Saturday 5 November 2016

T-55: The Third World's Main Argument

UralVagonZavod: a change in generations

The T-54, a logical improvement on the T-44, was designed at factory #183 in Nizhniy Tagil (the future UralVagonZavod), and was the main tank of the first post-war decade. The first T-54 prototypes were created during WWII, in late 1944 and early 1945. The tank was accepted into service in 1946, and production began that same year. The T-54 was ahead of other tanks in its class in all parameters. The design was so progressive that the Soviet Army had no need to develop a replacement for over a decade. This success can be largely explained by the fact that Nizhniy Tagil was home to a unique group of engineers who created the legendary T-34 during the war and the first few post-war years. They were evacuated along with factory #183 from Kharkov and continued working in the Urals.
The T-54B tank. External differences between this tank and the T-55 are so slight that foreign sources often call both tanks T-54/T-55.

The war ended, and it was necessary to rebuild Soviet industry. Many industrial groups returned to their homes. No matter how much factory management tried to convince Kharkov engineers to stay, they were eager to return as well. In the fall of 1951, the chief designer of the bureau, Aleksandr Aleksandrovich Morozov, fell ill with a gastric ulcer, and had surgery in November. The author is unaware of the details of his recovery, but in December he was appointed as the head of the design bureau at the Kharkov factory, restored after the war. Morozov worked there in the 1930s on the A-20 and A-32 (which evolved into the T-34).

Aleksandr Aleksandrovich Morozov

Other Kharkovites followed their chief designer from the Urals to the Ukraine. Morozov took the core of the design team with him. The remainder of the design bureau in Nizhniy Tagil was tasked with ensuring that T-34, T-44, and T-54 blueprints used in production (recall that the T-54 was built at many factories, including ones in Poland, China, and Czechoslovakia) were identical to the originals. The bureau also had to improve and modernize the T-54 tank. However, the ambitious collective that remained, used to creative work, was not satisfied with this arrangement. Interestingly enough, factory management was also interested in changing tank models. The issue was that until Kosygin's reform in 1965, Soviet factories had to reduce the cost of their products by 15% annually. Every year, the factory received less money from its customer, and unless the factory's products were regularly refreshed, the factory could begin losing money. Since the factories were working on a limited budget, they could not reward its workers and motivate them with holiday packages, build recreational facilities, etc. The management could not expect awards and career growth. A new tank would mean that a margin could be built into its price to be lowered as the years went on. The government would receive a new tank with improved characteristics (the cost of the T-54, T-55, and T-62 was almost the same) and the factory would be rewarded with a few years of wealth.

The front entrance of UralVagonZavod.

Tagil without Morozov

In July of 1953, a young engineer was promoted to the position of the factory's chief designer: Leonid Nikolayevich Kartsev. At the end of the year (despite the fact that his design bureau was lacking designers, industrial capacity, and experience) he managed to obtain the permission to build a tank for a tender. Initially the tender was only open to Morozov's designers in Kharkov. The new tank would have 10% more armour, firepower, and maneuverability than of the T-54.

Leonid Nikolayevich Kartsev

The new project was indexed "Object 140". The tank was the first to use aluminium road wheels, a longer gun than the T-54, and other less significant features. However, after the tank was built in metal, it was clear that the result was difficult to build, maintain, and repair. After building the prototype, the design bureau declined to participate in the tender.


An experimental prototype of the Object 140 medium tank.

Instead, the design bureau opted to improve the T-54. Underwater driving equipment was installed, which allowed it to cross water hazards up to 5 meters deep and 500 meters wide, a gun stabilizer, night vision devices for the driver and commander, and a night vision sight for the gunner. The new tank was indexed T-54B.

A tragic event was narrowly avoided during testing of the stabilizer, a prototype of which poorly stabilized the gun in the vertical plane. Kartsev wrote in his memoirs: "One of the designers of the stabilizer, A.S. Lipkin, decided to test it by hanging off the gun barrel with the stabilizer enabled. under his weight, the gun did not lower. He yelled happily: "Yes! The stabilizer works!" At the same time, a scream emanated from the deputy chief designer of the factory that built the stabilizer, F.N. Avdeev. Turns out that he was in the tank and stuck his head in between the breech and ceiling to ensure that the stabilizer hydraulic cylinder wasn't leaking, and Lipkin jumped on the gun at the same time. Serious consequences were only avoided since Lipkin was not a large man."

