Monday 30 September 2013

Artillery Wishlist for 1940

The Supreme Military Council made a recommendation in May of 1940 regarding the state of artillery in the Red Army. The first half is about AA guns, and falls outside of the scope of this blog, but about halfway through, we get some juicy tidbits.

4. Consider large caliber artillery a task of utmost importance. Develop 210 mm field guns, 305 mm field howitzers in 1941, and 356 mm guns and 500 mm howitzers on rails for 1942. Develop and build prototypes of a 450 mm field howitzer in 1941.

5. On anti-tank guns:
Organize the manufacture of 45 mm shrapnel shells, producing 200,000 of them in 1940. GAU should develop an anti-tank gun, 50-60 mm in caliber, that can penetrate 50 mm of armour at 1000 meters.

Regimental guns:
Regimental guns currently being developed do not match the requirements of regimental guns due to being too heavy (900 kg). Currently developed guns should be completed and tested. In 1941, develop a new regimental gun, that weighs no more than 500 kg, has a 5 km range, and is not made for fighting tanks.
Medium caliber tank gun:
Leave the L-11 tank gun for 1940 Gradually shift to the F-32 and develop a new, more powerful tank gun  that is capable of fighting modern tanks. Hold the development of the F-32 until this issue is resolved.

6. On the armour piercing capabilities of field artillery.

Develop AP shells for the following artillery systems:
  • 152 mm model 1938 howitzer
  • 107 mm model 1910/30 gun
  • 122 mm model 1931 gun
  • 152 mm model 1935 gun
  • 152 mm model 1937 gun"
As always, let's see how successful these requests were. The massive artillery isn't really my department (I included it for fans of large numbers), but it looks like they got somewhere, combining the 450 mm requirement and the rail requirement into...something.

CAMD RF 81-12104-36

The request for a 50-60 mm AT gun was met with the 57 mm ZiS-2. According to the table here, it overfulfilled the penetration requirement, with 75 mm of penetration (against armour at 30 degrees, no less) at 1000 meters. Similar results are achieved by the ZiS-4 here.

The request for a lighter regimental gun was almost satisfied with the model 1943 regimental gun. At 600 kg of combat weight, and with a 4200 meter range, it doesn't quite get there. Also, unlike in the requirement, it was issued with HEAT shells, making it capable at fighting enemy tanks at under 1000 meters.

The development of AP shells for the listed artillery systems was very much successful, and is explored in another article.

A GABTU wishlist for 1940 (CAMD RF 38-11355-10)  also has some artillery components in it:

"On artillery:
  1. Immediately mass produce the 107 mm M-60 gun.
  2. Order the 107 mm mountain gun.
  3. Accelerate the trials of 203 mm howitzers.
  4. Accelerate the trials of AP shells for 107 mm, 122 mm, and 152 mm guns.
  5. Select the best possible 76 mm AP shell, and equip 76 mm model 1933 AA guns with it.
  6. Develop armour piercing shells for the 122 mm model 1938 howitzer, 152 mm model 1937 gun-howitzer, and 152 mm model 1938 howitzer.
  7. Develop armour piercing shells for 37 mm, 45 mm, and 85 mm AA guns."

Sunday 29 September 2013

Soviet Porsche

Dr. Porsche's gloomy Teutonic genius preference for electric transmissions is well known. These were successfully (depending on the definition of successful, I suppose) used in Ferdinand and Maus tanks. However, Porsche wasn't the only one with these bright ideas. The Soviets had a go at it too:

CAMD RF 38-11355-22

"Assistant professor Bogoyavlenskiy designed an electrical transmission for the KV tank and submitted it to GABTU in October of 1940.

Fig. 1

After working on this issue, it was discovered that the specially constructed electrical transmission can be placed within the existing transmission compartment of the KV tank. Fig. 1 shows the diesel generator and two motors in the transmission compartment. According to preliminary calculations performed at the Academy, there is also a possibility of arranging the transmission parallel to the tank's hull, the same way that it is currently placed in a KV tank."

Your eyes do not deceive you. In order to attach the generator to the V2 engine, the entire setup had to be placed diagonally. 

Saturday 28 September 2013

Schwere Panzerbuchse 41

I have previously explored the effectiveness of Soviet AT weapons, so now let's look at the German side. The data is not as complete, as it only shows effectiveness against side armour, shooting at the larger profile, but it's something. The following is a captured and translated German document.

"When the Russian tanks attacked on 9.4.1942 and 11.4.1942, they mainly tried to break through to the main battlefield on the south shore of the lake, south of Koia-Assan. The tanks, at first, could not be spotted from the observation point, as they approached through a valley. The tanks were spotted when they were to the left of our positions, occasionally already behind us, or returning to their positions. Tanks were not shot at the front, but at the sides, and usually the rear.

The following types of tanks were destroyed:
  • 09.4.1942: 9 T-26, 2 BT-7
  • 11.4.1942: 4 T-60
The tanks were shot at the following approximate distances, and took the following amounts of rounds:
  • 1 T-26 at 40 meters, 3 shots.
  • 3 T-26 at 100 meters, 3 shots each.
  • 2 T-26 at 150 meters, first in 1 shot, second with 5 shots.
  • 1 BT-7 at 400 meters, approximately with 9 shots.
  • 2 T-60 at 550 meters, approximately 6 shots each.
  • 3 T-26 at 600 meters, approximately 10 shots each.
  • 1 BT-7 at 600 meters, approximately 10 shots.
Aside from three tanks, all caught fire. On April 9th, close to the evening, a reinforced 44 ton KV tank came. We shot at it fruitlessly during the day, and, on its way back, 12 times at a range of 50 meters. The KV had a trail of smoke coming out of the rear, but kept going towards its positions and disappeared. On May 11th, a burning T-60 approached from the rear. We fired at it twice, and the crew bailed. "

CAMD RF 38-11355-651

The effectiveness seems similar to the Soviet infantry AT weapons previously explored: good against light vehicles from the sides and rear at a few hundred meters, and not against much else. Of course, in German tradition, the gun is much more complicated and expensive. Unlike the Soviet PTRD and PTRS, which were pretty ordinary large caliber rifles, the sPzB 41 was a squeeze-bore weapon, closer to a light AT gun than a rifle. At a much greater cost and much higher mass, the weapon is as effective as its Soviet equivalent.

Thursday 26 September 2013

GABTU's Tank Wishlist for 1940

The Red Army received a new heavy tank in 1940, and GABTU wasted no time before demanding more things from it. CAMD RF 38-11355-10 tells us the full story.

