RT-20P / SS-15 SCROOGE - Western Views
Although the RT-20P missile was first displayed in the Moscow parade of November 1965, the flight test program did not begin until October 1967. Foreign military experts named the Soviet self-propelled launcher with a small intercontinental missile the "Iron Maiden".
The RT-20P represented several Western intelligence failures
- Western intelligence was initially puzzled as to whether the the SCROOGE canister housed a solid fuel or liquid fuel missile, as the canister dimensions seemed inconsistent with either alternative. Western intelligence evenutally correctly determined that the missile had a storable liquid-propellant second stage, but could not determine with confidence whether the first stage used liquid or solid propellants. A large missile with a solid first stage and liquid second stage was contrary to Western engineering practice [the Nike Hercules SAM being the notable exception]. In fact, the RT-20P had such a very un-American design, which accounted in part for the puzzling dimensions of the SCROOGE cannister.
- Western intelligence had difficulty understanding the SCROOGE, in part due to an assumption that the missile was tappered, with upper stages having smaller diameter than lower stages. This was reasonable, as contemporaneous and presumably similar missiles such as the SS-13 had such a tapered configuration. In fact, the RT-20P missile inside the SCROOGE cannister was not tapered, but had a contant diameter throughout the length of the missile. The provided more propellant loading than a tapered missile.
- Western intelligence was puzzled, at least initially, as to whether the RT-20P was a two or three-stage system.
- The RT-20P missile was the first Soviet mobile ICBM, although Western sources generally viewed the SS-X-15 as a theater-range ballistic missile rather than a true full range ICBM.
- Probably the greatest Western misconception of the RT-20P / SS-15 SCROOGE program was the implicit assumption that it represented a "successful" Soviet program, and that any residual puzzles were a failure of ingenuity of Western intelligence. In fact, the program was not successful, and over time the Soviets had no more success in understanding the program's "ideology" than Western intelligence - the more it was studied by the Soviets, the less it was understood, and eventually it was cancelled.
Two missile research and development programs -- the SS-13 and SS-X-15 ICBMs -- were undertaken at Plesetsk, both apparently with limited success. Only eight missiles were launched there in the SS-X-15 test and development program.
The Soviets displayed a new type of strategic missile system, subsequently nicknamed the SCROOGE, for the first time on the 07 November 1965 Moscow Parade. It comprised a tracked prime mover, similar to SCAMP, carrying a 65.5-foot-long cylindrical canister. Russian commentators claimed that these vehicles were "inter-continental small dimension solid-fuel rockets on self-propelled tracked launch installations". Two units were on display and were positioned in the order of march between SASIN and SCRAG [all three missiles were deceptive].
The UK Ministry of Defence, Directorate of Scientific And Technical Intelligence (DSTI), provided an assessment of the SCROOGE in December 1966 after the Moscow parade of November 1966. According to this report, "The Russians stated that SCROOGE houses a solid-propelled ICBM. However, though there is no evidence that they have deliberately lied in the past, this claim of solid propellants cannot be blindly accepted. The current political situation seems to have persuaded the Russians that some capital can be made out of proving to the world that they too have solid-propelled ICBMs and that the West are wrong to think otherwise.
"The construction of the SCROOGE canister and the inferences drawn from it do not favour one type of propulsion over another. The rear of the canister almost certainly houses a gas generator for cold ejection of the missile. This in itself does not suggest a particular type of propulsion as the cold-start principle is equally applicable to either solid or liquid rockets. However, the usually lower launch accelerations from a liquid propellant rocket would make cold ejection essential for such a missile launched from a closed tube; the higher acceleration from a solid rocket would permit it to escape before catastrophic damage was done to the tube by the efflux. Cold ejection would provide either type with a small velocity bonus which by be a reason for using it with a solid rocket. In summary, while a closed tube without a gas generator would almost certainly imply that the missile was solid propelled, the presence of the cold-ejection equipment does not necessarily indicate a liquid propellant system though it would be essential if the missile were so powered."