Meanwhile, the question of a new tank for the Soviet Army still had no answer, and novelties piled up at the design bureau, both from the bureau itself and subcontractors. The Kirov factory in Leningrad developed an automatic fire extinguisher system that factory management didn't want to use on its own tanks. Morozov's bureau designed a planetary transmission that was more reliable and long-lasting than the cylindrical one used at the time. The Kubinka proving grounds designed thermal smoke emitters to replace disposable smoke bombs that increased the weight of the tank and could not provide lasting smoke cover. Dropping external smoke bombs allowed the tank to receive two new fuel tanks with a total capacity of 400 Liters.

T-55 tank equipped with underwater driving equipment after crossing a water hazard.

Object 155: new tank or T-54 modernization?

In October of 1955, development of a new tank began, the Object 155. The Chelyabinsk Tractor Factory modernized the V-54 diesel (previously used on the T-54), increasing its power output from 520 to 580 hp. The new engine was indexed V-55V, and let the new tank reach a speed of 48 kph on a road with 450 km of range.

The new tank used the modernized T-54B turret. Aside from aforementioned novelties, the tank used slotted fuel tanks. This allowed them to store not only fuel, but also ammunition. The ammunition capacity of the tank increased by 9 shells (from 34 to 43, or a 26% improvement) and the fuel capacity was increased by 680 Liters, a 50% improvement. Some fuel was placed in the front section of the tank, which posed the question of whether or not the fuel was in danger of detonation if the tank was hit. However, proving grounds trials showed that when hit with a HEAT shell, the diesel fuel leaked out harmlessly, and the fuel tanks served as additional protection from spalling. Note that the designers of the Leopard 2 lined the sides of the driver's compartment with fuel tanks as well, not considering this particularly extraordinary. Removable tanks of compressed air that were previously used to start the tank in cold weather were replaced with a powerful compressor. Now the air starter became the main way to start the tank, which made the batteries last longer.

Fuel system of the T-72 tank, inherited from the T-55 and T-52. The front and rear slotted fuel tanks are visible.  

For the first time in the history of Soviet tank building, the tank used an NBC protection system. If radiation higher than normal was detected, pyrotechnic charges went off and automatically sealed the tank. Air sucked into the tank went through a filter that removed radioactive dust and poisonous substances, and positive pressure inside the tank prevented air from entering in other ways.

In the middle of 1957, the tank was accepted into service under the index T-55. It was supposed to begin production on January 1st, 1958, but the country was going through reforms: industry ministries were abolished and replaced with Councils of National Economy. In connection with this, no new items were introduced into production. Meanwhile, the factory needed electronic NBC protection controllers that could not be made internally. Calls and letters to the Ministry of Transport Machinebuilding went without answer, as its staff was too busy. Kartsev sent a letter to the Chelyabinsk Electrical Machinery Factory, insisting that the Ministry ordered that they send off a batch of controllers by December 31st, 1957. Without the ability to confirm that such an order was made, the factory decided to play it safe and supply the requested batch of controllers.

The first batches of the T-55 had no DShKM AA machinegun, since at modern speeds, it was impossible to shoot down an airplane with one. As NATO countries began adopting helicopters into service, the DShKM was installed near the loader's hatch. Later, in the early 1970s, it was replaced with the 12.7 mm NSV Utes machinegun.

The T-55 tank. Initially, it was produced without an AA machinegun.

The gun remained the same as on the T-54: the 100 mm rifled D-10TS (a modernized version of the gun used on the SU-100 during WWII).


A D-10TS gun in the turret of a T-55 tank.

The tank was constantly modernized. In 1960, a prismatic observation device for the gunner was introduced. It was discovered that if the gunner only looked through the sight, his vestibular apparatus was upset and he began to feel ill. The observation device was removed in the T-54 and T-55 tanks in favour of the night vision sight. Now it had to be returned, without sacrificing the night vision. The driver, commander, and gunner's prismatic observation devices, which quickly became covered in dust, received air and fluid cleaning systems.

Trial by combat

The first time the T-55 saw battle was during the Six-Day War. The Israeli Defense Force attacked Egyptian forces in the Gaza Strip and Sinai peninsula, Syrian forces on Golan Heights, and Jordanian forces in Eastern Jerusalem and on the west bank of the Jordan river. Shortly before the war started, in 1965-67, Egypt received 150 T-34-85 and T-55 tanks from the USSR.

Egyptian T-55, knocked out on the Sinai peninsula in 1967.