  1. The KV tank must have a 76 mm gun with a muzzle velocity of at least 800 m/s, in order to penetrate 70-80 mm of armour at 1000 meters. The gun must fire quickly, and have sufficient stock of ammunition. Must have an armour piercing shell and a high explosive grenade.
    At this time, the most appropriate gun is the AA gun model 1931. The tank should also have 90-100 mm of armour.
  2. The KV-2 tank must have a 107 mm gun with a muzzle velocity of 730-750 m/s in order to penetrate 100-110 mm of armour at 1000 meters. The gun must fire quickly, have high penetration, and have sufficient stock of ammunition. Must have an armour piercing shell and a high explosive grenade.
    At the time, the most appropriate gun is the 107 mm M-60 gun.
  3. Build heavy self propelled armoured artillery to destroy pillboxes. Use a 122, 130, 152, and 180 mm guns. 
    1. The most realistic way of solving this problem is the production of an SPG on the SMK or T-100 chassis, and installing a 100-130 mm gun on it, giving it an AP shell capable of penetrating 130-150 mm, and an HE shell. 
    2. In short order, develop an experimental 152 mm model 1935 gun (Br-2) mount on the SMK tank, supply the system with an AP shell capable of penetrating 150-160 mm of armour, and a concrete wall 1.5 meters thick.
      The gun must be protected by 60-70 mm of armour and weigh no more than 65 tons.
    3. Install a 180 mm gun on the SMK chassis. If necessary, alter the chassis, and reduce armour. [This entire paragraph is scratched out]
  4. During the transitional period:
    1. Manufacture KV tanks with a 152 mm model 1938 howitzer (M-10).
    2. Manufacture KV tanks with L-11 guns and regular shells.
    3. Immediately develop a mount for the 76 mm AA gun model 1931 and the M-60 107 mm gun.
    4. Immediately begin producing the T-100 with a 130 mm gun, and begin work on installing a 152 mm model 1935 (Br-2) gun on the SMK.
    5. Install 122, 130, and 152 mm guns on the T-35 and simultaneously test armour screens.
    6. Have two types of T-34 tanks, ones with 45 mm guns, and ones with 76 mm guns. Improve the armour piercing capability of the 45 mm gun, and use F-32 or F-34 guns.
    7. All tanks must use DS machineguns with thickened barrels, as they allow for longer continuous fire than the DT."
That's a lot of requirements. Let's go through and see which ones came true.

The first one came from the L-11's already insufficient AP performance. The F-32 gun that the KV-1 was stuck with had the same ballistic properties. The KV-1 didn't get a gun that satisfied this requirement until the ZiS-5. Next, the KV-2's 107. The tank was tested with a gun of that caliber, and it met the penetration requirements, but the KV-2 had no worthy opponents in 1941, and production ceased. 

Heavy self propelled guns are a whole different topic. The SU-100-Y definitely satisfied the 130 mm bunker buster requirement. The requirement for a mobile 152 mm gun wasn't met until the SU-152. The Br-2 was mounted on several self-propelled platforms, but never mass produced in that configuration. Its half-AP shell could penetrate 180 mm of armour, so that requirement is satisfied. 

The KV with an M-10 was certainly manufactured (KV-2). The KV-1 eventually switched to the F-32, and then ZiS-5 guns. The model 1931 AA gun was only ever tested in the T-34, and then discarded, as it was not necessary with the advent of the T-34-85. The T-100 with a 130 mm gun was the SU-100-Y, so that one was successful. The T-35 with a 152 mm gun wish was granted, in the shape of the SU-14, but only two were built.  

Plans were drafted to built T-34s with 45 mm guns in the event of a shortage of 76 mm guns, but such a shortage never happened. The T-34 received the F-34 in 1941. The AP capability of 45 mm guns was improved, with the 45 mm AT gun model 1942.

A number of these requirements was drafted with the Winter War in mind, when the Red Army was stuck on Finnish defensive lines. When Germany invaded, the USSR no longer had any use for bunker busters, as the bunkers they would have to one day storm were hundreds of kilometers away. Additionally, Germany did not bring any tanks with armour as thick as was foreseen, so 107 mm guns with ridiculous penetration were not needed.

Spring HEAT

"Memo on the question of armour-burning shells

Scraps of information of armour-burning shells used in the German army appeared back during the events in Spain (1937-1938). Additionally, a German patent for such a device is known.
The attempt to recreate the patent, and special research of the question, performed over 3 years at the Leningrad Chemical-Technological Institute, Red Army Artillery Academy, Scientific-Investigative Institute #6, and the Special Technical Bureau of the NKVD (letters are rubbed off and hard to make out, it might not be NKVD) gave no satisfactory results.
According to the latest information, the Germans allegedly have a shell capable of burning through armour, but no such shells were found among captured trophies. On March 31st, a HEAT shell was found for the German 76 mm gun, which, according to latest information, also exists for the 75 mm infantry gun. 
The shell is currently being examined by the Artkom GAU and NII-6.
In order to increase the armour piercing power of our 76 mm regimental gun, it is reasonable to finish development of a HEAT shell for it. 
At the same time, it is necessary to continue examining armour-burning objects of the thermite type."

As Soviet intelligence noticed, these HEAT shells were, in fact, difficult to obtain.

“After meeting with the general staff and divisional commanders of the 4th Panzer Group, Feldmarshal von Kluge once again asked to allow the use of “red-tipped” shells, giving the following as the reason:

“Holding back Russian tanks in an attack, particularly T-34s and heavy tanks, demands great effort on the part of our exhausted and battle-worn infantry. The existing methods of fighting T-34s and heavy tanks are insufficient. If the infantry’s load is lightened, they can resume completion of their objectives, despite their smaller numbers. ”

I can only support this request.

General von Bock”

"Red-tipped shells", or Pzgr Rot (tank grenade red), were HEAT shells. 

Franz Halder's diary also mentions HEAT shells. 

“December 22nd, 1941. 184th day of the war.

Forces of the south flank of the 4th army, south-east of Kaluga, are encircled by the enemy, who is also advancing on Tarusy. The condition on this section of the front is grave. It is not known when this crisis can be resolved. Regardless, the order to retreat was not given. The only order given was on the use of HEAT shells. {349}

{349} Hitler still disallowed use of these new shells”

“January 11th, 1942 (Sunday). 204th day of the war.

Hitler: hold Merdyn and cover the breach in the north. Attempt to do so before the front at Merdyn wavers. Move forces from the rear. Advance with the 9th army to cover the breach at Rzhev. There is no time for preparations of defensive positions. Any time we manage to win is to be used to cover breaches in our lines. Holding Suhinichi takes priority. Should we use shells with the red tip? {407} A counterattack from the south still remains our goal.

{407} Those were the markings of a HEAT artillery shell.”

