forum military.ir

Source: Forum military.ir

TEHRAN, 2011, May 22 -- The Qiam-1 missile was delivered now to the Aerospace Force of the Islamic Revolution Guards. Iranian television showed 10 missiles inside a hanger.
No details given on the technology used in the making of the missile. The rocket is very likely a derivative of the Shahab-2, itself derived from the Soviet Scud-B.
The Qiam design reduces the possibility of being detected by enemy anti-missile systems and the omission of its fins has increased the missile speed. These new missiles enjoy supersonic speed and cannot be tracked or intercepted by the enemy.
The new technology installed inside the missile enables it to fly towards targets without stabilizer fins, but instead with an advanced navigation and guidance system. The Qiam-1 was test-fired in August 2010.
 

Al-Hussein (Scud-B)

Al-Abbas (homemade)

The Iraqi Al-Hussein missiles was a Soviet Scud-B missiles (export varinat with conventional warehead). The Al-Hussein missile used TM-185 and AK-27I propellants.

The mysterious long Al-Abbas missile was a complete new homemade missile on base of cannibalised Scud missiles. On a rare photo we can see a three-part tandem arrangement of tanks :
A short tank on top, in the middle a long tank for the oxidizer, and below a tank for the fuel. It is believed that the short tank UDMH contains, the middle tank AK-20K (or AK-27I), and the lower tank TG-02 (or TM-185). The combination of UDMH + TG-02 (known as AZ-11) with AK-20K was tested on the Al-Samoud missiles. While on the Al-Samoud the AZ-11 fuel was mixed in one tank, was preferred the mixture from two tanks during flight on the Al-Abbas.

Iraqi AK-27 storage containers

Iraqi Scud-B engine

A rare picture of an Iraqi experimental Scud engine
 with nozzle expansion
(planned for the Al-Abid second stage)

       
Iraqi Al-Hussein

Al-Hussein

Iraqi Al-Abbas
in launch position on static pad

Iraqi Al-Abbas on parade

Iraqi Scud-B (Al-Hussein) on Soviet standard TEL

A rare picture with an Iraqi  Al-Abbas on TEL without erector
Al-Abbas was fired from a static pad !

Rear of a Iraqi Scud-B  missile with jet vanes

Destroyed Iraqi Scud-B missile with visibly engine S5.2

                   
                                    Iraqi Scud-B remains                                                                              Al-Abid test launch vehicle probably have used a cluster of Al-Abbas missiles
  

R-17M (8K14M, Scud-M)

A missile variant with extended fuel tanks and range up to 500 km. R & D conducted by SKB-385. Tests at the Kapustin Yar were carried out in 1964-1965. The test results established that the missile has a low accuracy and lack of structural strength. The further development was stopped (?) or there is another unknown variant (here named R-17M).

During the war in Afghanistan the Soviets tested a new type of Scud missiles with a range of 500 km. With the Soviet retreat from Afghanistan in 1989, this missile vanished from the public minds. One year later, in 1990, the DPRK fired one Scud missile with a range of 500 km. The striking similarity to a new Scud missile was ignored. This North Korean Scud missile is known under the designation “Hwasong-6”.

In reference to the Scud-B used propellants - specially the used fuel - in the sources it gives considerable differences. Frequently UDMH is called also. Accordingly the official Scud-B handbook is used however Hydrocarbons. At places in Afghanistan have been found alleged UDMH-containers now, which stand in connection with Soviet Scud rockets from the war in Afghanistan. Since is supposed, that also other Scud's were stationed, the idea is obvious, that this missile is of other quality as the Scud-B. Then the engine is the problem.   Up to now no photos are known, which Scud-M rockets presents sure.

Alleged UDMH storage containers in Afghanistan

Excerpt

Rocket fuel storage area
Location 2: It served as a storage area for cylindrical containers presumably filled with the rocket propellant dimethylhydrazine (UDMH). All of 107 containers – with an estimated capacity of 500 litres each – were kept in two separate stockpiles.
Closer inspection of the open containers revealed the presence of a white residue at the bottom.
Although none of the containers were found to be leaking, a faint, acrid, ammonia-like odour was clearly perceptible in their immediate vicinity.
These olfactory indications are consistent with the degradation process of hydrazine compounds, which form ammonia, hydrogen, and nitrogen when exposed to ultraviolet radiation (WHO, 1987).

Soil quality
Methylhydrazine was found in elevated concentrations in two composite samples, including that recovered from the superficial soil surrounding the rocket fuel containers stored at ground level (location 2). A pH of 3.9 was also recorded from this particular sample, suggesting that the soil in this area was reasonably acidic.
Given that hydrazines are basic compounds, the low pH reading could be attributable to a spill or leak of nitric acid in the past. This hypothesis is further supported by the relatively strong presence of nitrates in samples taken from this area, suggesting that UDMH and nitric acid were mixed there during rocket fuelling.

Note: The results of field studies are unfortunately not convincing.

       
                                                                                  Most likely a Scud-M
                                                                              (Hwasong-6)

Comparison between Scud-B and Scud-M (?) engine

Without heat exchanger tube !
  

Hwasong-6 (Scud-M)

In 1998, North Korea attempted to launch a small satellite for the first time. The rocket that was used for this mission, the so-called Taepo Dong-1 (Paektusan-1), was seen only once at this very occasion, and never again. According to available imagery, the first stage was a Nodong, and the dimensions of the second stage seemed similar to Scud. But this stage was equipped with an engine with varying thrust level, a feature that no Scud-B engine is able to do.
The upper stage of the North Korean Taepo Dong-1 space launcher was probably a Soviet Scud-M (Hwasong-6). missile. The propellant is consequently a combination of  UDMH/AK-27 propellants.
The fuel supply was adjustable so that the engine could burn with a thrust level of 100% and 30%.

                 TD-1                        Hwasong-6

  
TD-1 upper stage is a Hwasong-6

Sources:   http://military.tomsk.ru/blog/topic/210/topics.html
                   http://www.rwd-mb3.de/pages/8k14c.htm
                   http://www.peterhall.de/srbm/missiles/ussr/8k11/scud15.htm
                   http://9k72.ru/page.php?38 (link dead)
                   http://postconflict.unep.ch/publications/afghanistan_cont.pdf
                   http://www.thespacereview.com/archive/1498.pdf
                   http://www.c-x-i.eu/wp-content/Schmucker-Schiller-The_Missile_Show_DRAFT_10-05-05-1.pdf