Wednesday 31 July 2013

Cheating at Statistics 3: Standards

Previously, I have shown how you can deviously inflate your kills, while mitigating your losses. Let's take a look at another situation where what is written down is not what really happened.

In March of 1944, several German s.Pz.Abts. were busy fighting the Soviets, and losing badly. Memoirs of the 4th Tank Army commander Lelushenko tell of "72 tanks captured, including 49 Tigers". Now, one can claim cases of misidentification, but in this case, journalists did their job well. Photos taken on March 13th definitely show a number of Tigers.

Photo from the Uman captured and destroyed vehicle collection point.

So, as you can see, these Tigers clearly exist. Let's look through claims of losses from the German side. S.Pz.Abt 503, 507 and 509 were present in the area around March. Let's see how their accounting went:

The 503rd claims to have lost 2 vehicles on March 9th, and 8 more up March 29th. The 507th reports 4 lost vehicles in all of March. The 509th reports 5 vehicles lost in all of March.

Wait, what happened? That's less than 20 Tigers lost in all of March, when the Soviets have over twice that in the first two weeks, with photographic evidence! Where did they come from? The answer lies at the end of the month. On March 30th, 24 losses are recorded, 21 of which are marked as "destroyed by their own crew". The fact that these vehicles have long been photographed at Soviet collections points makes that claim doubtful. 

There you have it, some creative accounting in how and when a vehicle counts as destroyed, and you end up with an invincible fighting force! On paper, at least.

In contrast, let's take a look at how the Soviets did it.

Here we have some losses from various causes (artillery fire, mines and explosives, aircraft, unrecoverable losses, technical losses). Look at that technical losses field! The numbers are huge! 84 tanks lost to artillery fire in total, compared to 468 breakdowns? That sounds hard to believe. Thankfully, the description clears things up.

"The technical losses field also includes vehicles stuck in mud, even for a short time, and tanks requiring repairs, where one tank could undergo several repairs, and count several times. Tanks needing medium or heavy repairs are also counted. As a result, the amount of losses is larger than the total amount of tanks."

There you have it, the two sides treat losses radically differently. Soviets can count one tank as lost multiple times (the same tank can also be "built" multiple times, if a hull is shipped back to the factory for refurbishment), while the Germans don't count the tank as lost at all until they are sure that they cannot reclaim it. Who knows how many Tigers were recovered, repaired, and sent into battle again, never counting as a loss until meeting their final resting place on the battlefield. 

These, and many other examples, readily demonstrate that one must always be cautious when comparing numbers written down by different organizations, as similar terms often carry vastly different meanings. 

Tuesday 30 July 2013

Cheating at Statistics 2

Previously, I talked about how it's possible to mask your losses against the enemy. In this article, I will explore how it's possible to inflate your own victories!

A fragment of the German 3rd Panzer Regiment operations report. On February 18th and 19th, 1942, they claim to have destroyed 14 T-34s, 1 KV-1, 1 KV-2, and damaged another 2 T-34s and KV-1s. Let's see the records from the Soviet side.

The document lists the losses of the 1st Guards Tank Brigade on February 18-21 of the same year, which was opposing the 3rd Panzer Regiment. KV tanks are mentioned twice.

"4. 2 KV tanks, while attacking the village of Arzhaniki, while crossing the valley 400 meters from the village, were stuck in the snow. It was not possible to pull them out with 2 T-34s, and the enemy does not allow the tanks to be towed, keeping them under mortar and artillery fire."
"7. A KV tank, while on a combat mission, received 15 penetrations with thermite shells and burned up."

The report also gives 8 T-34s that were destroyed, burned up, stuck in the snow, or otherwise lost, compared to the 14 German claimed to have destroyed.

Somehow, 1 destroyed KV and 2 stuck in snow turned into 2 destroyed and 2 damaged KVs, even with the extra two days that the Soviet report covers. Pretty sneaky!

Finally, let's compare the maps, to make sure they were really fighting each other.

The top is the German reconnaissance map. The bottom is the Soviet map of losses. There are only ten on the map. One of the missing T-34s disappeared without a trace.

Here is the story of a smaller statistic padding. On June 24th, 1941, while Von Seckendorff was getting acquainted with his first KV, another assault was happening just 50 km away from Raseiniai, at Seta. A KV-2 was to do the same thing as the Raseiniai KV: take a position at a road, and block the advance of German forces. Unlike the almost mythical Raseiniai KV, the tank was extensively photographed.

According to Oberleutnant Schmidt, he and his 5 Pz 38(t)s engaged a KV-2 tank. The 37 mm shells bounced off it, and it was only possible to knock it out by jamming the turret ring. However, looking at the photo, the turret ring is intact. Here is a better one.

Judging by this photo, the turret ring is has a dent on it, but was not penetrated. It would appear that the recoil mechanisms have failed after being shot through, but the tank is visible with the gun properly extended. It is likely that the Germans shot up the abandoned tank. Some sources indicate that the tank was blown up by the crew. The lack of photos of prisoners seems to confirm this theory. Nevertheless, Schmidt readily took credit for this, reporting that he knocked out 14 Soviet tanks and one super-heavy tank.

Monday 29 July 2013

Soviet Medium Tank Destroyers

Way back in the summer of 1940, engineers were already trying to fit an 85 mm gun into a T-34. Two T-34 hulls were shipped to factory #8 for this project. The easiest way to do this was to put it in a brand new open topped turret. The project stalled, but was revived in November of 1941. It was then that the project received the index U-20.

The U-20 consisted of a 52-K 85 mm AA gun on a mount from the M-30 122 mm gun. Three crew members occupied the turret, much like in the later T-34-85. The turret armour was not very thick, 45 mm in the front, and 20 mm on the sides. The TD carried 76 rounds of ammunition, 20 rounds in a ready-rack in the turret. The height of the vehicle was 2790 mm. In April of 1942, GAU decided not to build a U-20.

CAMD RF 81-12038-90

A more compact version of the U-20, the U-20-II, was developed in parallel.

The U-20-II had much more armour compared to the U-20, 75 mm in the front and 40 mm on the sides. The tank was shortened to 2475 mm in height, at the cost of a smaller 60 round ammo rack. The project met the same fate as the U-20, scrapped in April of 1942.

CAMD RF 81-12038-90

Another curious project on the T-34 chassis was the SU-2-122, ordered in December of 1942. Like with the SU-122 that everyone is familiar with at this point, the project was based on the T-34 chassis and was meant to provide indirect fire with 122 mm shells. However, instead of one M-30 howitzer, it had two.

CAMD RF 81-12063-13

The two guns would be capable of firing simultaneously. The mass of the tank was 35 tons, and resulted in having to lengthen the T-34 hull by one road wheel, bringing to total up to six. The project was cancelled before being built.

Speaking of the SU-122, here's a predecessor project, the ZIK-10, combining a U-11 howitzer and the T-34 hull.

Moving on to more projects on the SU-85 hull, the 85 mm gun was deemed to be less than what the platform could handle. The A-19 gun, that has already proven itself in combat with the enemy, was fitted into the unmodified casemate, resulting in a project called SU-D25. A similar project, the SU-D15, was armed with a 152 mm D-15 howitzer. 

SU-D25 (top) and SU-D15 (bottom). Retrieved from Solyankin et al, Soviet Medium SPGs 1941-1945

Sunday 28 July 2013

Ballistic Tables of the 8.8 cm L/71 KwK 43

I have written previously on the precision of various tank guns, and the "long 88" 88L/71 KwK 43 showed up in those comparisons. Sadly, the only data I had was the percentage chance to hit a target of a certain size, which, while allowing for a crude comparison, didn't give me the numbers I needed. However, thanks to some enterprising folks at Tank-Net, I have a ballistics table for the gun! From H.Dv.119/329 - Vorläufige Schußtafel für die 8,8 cm Kw.K. 43 u. 8,8 cm Pak 43 (Sept. 44), pp. 104-107:

How convenient, the precision figures are also for 50% dispersion, which makes it nice and easy to compare them with the Soviet ones without doing any math. Columns 5, 6, and 7 are for depth, width, and height, respectively. Units are in meters.

The dispersion at 1000 meters is pretty small: 30 cm in width and 50 cm in height. However, let's compare that to some values from the previous article:

  • F-34: 30 cm by 30 cm
  • M2: 30 cm by 30 cm
  • sFH18 105: 20 cm by 40 cm
  • ML-20S: 33 cm by 22 cm
Not very impressive anymore, is it? The allegedly superior precision of the very long 88 mm gun pales in comparison with guns on tanks some consider inferior (T-34 and M3 Lee) and short barreled howitzers, which are also typically considered imprecise. 