Tuesday 24 September 2013


"In order to solve the issue of arming the KV-1 tank manufactured by the Chelyabinsk Tractor Factory, the workers of factory #92, factory director comrade Elyan, chief engineer comrade Grabin, and chief of the OGK sub-department comrade Muravyev, determined the following:
  1. In August of this year, factory #92, while mounting the F-34 gun on the KV-1, reinforced the gun mount as a result of having to move the trunnions in order to balance the gun (which takes as much effort as making a new mount).
  2. The resulting 76.2 mm caliber gun is called "ZiS-5" by the factory, and is preferable for installation in the KV-1 tank for the following reasons:
    1. The mount is sturdier, with 15 mm walls instead of 8 mm.
    2. The button firing mechanism is made according to the Artkom GAU KA journals, and is superior in performance. 
    3. A T-900 4x sight is used instead of a 2.5x sight, in order to reduce the opening in the gun mantlet.
    4. The muzzle velocity of the armour piercing shell can be increased to 780 m/s with a special charge, which increases penetration to 75 mm at 1000 meters.
  3. Factory #92 received an order from Moscow to cease manufacturing of prototypes, despite the fact that parts for 25 prototypes have already been produced.
  4. Since the Kirov factory has stopped supplying ChTZ with F-32 guns as of August this year, ChTZ was ordered to install the F-34 gun on the KV-1, with all required mount trunnion changes. In order to assist in this, one engineer from factory #92 was sent to ChTZ by airplane with one F-34 gun, and later, 16 more F-34 guns were sent by rail. If necessary, factory #92 can send more of its employees.
  1. It will take as much time to adapt the F-34 gun to the KV-1 as it would take to produce the ZiS-5 gun.
  2. No additional equipment is required to produce the ZiS-5 gun. Required tools have already been ordered by the factory. The factory has necessary blueprints and instruments.
  3. Factory #92 can start manufacturing ZiS-5 guns at the cost of removing other guns from production, such as the F-34.
  4. Major-General comrade Grabin made it clear that he can produce 20-25 ZiS-5 guns in excess of the factory's quota.
  5. Major-General comrade Grabin stated that all he saw on the issue of producing the ZiS-5 is talk, and despite its advantages, there is no singular decision. If this continues, he will have to write to Stalin personally.
September 27th, 1941"
CAMD RF 38-11355-148

Letters to Stalin or not, but the ZiS-5 gun made it into mass production for the KV-1. The special AP shell, on the other hand, didn't, as every source that I have read gives identical ballistics for the F-34 and ZiS-5. 

IS Gun Upgrades

At the first stages of IS tank development, three objects were tested: 237 (what ends up being the IS), 238 (KV-1S with the 85 mm S-31 gun) and 239 (KV-85 prototype). A number of requirements were drafted to improve the prototypes. Item 6 of the list was by far the most interesting.

CAMD RF 38-11355-1788

"Along with artillery engineering bureaus, develop:
  1. A gun mount, and a turret, that can carry barrels of the following calibers: 85, 100, 122, 152. The loader is to be positioned on the left, the gunner and commander to the right.
  2. Installation of a [illegible] optical sight, in conjunction with the MK-IV observation device.
  3. A hydraulic gun stabilizer.
  4. A breech-loaded 50 mm mortar for self-defense and flares.
  5. A gun position indicator for the commander and gunner, indicating the gun's angle and quadrant."

Monday 23 September 2013

Germans on Soviet Tactics

I wrote about a Soviet view of German tactics previously. Now, let's look at the other way around. CAMD RF 239-2220-87 contains several German documents discussing Soviet tactics, dated from October 1942 to February 1943.

"Russians preparations for an assault have the following characteristics:
  • Good camouflage of all movement, especially of tanks, that has to do with getting into position.
  • Complete radio silence of all advancing units, especially tank units.
  • Most marches are done at night.
  • The entire front is surveyed by strike teams (up to a regiment), acting irregularly, over a large span of time, and not raising suspicion, that establish weak points in defenses. The activity of this scouting increases notably two days before an offensive.
  • Artillery does not take ranging shots.
  • Bombing of bases and headquarters increases several days before an offensive.
Conclusions: It is known that the Russians can skillfully conduct readiness operations without arousing suspicion. 

A Russian offensive is characterized by their skillful confusion of the enemy, and excellent disguise of preparations, to the point that the location of the main strike is often unknown until the last minute. 
  • Short artillery bursts cover areas ahead of the advance. Large amounts of rocket artillery, and regular amounts of heavy artillery are used.
  • After a successful breach, tank brigades are sent in to complete operation tasks.
  • The tanks' success is then furthered by infantry, which moves in on trucks (up to a battalion of infantry per tank battalion) and cavalry.
  • Russians, with surprising decisiveness, aim their tanks attacks straight at joints between our units, which usually allows them to break through our main defensive line.
When the enemy uses tanks to defend against our attacks, they use the following tactic: tanks quickly take up positions on reverse slopes, and, with the use of forward observers, fire from large distances (2000-4000 meters), where out AT methods cannot reach them."

Another interesting note: "Sometimes, the top part of the tank is covered in fabric, and the lower part is covered in mud and ice, so magnetic AT mines do not attach."

That's one way to make cheaper Zimmerit, I guess. 

"Recently, when the Russians deflect our tank attacks, they use large amounts of AT rifles (entire battalions), and create defensive lines with them. The use of AT rifles has overtaken the use of incendiary bottles. The Russians skillfully apply their AT rifles, opening fire at close range, at weak spots of our tanks. The main enemy of our tanks are Russian AT rifles, used in massive amounts. The less tanks we have, the larger the chance that the tank attack will stall."

That one is interesting. Looks like the 14.5 mm AT rifles remained effective well into 1943. Another one:

"Long and dark nights, the closeness of enemy soldiers to nature, and excellent knowledge of terrain assist in these attacks. Characteristics of the attacks are as follows:
  • Mastery of camouflage of all preparations, complete and utter silence.
  • Approach of critical positions by large forces in the dark.
  • A lack of artillery barrages, but sudden breakthroughs in weak parts of the front, scouted out in advance.
  • Breakthroughs happen with large forces, moving closely. Soldiers move close to each other to maintain direction.
  • At dawn, tanks follow infantry, as well as motorized infantry (on trucks), cavalry, and support guns."
Soviet scouts seem to pop up a lot. Let's see what the Germans thought of them specifically. From an interrogation of German Colonel Hans-Heinrich Yanus, commander of Kampfgruppe Yanus. 

"The first advantage of the Russians is in their dedicated scouting units. The Russians, with great skill, use the terrain to approach our lines undetected, and even move through them. Russian scouts are skilled in camouflage, and have great patience, which German scouts lack. If you tell a German to scout village N (of, say, 20 houses), he will come back and report "the village is occupied by the enemy". If a Russian scout team receives the same order, they will approach the village, and set up at convenient locations. They will watch the village from these locations for hours. If a soldiers leaves the house with 6 pots, the Russians will know that six soldiers are staying there. If a Russian sees a soldier leaving a building with a file folder, he will note that it is likely there is a headquarters in it, and there are up to ten soldiers (secretaries, adjutants, messengers, etc). As a result, the Russians do not stop at a useless report of "the enemy is in the village", but will precisely report on the enemy in the village."

Sunday 22 September 2013

Hetzer? I hardly know 'er!

If you ask a lot of people what a Hetzer is, they will show you a Jagdpanzer 38(t). These people include even the knowledgeable folks at Wargaming. However, it appears that neither the Germans nor the Czechs called it "Hetzer".

