The Missing SUs

SU stands for "Samohodnaya Ustanovka" (self-propelled mount). It is an index used to designate an artillery system on a self propelled chassis. It has been applied to many types of vehicles: trucks, tractors, tanks. Only one factor is common: the vehicle consists of a gun mounted on something that previously did not have that gun. Interestingly enough, while in English literature turretless tanks are split into the categories of tank destroyers and self propelled artillery, Russian has no such distinction. A turretless tank is called SAU: Samohodyana Artilleriyskaya Ustanovka (self-propelled artillery mount). Some tanks could fill the role of both TD and SPG. The SU-152 and all of its successors had the ability to provide indirect fire, while commonly seen as tank destroyers in historical documents. In the Russian WoT, they are split into "Art-SAU" (artillery) and PT-SAU (tank destroyers).

The numbers that follow the index could mean a number of things. They could mean the caliber (SU-152), tank of origin (SU-26), or be a sequential index (SU-5). This article will go through the SU indexed vehicles, and give a brief description of them.

SU-1

The SU-1 was developed way back in 1931 on the T-26 chassis. A 76.2 mm short barreled model 1927 gun was located in a casemate. Gun depression was -5 degrees, elevation was 23 degrees 30 minutes, and horizontal aiming was 5 degrees each way. The vehicle also had two DT machine guns. It had armour up to 13 mm thick, and could achieve a speed of up to 30 kph. Tested in December of 1931, it did not pass trials. An improved version based on the T-26-4 was developed, but never built.

SU-2

The index SU-2 was given to a more artillery-like vehicle, a 76.2 mm model 1902 gun on the back of a Kommunar 9GU tractor. The gun could rotate 360 degrees. The vehicle had 10 mm of armour all around. It could reach a maximum speed of 12 kph, and did not pass trials. Read about other Soviet tractor tank projects here.

SU-3

Going back to a tank-like vehicle, the SU-3 (also called SU-76K, or T-27K) was based on the T-27 tankette. It was created in 1933 to accompany scout groups and cavalry, which explains its relatively high speed compared to the previous SUs (45 kph). The gun was a recoilless 76.2 mm "K" Kurchevskiy semi-automatic gun, installed instead of the regular machine gun. Its traverse was quite small: 5 degrees to the side, 1 down, 5 up. Armour was up to 9 mm.

SU-4

The SU-4 was vastly different from previous vehicles. While using the same Kurchevskiy 76.2 mm recoilless gun, it was mounted on a GAZ-A truck, instead of a tracked vehicle. Unlike with the SU-3's limited traverse, the gun could rotate 360 degrees. The armour was not thick: the 6 mm gun shield was the only armoured component of the vehicle. Thanks to this, the SU-4 could reach a 63.2 kph top speed. 23 of these vehicles were built from 1934 to 1937. Colonel-general Arhipov recalls them favourably in his book "Time of Tank Attacks". He doesn't call them by name, referring to them as "recoilless guns on a rotating mount on the back of a truck", but their effectiveness in battle was unambiguous: "The howitzer division and recoilless guns worked very effectively. The shell from such a gun could effortlessly penetrate the front armour of German medium tanks, not to mention the light PzI and PzII."

SU-5

The in-game SU-5 isn't actually called SU-5. The vehicle in game could be either a SU-5-2 or SU-5-3, depending on the gun you put on it. The first vehicle to earn the SU-5 designation was another Kommunar 9GU based vehicle, this time with no armour at all, and a 76.2 mm model 1915 AA gun. A prototype was manufactured and built in 1932, but scrapped due to the Kommunar 9GU chassis being too weak for a 76.2 mm gun.

SU-6

The SU-6 was built in 1934, again on a T-26 chassis. A prototype was built in 1935. In 1937, four more SU-6es were built. The hull of a SU-6 was wider and longer than a T-26, with an extra road wheel and folding 8 mm thick armoured sides to protect the crew during transit. The SPG was armed with a model 1931 76.2 mm 3K AA gun. The gun could rotate fully, elevate to 82 degrees, and depress to -5 degrees. The rate of fire was 20 RPM. During trials, it was also equipped with a 37 mm AA autocannon.

SU-7

The SU-7 was a heavy SPG with a 203 mm B-4 or 305 mm Br-18 howitzers, based on a special chassis developed at factory #185, based on the T-35. Gun elevation was up to 52 degrees with the B-4, or 70 degrees with the Br-18. The gun had a horizontal traverse of 84 degrees. The project also called for a 400 mm mortar, but it was dropped from the later versions of the design.  Elements of the SPG were built, but scrapped when all heavy SPG projects were cancelled in 1937.