Friday 26 July 2013

King Tigers at Ogledow

I have posted a number of articles regarding testing of a Tiger II. But where did the Red Army get one of those relatively rare vehicles, especially intact? How long were these King Tigers roaming around the Eastern Front? The answers to all of these questions lie in the tank battle at the villages of Ogledow, Nemetzine, Zarez, Poniki, and Mokre, between the 501st s.Pz.Abt and elements of the 6th Guards Tank Army, namely the previously mentioned 53rd Guards Tank Brigade. The engagement is long and complicated. A map drawn up by one of the combatants is included at the end of the article, to clarify what happened where.

The story starts shortly before the battle. A German prisoner mentioned "Panther tanks" being delivered. Of course, he didn't know (or didn't admit to knowing) the difference between the similar looking Panther and Tiger II tanks. Indeed, the difference is much less than between a Tiger and Tiger II. Even the Soviet report on tests of the captured vehicle describes it as "a modernization of the Panther tank".

On the night before the battle, August 11th, 1944, a T-34-85 commanded by Guards Junior Lieutenant Oskin, and another T-34-85, commanded by Guards Captain Ivushkin, accompanied by infantry tank riders, approached the village of Ogledow. Since several Panther tanks have been immobilized and subsequently destroyed in the sandy terrain around the cluster of villages, the Germans were expected to move through the more reliable terrain. Ivushkin's tanks set up in a field. It is a well known historical fact that the tanks were disguised as haystacks, but there is more to that story, told by Oskin himself. At first, Oskin's crew simply covered the tank in hay. The result was a massive 3 meter tall haystack, with a 5 meter long gun barrel sticking out. Since it was quite suspicious compared to other haystacks in the field, barely a meter tall, the rest of the night was spent consolidating the smaller haystacks into more tank-like ones.

The morning of August 13th was very foggy, concealing the Soviet ambush. At 7:00 am, on August 13th, Ivushkin reported hearing a number of tanks approaching. These were eleven of the brand new Tiger II tanks. The new Tigers were accompanied by several APCs with infantry.

The tanks became visible to the 53rd's GTB. This is how the commander describes what happened next:
"A monstrous tank emerged from the valley. It moved in bursts, losing traction in the sand. Major Korobov radioed in from the left flank: "They're coming." I replied "Don't be hasty! Open fire from 400 meters." Another tank emerged, and then a third. They were very much spaced out, by the time the third tank emerged, the first already passed Ivushkin's ambush. "Fire?", he inquired. "Fire!", I replied. I saw the haystack that Oskin's tank was camouflaged as move. His gun barrel emerged. It twitched, again and again. Oskin opened fire. I saw how black holes appeared in the sides of enemy tanks, one after another. One tank started burning. The third rotated his front to face Oskin, but his track was knocked off, he could not complete his maneuver, and was finished off.

Soviet soldiers posing with a knocked out King Tiger.

I sent a radio signal, "307 - 305", to all units. Thirty guns fired directly, and the howitzer divisions covered the valley in indirect fire. Ogledow was concealed in a cloud of sand."

By the end of the day, the 53rd occupied the south side of Height 247.9, 300 meters eastward of Ogledow. Two tanks from the 3rd Tank Battalion and a company of submachine gunners were sent into the village, and cleared it of the enemy by 8:00 am. Among the houses of the village stood more Tiger IIs that retreated when the attack failed and were abandoned by their crews. Only then did the Soviets realize that they were dealing with new tanks. Oskin initially reported that he knocked out 3 Panthers.

V. S. Arhipov describes these events: "Two hours later, relative silence stood over the battlefield. Scouts reported that there are two undamaged tanks closer to Ogledow. They were stuck in the sand at the turn. On our left flank, we found another one. It drove into a swampy pool and was left there. The crew was in such a hurry to leave, they forgot their documents. Turns out, these new tanks weighed 68 tons..."

King Tiger #502, captured at Ogledow.

These actions are highlighted in red on the map.

However, the battle was not yet over, and there were more new tanks to fight. Infantry advancing in the direction of Zarez was stopped by fire from more Tiger IIs. A platoon of IS-2 tanks led by Senior Lieutenant Klimenkov entered the battle. Klimenkov took out two Tiger IIs, one of which caught fire. The fate of the other is more interesting.

"Before dawn, a tank platoon led by the company commander Klimenkov took his initial position near Ogledow. 2nd Battalion 294th SP attacked Ogledow. Its progress was halted by enemy tanks, hidden behind a house and some bushes behind the south outskirts of Ogledow. Infantry was stalled, and we sent a report to Klimenkov. Comrade Klimenkov took a high position, and made two shots, destroying the house the tank was hiding behind. The enemy tank retreated, but Klimenkov knocked off a track with the next shot. The enemy left the tank and fled. Our infantry captured the tank turned the turret towards the enemy, and opened fire."

Klimenkov's actions are highlighted in blue on the map. The infantry still falls within the red zone.

Seven Tiger IIs moved in from the direction of Mokre. An IS-2 belonging to Guards Senior Lieutenant Udalov opened fire at 800 meters, destroying two Tiger IIs, one of which also burned. The German tanks retreated, regrouped, and advanced on Poniki. Lieutenant Belyakov's IS-2 was in ambush in that direction. Opening fire at the column from 1000 meters, he set fire to one Tiger II. The rest turned back.

These actions are highlighted in green on the map.

Over the 3 days of fighting, from August 11 to August 13, seven Tiger IIs were irreparably destroyed, and six were captured intact or mostly intact. One was a commander's vehicle with maps and instruction manuals for the new tanks. A prisoner confirmed the losses. On August 16th, a prisoner from the 501st s.Pz.Abt confirmed that the battalion was formed with 20 Tiger II tanks and 20 PzIV tanks. Currently, the battalion only possessed 26 tanks.

The commander of the 53rd recalls: " is hard to tell who destroyed which tanks. Two battalions opened fire at once, Mazurin's and Korobov's, as well as two artillery battalions were were assigned (185th howitzer and 1645th light), and two SPG regiments (1893rd and 385th). Ground attack planes worked effectively. Oskin's crew definitely burned 3 tanks and knocked out one. Aleksandr Petrovich [Oskin] himself earned a Hero of the Soviet Union. [His gunner] Abubakir Merhaydarov got an Order of Lenin. All crew members were awarded medals. "

The 52nd Guards Tank Brigade also ran into some new Tigers. Two T-34-85 tanks were partially buried west of Staszow. The commander of the 52nd GTB describes what happened: "Early in the morning, we saw a "frame" in the sky, a fire correction scout plane. It flew over our sector and disappeared. Shortly after, enemy artillery opened fire. The shells missed and hit behind us, at the forest clearing and the outskirts of the village. "The Tigers and Panthers are coming", [company commander] Tokarev told me, after the artillery stopped. "I'll be in the trench, visibility is better there. Georgiy (Senior Sergeant, tank gunner), watch out." The loaders stared into the distance where the sound of engines was coming from. After several minutes, tanks emerged behind a hill, showing their sides. The Germans did not expect an ambush.
"Five, six, seven...twelve...," counted Komarichev. "Twenty! Twenty, with infantry!"
"Do not fret, Zhora, we are Guardsmen! Load armour piercing!"

Junior Lieutenant Kraynev's tank also spotted the enemy. At five hunded meters, Komarichev and Kraynev opened fire. Komarichev's shot set a King Tiger on fire, Kraynev knocked out another. The fascists tried to break through to the forest clearing. After taking severe losses, the Germans retreated. They did not advance on our defensive lines again."

The losses were heavy indeed. After expending nearly all of their ammunition, the ambush took out 14 Tigers and Panthers. The contributions of the 52nd are not present in the map drawn up by the 53rd, but the approximate area of their ambush is highlighted in yellow. Interestingly, Popov (Konstruktor Boyevih Mashin) writes that Oskin destroyed three Tiger IIs, and damaged another. Other literature agrees with Popov's version of events.

The figures accepted by historians, after going through everyone's kill claims are as follows:
Klimenkov's IS-2 took out two Tiger IIs, 14 and 15 on the map.
Udalov's IS-2 took out three Tiger IIs, 2, 6, and 7 on the map.
Belyakov's IS-2 took out one Tiger II, 16 on the map.
Oskin, supported by artillery, took out three Tiger IIs, 8, 9, and 10 on the map.
A raid by elements of the 53rd GTB captured four Tiger IIs, 11, 12, and 13 on the map, one not shown (it is present on Arhipov's original map).

This is a sketch of the area, as composed by Brigade Commander Arhipov, showing locations of the tanks in question. Regrettably, the map only has some of the action on it.

The following map is a little nicer, and more complete. I have shaded various portions of the map where various events described in this article took place.

Memoir text and elements of the battle summary retrieved from and Konstruktor Boyevih Mashin, Popov et al. Lenizdat, 1988. Handwritten materials retrieved from CAMD RF. 

Wednesday 24 July 2013

World of Tanks History Section: Tiger

It is hard to argue with the claim that the German PzKpfw VI Tiger tank is a symbol of the armoured forces of the Third Reich. Despite being far from perfect, this armoured vehicle became one of the pinnacles of the German tank building school in WWII.

