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Last Updated: Mon Jan 27 11:18:09 UTC 2014

NKMZ 40V6M/40V6MD/40V6MT Universal Mobile Mast
НКМЗ 40В6М/40В6МД/
40В6МТ Универсальная Передвижная Вышка

Technical Report APA-TR-2009-0504

by Dr Carlo Kopp, AFAIAA, SMIEEE, PEng
May 2009
Updated May, June 2011
Updated April, 2012
Text, Line Art © 2009 - 2012 Carlo Kopp

A deployed S-300PS / SA-10B battery showing the 5N63S Flap Lid B and 5N66 Clam Shell A deployed on 40V6M 24 metre masts. Note the MAZ-7910 radar vehicle with the antenna head removed (Russian internet image).


The 40V6M/MD family of mobile mast systems is a ubiquitous feature of the Russian air defence landscape, used with more different radar types than any other design. The 40V6M/MD has no known equivalents in the West, and represents a uniquely Soviet approach to standardising the deployment of radar equipment. While the headlong drive to high mobility shoot-and-scoot radar and missile systems has seen the 40V6M/MD decline in popularity with many clients, this mast design remains on offer in catalogues and brochures for most of the latest Russian radar designs, be they with mechanically steered antennas or phased arrays.

The first known application of the 40V6M series was as part of the early S-300PT / SA-10 Grumble A semi-mobile Surface to Air Missile system, employed to elevate the 5N63 Flap Lid engagement radar, the 36D6/ST-68U/UM Tin Shield acquisition radar, and the 5N66/5N66M Clam Shell FMCW low altitude acquisition radar.

The stated motives behind the development and deployment of the 40V6M/MD masts were to provide acceptable low altitude coverage footprint for the S-300PT system, tasked with intercepting low flying nuclear armed Strategic Air Command B-52G/H, FB-111A bombers, and the AGM-86B ACLM and MGM-109G GLCM cruise missiles, all of which were considered terminal threats to the Rodina. The severity of the threat justified the considerable expense in developing a complex high payload mast system, suitable for deployment in often complex terrain, and in often highly adverse climatic and weather conditions.

A particular problem the Soviets faced during this period was the diverse geography of the Soviet Union and its Warsaw Pact client states. Terrain varied widely, from flat central Asian steppes, tundra and taiga, to hilly and often mountainous terrain in European Russia, Central Europe, the Caucasus, the Urals, and the foothills of the Himalayas. Where elevated terrain was available, sites for placing S-300PT battery radars would be abundant. Many areas of European Russia and Siberia are heavily forested with tall conifer and deciduous trees, presenting an additional problem with achieving good antenna elevation above terrain and foliage.

Physics mostly do not favour low altitude radar propagation. The curvature of the earth is a primary consideration, as it limits geometrical line of sight to targets. Refraction, the byproduct of decreasing atmospheric density with increasing altitude, favours propagation by "bending" the ray path over horizon, but this effect only becomes significant at tens of nautical miles of range to a target, or greater.

Elevating a radar antenna by using a mast will directly increase the useful range against a low altitude target. It also aids in detection of high flying targets at much longer ranges, by reducing the necessary depression angle of the antenna boresight required to see such targets.

Development of 40V6 family of masts started during the 1970s, with the design entering production around 1980. The design and manufacture was performed by the  NKMZ (Novokramatorsky Mashinostroitelny Zavod - http://www.nkmz.com/) in the Ukraine, best known for the design and manufacture of space launch vehicle gantries and associated support equipment. Key design personnel were given in 1985 Soviet government awards for their technical achievement on the 40V6 project.

A key design imperative was stability of the design under high wind loading and near miss nuclear attacks. Ukrainian sources claim that a simulated nuclear blast overpressure wave failed to topple the 40V6M, only causing one of the outriggers to lift off the ground, with the mast returning to its stable position.

No summary figures for the total number of 40V6M/MD systems built have ever been disclosed, but a number in the hundreds is supportable, as one or more masts were deployed with each S-300PT battery, and the mast was also supplied with standalone Tin Shield and Clam Shell installations.

In 2004, following the breakdown in relations between Russia and the Ukraine, NKMZ ceased manufacturing products for the Russian military-industrial complex. As the 40V6M/MD remains on offer as part of Russian supplied radar and SAM system packages, including new build S-300PMU2 Favorit and S-400 systems, it is likely that warehoused units and/or refurbished former Russian stocks are being supplied, although production of new hardware in Russia cannot be ruled out. Recent Russian publications on military tow tractors cite two more variants of the design, the 40V6M-R and 40V6M-R0, but no open source details of these designs have been published as yet.