"December 10, 1945

To Deputy Chief of the Eastern Europe Directorate of the USSR NKVT, Comrade Vozzhov

The provided report on tanks manufactured at the Skoda factory states that 1200 "G-13" tank destroyers are incomplete. 150 of these tanks can be assembled from existing parts, while 1050 tanks are 45-60% complete.

To complete the 1050 tanks, there are 78 guns available. The remaining guns and mechanisms would have to be manufactured.

I do not think that it is reasonable to complete the manufacture of these tanks.

Chief of the Head Tank Directorate of the Red Army, Lieutenant-General of the Tank Forces, Vershinin."

CAMD RF 38-11355-3015

As for the Germans, a translated copy of their plans for March-August 1945 (CAMD RF 38-11355-2725) lists a "hunter tank 38" and "hunter tank 38 D", which are obviously "Jagdpanzer 38(t)" and "Jagdpanzer 38(d)", respectively.

Saturday 21 September 2013

KV-1 vs Tiger

Fans of comparing tanks and counting numbers should be interested in this episode of the Leningrad Front, when elements of the Independent Guards Breakthrough Tank Regiment engaged the 502nd German Heavy Tank Battalion on the Leningrad Front, between July 22nd, 1943 and August 24th, 1943. For those that believe the KV was worthless at that point, prepare to be shocked and amazed.

CAMD RF 3722-95328-2

Part 1 of the first page shows the various dates and how many tanks were available. The first column is the amount of tanks that participated in battle, and the second is how many tanks were available for battle.

Part 2 of the first page shows the accomplishments of the regiment in that time. Total destroyed:
Tiger tanks: 9
PzIII tanks: 2
PzIV tanks: 3
Pillboxes: 39
AT guns: 13
105 mm guns: 4
Mortars: 15
Machine guns: 28
Ammunition depots: 2
Soldiers: about 700

After that, the report gets more in-depth.

"3. 4 Tigers tanks were destroyed with AP shells from 300-400 meters. Five Tiger tanks were destroyed with subcaliber shells. PzIII and PzIV tanks were destroyed with AP shells. Destroyed enemy tanks that were examined by our staff have penetrations in the turret and sides. One tank, knocked out on August 22nd, has a breach next to the driver's hatch made by an armour piercing shell.

4. The regiment lost 44 tanks in combat, out of those:
  • 8 were destroyed by artillery fire
  • 29 were immobilized by artillery and tank fire
  • 7 were immobilized by mines and explosives
5. Co-operation between tanks and artillery was achieved by having a special radio station in the artillery battery dedicated to communicating with the tanks. The tanks had a map of artillery coordinates. Artillery fire was called in by radio. This tactic was effective when deflecting enemy counterattacks. Tanks could call artillery fire in a timely manner. A forward observer was not assigned to the tank regiment, as one was unavailable at the time. The tank crews were responsible for correcting fire."

However, these weren't just simple KVs. Avid readers of my blog may remember the 31st for a certain special tank they were issued. 

Another interesting fact is that even though the Tiger's gun was very capable of destroying a KV, most of the "casualties" were just damage to the suspension. On average, each tank was "knocked out" more than twice (20 tanks vs 44 casualties). However, once you apply German metrics for losses to both sides, the picture becomes completely different: 8 "obsolete" KVs lost, compared to 9 Tigers, and with a nice bonus of 5 lesser German tanks. If you look at the report more closely, the famous Tigers have a pretty abysmal kill ratio: all 8 are credited to anti-tank artillery. 

One final note on Soviet actions in this battle: out of the 44 tanks "destroyed", only six crew members died. That's pretty good survivability, especially if you notice the machine guns and pillboxes that, no doubt, would not let the crewmen evacuate safely.

Now, on to the German side. Thankfully, Schneider reproduces the German combat diaries in Tigers in Combat, so it is not difficult to search for them. Unfortunately, the diary is not as detailed as I would like it to be (there is not even any mention of KV tanks), but it does confirm that the 502nd s.Pz.Abt took a heavy pounding at Leningrad in this time. 44 tanks are in possession of the battalion at the beginning of the period in question, down to 6 towards the end. 

Thursday 19 September 2013

D-30 Gun for the IS-6

In 1944-1945, Soviet heavy tank industry was at its peak. A very interesting vehicle was being developed, the IS-6. Unlike its "predecessors" IS-3 and IS-4, (IS series indexing was not at all sequential), it did not just get a D-25T, but a more advanced gun, the D-30:

CAMD RF 81-12038-681

"On the question of experimental works at factory #9 for the 4th quarter

In addition to the experimental works at factory #9 that I have wrote about in quarterly reports, the following were completed in the 4th quarter:

1. 122 mm "D-30" tank gun with ballistics from the "D-25" tank gun.

Factory #9 completed experiments on the prototype tank gun (under its own initiative), which consists of:

  1. D-25's monobloc;
  2. D-10's breech and gas block;
  3. Balancing mechanism with two springs;
  4. Lengthened D-25 mount;
  5. Fume extractor mechanism.
The experimental D-30 system was tested by firing 30 special strengthened shells from a special stand.

Before shooting, markings were placed on the D-30. The gun fired 30 shells successfully. After shooting, the markings were not deformed. All mechanisms of the gun perform satisfactorily. The full report on the D-30 test was sent to the GAU Artkom indexed #1595/42s on December 5th, 1944 by factory #9. 

In December, after the tests, the gun was sent to factory #100 for installation in the IS-6 tank and continuation of trials."

The D-25 was considered powerful enough for years to come, and, as such, its firepower was not increased. However, the rate of fire was increased in two ways. One is the improved breech, which makes loading easier. That's not that interesting, at least not as interesting as the fume extractor. Existing IS-2 tanks could already fire fast enough that ventilation of the crew compartment could not keep up. The fume extractor expelled the fumes from the burning gunpowder from the front of the barrel, so they could not rush back when the breech was open after a shot, allowing the tankers to fire much faster without succumbing to CO poisoning. 

T-35's Last Battles

The T-35 was a Soviet heavy tank that started development in 1932, and production in 1933. It was out of production in 1939, and was hopelessly obsolete in 1941, inferior in firepower not only to the heavy KV, but to the medium T-34, and even some models of the T-28. Nevertheless, a tank is a tank, and the USSR sent it into battle along with everything else they could.

On June 22nd, 1941, 59 T-35 tanks existed in the Red Army, distributed as follows:
  • 51 assigned to the 8th Mechanized Corps of the Kiev Special Military District.
    • 5 vehicles were in need of moderate repairs.
    • 4 vehicles were in need of major repairs, and 3 of those were sent to factory #183.
  • 2 assigned to the Military Academy of Motorization and Mechanization.
  • 6 assigned to the 2nd Saratov Tank School.
    • 2 vehicles were in need of major repairs, and sent to factory #183.
Up to this point, the T-35 participated in no wars. Its career was not going to be long. In the 34th Tank Division's journal, the T-35 pops up several times:

"...On June 22nd, 1941, the division possesses 7 KV, 38 T-35, 238 T-26, and 25 BT tanks... June 24th, when the division was at the forest Yavorov-Grudek-Yagellonskiy, about 17 T-35s remained...
...June 26th, 10 T-35s fell behind...
...June 27th, all remaining T-35s fell behind..."