Initially, German tank doctrine did not anticipate the need of a more powerful tank than a PzIV with a short 75 mm gun. After looking at their neighbours, the Germans realized that this vehicle was insufficient to storm the heavily fortified Maginot line. British Matilda tanks were also too armoured for the German Panzers to deal with them effectively. In 1937, the German armed forces ordered a breakthrough tank. Initially, the Henschel company took up this task, led by Erwin Aders. It created the DW1 and DW2 vehicles which, despite not going through to mass production, allowed Aders to gather valuable experience for creating the Tiger tank.

Despite the general opinion, Germany did not start the war with countless indestructible tank forces. The Wehrmacht's victories depended more on sudden and effective doctrine than technological advancements. Only after attacking the USSR, and meeting T-34 and KV-1 tanks, did the Germans realize they needed a new tank, and fast. It cannot be said that the Tiger was the answer to this need. The long-barreled 75 mm KwK 40 was adopted much earlier, allowing combat with "thick-skinned" Soviet tanks.

The idea of a heavy tank with thick armour and powerful armament was proposed to Hitler in May of 1941. Every tank unit was to be assigned 20 of these vehicles to increase its power. The project to create this idea in metal was assigned to two companies. The first was Aders' bureau, which was currently developing the VK 36.01(H). The second was Porsche, Hitler's favourite, despite his experience with automobiles, rather than tanks. The experimental vehicles were to be presented to the Fuhrer in May-June of 1942.

Henschel built their experimental VK 36.01(H). Thanks to tried and true components, the tank started out with a reliable suspension and transmission. However, the armament was problematic. The 75 mm squeezebore gun, developed by Krupp, fired armour-piercing shells with 1 kg tungsten cores. Such a wasteful use of expensive and rare metal was unacceptable, and the tank was rejected.

Aders' competitor Porsche decided to re-use some components from his previous experiment, the VK 30.01(P). His new creation, the VK 45.01(P), posessed the same layout and electomechanical transmission. Porsche's prototype was built with an 88 mm KwK 36, based on the famous FlaK 18/36 AA gun. The tank variant of the gun had a muzzle brake and an electric firing mechanism. Porsche, knowing Hitler's preference, counted on victory in the tender, and did not hesitate to order turrets and hulls for his tank.

Aders, despite his rejected prototype, did not give up. He redesigned his tank to use the same gun as Porsche. As a result, when the chassis was finished, there was not yet a turret for it. At the same time, Hitler had the idea to send both prototypes to the front, without trials. After that, he demanded 60 tanks from Porsche and 25 from Henschel by the fall. This was not possible, but the engineers did not date tell Hitler. To produce at least some tanks before the deadline, Aders' chassis was equipped with Porsche's turret.

The vehicles were presented to Hitler on his birthday. Here, Porsche made a mistake. He decided to have his tank drive off the railroad platform. The heavy tank sank into the ground. Aders did not take any risks, and unloaded his tank with a crane. During trials, both vehicles demonstrated strengths and weaknesses. Porsche's vehicle was faster, but Henschel's was more maneuverable. The VK 45.01(H) engine caught fire, and the VK 45.01(P)'s transmission was unreliable. Initially, Hitler wanted both vehicles to enter production, but his generals convinced him that Erwin Aders' vehicle was preferable. The Fuhrer, despite his preference for Porsche, was forced to agree. The unwanted hulls that Porsche ordered were later used to build Ferdinand tank destroyers.

The new tank was named PzKpfw VI Tiger. Its production started in August of 1942. Throughout the war, the tank was built in one modification, but with many small changes and improvements.

A special tank unit was created just for the Tiger: the Heavy Tank Battalion. Depending on the situation, the battalion would fight independently, or re-enforcing another unit. New crews were trained on the Paderborn base of the 500th reserve battalion. Tankers were picked both from experiences crews and recruits. Initially, all of these were volunteers, eager to try out these wonder-tanks.

The first Tigers made it to the Eastern Front in August of 1942. The 1st company of the 502nd battalion unloaded at the Mga station, close to Leningrad. Hitler insisted that these new tanks see action, and the hurried engineers did not have time to properly tune the vehicles. They started breaking down as soon as they arrived. The engine of one Tiger caught fire. The mechanics spent until the middle of September repairing the tanks. Some parts had to be flown in from Germany.

The first combat experience of the Tigers was very unfortunate. One tank stalled, and had to be abandoned. Three more were stuck in a swamp, and towed out with great difficulty. The abandoned tank was blown up. In January of 1943, another Tiger, undamaged, was captured by Soviet forces on the Volhov front. After studying these two trophies, guides on how to combat Tigers were written.

Further battles against Tigers at Rostov, Kharkov, and Leningrad proved that the tank can be a menacing opponent. Its thick armour could withstand the majority of guns. Reliable penetrations could only be achieved at the sides and rear. The tanks were also often disabled by knocking off their tracks with a shell or grenade. Incendiary bottles were also widely used, and were very dangerous to Tigers. Burning fluid, leaking through air ducts, ignited the engine.

Tigers first entered battle in Africa on December 1st, 1942. A company from the 501st heavy battalion was sent to assist Rommel's retreating forces. At Tebourba, the Germans achieved total victory, destroying 134 American and British tanks with minimal losses. However, the company commander died in that battle. Tigers continued to fight in groups of 2-5 vehicles, delivering heavy losses to the Allies.

Africa was a difficult test for the Tiger. Constant overheating, dust, and poor roads led to frequent breakdowns. Drawbacks of the design that nobody had time to fix made themselves known.

In April of 1943, the Germans were totally defeated in Africa. All Tigers that were still operational were either destroyed or fell into the hands of the Allies.

139 Tigers fought at Kursk. Due to this small amount, they were unable to affect the course of the battle, especially since they were scattered in small groups. However, at the time, the Tiger's fame was rampant, and any German tank could be mistaken for a Tiger, especially PzIVs. The Tigers served well in combat, especially when given the opportunity to open fire at a distance from which Soviet tank and anti-tank guns could not penetrate it.

Tigers fought throughout the entire war, remaining a dangerous opponent for any Allied tank.

Overall, Erwin Aders created the best German heavy tank of the war. Its armour and armament were well balanced. For its mass, the vehicle was decently maneuverable. The smooth travel of the interleaved road wheels allowed fire on the move. Driving the tank was so easy, that the Germans had a saying: "You are so unskilled, all you can drive is a Tiger!". On the other hand, it was exceptionally expensive and difficult to repair. Repairs of a damaged road wheel could take up to 3 days. The gearbox could not be replaced without removing the turret.

Tiger crews reflect well on its combat abilities. Aders himself earned the honourable title of "Father of the Tigers". The tank remains popular to this day. Many books are written on it, many scale models are manufactured, you can see the tank in many video games. Many examples of this tank survive, some of which are still operational.

Original article available here.

Monday 22 July 2013

Christie Tank Trials and Foreign Interest

It's no secret that the Soviets were very interested in Christie's tanks, but so were lots of other people. Here is a translation of a dialogue between several American officials, sent by Stalin to Kirov (RGASPI 558-11-746). The document covers foreign interest in the Christie tanks, and then discusses their trials in depth. A great depth. Maybe too great (it's really, really long).

"Barbour: I presume that he sold two tanks to the Russians because we bought only one tank instead of six.
General Hoff (chief of armament): I know that he sold two tanks to the Russian government, but I don't think it has anything to do with our contract. It is likely that he sold two tanks because we only bought one.
Barbour: He told me that if we bought six tanks, he would not sell two to the Russians. He said that the tanks were present, and available for inspection if we wanted to buy. I think that, if these tanks really had something to offer in the area of high speed tanks or vehicles, we should not have allowed foreign governments to purchase them before we had a chance to test. If these tanks cost us $250,000, let's make sure that this sum was not spent in vain.
General Hoff: It would not have stopped him from selling tanks to other governments. He already sold one to the Japanese government.
Barbour: I don't know anything about selling a tank to Japan. He only told me about selling to Poland and Russia.
General Hoff: I think that the sale to Poland did not go through.
Barbour: I have also heard this.

Tanks in service

Barbour: Let us discuss the issue of tanks in service. Before we discuss this issue, I would like to ask a few questions. Tanks are used by infantry?
General Fuqua (inspector of infantry): Yes, sir.
Barbour: Then tanks are entirely commanded by infantry?
General Fuqua: Yes, sir.