DSTI further noted that "To have based the missile assessment solely on the dimensional restrictions of the canister would have been dangerous and misleading... For considerations of economy, it would seem reasonable to expect SAVAGE to be the missile within the SROOGE canister. However, although the diameters match up well, SAVAGE is 6½ too long. even if the warhead and guidance package were removed, the remainder is still too long. In any case, carrying a missile with these parts separated would severely impact the advantage gained by the mobility of the system.
"An alternative, still using SAVAGE parts, would be to assume the canister houses a two-stage missile. However, such a missile, accepting even the most optimistic characteristics, would have a range of less than 3,000 nm which would be only of very limited use as an ICBM against targets in the United States even if SCROOGE were deployed in the far north and north-east of Russia. The possibility was considered that one of the stages of SAVAGE might have been shortened to permit it to fit into the canister. However, the ratio of the stage weights estimated for the paraded SAVAGE is fairly close to optimum and any such shortening would not be sound engineering practice.
"A much better solution if SAVAGE were required to fit into SCROOGE would have been to make the canister longer. It was thus concluded that neither SAVAGE nor a missile made up of any of its components were intended for use with the SCROOGE system. There is a possibility that a three stage solid fueled rocket recently [ie, 1966] tested by the Russians may be associated with either SAVAGE or SCROOGE or possibly both. However, insufficient is known of the vehicle at present to proceed further with this suggestion."
DSTI further noted that "Intercepts of Russian telemetry have permitted an assessment, as yet incomplete, of the two-stage liquid rocket ICBM, SS-11. The parameters deduced show that SS-11 is the only known Soviet liquid-powered missile which is not incompatible with the size limitations of SCROOGE. .... If a liquid rocket, it is probably the SS-11 having a range of about 5,200+ nm with a 1,500 lb. payload. .. An alternative suggestion is that the SCROOGE canisters shown on the parade are smaller than the intended in-service versions. Some collateral evidence exists to the effect that the SS-11 may be designed for firing from tubes slightly larger than SCROOGE .... "
DSTI observed that "It is not envisaged that the SCROOGE system would constantly roam selected areas of Russia and be prepared to launch from anywhere at extremely short notice. A much more likely concept is one where several transporter / launchers are held in readiness at one base area, possibly underground, but with road or track access, and which disperse to pre-surveyed by unprepared sites on receipt of a given alert condition. The launch sites would not be more that 30-50 nm from the base and base areas would be very difficult to detect. It is most unlikely that a canister would be used for more than one launch but the vehicle could certainly be re-equipped with a complete missile / canister unit at the base. However, it is unlikely that this could be completed in less than 24 hours and may not be considered worthwhile."
A missile believed to have been the SS-X-15 was seen in a Moscow parade in 1967, housed in a canister on a Scrooge-type TEL. On the basis of this observation, the missile was estimated to be about 59 feet in length, with a diameter between 5.5 and 6.3 feet.
Designed as a mobile ICBM, the two-stage SS-X-15 was first noted being launched on the Plesetsk range on 12 February 1968, though unsuccessfully. Following this initial flight, two additional launches were noted in 1968 -- on 18 June and 2 July. Both of these launches were successful, impacting on Kamchatka. The SS-X-15 test and development program apparently progressed slowly following these 1968 launches. Nine test launches were conducted from the Plesetsk test site with a total of eight being detected before the program apparently was abandoned following a successful flight in August 1967.
The missile was estimated to be capable of carrying a reentry vehicle weighing between 1,000 and 1,500 pounds, with a maximum range of approximately 4,200 nautical miles. Employing inertial guidance, the CEP of the probable liquid-fueled SS-X-15 was estimated at one nautical mile.
Only sparse information was available concerning this missile. It could not be discerned on the basis of available data how far it progressed into its test and development program, or if it in fact reached operational capability.
The development of the RT-20P missile was officially halted in October 1969, and the SS-X-15 was not deployed operationally.
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