The IDF executed a classic "blitzkrieg". Most of Egypt's aircraft were destroyed on the ground in the first few hours of the war, earning them air superiority. After that, tanks went into battle. The main force of the IDF was composed of modernized British Centurion tanks. The Israeli versions were called Sho't (whip) and Sho't Kal (light whip). The main feature of these tanks was the 105 mm L7A1 tank gun, fully capable of penetrating the T-55. The IDF lost 122 tanks on the Sinai peninsula, but the Egyptian losses were much greater: out of 935 tanks, 820 were destroyed or captured, including 82 T-55 tanks. After a slight modernization, they were adopted into service under the index Tiran-5. A part of the tanks were equipped with new American M68 guns and were called Tiran-5Sh from the word "sharir" (strong).

Modernized T-55 (Tiran-5Sh) tanks on parade in Tel Aviv.

In August of 1968, Operation Danube began, where Soviet forces entered Czechoslovakia. Other Warsaw Pact forces followed, bringing T-55 tanks. Since combat was avoided, the T-55 did not get to fight. The Soviet Central Forces Group had its HQ in Milovice from 1968 to 1991. Soviet tanks that were removed from Prague were housed there. In the 90s, a technical park was created on that spot, where anyone who wishes can ride military and civilian vehicles, including a T-55.

T-55 in Prague, 1968,

In 1969, during the War of Attrition, Israel carried out a diversionary raid into Egyptian territory, called Operation Raviv. On September 9th, at 3:37, 6 captured T-55s and 3 BTR-50s landed on the shore of the Suez canal 40 km south of Suez. The tanks were painted in desert yellow, like Egyptian tanks were. After landing, the group moved south along the canal, destroying all military objects in its path. It attacked an Egyptian military base in Abu Darag and also destroyed 12 AA posts. The group traveled 45 km in 10 hours and was evacuated to Sinai by ships. Due to the element of surprise and thorough preparations, the Egyptian forces did not have time to react to this raid. The IDF lost 4 men during this battle, while the Egyptian losses are evaluated at 100-200 men. According to the Israelis, one of them was a Soviet military advisor with the rank of general.

Landing of tanks on Egyptian shores during Operation Raviv, 1969.

During the Yom Kippur War of 1973, T-55 tanks were used by Egypt and Syria, while the IDF continued to use its Tiran-5s. During fighting for the Golan Heights on the night of October 6th to October 7th, Syrian tanks had the advantage, as they were equipped with night vision sights unlike its Sho't Kal opponents. However, the poor training of crews and cowardice of commanders resulted in the first wave of Syrian tanks being destroyed, and a significant part of the crews that were supposed to make up the second and third waves fled from the battlefield.

Tankers of the IDF 7th Armoured Brigade used the small depression angle of the T-55 (-5°, compared to the Sho't Kal's -10°). When Syrian tanks crested a hill, they ended up higher than Israeli tanks, forcing them to drive forward before they could engage the enemy. Meanwhile, the Israeli tanks, whose guns could elevate to +18°, could safely fire at the enemy.

Knocked out T-55s at Golan Heights.

When Israeli reserve 146th and 210th tank divisions, mobilized within 24 hours, knocked the enemy off Golan Heights and entered Syrian territory, they were attacked in the flank by Iraq's 3rd Tank Division, armed with T-55 tanks, on the night of October 12th to October 13th. This attack cost the Iraqis 17 tanks. After, they were caught in an Israeli ambush and lost about 80 more tanks. These events showed that the results of a battle are decided not so much by technical characteristics of tanks, but the training of their crews, their courage, and experience. Iraqi tankers had no combat experience at all.

The situation on the Sinai Peninsula unfolded differently. Egyptian divisions trained to cross the Suez Canal under the supervision of Soviet military advisors until perfection. The Egyptian forces were capable of crossing it in minutes. Hundreds of Egyptian T-54s, T-55s, and T-62s were sent into the resulting breach. On October 7th and 8th, the IDS, which concentrated most of its tanks on the Egyptian front, attempted to counterattack. The fastest tanks of the IDF were sent into battle: 150 Magach 6 and Magach 6 Alef (modernized American M60 and M60A1). Their advantage over the T-55 was in the American M68 gun (L7A1 produced under license), the effective range of which was over 3 km, while the Soviet tanks only had an effective range of 2 km. The IDF 460th Tank brigade managed to knock out several Egyptian tanks from the limit of their maximum range. The Israelis claimed that they knocked out 67 T-55 and T-62 tanks.

Israeli T-55 tank, previously captured from the Egyptians, knocked out in the streets of Suez.