Trials of Christie tanks

Barbour: Are you familiar with Christie tanks?
General Fuqua: Well familiar, sir. I was inside one during movement.
Barbour: Do you possess reports from infantry officers that tested this tank?
General Fuqua: We never tested the Christie tank. We tested the Christie chassis. The tank commission, combined with the cavalry commission, which was looking for a new chassis for armoured cars, gave a very good impression of it, which led to a request to purchase one or more. The request was approved, and we bought one tank. The tank cost $55,000. We still have not received it. I just received a letter that it will be ready by the end of the year (1930).
Barbour: Did you see any complete tank?
General Fuqua: No, sir, only the chassis that I reported on.
Barbour: What was the vehicle that was driving around?
General Fuqua: That was the chassis that I described. It was not an armed and armoured vehicle. We didn't test it personally, but I received a report from a tank expert that considers it promising.
Barbour: What of the tank that you had last year? The one that was used and shown off to everyone?
General Fuqua: I deem it good. I consulted both commissions and talked to all officers that had anything to do with tanks during the war. All unanimously agreed that the chassis should be developed into a tank, which is what we did.
Barbour: Did this support the purchase of 4 tanks that you received funding for last year?
General Fuqua: Yes, we recommended this.
Barbour: I think that General Williams recommended this also.
General Fuqua: In his report, he considered it necessary to buy four or five of these tanks for the final evaluation of whether or not they are useful to our goals.
Barbour: Do you know, and can you tell the committee, what has changed regarding this purchase?
General Fuqua: Yes. Plans changed, since Christie's tank is still untested. From the department of armament's point of view, it is more correct to purchase one tank and test it, instead of buying five or six tanks that might prove unsatisfactory. A decision was made to test one tank before buying the other five.
Barbour: Can the tests be fully completed with one tank?
General Fuqua: Mechanical tests can be completed.
Barbour: I understand that General Williams, claimed that at least four or five tanks are necessary last year.
General Fuqua: I do not think that complete tests can be performed with just one tank. The services that use tanks are mostly interested in methods of combating tanks. Future tanks will be very fast than tanks used in the world war. The issue of using these fast tanks is one of life and death. Tests like these cannot be performed with one tank. Five tanks represent a single tactical unit (a platoon) and issues of coordination between infantry and fast tanks can only be explored with the use of several tanks. These tests with infantry are much more important than mechanical tests. If the Christie tank is delivered and passes mechanical tests, it is necessary to, as soon as possible, purchase at least five additional units of this tank.
Barbour: So you consider it correct to purchase five or six tanks to test one tank?
General Fuqua: The chief of the infantry directorate expressed a desire for six tanks.
Barbour: Were the proposals announced?
General Fuqua: Yes, sir.
Barbour: And received?
General Fuqua: Yes, they were received.
Barbour: For six tanks. These proposals did not exceed the sum of $250,000, prepared for this matter?
General Fuqua: Correct, sir.
Barbour: You observed the Christie tanks. Were they a promising weapon?
General Fuqua: Very promising. However, at the end, we decided to purchase just one tank.
Collins: Did you make this decision when the war minister already made his?
General Fuqua: I did not know about this. Perhaps it was so. However, at the time, I was not aware of it, Mr. Collins, and agreed, since one tank is better than none.
Barbour: The plan changed after the tender was announced. The bids were received, after which it was decided to buy six.
General Fuqua: Yes, but after that, we held another meeting, where it was decided to buy one.
Taber: Is this tank complete enough that you can make a decision on whether or not it is reasonable to order a large amount of these tanks?
General Fuqua: Yes, sir.
Taber: This precise model?
General Fuqua: By the unofficial answer, this is exactly the tank that we desire to purchase.
Barbour: The trial tank had a powerful gun, didn't it?
General Fuqua: That was not a tank. It was just the chassis. I have never seen the tank. My report uses the report of an officer who has seen the tank.
Barnour: And the report is classified?
General Fuqua: The report was a personal memo, sent to me by an officer that was keeping track of the project. I have no objections to adding it to the minutes.
Barbour: Pass it here.

Report on the trials of Christie tanks

General Fuqua: With your permission, I will read the most important part of this note.

The officer spent several days at Rueil [Note: another possible mitransliteration. Original: Руей], starting from November 24th. He observed trials of two Christie tanks that were built for Russia. He personally rode in one of those tanks for 30 miles off-road. He found the travel to be light and gentle. The two tanks were attached together, with little difficulty. The tank could climb a 43 degree slope of liquid mud with no difficulty. The entire tank, with no turret, weighs 8 tons. The armour is composed of plates half an inch thick. The internal layer is composed of a soft steel, 3/16 of an inch thick. The proposed mass, with a turret, gun, crew, and armament is over 10 tons. The Russian tank, while moving on wheels, moves using a drive mechanism. The American tank uses a chain mechanism. The officer says that a drive mechanism will allow a much faster process of converting the tank from tracks to wheels.
Currently, Mr. Christie is building a tank for Poland. This tank is not the same as the one for Russia. I heard that the contract for that tank has been annulled. The tank would have been finished at the same time as the American tank. The officer considers that the American tank will be finished in about 3 weeks. It will be delivered to Fort Meade, and also to Washington, so interested parties may see it.
The tank is 5 feet tall without a turret, and about 7 feet tall with.
The officer points out that a lot of car factory representatives were present at the trials. All present rode the tank, and were impressed by the smoothness and lightness with which the tank crossed terrain, and had a very high opinion of the individual spring suspension, which, in their opinion, allowed the tank to move smoother than a car.
The officer points out that the Polish tank, without a buyer, can be sold to the government if such is deemed necessary and sufficient funding is provided.
Barbour: Do you know how the Russian government managed to purchase such a tank?
General Fuqua: No, sir.

Trials of Christie tanks show its superiority to other types of tanks

Barbour: And so, on the Christie tank.
Colonel Cooper (chief of the tank school): Yes, sir. In October of 1928, Mr. Christie delivered a tank chassis to Fort Meier. The tank commission, along with General Sammeral (former head of the general staff), General Wells, and many other officers, traveled to Fort Meier and observed the trials of the chassis. Trials revealed a stunning speed, off-road performance, and smoothness of travel, to the point that we immediately thought that we have received a vehicle that satisfies all of our requirements. We weren't interested in the ability to put any hull on that chassis. We did not care, since the smoothness of travel was achieved. We do not mind shaking on the move, but we do mind the negative effect that has on the gunner. When I first saw Christie's tank, I thought that it was a tanker's dream. General Wells asked Colonel Escridge, who was the chair of the tank commission, if it was possible to get Mr. Christie to let us put his tank through trials without paying for it, making any promises, or being responsible for damage it might suffer. I was tasked with preparing the contract and having it approved, which I did.
The contract freed the government of all responsibility in the event of damage to Mr. Christie's tank. Mr. Christie delivered his tank to the tank school, where we did things to it that we would never to do our own tanks, since it was still Mr. Christie's property. The tank had weaknesses, but these were mechanical weaknesses, and not at all caused by the design itself. Mr. Christie is not a wealthy man, and used his savings to perfect his vehicles. He could not afford to have first-class craftsmen do metalwork for him. The first problem occurred when one of the wheel prongs broke. The wheels travel idly. The front drive wheel, which pulls the tank, cannot function. There were first two of these prongs, but one broke after a sharp turn. We examined it, and turns out there was a crack in a cast round part. If Mr. Christie had the means, this part could be forged. Such a breakdown would have disabled any other tank in our possession. Captain Tarp took off 8-10 track links and the tank was able to drive back to the repair base. Any other tank would have to have its tracks removed completely, and drive back to base on wheels.
Shall I continue?
Barbour: Yes, this is very interesting.
Colonel Cooper: These tanks represent a strategic reserve of the general staff. In other words, if a section of terrain is discovered that is suitable for using tanks, they will be assigned to aid an offensive. The tanks we had previously would have to be taken there by railroad, or with special heavy trucks. Our light tank regiment has 223 light tanks, and we would need 223 trucks capable of carrying 8 ton loads. These trucks cost $8000. The trucks would cost $1,800,000, and make an additional 223 engines that we have to care for in the field. This makes supplying the unit difficult, and makes operating the unit more complicated from a mechanical point of view to the point where we recoil in horror at the though that a war might start before our logistical system can satisfy our needs. We have witnessed that the Christie tank moves perfectly on rubber wheels. Mr. Christie made four or more trips between the Meade and Roway camps on wheels. If I am not mistaken, that is 1200 or 1400 km that the tank traveled on wheels. Tanks could be positioned 80 km behind the front lines. They are sent forward by road so that they can enter the battle at the right time. This distance takes 2.5 hours. This way, if we move at night, we can deliver the tank to its mission start on wheels, and then switch it to tracks. This job can be done by two people in a relatively short amount of time.
The tank will be equipped with armour that satisfies our requirements. Of course, we won't cross reasonable boundaries, but since tanks will be the first to assault the front lines, they must be armed accordingly. I am of the opinion that the Christie tanks offer us this possibility. I do not, by any means, think that Christie tanks are perfect, but I think that the suspension provides for an excellent gun platform, with which the gunner never needs to take his eye off the sight. I think the tank will double our offensive capability. At the time, we open fire at 400 yards. I know that the English teach to open fire at 1200 yards. If we fight a war with the English, and their tanks open fire at 1200 yards against our 400 yards, the result is obvious.
Barbour: Do you think that the Christie tank, in its current state, or in the state you saw it at the Meade camp, superior to the tanks we currently possess?
Colonel Cooper: Mr. Barbour, I will answer without hesitation that the vehicle is superior to everything we have in that field, or that we had in the past 10 years. It is beyond compare.
It is important to keep in mind that the army does not need a large amount of tanks, but in the last 12 years, we sat by an waited for a perfection of this weapon that would allow us to study it. We can theorize as much as we want, but that will be fruitless until we practically see how it behaves in battle, how we can supply it with fuel and ammunition, how to keep in contact with it. For 12 years, we have waited to begin this work, and we have not yet had a chance to begin.
Barbour: You spoke of mechanical defects. Are these serious?
Colonel Cooper: No, sir. Not one of them was serious. Christie periodically took his tank back, and replaced parts. Considering the materials that were used to make the chassis, this is the best possible job that could have been done by a man of his means. It is surprising that the tank continues to work after all we have done to it.