SU-8

You should all know the SU-8 from the Soviet artillery tree (where, at least until the next patch, it occupies a spot at tier 5). However, it differs somewhat from the historical SU-8. The SU-8 started development in 1934, as a mobile AA gun. For this task, it was armed with a 76.2 mm 3K AA gun. Like with the SU-6, it could rotate fully. The armour ranged from 8-20 mm, with 15 mm folding screens to protect the crew. Two variants of the SPG existed: one with a front mounted gun, and one with a rear mounted gun. Although, technically, both guns were located in front of the T-28 chassis. In the case of the "rear" gun (the one in game), the chassis was reversed. The speed of the front gun SU-8 was 40 kph, and the speed of the rear gun SU-8 was 48 kph.

SU-10

SU-10 (or SU-BU-10) was a coastal gun project developed in 1933. The vehicle consisted of a 152.4 mm B-10 naval gun on a T-28 chassis, with a curious feature: when deployed, the SPG could rotate 360 degrees using a special deployable mount. In this mode, the engine power would rotate the SPG instead of moving the tracks. The armour of this vehicle was between 8 and 20 mm, and its projected speed was 20 kph.

SU-12

SU-12 was another truck project. In 1933, 76.2 mm model 1927 guns were mounted on Morland and GAZ-AAA trucks in a fully rotating turret. Despite the turret technically being able to rotate fully, firing with the gun forward was a bad idea, as the gases exiting the barrel would bend the roof. The safe range of fire was 270 degrees. Unlike with the SU-4, the crew was protected from four sides by 4 mm thick shields, instead of just one. After successful trials in 1933, 99 vehicles were produced. These vehicles fought at Khalkin-Gol, Lake Hasan, and in the Winter War. No combat losses of these vehicles have been recorded. They were largely taken out of service due to obsolescence of their armament. Even upon their creation, the RKKA saw them as a temporary measure until the development of superior SPGs.

The SU-76 prototype developed by factory #38 was also tested under the index SU-12, with a SU-76M indexed SU-12M.

SU-14

The SU-14 was developed in 1933, and a prototype was built in 1934. It mounted a 203 mm B-4 howitzer on a chassis made of T-28 and T-35 components. The B-4 was replaced with a 152 mm B-30 gun (ironically, the upgrade path in the game is the opposite).

The SU-14-1 was built on the superior T-35 chassis. The armament was a B-4 howitzer. The SPG was made ligher by reduction of side skirts from 10 mm to 6 mm. A variant of the SU-14-1, SU-14-Br2, was equipped with an armoured casemate and a Br-2 gun.

The SU-14 is in game, but again, not really. The tank that is in game right now is the SU-14-2. It was a SU-14, equipped with armour screens, to serve as a bunker buster in Karelia. A real SU-14 seems to be on its way in the next patch.

To make things even more confusing, the SU-152, developed under the index KV-14, is accepted into production under the name SU-14.

SU-15, SU-15M and SU-16

These two vehicles were proposed  SU-76 variants. SU-15 was a SU-76 with a larger, fully enclosed fighting compartment, a S-15 76.2 mm gun, and GAZ-203 dual engines. The SU-16 was completely based on the production T-70, featuring a shorter hull. It was armed with the same S-15 gun.

SU-15M borrowed the semi-closed layout of the SU-16, while keeping the longer length, with dual GAZ-202 engines.

This is the end of the SPGs and TDs with SU in their name that were numbered sequentially.

"Buff my tank" - Matilda II

Author: Vollketten (US server)

SS: here we have a little article made by Vollketten and submitted to me. Enjoy!

For those of you who read The Challenger’s threads on the EU server you may be aware that the correct name for the Matilda II should in fact be Matilda Senior. In game we all know it as the Matilda II and it has decent armour, decent gun but terrible speed.