ST-68UM Tin Shield acquisition radars deployed on a 40V6M mast. Above: This uncommon perspective of the system is revealing, insofar as it shows the use of the mast to position the radar phase centre above the treetops, in typical Russian rural forested terrain. The image also shows clearly the splayed out outriggers, the Tin Shield equipment van, and the MAZ-537 tractor. Below: another Tin Shield in forested terrain (Russian Internet images).

An excellent study of the 5N66M Clam Shell B antenna system by Said Aminov, produced at Togliati in Russia (© 2009, Said Aminov).

40V6M/MD Universal Mobile Mast Design

The 40V6M/MD is a large item of equipment, by any measure, this being a consequence of the need to elevate radar antenna head subsytems often massing 10 tonnes or more, and withstand wind speeds of ~60 knots [30 m/s] during operation, and ~100 knots [50 m/s] when erected but not operating the radar.

Two configurations are most commonly used, these being the shorter 78 ft 40V6M and taller 127 ft 40V6MD. The cited mast heights in Russian literature are 24 metres and 40 metres, respectively, and actually refer to the elevation of the antenna phase centre when mounted on the mast, rather than the physical height of the antenna.

Above: Detail of the base of the 40V6M mast system, showing the splayed out outriggers. Below: detail of 40V6M at Elektrostal', with the mast in stowed position, but outriggers deployed (© 2010, Leonid Varlamov).

Both the 40V6M and 40V6MD use a rigid base support frame built as a semi-trailer, which mounts the elevating mast. The system is deployed by first positioning the trailer, decoupling the tractor, swinging out the outriggers and locking them into position, then attaching the radar head, and then finally elevating the mast and locking it into position. The cited deployment time is usually ~1 hr for this configuration.

The 40V6MD is more complicated in deployment, as the upper segment  with the radar head has to be positioned and mounted by a separate crane before the radar head can be attached. The cited deployment time is usually ~2 hr for this configuration. This is shown in Annex B.

In Russian service the 40V6M base mast system semi-trailer is usually towed by the legacy MAZ-537 65 tonne payload 8 x 8 tow tractor, developed during the 1960s as a tank transporter and artillery tractor, but also widely used for transporting ballistic missiles. Any 65-70 tonne class tank transporter tow tractor with a compatible coupling could be used.

40V6MD upper segment carried on 5T58-2 transporter, towed by BAZ-6402-015 tractor (BZKT).

The 40V6MD upper segment is carried by a modified 5T58 missile transporter semi-trailer, also built by NKMZ, and usually towed by a 6 x 6 KrAZ-260 tractor. The latter is often used to transport antenna heads (e.g. 76N6 Clam Shell) and other associated equipment. In late production S-300PMU2 and S-400 systems the 5T58-2 is towed by a new 6 x 6 BAZ-6402-015 tractor.

While the MAZ-537 remains in use, recent publications indicate that it is to be replaced as the 40V6M/MD tow tractor by the new BZKT BAZ-6403.01 Voshchina.

In mobility terms, the 40V6M/MD system cannot compete with the now defacto standard 5 minute shoot-and-scoot SAM system configurations, but this must be weighed against the increased coverage the mast system provides. The ability to relocate a mast equipped radar in 1-2 hours provides sufficient mobility to defeat the targeting cycle of most cruise missiles. Given the new doctrine of actively defending sites using SPAAGs and point defence SAMs, a 1-2 hour redeployment cycle may well be sufficient to achieve good survivability in combat.

For the forseeable future the 40V6M/MD will provide a unique advantage to users of Russian radar and SAM systems.

40V6 Universal Mobile Mast Variants and Derivatives

There are a number of different subtypes and variants of the basic mast design, not all of which are described in Russian lietrature.

40V6 Universal Mobile Mast Variants
40В6 - универсальная передвижная вышка
40В6-Р-01 - универсальная передвижная вышка
40В6М - универсальная передвижная вышка (удлиненная)
40В6М-Р - универсальная передвижная вышка (удлиненная)
40В6М-Р-01 - универсальная передвижная вышка (удлиненная)
40В6М1 - универсальная передвижная вышка
40В6М2 - универсальная передвижная вышка
40В6МД - универсальная передвижная вышка (с надставкой)
40В6МТ - универсальная передвижная вышка
40В6МТ-Р - универсальная передвижная вышка

In 2011 the Russian MoD disclosed the configuration of the 40V6MT, a revised mast design intended for the late production S-400 Triumf / SA-21 and new S-500 Triumfator M SAM systems.