Trials of the Christie tank from Fort Meade to Gettysburg and back.

Barbour: The committee was informed that the trials involve 8 hours of movement on tracks.
Taber: I recall that the specifics were 8 hours to travel 320 km on wheels and 7 hours to travel 220 km on tracks.
Barbour: Is it not considered that there is no tank that can travel 60 km without breakdowns?
Colonel Cooper: I have seen such an assertion many times.
Barbour: What news do you have in that regard?
Colonel Cooper: The Christie tank left Fort Meade at 6:30 am and arrived at Gettysburg, a distance of 115 km, on wheels. The tank immediately left Getttysburg. It took 2 hours to return to Fort Meade, right on time for breakfast. It traveled for 2.5 hours on a concrete road, which is the toughest trial for a tank. The tracks on the vehicle were about 8 years old, since Christie was too poor to buy new ones. The tracks held. We only stopped once to fix them. We performed these trials on T1E1 and T1E2 tanks, and it took three days.
Barbour: Were there mechanical difficulties with the tanks?
Colonel Cooper: Yes, sir. We ended up having to load some of them on trucks. It was hopeless to try and make them move on their own power. These tanks look pitiful in comparison to Christie's.
Barbour: Allow me to pose a question. You insist that the tank seen at Fort Meade is superior to everything we have seen in that field. At the same time, you say that it is far from ideal.
Colonel Cooper: Yes, that is correct.
Barbour: Do you think that the army should continue trials of the Christie tank, with the goal of accepting it as a standard in the army?
Colonel Cooper: I am deeply sure of this. I am sure that we must continue this work. The changes Mr. Christie made that were recommended by the commission last year made the tank so reliable, that it can withstand trials you cannot even conceive of.

Characteristics of trials of the Christie tank

Barbour: You said that you did things to this tank that you would never do to your own possessions. What were the trials of which you spoke?
Colonel Cooper: We crossed swamps that none of our tanks could cross.
Barbour: How deep were these swamps?
Colonel Cooper: Deep enough that you could only see the driver's head. I estimate, about 4 feet.
Barbour: And the tank kept moving?
Colonel Cooper: Yes, sir. The tank moved as though it was on solid ground. We also drove at a reasonably fast speed through several logs positioned short distances apart. We wanted to see what would happen with the tank if it had to cross obstructions of this nature.
Barbour: What was the diameter of these logs?
Colonel Cooper: Most of them were 10, 12, or 13 inches in diameter. They were thick enough to throw the driver in the air in any other tank. The tank could also climb hills at a high speed that other tanks could barely climb at a low speed. It is obvious that you need a lot of force from the front wheels when climbing a hill like that. It is surprising that the tank was capable of it. Another trial, a jump at high speed. This happens when you drive to the end of a trench, jump, and then stop. The tank stops on the ground, several feet from where it jumped.
Barbour: How high did it jump?
Colonel Cooper: I think that the tank lifted 1.5 feet above the ground. It was not touching the ground at all, and came to a stop 8 feet from where it jumped.
Barbour: Do you think that the tank could jump while going up or down an incline?
Colonel Cooper: Yes, sir. For example, if the tank is driving on a flat surface, it can jump down, provided the height is not too great.
Barbour: How low can it jump?
Colonel Cooper: Not very. About 1.5 feet.
Barbour: But the vehicle you tested was not a tank, only a chassis.
Colonel Cooper: Yes, sir. When Mr. Christie took his tank from us in July, the infantry did not possess the means to acquire it, but cavalry had the means to acquire an armoured car or similar vehicle. That is when they took it from us, and presented it to the cavalry commission. Mr. Christie transported it to Newark and added some more armour. The tank used to weigh 5.5 tons, but now it weighed 8.5 tons. This was a tank in every way, except for its lack of turret.
Barbour: How heavy would the tank be with a turret and a gun?
Colonel Cooper: We expect the turret to add about 2 tons.
Barbour: So, 10 tons?
Colonel Cooper: Yes, about 10 tons.
Barbour: Is the tank designed to carry a gunner, and protect him?
Colonel Cooper: Yes, sir.
Barbour: And the driver also?
Colonel Cooper: Yes, sir.
Barbour: I understand that Christie is developing a new tank, 12-13 tons. Do you think that a heavier or a lighter tank is better?
Colonel Cooper: A lighter tank is preferable. Although, a difference of a few tons is not important. It is more important to consider the way these tanks are used.
Barbour: Can you use both samples?
Colonel Cooper: Yes, sir.
Barbour: You said that the Christie tanks provide smoother and lighter travel than old types of tanks?
Colonel Cooper: Yes, sir.
Barbour: Do you think that the tank you tested is a light tank, and can be used as such?
Colonel Cooper: In order to carry the additional weight of the gun and turret, Christie did what any engineer would do, and reinforced the chassis. As such, it is not correct to consider the chassis that we tested before. We will have a heavier chassis because it was modified to withstand a larger weight. We cannot, for example, put ton after ton on the same axle. We must increase the mass the axle can withstand.
Barbour: So, we must add the weight of the turret and such, and add the weight of the reinforced mechanisms?
Colonel Cooper: Yes, sir. I think that the issue was very well resolved. Captain Tarp can tell you more on this subject, since he spent 4 days at Christie's workshop last week. It seems that mass was not greatly increased due to higher quality of metals used in the construction. I think that many changes happened in this category. Of course, we cannot be sure until we weigh it.
Taber: Of course, don't guess. We will not gain anything by assuming things, especially since the tank will be ready so soon.

Disadvantages of the T1 tank compared to the Christie tank

Wright: Colonel, you talked about three or four major deficiencies of the T1E1 and T1E2, which, in your opinion, cannot be corrected?
Colonel Cooper: Yes, sir.
Wright: Are these deficiencies corrected in Christie's tanks?
Colonel Cooper: Completely, sir! The engine is in the rear. In other words, the tank is protected from the smoke and dust that the engine produces when working. The driver sits in the front, and can see perfectly what is happening in front of the tank.
Wright: He does not sit on top of the engine?
Colonel Cooper: The engine is in the rear. It is separated from the crew compartment. As a result, it is not hot, or at least as cool as possible in a closed metal box. the third deficiency I mentioned was the awful jumping of the gun, making it impossible for the driver to aim. The gun constantly moved up and down, as the tank did. The Christie tank gracefully handles bumps and inclines, and the gunner can follow the gun sight.
Wright: As I understand, Colonel, it is very difficult to safeguard the crew in modern tanks or the T1E1 and T1E2 tanks.
Colonel Cooper: Are you talking about T1E1 and T1E2 tanks?
Wright: As you said, it is difficult for the gunner to service the gun.
Colonel Cooper: Captain Cullen, an instructor at the tank school, has one of the largest black eyes I have ever seen, delivered by his tank's gun sight.
Wright: I think it would be very unpleasant to be shaken up so much that you hit the ceiling.
Colonel Cooper: Captain Tarp suffered from this. He hit his head on the ceiling.
Wright: As I remember, there was a claim made to the commission that when installing a turret, or in other words, making the tank complete, we must make the tank 1.5-2 feet longer to make room for the gunner and driver, and thus increase its weight. Is that correct?
Colonel Cooper: No, sir. I don't think that this would add half an inch to the tank's length.
Taber: When the tank arrives, you can make your own conclusions regarding its mechanical reliability.
Colonel Cooper: Yes, sir.
Taber: What about speed and lightness of controls?
Colonel Cooper: I can give you an answer if I knew if you wished to investigate a tank of this size, or a smaller or larger tank.
Taber: You will have the opportunity to test types of tanks with the initial chassis that, possibly, will be unsatisfactory.
Colonel Cooper: Initially, the chassis was the product of an extremely poor man. Despite doing things to it that we should not have done, it held out. We wanted to answer a series of questions with government vehicles, but we would not hesitate to explore them on Mr. Christie's vehicle, since we didn't want to break his only tank.
Barbour: Colonel Cooper, we are thankful for this information.