On October 8th, 50 Magach tanks from the 460th brigade participated in an attack of about 200 Israeli tanks from various tank brigades. This attack went down in history under the name of the Battle at El Ferdan Bridge. The bridge connected the eastern shore of the Suez Canal with the western (the Sinai Peninsula), and was destroyed back in the Six-Day War in 1967. During the attack, one battalion of the 460th brigade took heavy losses from Egyptian infantry and retreated. The second, armed with 25 Magach tanks, decided to attack with tanks from other brigades. Having intercepted an Israeli transmission, the Egyptians knew about the attack. They let the Israeli tank wedge drive into an encirclement and destroyed it with flanking fire from T-54 and T-55 tanks as well as infantry anti-tank weapons. Only 4 Magachs out of 25 managed to get out. The other brigades lost almost all of their tanks as well. Israeli tankers recalled that the front armour of the Sho't and Magach could not withstand hits from new shells used by Egyptian T-54s and T-55s.

Syrian T-55 at Golan Heights, 1973.

The Egyptians were unable to take advantage of their success. Their tank columns stalled and the IDF retook initiative. Mobilized reserves executed a counterattack against the Egyptian forces, which, having carried out the plan written for them by Soviet military specialists, had no idea what to do next. No new orders came from high command. Soon, the Israelis broke through to Egyptian territory and Arab politicians were forced to sue for peace.

Syrian T-55 fighting in Lebanon, 1982.

Third world workhorse

The next Arab-Israeli conflict was the Lebanon War of 1982. By then the T-55 was obsolete, but still made up a significant part of the Syrian tank fleet, even though it was slowly displaced by T-62s and T-72s. Meanwhile, Israel also kept using its Tiran-5 tanks. The war was fought between the Palestinian Liberation Organization side and Israel. Heavy fighting took place on June 11th, 1982, near Beirut, where the 85th Independent Tank Brigade and several tank companies from the Syrian army armed with T-54s and T-55s were on the defensive. Initially, the Israelis managed to force Syrians out of Beirut and reach the southern part of the Beirut airport. A battalion of T-54 and T-55 tanks accompanied by three companies of special forces managed to hold the Israeli offensive here.

Column of Indian T-55 tanks on the march to Dhaka, Bangladesh. A fake fume extractor can be seen in the photograph.

As a part of Indian tank forces, the T-55 fought in the Third Indo-Pakistani War, as a result of which Bangladesh became independent. Indian tankers added fake fume extractors to their gun barrels in order to differentiate them from Pakistani tanks. 

During the Vietnam War, the forces of the Democratic Republic of Vietnam received many T-54B and T-55 tanks from the USSR in the concluding stage of the war. 600 T-55 tanks were received in 1973-1975, playing an active part in the defeat of South Vietnam's army.

South Vietnamese commandos preparing to destroy a T-55 tank column that entered the city of Vũng Tàu.

T-55 tanks also fought in Afghanistan, as well as in almost all conflicts in the 1990s in former Soviet states and the Balkans. Fighting in mountainous terrain revealed that the T-55 and T-62 had insufficient gun depression. Overall, the T-55 showed itself a reliable, if obsolete, fighting machine. Its armour was reinforced with additional Kontakt-1 ERA and the gun sight and stabilizer were also modernized.

T-55 tanks were used by the Libyan army, and took part in the Chad-Libya conflicts, as well as the Libyan Civil War of 2011. As of July of 2014, these tanks are actively used by all sides in the Syrian Civil War. The Kharkov Malyshev Transport Machinebuilding Factory designed a modernized variant of the T-55, called T-55AMG. Kharkov engineers also created a curious hybrid of a T-64 with a T-55 turret. At least one such tank is known. It is possible that similar tanks are currently fighting in the Donbass. 

Libyan T-55 fighting in Misurata

T-55AGM, a Ukrainian modernization of the T-55

21 comments:

  1. Hello Peter. I was wondering, do you have any archive information on the T-54, besides what you have already posted?

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  2. The Object 140 photo seems to be the same as the one about the tank in Indian service?

    On a different note, judging by the photographs a professional requirement for becoming a great tank designer appears to be a set of truly epic eyebrows! :U

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  3. Hello Peter

    I was wondering if you have any data about the internal volume of T-54/55 turret. When a 100mm gun was installed in IS-2 the ROF did not really change due to internal volume. On the other hand the ROF of a T-54/55 was higher. The turret diameter is the same, at 1800mm.

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  4. The main problem with ROF was the lack of a bore evacuator with large calibre guns, which consume large propellant charges during firing.
    You can´t fire at peak rof because once You opening the breech to reload, smoke pours into the turret. A lot of it. If "bottled up", and running high rof, the cramped turret space is soon filled by the propellent products making operation impossible unless You wear oxygen masks.