It is no wonder that the massive T-35s were lost and left behind. The tank was large, with relatively weak armour. In 1941, when fuel and parts were scarce, it would be very reasonable to abandon such a wasteful tank as a T-35.

There is a more detailed list of how and where T-35s were lost:

67th Tank Regiment:

June 24th
  • #200-04, 196-94, 148-50 were left behind during repairs. Armament and optics removed, tanks were blown up.
  • #220-29, #213-35 got stuck in a swamp during retreat.
  • #220-27, #537-80 suffered mechanical failure at Grudek-Yagellonskiy. The vehicles were left behind, their machine guns and ammunition removed and buried.
June 26th
  • #200-08 suffered mechanical failure at Sudova Vishnya, armament and optics removed, tank was left behind.
June 28th
  • #288-14 disappeared along with its crew next to Zapit.
June 29th
  • #988-17, #183-16 require repairs, were left at Lvov without optics or armament.
  • #288-11 fell from a bridge and was lost with its crew.
  • #715-61 was left 15 km past Lvov due to mechanical failure, machine guns were removed.
  • #148-25 was left at Zapit due to a broken reduction gear.
  • #715-62 was left at L<illegible>e without machine guns due to a broken fan belt.
June 30th
  • #339-30, 744-61 were left behind due to mechanical failure, without armament or optics.
  • #200-09 was destroyed by enemy fire. Armament and optics removed.
  • #399-48 was lost at Belo-Kamenka.
  • #183-03's engine gave out, was abandoned at Belo-Kamenka. Armament and ammunition were removed and buried.
  • #148-39 was destroyed at Verbi.
  • #220-25 was destroyed at Ptichye.
  • #988-16 was destroyed at Ptichye during a counterattack.
  • #339-68 was destroyed at Brody.
  • #200-10 was destroyed at Ptichye during a counterattack.
July 1st
  • #988-16 broke down. It was left at Zolochuv. Armament, optics, and ammunition removed, and handed over to the Zolochuv warehouse.
  • #744-63 left on the road from Zolochuv to Tarnopol, machine guns were removed.
  • #288-74 suffered a failure of friction clutches. It was burned by its crew at Tarnopol.
  • #148-22 was left in the forest next to Sasovo, machine guns were removed, optics removed and buried.
July 2nd
  • #196-96 suffered a failure of a reduction gear. It was left at Tarnopol with no armament.
68th Tank Regiment:

June 25th
  • #197-01's main clutch burned, abandoned 20 km east of Grudek.
June 26th
  • #288-43's main clutch burned, abandoned at Grudek.
  • #744-62's main clutch burned. All ammunition was expended. Abandoned at Grudek.
June 29th
  • #183-16 was left 20 km from Lvov.
June 30th
  • #234-35 fell in a river close to Ivankovtsy.
  • #238-69 and #537-70 were left behind due to mechanical failure. The former was left between Busk and Krasne, the latter between Ozhidev and Olesko.
July 2nd
  • #744-67 was left at Zhidin due to mechanical failure.
July 3rd
  • #234-42 was left at Zapytov due to failure of the friction clutch.
July 8th
  • #200-05 was left at Zolovchuv due to mechanical failure.
July 9th
  • #744-65 was left between Tarnopol and Volochinsk due to mechanical failure.
  • #183-06 had its brakes fail, and was left at Volochinsk.
  • #744-66 suffered failure of the friction drive, and was left at Beo<illegible>
  • #196-75 suffered a failure of the friction drive, and had no batteries. Was left at De<illegible>
  • #744-64, #196-95, #330-75 were left at Grudek, needing moderate repairs.
But what about the five T-35s that were sent to factory #183 at Kharkov? Four of them were most likely never repaired. On August 21st, long after all other T-35s were lost, GABTU chief Fedorenko issued the following telegram: "The 4 T-35 tanks ## 148-30, 537-90, 220-28, and 197-02 are to be repaired until they are capable of independent movement, equipped with appropriate armament, and sent to GABTU KA. Inform me when they are ready." As you can see, one T-35 was repaired, and sent to battle.

Note: the document is fairly illegible. 238, 288, and 988 could all be 288. Also, #183-16 is present twice, due to poor legibility.

Original article available here.

Tuesday 17 September 2013

The One with the Rifle Shoots

Popular history is filled to the brim with images of Red Army soldiers that are sent to the front without weapons, or without ammunition, left to their own devices by a cruel regime that cannot supply them with what they need to fight the enemy. If you look at very specific excerpts from archive sources, it appears to be true.

"The military districts' bookkeeping data does not fully reflect the real stocks of weapons and ammunition. Inspections of the Moscow Military Disctrict showed abysmal accounting of military resources."

Seems pretty hopeless, right? Well, here's the full text of the document.

"The People's Commissariat of Government Control of the USSR inspected the stock of weapons and armament on June 30th and July 1st of this year on the 32 MVO warehouses and 2 central NKO armament bases.

The inspection determined that on bases of units that already left for the front, in Moscow and its suburbs alone, 22 thousand rifles, 2,346 machineguns, 247 mortars, 483 guns and howitzers, 4,064,600 rifle cartridges, 52,177 shells, 8,952 hand grenades, etc., were left unissued. 

The two GAU KA bases contain 62,623 rifles, 92,756 pistols and revolvers, 724 mounted machineguns, 3,107 handheld machineguns, 149 mortars, 1,748 howitzers, 3,649,700 rifle cartidges, and 8,449 shells.
The People's Commissariat of Government Control issued a request for lists of armament and ammunition to the military districts. By noon on July 2nd, information from the MVO, HVO, SKVO, ZakVO, YrVO, and KOVO arrived. The lists are attached.

The military districts' bookkeeping data does not fully reflect the real stocks of weapons and ammunition. Inspections of the Moscow Military District showed abysmal accounting of military resources. Unit and base warehouses contain more armament and ammunition than the District records indicate. 

The "Vystrel" courses should have 1,620 rifles. In reality, they have 1,780. Instead of 115 machineguns, they had 220. The Moscow Military-Political School had 16 machineguns issued to it, and 104 on the day of inspection. The 1st Moscow Artillery School had 29 machineguns instead of 9, the 1st Communications Regiment was not supposed to have any machineguns, but had 5. The #38 Okruzhnoy warehouse was supposed to have 13087 rifles, but had 830 rifles more. The warehouse also had a surplus of 88,681 rifle cartridges."

So there you have it, instead of not enough guns, the Soviets had too many guns. Truly, a unique problem in history.