Major Brett's Testimony

Barbour: What do you think about this Christie tank?
Major Brett: I think that the Christie tank is a more attractive vehicle than any currently in use by any armed forces.
Barbour: Compare it to modern tanks we possess.
Major Brett: We only possess one tank, Mr. Barbour.
Barbour: T1E1?
Major Brett: No, sir, I did not mean that tank.
Barbour: I meant the types of tanks that we possess.
Major Brett: We possess several types of Christie tanks, different from the T1E1.
Barbour: How valuable are Christie tanks, compared to other types of tanks, for tank operations, as in all the goals which a tank is meant to accomplish.
Major Brett: There can be no comparison. I do not wish to mislead you, but the Christie chassis can be used in several tanks with different sizes and weights, as well as on trucks, self propelled gun mounts, and many other tasks. For example, the currently developed tanks are of the 4-wheeled suspension type. There are no reasons why they cannot be converted to 3-wheel suspension types, resulting in a light tank, despite us not endorsing that term. This can radically reduce mass, and give us a smaller tank, or increase it, and give us a larger tank.
Barbour: Is there some kind of limit to a tank's size?
Major Brett: There is a tactical limit.
Barbour: What does that mean?
Major Brett: Tactics suggest that a tank of this type should not surpass 20 tons.
Barbour: From your observations of the trials, can you make the conclusion that the ministry needs to acquire a number of these tanks, set them as the standard tank of the army, or do more trials need to be performed before accepting them?
Major Brett: It is difficult to answer this question, Mr. Barbour. The Christie chassis currently satisfies the requirements of the tank forces. We know that any mechanism has defects, and we must be ready for them. There is no such thing as a perfect machine, no matter how much you pay for it. Currently, it is not as important for the tank forces to move forward mechanically and build new tanks for the future, as it is to develop tactical requirements. The most important requirement is speed. No tank of the tractor type, developed until now, could match our speed requirement, either on a strategic or tactical scale.
Barbour: What is the performance of Christie tanks compared to tanks of other armies?
Major Brett: Christie's tank is the only one in the world with strategic mobility. No other tank in the world has been made with it in mind. The strategic mobility of other tanks depends on trucks, which deliver them to the battlefield.
Barbour: Was this strategic mobility proven?
Major Brett: Yes, sir. Tactically, the speed of this tank surpasses all other tanks. The fastest tank I have seen was the Vickers tank, which reached 46 kph.
Barbour: Do you have the latest Christie tank for trials?
Major Brett: No, sir, we do not have the latest Christie tank.
Barbour: Does the tank you tested at camp Meade provide enough information for you to decide if it is worth buying?
Major Brett: Yes, sir. Considering the principles of the tank forces, doing so is in the interests of national defense. However, we did not make any conclusions tactically. We think, or at least I think, that we will solve very important issues and will be able to explore tactical issues of national defense, if we accept the Christie tank as it is.
Barbour: You think that it has been through enough trials?
Major Brett: Obviously, we will continue tactical and mechanical trials. The issue of a complete tank does not interest us, as the Tank Corps can develop our own hull. We wanted to consult on the layout of the fighting compartment, what type of tank is needed, where the driver would go, etc. However, while we are interested in one specific vehicle, especially since the vehicle does not even have a fixed weight, and is not finished due to its lack of turret, we cannot make an evaluation of its power. At this horsepower, adding two tons is pretty simple. When the issue of rejecting a tank because it has no turret arises, we do not very much care about those details.
Barbour: Is it possible to drive a Christie tank at maximum speed with the driver inside?
Major Brett: Yes, sir.
Barbour: And the driver will look through an observation port?
Major Brett: He uses the sight and the observation port. During shooting, he uses the sight. During driving, he uses the observation port.
That is also an important issue, Mr. Barbour. We have several types of vision devices on the tank. One is a port that is a narrow slit in the tank's armour, which does not allow bullets to pass through. It is only 3/10 of an inch in size. There are several of these slits, which can be covered up. Of course, if the tank is not under fire, there is no need for this precaution, but it is necessary to keep them closed when the tank is in danger. You can keep it open at 7/10 when the tank is not on enemy territory and not under fire.
Barbour: Do you have any statements on the Christie tank that you would like to share with the commission?
Major Brett: I would like to point out one thing. I am very interested in receiving the best tank for national defense. I think that the Christie tank, the one that carries within itself its method of delivery (the wheel drive), and then, on its own power, provides tactical mobility with its tracks, is the most economical, not only financially, but tactically. It is very difficult for a commander of a tank regiment to manage 223 tanks, as well as the trucks necessary to transport them, especially when he has to hold against an attack from the ground or air. This would demoralize the regiment. With wheeled tanks, there is less of a threat from a ground or air attack, as we would possess equal chances. Bombs pose no danger to a tank, outside of a direct impact, but are dangerous to trucks, as they can damage unprotected components with shrapnel. The most important thing about the Christie tank is that it provides flexibility to the commander, strategic power, and strategic mobility.