40V6MT Universal Mobile Mast System

The new 40V6MT replaces the legacy 40V6M/MD series. It appears to be an entirely new design with a different outrigger arrangement, and revised elevating mechanism. It is towed by a BAZ-6403.01 tractor.

Annex A 40V6M/MD Tow Tractors and Deployment

40V6M/MD Tow Tractors

40V6M mast system stowed during road transit, towed by the legacy MAZ-537 tractor. The design has excellent road mobility but the 1-2 hr deployment and stow time does not qualify it as a 'shoot and scoot' system. Below the MAZ-537, which despite its age still remains widely used. It was designed as a heavy artillery tow tractor but later used to tow ballistic missile transporters and other large payloads.

KET-T heavy recovery vehicle based on the 1960s MAZ-537 artillery and missile tow tractor., the latter well known as a tow vehicle for larger ballistic missiles. Despite the age of this vehicle it continues to be used to tow the NKMZ 40V6M/MD mobile radar masts (© 2011, Vitaliy Kuzmin).

Above/below: a 40V6M mast towed by a MAZ-537, in difficulty. These images show the antenna head mounting, and the main pivots for the mast and outriggers (Vestnik PVO).

A 40V6M mast system being transported by flatbed rail car (Russian internet image).


The new BZKT BAZ-6403.01 is a dedicated tractor for semi-trailer payloads, such as tank transporters and fuel tankers. It is also intended to tow the 91N6 Big Bird radar and 40V6M series mobile mast systems (Russian Internet).


Late model 5T58-2 S-400 transporter towed by BAZ-6402-015 tractor. The upper mast segment of the 40V6MD is carried on a 5T58-2 in late build S-300PMU2 and S-400 systems (image © 2011 Michael Jerdev).

40V6M Mast Deployment

The deployment of the 76N6 Clam Shell requires that the splayed outriggers be deployed before the mast is hydraulically elevated. This image gives a good measure of the size of this radar (upper). Slovakian Army S-300PMU battery elevating a 76N6 Clam Shell. Note the progressive tilt of the antenna assembly during elevation (lower - Slovakian MoD image).

Background - a 76N6 Clam Shell on the 40V6M mast almost fully elevated. The foreground image is a 5P85TE1 TEL.

Erecting the extended height 40V6MD mast arrangement requires the use of an 80 tonne crane, the KT-80 on a MAZ-7916 is most often used for this purpose - the vehicle is based on the RSD-10/SS-20 IRBM TEL. The 40V6MD requires three semitrailers for movement.

A derelict 40V6M mast system in stowed configuration, above tow tractor end, below antenna head end. Note the cable ducting leading up the mast to the antenna head (Russian internet images).

Annex B 40V6MD Extended Height Mobile Mast

In February, 2010, Michael Jerdev visited the Elektrostal' base outside Moscow, home to the 3rd Surface to Air Missile Battalion of  PVO Unit 61996, equipped with early variants of the S-400 SAM system. At least two examples of the 40V6MD are hosted at this base, and detailed imagery of one partially deployed 40V6MD mast system, the example in excellent condition, was collected.
All images © 2010, Michael Jerdev

Partially deployed 40V6MD.


Detail of partially deployed 40V6MD.

Detail of upper mast segment of partially deployed 40V6MD.


Detail of stowed lower mast segment of partially deployed 40V6MD.


Detail of stowed lower mast segment hydraulic actuators.


Above, below: detail of segment join hinge and rigid A-frame. The latter is used to maintain alignment of the upper segment, and the lower segment is lifted from horizontal to vertical position.

40V6MD Fully Deployed

The LEMZ 5N66 Clam Shell 2D FMCW acquisition radar deployed on the 127 ft 40V6MD extended height elevating mast (Russian Internet).

A pair of colocated
127 ft 40V6MD extended height elevating masts at an unspecified Russian site, mounting a 5N63 Flap Lid and 5N66 Clam Shell (Russian Internet).

Annex C Systems Employing the 40V6M/MD Mobile Mast System

LEMZ 5N66/5N66M/76N6E Clam Shell FMCW Acquisition Radar

76N6 Nizkovysotniy Obnaruzhitel'

Above/below: 76N6 Clam Shell with 78 ft 40V6M mast for improved low altitude coverage.

An excellent study of the 5N66M Clam Shell B antenna system by Said Aminov, produced at Togliati in Russia (© 2009, Said Aminov).

Greek Cypriot S-300PMU1 battery. In the foreground the stowed 30N6E1 Tomb Stone (Flap Lid), in the background the deployed 76N6 Clam Shell with 40V6M mast.