Western Anti-Tank Teams

The Soviet envoys in America didn't just learn about their tanks, they learned about their infantry, too.

CAMD RF 81-12063-19

"The figure illustrates an attack on a damaged enemy tank by a combat team.
  • Soldiers practice throwing grenades and incendiary bottles at enemy tanks.
  • Mines of all types and their uses are also included in the program.
  • In case there are no grenades, the soldiers are taught to manufacture simple explosives. For this, they take TNT (an explosive substance), and a detonator. All of this is wrapped in a fabric sack, cloth, sock, etc. So this improvised grenade does not slide off the enemy tank, and sticks to it, it is coated in thick grease or sap. 
  • AT teams do not only learn to use their equipment in theory, or only read about tactics of tank fighting, but apply their knowledge in special obstacle courses or "tank hunting" courses."
Anyone who watched Saving Private Ryan should remember the part with the "standard GI sock". It was surprisingly accurate!

This is all pretty routine. However, the British had a more creative way to fight tanks!

Yup, those are two British Home Guardsmen, with a Molotov catapult. I wonder how well those worked.

Monday 16 September 2013

Soviet Heavy Assault Guns

In 1939, Joseph Kotin developed a heavy tank that would later become known as the KV-1. This heavy tank had thick, sloped armour, and a powerful gun. In 1941, that tank became the platform of choice for the development of a heavy assault gun. Reports from the front suggested that towed artillery cannot rapidly follow advancing tanks and infantry. A tank that could bring the firepower of several field guns was needed.

Initial KV prototype. Unlike the multi-turreted SMK and T-100 tanks that competed with it, both guns were combined in one turret.

The first solution to this problem was quite original. Despite his initial dislike of the KV-1's two guns, Stalin gave the order for a three-gun mount.

"By personal order of People's Commissar of Defense Comrade Stalin, Kirov factory (in Chelyabinsk ChTZ) is developing triple gun mount (two 45 mm tank guns and one 76 mm F-34). For development of these SPGs, Kirov factory needs four 45 mm guns urgently. In order to mass produce a KV with three guns, it is necessary to supply the Kirov factory with 180 such guns in December of 1941, and 260 in January of 1942, without recoil mechanisms, semi-automatic mechanisms, or sights." - CAMD RF 81-12104-79

Two guns made the KV's turret crowded enough, so the turret had to go. The result resembled the ultimate conclusion of that project, the SU-152. A front fighting compartment on the KV-1 hull, with up to 100 mm of front armour, fully enclosed from all sides. The armament is where the construction differed radically. Instead of the commonly seen one gun, the new SPG (indexed KV-7) had multiple. Different versions had 2 45 mm model 1932/34 guns and 1 76 mm F-34 gun (U-13), and 2 76 mm guns (U-14). Regardless of the configuration, the guns shared a mantlet, and aiming mechanisms. The guns could either fire independently, or all at once. The three gun variant stored 93 shells for the 76 mm gun and 200 45 mm shells. The two 76 mm gun variant had 150 shells.

KV-7, first variant. The second 45 mm gun is almost completely covered by the 76 mm gun. From Solyankin et al, Soviet Heavy SPGs 1941-1945.

KV-7, second variant. From Solyankin et al, Soviet Heavy SPGs, 1941-1945.

At this point, Stalin seems to change his mind. "Why have three guns? Put one in, but a good one!" However, his opinion of the developments was not entirely negative, as he promoted Kotin from colonel to general on that same day.

The KV-7 comes up in a phone conversation between Zaltsmann and Stalin on January 24th, 1942.

4. The KV-7, with two guns in a fixed turret, must be lighter than the KV-1. Comrade Stalin agrees that it should be made lighter by reducing the front armour to 85 mm.
5. Comrade Zaltsmann reports that the KV-9 project with an M-30 artillery system is ready. He is satisfied with the project, as is the GABTU representative at the factory. The KV-9 should replace the KV-7. Comrade Stalin requests that the factory and representative prepare a document for him.

More solid criticisms were compiled by assistant of the head of the 4th division, 3rd department of GABTU, Major Gorohov.

"Conclusions on the KV-7 self propelled gun mount, manufactured by the Kirov factory.

After familiarizing myself with this vehicle, and shooting from it, I deem it unsatisfactory for the army due to the following reasons:
  1. It is helpless when fighting tanks. The angle of fire is only 15 degrees to each side.
  2. It cannot be used to combat concrete bunkers, as the caliber is too small.
  3. I think it is more reasonable to install a large caliber gun, approximately 152 mm, like the M-10 gun on the KV-2."
And so the KV-7 idea was buried. However, the need for a heavy SPG was not. At Uralmash, two SPGs were in development in this time: U-18 and U-19.

U-19. CAMD RF 81-12038-117

The vehicle had 75 mm of armour at the front, 60 on the side, 30 on the roof (which was removable to facilitate loading). The mass of this project reached 66 tons, and height was 3505 mm (even taller than a Maus). The gun was the powerful 203 mm B-4 howitzer. The project was very short lived, and was declined in September of the same year.

The U-18 mounted a ML-20 howitzer in the KV-1 hull. This project was a lot more successful, serving as a base for the SU-152 project.

U-18 152 mm SPG project. From Solyankin et al, Soviet Heavy SPGs, 1941-1945

The U-18 wasn't the only project to put a 152 mm gun on a KV-1, and factory #8 wasn't only dealing with medium SPGs. Another project of theirs was the ZIK-20, an ML-20 gun mounted on a KV chassis, started in Spring of 1942. Front armour was 105 mm, side armour 75 mm.

CAMD RF 81-12038-117

This looks like a taller SU-152, but with one interesting difference: there is no muzzle brake. The project made it as far as a wooden model. However, at that point, the KV-1 ceased production, and the KV-1S was to be the new heavy SPG base. 

However, before the ZIK-20's demise, it was equipped with an even more optimistic artillery system: a Br-2 152.4 mm gun.

CAMD RF 81-12038-269

In order to offset the massive gun, the front armour was reduced to 75 mm (or 60 on a KV-1S chassis). The accompanying document also states that, since the Br-2 uses the same mount as the B-4 and U-3 203 mm howitzers, it is possible to install them in a ZIK-20. This project was never built, but the idea of a high powered 152.4 mm gun in an SPG remained for a few years. 

Another attempt at a 203 mm gun was undertaken at Perm in 1943, indexed SU-203. A "SU-14 type" SPG was equipped with a 203 M-4 mortar, based on the B-4 howitzer. The ammunition used by the two was the same. 20 100 kg shells were stored inside the tank.

CAMD RF 81-12063-11

From Solyankin et al, Soviet Heavy SPGs, 1941-1945. 

The gun mechanisms were so massive, that the driver had to be moved to the right. The fighting compartment  got much smaller, pushing out the gunner. His position, as on the T-34, was filled by the commander. 
As for mass, the M-4 was previously used on the ML-20 mount with no modifications, as corps level artillery. The resulting SPG would not have been significantly heavier. However, bigger is not necessarily better. Due to the short barrel and low velocity, the M-4 could only penetrate 80 cm of concrete, where the ML-20 could penetrate 140 cm. The Br-2 that engineers tried to cram into a ZIK-20 could penetrate 2 meters of concrete. 