Advantages of the Christie tank

Barbour: Are you familiar with the Christie tank?
Captain Tarp (head of the experimental tank department): Yes, sir, with every aspect of it.
Barbour: Please tell the commission everything you know about this tank.
Captain Tarp: When the tank arrived at Fort Meier, the officers familiar with tanks immediately saw that this was an interesting and promising vehicle. As it was, there were parts of the tank in its current state I did not like, namely that it did not have armament, the gears switched so fast, it was hard for the tank to move slowly, and it had old tracks that traveled 2000 miles on the old McFadden tank several years ago. We also tested it, but that's a thing of the past.
Barbour: Did you test it at Fort Meade?
Captain Tarp: Yes, sir. It weighed 5.5 tons. Some people think that it would be worthless if it weighed more. When we sent it back, its mass grew three tons. But it was an overall gain, and the tank became easier to control, and travel became smoother. While the tank was there...
Barbour: At Fort Meade?
Captain Tarp: No, at Christie's workshop. We got a new gearbox, and could control the tank as well at low speeds as at high speeds. Since the tank needs to be able to move slowly to avoid craters and trenches, this was a big improvement. During the trials, several weaknesses were discovered, and easily corrected. The new tank that he is building had some things that we did not like. We asked him to change them, and he did, at his own cost.
Barbour: in the new tank?
Captain Tarp: Yes, sir. In the new tank, we wanted to driver to be placed in the front of the tank, where he could see the ground when descending into a crater or a trench, and he put the driver in the front. In the current tank, the gunner is placed to the rear. He should be in the center, where it shakes less. When the gunner is in the rear or the front, he shakes too much when the tank moves through harsh terrain. We try to avoid this. We also want the gunner to be protected.
Barbour: The same way it happens on a ship?
Captain Tarp: Yes, sir. The center of the ship is the calmest spot. The same is true of a tank. It is hard to aim with a gunner that sits in the rear of the tank, like on the T1E1 and T1E2. The gunner cannot shoot accurately in this position, and we do not want him there.
Barbour: Have you seen the tank that Mr. Christie is working on right now?
Captain Tarp: Yes, sir.
Barbour: What do you think of it?
Captain Tarp: I think that this is the best vehicle that has been developed in the area of tanks. It is ten years ahead of its time, and, I must say, Mr. Christie is always 10 years ahead of his time. He invented front drive wheels for a car, which are only now being implemented in practice.
Barbour: He invented that 10 years ago?
Captain Tarp: Yes, even more, close to 20 years ago. He is very creative, and full of new ideas. I don't think there are any barriers in the field of mechanics that he did not overcome.
Barbour: When did you see the latest tank?
Captain Tarp: In the end of November.
Barbour: When will it be ready for trials?
Captain Tarp: It will be ready by the start of next year (1931).
Barbour: When will you start trials?
Captain Tarp: Mr. Christie was going to bring the vehicle to Fort Meade and Washington before taking it to official trials at Aberdeen.
Barbour: Will the official trials be done by the supply commission?
Captain Tarp: It will be a joint commission.
Barbour: A joint commission made of tank officers and what others?
Captain Tarp: Cavalry and several other officers.
Barbour: Can this joint commission judge the adequacy of a tank?
Captain Tarp: No, sir. The commission just makes a report and recommendations.
Barbour: What do you do when there is a difference of opinions?
Captain Tarp: I don't know, sir.
Barbour: Allow me to put it this way. If there are different opinions between different branches, say, the tank officers think that the tank is a step forward, but the logisticsofficers do not agree. Cavalry agrees with the tank officers, and other officers do not consider the tank interesting. What happens in that case?
Captain Tarp: I don't know, sir. Usually the tank speaks for itself.
Barbour: Yes, you are right. The people that will have to service these vehicles and work inside them will always be able to talk about them.
Captain Tarp: Yes, sir. We know what kind of tank we need, but other people try to tell us what tank they think we need. Years of experience prove them wrong.
Barbour: that is not a practical method.
Captain Tarp: No, sir. I can read you a list of 15 complaints and show how they can be avoided, if you so choose. I have it with me. They are in the order that they were presented to the Christie tank, and none of them apply to it.
Barbour: Is it brief?
Captain Tarp: Yes, sir.
Barbour: Can you summarize each point in one or two phrases?
Captain Tarp: I think so, sir. One of the comments was that the vehicle was not good, since Christie's previous vehicles did not perform well. It is necessary to say that out of all vehicles bought from Christie for $839,000, only one was a tank, worth $89,000. All other vehicles were meant for towing guns.
The bad performance of the gun tractors absolutely does not apply to Christie's new tank.
"Tests performed in 1929 were very insufficiently exhaustive". The tank was tested for 14 months at Fort Meade. The tests cost $32,000, and Mr. Christie footed the bill. 14 months was enough time to explore the tank's construction. We are not too worried about what is on top. We are studying the suspension system, what we can expect from it, how well it performs.
Barbour: Would you build tanks based on this prototype?
Captain Tarp: Yes, sir. The department of logistics can put anything they want on top. We have our suspension system, this is exactly what we want.
"The vehicle being tested at Fort Meade is very different than the vehicle submitted by Mr. Christie for satisfying the requirements." That is true. That vehicle had characteristics we were unhappy with. We demanded that Mr. Christie make some changes, and he did. Some of the changes are listed here.
Barbour: After the changes, were the characteristics satisfactory?
Captain Tarp: Yes, sir. The new prototype was changed, and is even better.
Taber: The next prototype will probably change again.
Captain Tarp: Yes, sir. That is very likely. Currently, the system is good, as far as I can tell from the latest observations. I studied it very carefully.
"The requested price is too high."
The initial price was set at $35,000 per tank. When the department of logistics wanted to buy them, Christie asked for $40,000. As you can see, the price is not too unreasonable, especially since the $35,000 included blueprints, which would cost large amounts of money, and the right to manufacture our own tanks. OF course, this is a different matter. I will not fixate on it.
"The society of automotive engineers at the logistics committee gave a negative opinion of the proposed project".
When I was there last November, Mr. Majorie, the senior engineer from Mac, was also there. I invited him to take a ride on the tank for the first time. He was impressed by the mobility, lightness and ease of the controls, as well as the technical construction of the tank, and gave the highest praise for it.
"The proposed project has many crippling defects".
Some of the listed defects are "the tires are overloaded, like on a wheeled truck". This is incorrect. Each tire holds 1200 pounds of load, and the limit is about 2000 pounds.
Barbour: Are these sturdy rubber tires?
Captain Tarp: Yes, sir, very sturdy rubber tires.
"There is no track freeing mechanism".
This means that when some object gets between the tracks and wheels, the track stops. The Christie tank does not have a mechanism to free its tracks like other tanks do, but it has a similar mechanism. I could explain it to you in a technical manner. The wheels are suspended on springs, and they can rise and lower. When the track tightens, it attempts to bring all wheels up, and frees the object. Tests proved that this is a satisfactory method.
Here is the list of defects. Would you like me to stop here?
Barbour: Complaints against the tank?
Captain Tarp: No, sir, mechanical defects found by the department of logistics.
Barbour: How many are there?
Captain Tarp: 12-15.
Barbour: Tell me of the most notable ones.
"Lack of a differential when in wheeled mode"
Captain Tarp: The subject is the differential on the rear of a car, so one wheel can move slower than the other. Tests showed that this is unnecessary. A lack of a differential did not lead to any complications. All it does is slip, and we have determined that without it, there are no ill effects on the chassis.
"Mechanical joints where metal touches metal at high speeds".
They performed well during tests, and were not damaged.
"Lack of a regulator for attacking rear chains".
There is a regulator for gear chains. We would not use chains at all. We are against them, and recommend against it in future tanks that move with toothed wheels, like tractors, since a chain leads to a series of complications and gets in the way.
"The gearbox with sliding gears makes it difficult to switch gears at any speed and can lead to a failure to engage the gears".
This never happened during trials.
"A lack of a graphite rod or any other item for servicing auxiliary components of the engine or gearbox".
Mr. Christie invented a new system for servicing those parts, which is very satisfactory, and never caused us problems.
"Lack of an air filter for the engine".
Irrelevant. You can put on an air filter, if you want.
"Inaccessible engine".
The inaccessible engine isn't that important. It is important for us to know if we can exchange components, and how long that takes. It is not important if you can screw off the nut on the bottom of the engine. That is meaningless. We need to know if the engine can be removed, how fast the new gearbox can be installed, how quickly the tank can be ready for battle.
"The ground pressure of 10.5 psi is too great. It needs to be less than 7 psi".
This is incorrect. Data shows ground pressure to be 7-8 psi.
"There is no rear steering mechanism in wheeled mode, which is dangerous".
This is correct.
"There are no brakes".
This is incorrect. There are brakes, and always have been.
"The wheels are very poorly attached to the cantilever for a suspension with mobile tracks".
If this is true, there needs to be more evidence. Everything was fine in tests.
"The center of mass is too far back".
The center of mass coincides with the center of the tank, and is located where necessary.
"The blueprints are incomplete, contradicting, and unclear".
Mr. Christie did not show detailed blueprints to that commission.
"The tank only has a crew of two"
Taber: Did he show you detailed blueprints?
Captain Tarp: Yes, sir. In the future, we hope to construct a fighting compartment for three crewmen. We can do that later.
"The tank can only mount a 37 mm gun".
This tank can also have a 75 mm gun, if you so wish.
"The chassis weighs as much as a medium tank, but performs like a light tank".
This is incorrect. We do not build light, medium, or heavy tanks. We build tanks that solve specific problems.
"The tank has no well-defined role".
We can make a lighter tank with a specific role, but this tank also has a role, and heavy tanks also have their roles.
This tank is needed for fast breakthroughs of the enemy lines or fast flanking maneuvers, neither of which can be done with other tanks. Tanks meant to attack the enemy front lines are built differently. Armour on those tanks needs to be an inch or an inch and a half thick, so it can withstand anything the enemy can throw at it. For a tank of this type, that is not needed. It needs to be protected from .30 caliber. A heavy tank can go deal with anti-tank defenses. After that, we will send fast tanks to the breach, which will thrive in the area devoid of anti-tank defenses. This is only one way to use these tanks, of course.
"The crew compartment is unventilated".
The crew compartment is ventilated very well. The engine takes in air from the crew compartment. Additionally, I must add that, while impossible for the T1E1 and T1E2, we could protect this tank from gases in its current form. The engine and crew compartments need to be separated. If we can protect the crew compartment from external air, when we can use oxygen tanks to enable the tank to cross infected areas. With a tank that has the engine in the front, with the gunner and driver in the back, it is not possible to be protected from chemicals, and we must achieve this protection in tanks of other types.
"The hatches are unsatisfactory, and very dangerous if the tank catches fire or flips over".
We corrected this in our Christie project. Mr. Christie did not take this into account. He did not think that these things could happen, it is out of his scope. It is in ours, and we dealt with it.
"The tank is too heavy to be used in a mechanized division".
I have here a claim that the tank weighs about 30,000 pounds. This is 15 tons. The tank does not weigh that much. The last time I weighed it, the chassis weighed 8.6 tons. When we put on a turret, gun, ammunition, it will weigh about 11 tons.
"The two-man crew has to separate the track into three or four parts to remove it and continue on wheels".
This operation took 17 minutes when performed by 2 people at the test.
Additionally, 4 of these 15 defects in the Christie tank are present in the T1E1."

Sunday 21 July 2013

IS-2 vs. Big Cats at Lvov

In the middle of 1944, the Red Army launched a series of offensive operations, meant to take advantage of their strategic initiative, deliver crippling blows to the German land forces, and liberate pre-war Soviet territory. One of these operations was the Lvov-Sandomierz Offensive. In late July, vicious street fighting to re-take Lvov began. The 72nd Independent Guards Heavy Tank Regiment proved themselves particularly heroic in its liberation, earning them the adjective of "Lvovskiy". The award order, as always, tells a small part of the story:

"To the 72nd Independent Guards Heavy Tank Lvov Regiment

October 3rd, 1944

According to order #0387 from February 5th, and complying with instruction #172 "On payment of reward for destroyed enemy tanks", the Head of the Finance Directorate of the Red Army approves payment to the named crewmen for destruction of enemy heavy tanks.
  1. On July 21st, 1944, in the city of Lvov, in combat at the northern part of the Zelenaya street, an enemy heavy Panther tank was destroyed by fire from Guards Senior Lieutenant Almuhamedov,.
  2. On July 22nd, 1944, in the city of Lvov, in combat at the Academicheskaya square, an enemy heavy Panther tank was destroyed by fire from Guards Senior Lieutenant Almuhamedov,.
  3. On July 22nd, 1944, in the city of Lvov, in combat near the theater, an enemy heavy Panther tank was destroyed by fire from Guards Senior Lieutenant Almuhamedov.
  4. On August 4th, 1944, in combat at the north-western outskirts of Feltshin place, an enemy heavy Panther tank was destroyed by fire from Guards Senior Lieutenant Almuhamedov.
Pay the crew of Guards Senior Lieutenant Almuhamedov for four destroyed enemy heavy tanks, the total sum of:
  • Tank commander, Guards Senior Lieutenant Almuhamedov: 2000 rubles
  • Senior mechanic-driver, Guards Senior Technical Lieutenant Pisarev: 2000 rubles
  • Gunner, Guards Senior Sergeant Mazurin: 2000 rubles
  • Loader, Guards Senior Sergeant Porohnya: 800 rubles
  • Total: 6 800 rubles"
CAMD RF 3802-247172-1

In the interest of brevity, I will skip the full text of the rest of the award order, as it is similarly verbose. In total, 10 Panthers and 5 Tigers were destroyed by IS tanks of this regiment, for a total of 25 500 rubles of reward. Even though the loader appears to get shafted (200 rubles per tank, as opposed to 500), memoirs suggest that reward money was evenly split between all crew members. 

