Project STROP

Hello everyone,

today, we’re going to have a look at another Czechoslovak post-war project, although this time, it’s from the 80′s. It was developed under the code name of STROP (“ceiling”).


By the time the idea that the Czechoslovak army should get a new AA vehicle was mentioned in the 70′s, the army was still equipped with the legendary vz.53/59 twin 30mm self-propelled AA autocannon on Praga chassis, also known as “Ještěrka” (lizard) – why was it legendary? This vehicle was extremely rugged and found its way all across the globe. This wheeled SP-AA vehicle did however some notable flaws, that were relevant to the Czechoslovak army. For starters, it could be operated in areas affected by WMD’s. Its targetting system could not be connected to the effective command structure to the army and the gunner of the vehicle is practically exposed to shell fragments and small arms fire.

And thus an idea was born to provide the army with something more effective in the AA role. However, the research was complicated, took time and so it was only in 1981 when it was finally decided to properly modernize the aging “Ještěrka” AA vehicle. The development was further complicated by the fact that the at that point, indigenous AA autocannons were not being developed for quite some time and that the electronics industry was not properly developed either.


In the end, the task to create a new AA vehicle was given to the Research Institute 010, specifically its 01 Department in Slavičín, in the cooperation with Research Institute 060 in Vyškov and other 010 departments. The project recieved a code name “STROP”. The task for these institutes from 1982 was “to propose a modern AA system, that can be manufactured from parts provided by Czechoslovak industry only and by the end of 1984 to build and trial a prototype”.

The demands from the army were following:

- to passively find targets moving with speeds up to 300 m/s at the distance of 15-20km
- to identify targets at at least 10km distance
- to accurately aim in order to fire at at least 4km distance
- to be able to fire on both ground stationary and ground moving targets

The vehicle was to consist of:

- a lightly armored chassis, based on a modified BMP-1
- a turret system, consisting of two turret parts linked together, autocannons, targetting systems and servo drives
- fire control system for the operator
- primary power sources, such as batteries and a generator

The prototype of the vehicle was based on a regular BMP-1 with a turret removed. The hull was somewhat modified as well. The relatively bulky fire control system was inserted inside the vehicle compartment. BMP-1 was chosen as a platform because it was readily available, it did fit the criteria required (WMD protection) and the army had experience with it already. Following changes were made to the hull:

- removed all the equipment inside the squad compartment, such as air filters and periscopes, the holes after them were covered
- removed the smoke generator and the middle fuel tank, reducing the fuel capacity from 460 to 120 liters
- moved the vehicle batteries to the squad compartment
- removed the commander vision devices, his seat and other communication equipment
- strenghtening the hull of the vehicle by welding an additional “skeleton” on it for improved structural integrity
- installing a turret ring from the T-55 tank

Driver’s compartment was not changed. The prototype turret was practically the same as on the “Ještěrka”. The cannons (30mm) were practically unmodified, although in the future, it was proposed to replace them with something new. The manual fire controls of the original system were removed and new, automatized fire control system was attached to the turret. The system was extremely complicated and required a lot of trials. All in all, over 400 trials were performed. In the end, the parameters of the guns remained the same as on the earlier “Ještěrka” design (the guns were not modified, because it was decided they would be eventually replaced anyway).

The gun turret could traverse to 180 degrees to each side. The turret could turn as fast as 100 degrees per second in traverse (and 60 degrees per second in elevation). The maximum range of the TV targetting device and the range finder was 7 kilometers (under ideal conditions, it was possible to track a MiG 21 at 11 kilometers though). It was possible to start firing after 6 seconds from the point of target acquisition. The maximum firing distance was 4000m on target closing towards you, the effective firing distance was 1500-2000 meters.

First trials took place in 1984, more trials a year later. In the end however it was found that the BMP-1 with 6 roadwheels does not have sufficient carrying capability – a prolonged chassis with 7 roadwheels would have to be created, or the vehicle would have to be moved to a platform with wheels. And so, the prototype did not fulfill the expectations, but the experience served the developers well in the future. Project STROP was cancelled, but later on, another project – STROP II – was concieved, this time on a wheeled T815 truck chassis.

Weight: 15,17 tons
Length: 6,74m
Width: 2,94m
Height: 3,575m (combat position), 2,7m (travelling position)

Gun: twin 30mm Vz.53/59, -8/+80 elevation, 180 degrees traverse, 420-450 rounds per minute (per one gun), 50 rounds in a feeder

14 thoughts on “Project STROP

    • Would you expect armoured units to go into action without something mobile and tough enough to protect them against air attack ? Plus if you are exporting tanks it is a nice add on.

    • That is the dilema of todays weapons systems. It is hard to achieve a good balance between either single purpose systems/low capability/no protection with a low cost per unit VERSUS multiple purpose systems/high capability/good protection with a high cost per unit.

      Sure, they could have stuck those guns on the back of a Toyota pick-up Somali warlord style and it would have done the job of shooting down aircraft effectively but once you recognize the need to also protect your crew you will need something like this Chech project. There is no way around it.

        • Not sure if you LOLed at what i ment with it or the second possible meaning i just realised it could be. Anyway, glad i made your day happier. :-)

  1. SS, You definitely should check the awesome RTS series called WarGame. First and second part are now dirt cheap on Steam.
    (Yes, You can create all Czech army in WG: Air-Land Battle. There is Strop, T55 and several hundred other vehicles.
    Vydra is love, vydra is life)

    • Wargame … amazing …… especially east german/poland T-34-85 spamm , i at least spamm T-72M or T-55
      but last patch bring sci fi unit for ČSLA – T-72 with ATGM , i think we in real life have only few t-55 with ATGM & Hammer fire control system

      btw as conscrip i serve as gunner on Pldvk vz 53/59 (15 years ago ) , so i know throse guns well
      50 round (each magazine) is maximum but more common is 45 or less , fully loaded magazine weight 90 kg and must be loaded swiftly so loaders have hard life :-)

  2. Urm, was not STROP project based on Tatra chassis? The same chassis as on DANA self-propelled howitzers?

    edit: sorry, I see it, it was STROP II

  3. Why did the Czech army not use the ZSU 23-4 Shilka, or the Tunguska?

    Was it not a bit of a waste of money to develop a new vehicle when the Warsaw Pact allies had so many off-the-shelf components and systems ready or in use? I’m afraid I don’t understand the dynamics of arms development in the former countries of the Soviet Union enough. I also thought each country was assigned a certain area of expertise (which is why East Germany had to stop work on their Baade 152 jet airliner).

    • I am guessing the same reasons different NATO countries have different arms development programs. The Warsaw pact countries where not on such a short leash as many people believe, alternative projects where tolerated unless they threatened Soviet interests. Minor supplementary weapon systems where generally not blocked and every country wanted to maintain their indigenous expertise and know-how with these projects. Chechoslovakia especially had a long tradition of weapons development and production so they had a lot to keep alive.

      • You live and learn.

        That also explains why the Czechoslovaks were allowed to build their vz 58 rifles, despite the AK series.