Saturday 14 September 2013

Grabin's Superguns

During pre-war ridiculousness, Grabin came up with two pretty powerful guns: the 85 mm ZiS-23 (70 calibers in length) and 107 mm ZiS-24 (59 calibers in length).

CAMD RF 81-12104-147

The ZiS-23 shot its 10.5 kg shell at 1149 m/s. This is a heavier shell at a larger velocity than the German KwK 43, made 3 years later. As a result, it gets higher penetration: 219 mm at 100 meters (according to the de Marre equation, using the ZiS-S-53 as a reference). The ZiS-24 was no slouch either. Its 18.8 kg shell flying at 1013 m/s would also be able to penetrate 219 mm of armour at 100 meters (using the 107 mm model 1910/30 gun as reference). 

This is pretty excellent penetration for 1940, but just like with those ridiculous 107 mm guns, it was too much penetration. Current 76 mm and 85 mm guns were capable of combating any enemy armour, and there was no need for overpriced super weapons. According to some sources, the guns were manufactured, but never put through a proper set of trials.

World of Tanks History Section: TOG

After the end of WWI, the victorious nations wrapped it up so smoothly that Europe was a powder keg with a slow fuse. The question was when it would explode. By the middle of the 1930s, the answer was obvious: soon.

At the beginning of WWII, the British tank corps were numerous and disjoint. The reasons why the British failed to figure out what they wanted to do with their tanks falls outside the scope of this article. Let me just remind you that British tanks were split into two classes: slow and well protected infantry tanks and fast and lightly armoured cruisers.

In the summer of 1939, the British decided that they needed a heavy tank for operating in Europe. In September, a special committee was formed, and tasked to produce requirements for this new tank. The people in this committee were the same that solved a lot of tank questions in 1914-1918: Swinton, Wilson, D'Encur, and others. In October of 1939, they were officially named "Committee for development of a special vehicle for the Ministry of Supplies".

Britain and France were getting ready for combat with the assumption that the war will be positional. The committee relied on French experiences, which were all in a trench war. The committee was most interested in the B1 bis tank, which served as a source of inspiration for their task.

The vision of the project was to create a long tank, to make it more effective at traversing terrain covered in craters. The armour was to protect it from gun calibers up to and including 47 mm at 100 meters. The tank's speed was not supposed to be very high, 8 kph, with a range of 50 miles. The tank was to be equipped with a field gun in the front, two 40 mm guns in sponsons, and rotating machine gun turrets. The tank was to be delivered to battle via railroad.

Two companies were tasked with creating a prototype: "Foster" and "Harland and Wolf". Foster's engineers included members of the "Special vehicle committee". These people called themselves "The Old Gang", or "TOG". This initialism was used to name the tank that the old gang was making.

Blueprints for TOG I were ready in December of 1939. The tank was very British, combining advanced technological solutions with obviously obsolete elements. The stiff suspension allowed it to be simple and easy to produce, but was not much different from the suspension of the heavy tanks of WWI. The side-mounted guns were also ancient. On the other hand, the electric transmission made by English Electric Company was very interesting. The tank's engine powered two generators, which in turn spun the tracks with electric motors. Turning the steering wheel changed the voltage, which changed the speed of rotation of the tracks, and the TOG turned. Sadly, this was not a perfect setup. Engineers could not solve the problem with frequent deformation of tracks and wheels. The electromechanical transmission was ultimately discarded in favour of a hydraulic one, which was less reliable.

In October of 1940, the engineers discarded the sponsons. The TOG received a Matilda turret with a 40 mm gun and a 7.92 mm machine gun. The 75 mm field gun in the hull remained. The tracks were widened, to reduce ground pressure. This was the modification fitted with an electromechanical transmission. Due to poor cooling system performance, both the transmission and the engine were damaged.

At the same time, the TOG II was undergoing development. This tank had a lower suspension, and the turret was meant to carry a 57 mm gun. The 75 mm hull gun was gone. According to the blueprints, the sponsons were still present, but they were not included in the only prototype, built in 1941. The turret was missing too, with a wooden mockup taking its place. The TOG II R was meant to have a real one, but it was never built.

The last of the models was the TOG II*. It had a torsion bar suspension, thanks to which, the tank was sped up to 14 kph. It had a new turret, capable of housing a 76 mm gun. The TOG II* was the first British tank to use that caliber. The tank was never mass produced. It was already 1943, and even the British, with their odd opinions about tanks could see that their TOG was no match for German Tigers and Panthers.

The TOG project ended. The TOG II* turret was equipped with an electric motor and mounted on the Challenger tank.

Original article available here.

Friday 13 September 2013

Lend Lease Impressions: Valentine

A Valentine tank that fought in the Battle of Moscow, likely as a part of the 137th ITB. Photograph published in the Red Star newspaper on November 22nd, 1941.

"A Review of the Performance of English Valentine Tanks, Used by the 131st Independent Tank Battalion of the 50th Army
  1. Advantages
    1. Good firepower, especially when the mortar is used with domestic 50 mm rounds, which have a 200-250 meters greater range than English ones. Also, captured German ammunition can be used, when inserted in English belts.
    2. The armour protects the crew from armour piercing bullets and shells up to 45-50 meters.
    3. The tank handles well, moves quietly, and the elastic suspension allows accurate fire on the move.
    4. The engine is economical and reliable.
    5. The tank is small, but powerful.
  2. Disadvantages
    1. Poor performance on slippery terrain.
    2. The tracks are weak. Links and link pins break frequently.
    3. Gearbox gears frequently jam.
    4. Weak drive wheels and idlers. 
    5. Poor form of gun mantlet. Shells that hit it do not ricochet, and make the tank more vulnerable.
    6. Vulnerable spots: suspension, gun mantlet, engine grille.
    7. Lack of spare parts affects timely repairs and return to the battlefield.
    8. There are no HE-fragmentation shells.
Conclusions: the tank is good, and matches the requirements of modern war. Crews become proficient with it easily. It is adequate for use in the RKKA.

  1. Weld a spur to every 4-5th track to increase performance on slippery terrain (this works well in practice).
  2. Increase the quality of tracks, especially the pins.
  3. Supply with large amounts of spare parts, especially track links and pins.
  4. Use the 50 mm domestic mortar round (this works well in practice).
  5. Develop an HE-fragmentation shell for the gun.
  6. Supply with spare parts for armament."
CAMD RF 20.8-2534-5

This particular review stems from experience obtained during the Battle for Moscow. The lack of HE shells (the 2-pounder gun had very ineffective HE which was infrequently used) confirms that this was a pretty early Valentine. The presence of a "50 mm" mortar (the British used a 2-inch mortar on tanks for smoke launchers) is interesting, especially given its compatibility with Soviet ammunition. Sadly, the type of shell used is not specified. informs me that the only type of shell Soviet 50 mm mortars used was an HE-fragmentation one, so maybe it was a field attempt to compensate for the lack of HE shells for the 40 mm gun. 