These are just financial rewards. There were, of course, others. Here are some award orders:

"Comrade Baranenko, in combat for the Motherland against Germano-fascist invaders in the Lvov direction, showed bravery and knowledge of ambush combat. 
On July 20th, 1944, in the region of Peremyshleny, his crew destroyed two Tiger tanks, one Panther tank, and up to 60 soldiers and officers of the enemy, which allowed the capture of the settlement.
For skillful combat, both in ambush and in offensive battle, for destruction of two Tigers, a Panther, and up to 60 soldiers and officers of the enemy, and for the display of courage and bravery, he is worthy of the Order of the Red Banner award."

"A most brave and energetic gunner. During an enemy counterattack between July 17th, 1944 and July 23rd, 1944, during the destruction of the Brody group, he destroyed 5 enemy heavy tanks, 4 anti-tank guns, 10 machine gun nests, and up to 100 soldiers and officers of the enemy, demonstrating skill, courage, and bravery in battle. 
When his tank was damaged on July 25th, 1944, comrade Arslanov did not leave his tank, and destroyed 2 enemy SPGs, even though the enemy did not stop firing at his tank. Only when he was wounded and the tank was engulfed in flames did he leave the tank. 
For the damage done to the enemy and demonstration of courage and bravery in battle, he is worthy of the highest award of this government, the Hero of the Soviet Union."

"Guards Technical Lieutenant Ivanov, during combat for the Socialist Motherland from July 14th to 29th in the Lvov direction, during street combat for the city of Lvov, showed mastery of driving a heavy tank in the most difficult conditions of street combat.
Thanks to his excellent practical knowledge, his vehicle never stopped due to a breakdown, and constantly moved forward. The crew was always capable of fighting the enemy with an advantage from the positions that Ivanov would take. This crew destroyed two Panther tanks, five guns of various calibers with their crews, 4 vehicles carrying ammunition, 4 mortars, 10 trucks, and up to 50 enemy soldiers. 
For skillful maneuvering of a heavy tank on a difficult battlefield, which enabled the crew to destroy enemy vehicles and personnel, for personal courage and decisiveness, he is worth of the Order of the Patriotic War, Second Class."

Friday 19 July 2013

Gas Tanks, Fires, and Explosions

When a shell hits a tank's fuel tank, the outcome is always unpleasant. At the very least, it will lose fuel. The fuel might also catch fire, which, despite popular belief, happens to both diesel and gasoline tanks. If the concentration of vapours in the tank is correct, the gas tank might also explode. The question is, how often does this happen, and under what conditions? Soviet engineers decided to find out.

"Source #632/2
September 11, 1944


Responsible: Rozov, Kaminskiy, Shurov
Supervisor: Sarafanov

History of the topic

In the spring and summer battles of 1943, tank commanders began to note instances of T-34s destroyed by fire or detonation of fuel tanks. For example, during the summer of 1943, at Kursk, fires happened more often than on the T-70 by 4-9%. By the order of the Head of the BTU GBTU of the Red Army, Engineer-Colonel Afonin, a special commission was formed on September 11th, 1943. Our team was tasked with exploring the possibility of detonating the T-34's fuel tank using several armour-piercing measures, and the evaluation of the impact on the crew and internal equipment.


Examination of 72 tanks at SPAM bases, destroyed during the battle at Kursk, the commission found that most of them (68%) were destroyed by un-sealing of the fuel tanks and subsequent ignition of the diesel fuel. All these tanks were struck in the side or overtrack hull by an AP, HEAT, or HE shell. Approximately a third of the examined tanks lack one or two fuel tanks, and have damage to the welding seams due to the internal explosion. Only a small portion of the tanks have traces of internal explosion and fire (8%), while 24% of the vehicles were destroyed by explosions only, with no traces of fires. The ammunition remained undamaged in the racks. Acting on our orders, we examined specifically the cause of destruction by an exploding fuel tank.
Engineer-Colonel Gurov and Dr. Krutov, after examination of the tanks, suggested that the damage is caused by detonation of the front fuel tanks, after being hit with some kind of special German shell. Engineer-Major Firsov theorized that this could have happened after detonation of a high temperature shell inside the fuel tank, like one based on thermite. Comrade Sarafanov's team was ordered personally by the chief of the GBTU to investigate the possibility of detonation of the T-34's fuel tanks as a result of being hit with various types of shells used by the fascist armies.

Equipment used in the experiments

To evaluate the theories of comrades Gurov, Firsov, and Krutov, NII-48 and Uralmash built three T-34 full scale models from 35 mm thick armoured steel with a 135 liter (see blueprint #2) fuel tank. Also, as a result of letter #312-a sent on April 21st, 1944, the BTU supplied us with a T-34 hull, with equipment inside, but without armament.


The first test of the models happened on December 12th, 1943, from a 75 mm model 1940 tank gun, from 30 meters. During these tests, the fuel tank was fully filled with diesel fuel, according to comrade Afonin's letter from December 5th.

8 model 38 shells were fired, as well as 5 model 39/40 shells, and 5 HEAT shells. The results are as follows: the fuel tank was destroyed completely 3 times. The fuel ignited 4 times. No explosions were observed. When struck with a model 39/40 shell, the fragments were rapidly stopped. A full T-34 fuel tank cannot be a source of an explosion, and also offers protection from armour fragments and cores of model 39/40 shells.

Comrade Krutov suggested that gasoline would also be unable to explode when the tank is full. Comrade Fedin ordered a gas tank be installed. 3 model 38 shells and one HEAT shell were fired. No explosions. The gasoline ignited 2 times.

The second stage started on February 9th, 1944. The same gun was used, along with an 88 mm recoilless model 1943 gun, shooting 88 mm HEAT charges. The tests were done on tanks that were partially filled. Before this, the full tanks were driven around on a truck for 1-2 hours on a dirt road, and then fuel was partially drained from it.
Fourth series of shots. The tank was filled 10-25%. The tank explodes when hit by a HEAT shell at under 25% capacity. The explosion was equivalent to 30-50 grams of TNT. The fuel tank cover was knocked off. In the case of a gasoline tank, the explosion is 1.5 times weaker. The gas tank cover opens as a result of the explosion. Welding seams remain intact.
The effect of a detonation of a 75 mm AP shell with the red ring, equipped with 80 g of TNT and a 20 g detonator, is quite different. The explosive force grows several times over. The overtrack hull seams burst, and the roof of the model is deformed. The model becomes useless.


The best conditions for a detonation is a tank that is 10-15% full, and a detonation of the "rot" shell with 80 grams of TNT and 20 grams of phlegmatized explosive. The fumes detonate, resulting in a force equivalent to a 105-122 mm AP shell.
An even better effect is achieved by the detonation of the domestic 76.2 mm BR-530A shell, with 150 g of TNT, which is equivalent to a 152 mm shell with 400 g of TNT. With a reduced caliber, the likelihood of an explosion decreases drastically. 45 mm and 37 mm guns are nearly incapable of causing a detonation. An increase in caliber does not result in an increase of explosive effect. The optimal caliber is 75-85 mm and 50-100 grams of TNT, or a smaller amount of more powerful explosive substances (30-80 grams of A-1X-2 or 25-50 grams of phlegmatized cyclonite). The tank must be at least 100 liters in size. Tanks 30-50 liters in size do not result in significant increase of the shell's explosive force.

  1. Do not place fuel tanks inside the fighting compartment.
  2. Use fuel from rear tanks first, as they are less likely to be hit.
  3. Build fuel tanks that collect less vapours. As fuel is spent, replace it with an inflammable fluid or a gas that does not ignite. Before battle, flush fuel tanks with CO2, CO, or constantly ventilate front fuel tanks. 
  4. Half the size of fuel tanks in the fighting compartment.
  5. Place the fuel tanks behind airtight armoured plates.