Here are a few buffs we could have for it to make it the ultimate troll tank it could be and to correct some historical inaccuracies within the game model:

Speed: In August 1940 one Matilda was shipped to the USA for evaluation with a view to having it built over there. Although production never began in the USA Mr. L.E.Carr of the British Tank Mission designed a power pack featuring a pair of General Motor two-stroke diesels. An arrangement later adopted for some American medium tanks such as the M4A2 Sherman.
The Detroit Diesel Series 71 engine is a two stroke diesel engine and in the form of the inline 6-71 was adapted for use in the Canadian (and later by the British) built Valentine tanks under the nomenclature GMC 6004. As a twin unit though as used in some versions of the Sherman tank it was known as the 6046 Diesel. The 6-71 is a 7 litre unit which as an inline produced some 238 brake-horsepower (BHP). A twin unit would therefore deliver some 476 BHP. (355 Kilowatts).
The original engines being a twin AEC or Leyland Diesel unit putting out a paltry 174 BHP and 190 BHP gave a power to weight ratio of 6.55 hp/tonne. (6.57 hp/t in game). The new engines would give a blistering power to weight ration in the region of 15.5 hp/t. The top speed therefore could be increased by about 25% to a lighting fast 32 or 33 kmh albeit a very noisy 32 kmh. In real life the wear and tear involved would not have been fun but we don’t need to worry about this in the game.

Armour: Renowed for having very tough armour already the Matilda could get even more. Firstly for anyone living in a hole and was not already aware but the previous model of the Matilda Black Prince lacked an armoured collar around its larger turret. (Now corrected) Many of the surplus converted MBP hulls were shipped it appears to Britain’s commonwealth allies, most notably Australia where these hulls with added collars saw extensive action in the Far East against the Japanese. The collar already in game on the MBP would add a small 15mm thick spaced armour protective ring around the turret base and would look like this:

Secondly the Australians also had heavily armoured track guards to cover the front of the track as the Japanese AT gunners seemed very proficient (or just lucky) in hitting there and disabling their Matilda. Personally I think they look like giant knuckle dusters.

I don’t know whether these were made in the UK and shipped with the Matildas to Australia or if they were fabricated in Australia but either way they are quite substantial and although I can’t find the thickness of them anywhere yet or personally go and measure their thickness they would appear to be about 25mm thick.

Finally as you can see below in the front view of the MBP which uses the same hull there is a steep join between the curvy front glacis and the vertical plate in front of the driver.

But now look at the hull of a real Matilda tank:

Now if you noticed that the glacis slope on the model is wrong you win a prize. The real Matilda had a much more pronounced slope for the front casting which was a single piece rather than the very angled joint between the glacis and vertical section which we see in the in-game model this is due to manufacture. Although the design schematics indeed have a steep angle change it was cast in a single piece and therefore this was never acheived in real life.

Which brings me onto a final point on the armour. Although it was designed to be 78 mm thick due to the difficulties of casting such a thick piece of steel in that shape it was ALWAYS too thick when it came out and had to be ground down by hand on the inside (a very difficult and laborious process) to try and get to the desired thickness originally designed. In real life the front casting on the Matilda hull was generally 2 to 5% thicker than designed meaning it should be 1.56mm to 3.9mm thicker and therefore should be (in order to be realistic) 79.5 to 82mm thick at the front and commensurately thicker in other cast elements of the frontal armour as well.


Firepower: Mentioned previously on the FTR blog is this little Canadian beauty:

Known as the David gun, it is a six pounder shell casing necked down to fire the 2 pounder projectile. It may have been possible to mount this into the Matilda turret had the project come to fruition* and firing a shell at 1264 metres per second (1550 mps with a Littlejohn adaptor) this would be a substantial increase over the Mk.X-B  2 pounder gun. Brought into game this could deliver a significantly better armour penetration. This would be at the expense of a slightly smaller ammunition capacity inside the tank and a small reduction in the rate of fire.

(*Had this project gone further and production of the Matilda was undertaken in Canada of the USA there is no reason why this gun could not have been the weapon of choice)

Sources:
The Matilda Infantry Tank, David Fletcher
Secret Weapons of the Canadian Army, Roger V. Lucy
http://en.wikipedia.org/wiki/Detroit_Diesel_Series_71

4.5.2013

Very little info today (Storm is on vacation)

- it is possible that T92 will have its splash radius reduced in 0.8.6
- when you have a vehicle you want to unlock and it is possible to unlock from two vehicles (for various prices), you have both those vehicles unlocked and click on the "unlock" button in the tech tree, it will unlock for the cheaper price, BUT it will not take free XP into account (SS: example: you want to unlock vehicle A, that can be unlocked either from vehicle B for 50k XP or from vehicle C for 45k XP, vehicle B has 51k regular XP available, vehicle C has 10k XP available (eg. not enough), you also have 60k free XP available and you click on the "Research vehicle B" button, it will unlock for 45k FREE XP. Thus it's always better to unlock vehicles directly from concrete vehicle research panel)


A small bonus then: how are the new tanks doing on RU server? Data from last two weeks. (Source: wot-news.com)