Thursday 12 September 2013

Lend Lease Impressions: M4A4 Sherman

The M4A4 Sherman tank was not very popular in the United States. The US preferred the M4A3, the Soviets preferred the M4A2. Out of 7499 units produced, 7167 were sent to Great Britain. From CAMD RF 38-11355-1755:

  1. The American M4A4 medium tank is, overall, worse than the M4A2 medium tank.
  2. The 30-cylinder Chrysler gasoline engine is large and unwieldy, has many parts and assemblies, decreases the reliability of the tank, and increases difficulty of service. The engine provides good speed, but drastically lowers the tank's fuel efficiency, and increases cost. The fuel is more expensive than fuel for GMC engines in the M4A2 tank.
  3. The M4A4 tank is equivalent to the M4A2 tank in its armament, view range, crew comfort, and ammunition rack convenience.
  4. The hydroelectric turret traverse mechanism allows for faster and more convenient aiming of the main gun, compared to the hydraulic mechanism of the M4A2 turret. The commander's traverse switch allows for fire control on important targets, and allows the tank shift fire faster than the M4A2.
  5. Reliability of the suspension is identical to the M4A2 when using metallic tracks. The metallic tracks of the M4A4 have better traction than the metallic tracks of the M4A2."
30 cylinders? Oh yes. The M4A4 was powered by 5 six-cylinder car engines, put together in the Chrysler A57 Multibank. 

Wednesday 11 September 2013

Lend Lease Impressions: M3A1 Stuart

CAMD RF 38-11355-1561 covers testing of a new modification of the M3 Stuart light tank. Also, for convenience, it tests winter performance as well.

  1. After installing spurs, the speed decreases by 21-25% and fuel consumption increases 20-30%.
  2. The fuel consumption is acceptable when moving without spurs, and higher when moving with spurs. Oil consumption is acceptable.
  3. The tank does not carry enough fuel. Range is insufficient, especially when moving in snow with spurs.
  4. The maximum slope is 25 degrees in winter conditions, which is acceptable. The spurs increase the performance in the snow. The tank can tilt 24 degrees, after which it starts to slide. The tracks stay on the wheels well.
  5. The model 1942 tank has an electric Delko-Remi starter, which works reliably.
Evaluation of construction changes
  1. Welded armour plates are a positive change to the construction.
  2. The installation of a hydraulic turret rotation mechanism made it necessary to add a rotating turret basket. The turret basket is raised very high, due to the drive shaft. It takes up a lot of space in the fighting compartment, and makes crew conditions very cramped and uncomfortable. Crew working conditions got worse, instead of better.
  3. The hatches are very small. It is hard for the crew to enter and leave the tank. The conditions of emergency evacuation are unsatisfactory.
  4. Removing Browning machine guns from the turret platform was a correct move. Fire from these machine guns on 1941 models was ineffective.
  5. The installation of a thermostat on the engine oil reservoir is very useful. The thermostat helps with controlling oil temperature in very cold conditions."

Tuesday 10 September 2013

Shipping Karl Gerats

Seven self propelled heavy mortars named "Karl Gerat" (Karl device) were built by Germany during WWII. Obviously, as the war went on, the Soviets captured a number of them that operated on the Eastern Front.

"In the sector where the 4th Artillery Brigade is located, near the city of Uterborg, there are three 600 mm SPGs, numbered 1, 4, and 6, two of which are in the forest, and one in a destroyed hangar. These SPGs are of great interest to the GAU, and should be delivered to the USSR for testing. Determine the suitability of their delivery to the closest railroad station, what needs to be done in order to transport them, what train cars are necessary. Deliver a report no later than November 1st of this year."

And here is the response:

CAMD RF 81-12038-727

"I report that, out of the three 600 mm SPGs found 3 km north of Utenborg, only #6 can be restored. Others have serious damage to them, and completely non-functional motor groups. These SPGs weigh about 200 tons, so their delivery to the closest railroad station (Grune, 1.5 km) and subsequent loading is only possible if they are disassembled into the following components: barrel, recoil mechanism, control and aiming mechanisms, engine, tracks. The hull needs to be cut into pieces with a blowtorch and shipped separately due to its large weight (over 100 tons). In order to dismantle these SPGs, we need a special brigade with two powerful tractors, blowtorch, movable crane that can lift at least 20 tons, and special equipment for disassembly. 

For loading one SPG, the following are required:
  • Barrel: one platform, 50 tons
  • Recoil mechanisms: one platform, 20 tons
  • Engine: one platform, 20 tons
  • Tracks: one platform, 20 tons
  • Hull: 5 platforms, 50 tons
  • Two vehicles for transporting the barrel: 2 platforms, 20 tons
  • 1 shell for the SPG: one covered train car, 20 tons
Total: 6 50 ton platforms, 5 20 ton platforms, 1 20 ton covered train car.

Assign the organization of the transport of these SPGs to engineer-colonel comrade Alekseyev."

SPG #6 "Ziu" can be seen in the Kubinka museum with the gun and markings from #1 "Adam". 

Monday 9 September 2013

How To Build a Howitzer

Here's a beauty, the 305 mm model 1915 12-inch howitzer. Guns this big come with some assembly required, but in several easy steps, you too can be a proud owner of an artillery battery!

Step 1 is to built a foundation, because a gun of that caliber is going to hammer the ground hard. The foundation is composed of six layers. Here are layers one and two.

Three, four, five, and six! For those following along at home, that was step 1.

Step 2 is to put together another foundation, for the gun mount frame. This one takes 11 layers. I don't have pictures for layers 1-6, though.

11 layers of wooden beams later, step 2 is done. Can we put the gun down yet? Of course not!

More foundations! This is the frame for the gun mount. We're getting somewhere.

Next step is to add a railroad and 4 3-meter tall jacks. They will be used to move the gun mount on the frame, like so:

Next step is attaching the gun barrel. This part also needs the rails. It uses 1.5 meter tall jacks.

Now that the gun barrel is in position, it can be moved onto the gun mount.

After the barrel is attached to the mount, the entire assembly is lifted.

Using those 3 meter tall jacks, the barrel assembly is set into the foundation. The rails can now be removed. Figure 111 shows the gun in place. 

Now you need ammunition. That's a whole different story.

The ammunition cart gets its own rails and delivery mechanisms (the manual skims over this part). Figure 113 shows the gun in a dug-in emplacement (I hope you dug one out before step 1). The shell is lifted from the cart to the breech with a small crane.

The shell is rammed into the breech by that stick-like thing you see in the left part of the photograph. In figure 115, the howitzer is ready to fire!

In only 115 easy steps, you too can set up your own 305 mm model 1915 howitzer.