The year is 1951, world war two has just ended and things are once again heating up in the world. With Sweden being in the middle it is understandable that they would want to have a strong military. The current armoured vehicles however were not living up to that standard anymore. With outdated armour and lacklustre armament the need for a replacement became more prominent. The Royal Army Administration (swedish: Kungliga armeförvaltningen) conducted careful research into different tanks, including but not limited to: the German Panzerkampfwagen VI “königstiger”, The Panzerkampfwagen V “panther”, the American m4 “sherman’’ and the British churchill and the equally british centurion. In the end the administration decided that the best alternative would be the British centurion. This was because of the promise that the tank would receive upgrades in the future and thus making it a good long term choice.
The British army however reported that they would not be able to deliver any centurions until their own needs for vehicles were met. This was going to take between 5 and 15 years. Not willing to wait that long, the Swedish army commissioned KAF to create a Swedish domestic alternative.
This domestic design was supposed to be able to be used as infantry gun carriage as well as a tank destroyer. More specifically it was supposed to be able to destroy the infamous soviet is-3.
The project was conducted by the now defunct Landsverk AB.
The first part of the vehicle that was researched was the armament. The three suggested armaments are shown in this document:
Following main alternatives for weapons in project “Emil” has been researched:
- 12 cm cannon, L/40, Preassure max ca 2.600 kg/cm2, Muzzle velocity = 850 m/s, weight ca 13 kg.
Projectile, 12 cm HEAT with rotating shell and substantially repealed rotation for the blast cone. (HEATFS possible)
- 10.5 cm cannon, L/67, Preassure max ca 3.400 kg/cm2, Muzzle velocity = 1.080 m/s, weight = 17 kg.
Projectile, 10.5/7 cm sub calibre projectile, Muzzle velocity = 1.350 m/s, weight = 11 kg
- 15 cm smoothbore cannon L/40, Preassure max 2.600 kg/cm2, Muzzle velocity = 900 m/s, weight = 25 kg.
Projectile, 15/11 cm sub caliber fin stabilised HEAT round.
End of translation.
The table with numbers are penetration statistics at different distances. The measurements are in mm at an angle of 30 degrees which is approximately the angle of an is-3 front plate. The table shows that the 12cm HEAT can penetrate 140mm armour angled at 30 degrees at any range and the 15cm HEATFSDS can penetrate 160mm armour at 30 degrees at any range.
Yes you read that right, no it’s not a typo. The Strv KRV was supposed to fire HEATFSDS ammo, as in High Explosive Anti Tank Fin Stabilised Discarding Sabot. This unorthodox ammunition type was used so that the pressure in the cannon could be reduced while keeping the high muzzle velocity. It also allowed the fins of the projectile to be static which lowered the complexity and made the round more reliable.
After careful research of the different cannons and ammunition the 15/11 cm HEATFSDS was chosen as the preferred alternative with the 10.5/7 cm APDS as backup. The 12 cm alternative was knocked out due to the fact that it had an entirely different construction in comparison to the two others, thus making conversion between them impossible. Combined with the fact that the performance of the 15/11 round was significantly better all round made the 15 cm cannon the obvious choice.
The loading mechanism for the different cannons had already been designed. It functioned similarly to the loader in the french amx-13 light tank. With two cylindrical magazines housing both armour piercing rounds and high explosive. The maximum fire rate with the loader was a blistering 30 rounds per minute and the maximum ammo capacity of the vehicle with the 15 cm cannon was 12 rounds in the magazine and 24 rounds in total.
Next up is the vehicle itself.
It was decided from the beginning that this tank was to be a heavy tank. The armour was supposed to stop the infamous russian 122mm cannon found in the is-3. The hull design of the KRV was heavily inspired by the is-3s hull. With a 3 sided front plate.
Three designs were created:
Emil I which used the 12 cm cannon. (Never built, irrelevant)
Emil II which used the 15 cm cannon and a 665 hp engine (Also never built)
Emil III which was identical to the Emil II except for using a much stronger 810 hp engine. (chassi actually built)
Different armour layouts were considered for all three designs. The Emil I with 40/20 side armour was the original design that weighed 28 tonnes. This armour layout was decided to be too low and so a new weight limit was created. It was decided that the Emil I’s powerpack could handle a tank that weighed 30-34 tonnes while the Emil III could weigh 38-42 tonnes while retaining sufficient hp/tonne ratio.
The hp/tonne ratio of the Emil III design was to be 20. Allowing good manoeuvrability while also allowing additional weight to be added without going below the 15 hp/tonne designated limit that was created based on foreign designs performance.
This document shows the different armour layouts for the Strv KRV. The only differences between the different layouts was the side armour. All other armour was identical on all designs. Except from the front which had two different designs on its own.
The armour layouts were as follows:
- 40/20, meaning 40 side of turret, 20 side of hull.
- 60/30 –II–
- 80/40 –II–
Roof turret and engine bay: 18 mm
Roof over driver: 40 mm
Front bottom 30 mm
Rear bottom 15 mm
Back plate on alternatives a and b 30 mm (Turret and hull)
Back plate on alternative c 40 mm (Turret and hull)
The lower table describes two variations of frontal armour.
The angles are measured as 90 degrees being completely vertical and 0 degrees being completely horizontal. This means that 25 degrees is very, very angled.
Here is an image of what the finished tank would have looked like. (This image is of a mockup)
The lowest table in the previous document image is of the different variation combinations and their weight. This next document shows tables of the different variation combinations performance.
The top table shows dimensions for the Emil III 2c. The dimensions for different variations are slightly different because of different track width.
The middle table shows different hp/tonne ratios of the different variations. I can’t be bothered to translate this but I’m sure you can figure it out.
The lower table shows max speed , range and ground pressure for Emil 1, 2 and 3. Again, can’t be bothered to translate.
At least one chassi for the Strv KRV was built. I cannot find any information on which variation this was built as but we can assume that it is at least of the 2 variety with increased armour since the project was supposed to be future proof while estimations said tanks would only get heavier. What side armour was built I have no idea and can’t find any information built in one of the documents I have as source they said that they probably used at least the b variant with 60/30 mm armour. This is an image of the built chassi for the Strv KRV currently residing in the Arsenalen museum in Stockholm, sweden. Though currently not on display to the public:
Now quickly general performance statistics:
(Cant paste in tables from google docs so here is a screenshot of it instead)
And lastly, how the tank would perform in warthunder and why it should be added. Jesus, this took so long to write that I forgot I’m doing this to get a vehicle in a video game. Anywho. In war thunder i believe this tank would fit into a battle rating between 7.7 to 8.3. The well performing round combined with the utterly insane reload speed would make it a force to be reckoned with. The armour would also make it quite the tanky vehicle. Being able to stop shells with penetrating powers well above 200mm. I believe balancing the BR could get quite tricky since if you put it too high it’s armour becomes useless but too low and it becomes practically invincible. The small ammo supply and the even smaller ready rack does balance it out a bit though. Especially since the cannon could not be loaded manually.
It would definitely be a welcome addition to the Swedish tech tree as it would be the very first Swedish heavy added to war thunder. It would add a new play style to the Swedish tech tree and spice up the grind while also giving more options to choose from when the map calls for it.
Wikipedia: Stridsvagn KRV – Wikipedia
WoT forum post (Grrr) using real life documents as proof (I do not own these documents and have no way of acquiring them): https://web.archive.org/web/20161222101310/https://ritastatusreport.live/2016/11/21/the-lies-about-the-swedish-heavies/
91 page archived report on project KRV from 1952 (Primary source YAY):