5N59/36D6/ST-68U/UM Tin Shield Acquisition Radar

The 36D6/ST-68U Tin Shield is the most common medium/high altitude acquistion radar employed with older S-300PT/PS/PM/PMU batteries. It is sometimes deployed on the 40V6M mast.

Almaz 5N63/30N6/30N6E/E1/E2 Flap Lid / Tomb Stone Engagement Radars

30N6 / 40V6M Flap Lid A - the 40V6M and 40V6MD masts are most frequently used with the 76N6 and 30N6 series radars, usually paired with equal height masts. The 40V6M and 40V6MD masts remain a cited option for the S-400 system's 92N2E Grave Stone and 96L6 Cheese Board radars (© 2009, Said Aminov).

Detail of the 5N63 Flap Lid A  F1 radar head module deployed on 40V6M semi-mobile mast system, by Said Aminov, produced at the Togliati Museum in Russia. The dual plane monopulse circular polarised primary feed has been stripped and the concertina shroud has deteriorated. The operator consoles are in the F2 module, typically located on a truck. Later self-propelled 5N63S Flap Lid B variants retained the capability to deploy the F1S module on the 40V6M/MD mast, with the F2S module remaining attached to the MAZ-7910 8x8 vehicle chassis (© 2009, Said Aminov).

LEMZ 96L6E Cheese Board Acquisition Radar

VNIIRT 67N6E Gamma DE AESA Acquisition Radar

Annex D Soviet Radar Deployment Platforms

The 40V6M/MD appears to be the most widely deployed system for elevating radar heads employed by the Soviets, and also widely exported with the S-300P weapon system. It has one clear limitation, which is that a common adaptor for the upper mast turntable must be integrated on the base of the radar head. Equipment without such an adaptor, or too heavy for the 40V6M/MD, cannot be deployed using these masts.

During the Cold War an alternate scheme was also used, which involved large elevating or ramped platforms. Sufficient imagery exists to identify the use of these with a number of Soviet radar types, including the ST-68U/UM/36D6 Tin Shield, the P-35/37 Bar Lock series, and the 5N62 Square Pair engagement radar for the SA-5 Gammon long range SAM system.

At least two types of elevating platform are identifiable. In both designs, a platform can be lowered to ground level to permit equipment to be driven or towed on to the platform. The platform is then raised to operating height using a system of pulleys and cables, and once in situ, is locked into position. Unfortunately all currently available imagery does not show the detail of the platform design, pulley mechanisms, and locking restraints.

The former Czechoslovak SA-5 Gammon SAM sites employed very large prefabricated concrete platforms, with long ramps permitting the equipment to be towed directly to the platform. This design is static, unlike the steel construction Soviet platforms which could be disassembled and relocated to new sites if required. Movement of the Soviet platforms would still be a major effort and very time consuming given the size of the components.

Detailed data of the these designs has not appeared in the open source domain, and imagery appears mostly to be produced using amatuer photographic equipment as the platforms present as interesting landmarks.

This image depicts an example of the tubular construction elevating radar platform, hosting a Tin Shield acquisition radar. The site is on flat terrain so the intent was to increase radar low altitude coverage footprint (Russian Internet image).

A 19Zh6 Tin Shield operating from a fixed elevated platform, the whole semi-trailer being so emplaced. This installation is static, but affords stability, access and elevation which cannot be achieved using a 40V6M/MD mast (Czech Army).

This image depicts a derelict example of the tubular construction elevating radar platform, with the platform lowered for equipment deployment or removal. The design is modular in the sense that overall height could be adapted by changing the number of tubular leg segments during platform deployment. This example also shows the cable mechanism used to lower or raise the platform, on the aft pair of legs. The site is in forested terrain so the intent was to elevate the radar above the foliage (Russian Internet image).

Above, below: images of derelict example of the Soviet lattice construction radar platform. This design uses construction techniques akin to those used for railway and road bridges and is likely not intended for redeployment. To the left in the upper image, and in the foreground of the lower image, is a bunker intended to protect the radar vans and generator vans from both the elements, and overpressure effects produced by conventional or nuclear munitions (Russian Internet images).

Former Czechoslovak fixed platform at the Dobříš S-200VE / SA-5B Gammon SAM site. The 5N62V Square Pair B K-1V radar head van is located behind a protective screen (image Matej Kopecky).

5N62V Square Pair B K-1V radar head van on one of the Dobříš S-200VE / SA-5B Gammon SAM site platform (image Matej Kopecky).

Technical Report APA-TR-2009-0504

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