    RoF of T54/T55 increased once bore evacuators were refitted (IIRC, T54B and T55A). That and turret floor (in T55) were substantial improvements in handling of these tanks over T-44 and IS2/IS-3. The lack of it in older tanks limited the operational potential.

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    1. Yes, the turret volume getting filled with gasses was a problem in all WW2 tanks. I will check the data on ROF after bore evacuator was installed. However, IS-2 testing pointed at the internal volume and type of ammunition. 122mm had separated loading, while 100mm was unitary.

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  5. Not all tanks suffered by this. JAGDTIGER, JAGDPANTHER, JP-IV(lg) as well as PANTHER, TIGER-I and -II got bore evacuators for this reason to prevent accumulation of smoke inside the turret. The latter three also had rotating turret floors.

    Frequently, rof tests were not conducted fully bottled up, firing life full charge ammunition.

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    1. * looks at photos
      . . .
      I'm sorry, WHERE do you see a bore evacuator on ANY of those?


      Anyways, fume build-up doesn't *inherently* limit RoF; if need be crews could, and did, fire as fast as the loader could manage and then duly got heartily sick of the gasses afterwards.

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    3. Thanks to no turret basket in IS-2 loader has better access to propelants in the hull plus all projectilles and explosive amunition is on his side from the right of gun in compare to Tiger II. Plus it seems to me that loader has better access to propelants also because I see bigger gap between gun his seat and turret ring ! So reloading Tiger II main gun can be even more problematic if the loader use up all ammo from the right side of the turret.

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    4. The Tiger and Tiger II had some fun problems with reloading their guns, including the inability to see some of the ammunition if it wasn't a sunny day outside.

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    5. IIRC turret basket was not popular in the Sherman tanks used by Soviet crews as it reduced available space.

      Kellomies

      Yes, there were cases of Tiger crew members fainting due to accumulation of gases inside crew. Tiger II ROF varied quite a bit once ammunition in the turret was used.

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    6. I recall reading of at least one instance in Normandy of a Sherman crew getting sick with fume poisoning, too. Presumably not an unheard-of happenstance in particularly intense engagements in general.

      The main problem with the turret basket is that it meshes somewhat poorly with the transmission shaft if the final drive and engine are at opposite ends of the hull, and necessitates making the vehicle taller than it otherwise needs to be (with all the cascading size-related drawbacks that entails). Unless you make like Pz IV where the shaft and turret were shifted towards the opposing sides to avoid this, but as that solution wasn't more widely used (even in German tanks) it presumably had its own shortcomings. Probably constrained turret ring diameter or something.

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    7. The bore evacuator of higher powered guns (88mm L71 and 128mm guns, 75mm L70 and 88mm L56 were refitted with it) was attached to the breech, not to the barrel. It used overcompressed air to blow out smoke and residuals once the case was ejected not dissimilar to french post war bore evacuators.

      Accumulation of smoke inside the turret is a problem in protracted actions at high rof when large propellant amounts are handled by the gun. For the T54 gunner, he had three ready charges, incoveniently stored at the turret´s back. He could load them using his left hand but once used up, the lack of turret basket and bore evacuator will impact performance and severely increase the risk of accident. In practice, the tested rof was dropping from mean 14.6 sec to mean 15.4 sec.
      Target aquisition of the T54 was very time consuming, indicating poor FCS layout. Experienced crews required 15-20 sec to open fire on well observable targets, poorly observed targets required 34-60 sec.
      The high accumulation of gas while lacking a bore evacuator was outlined in reports as a problem. The error rate correlated with 0.1mg more CO for an increase of 10% ER in the turret.

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    8. I don't think that's called "bore evacuator" then which is a rather specific device around the barrel...

      A similar system added to the MGM-51 Shillelagh seems to be referred to as "closed breech scavenging system".

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  6. Altough "bore evacuator" is indeed freqently associated with barrel mounted systems, it is a neutral term and does not specifcy where the system is mounted, nor after which principles it works as long as it is intended to extract fumes from the barrel after firing. The german bore evacuator was not working according to the CBSS mentioned. The intent of the former was to not let smoke and residuals inside the turret while the latter was concerned primarely about possible residuals in the chamber, which may ignite the next round. The MGM51 used a partly consumable charge so cleanliness of the chamber was an utmost requirement.

    The closest parallel to the german breech mounted bore evacuator is the french post war breech mounted bore evacuator. Barrel mounted bore evacuators are a more elegant solution to the same problem because You get rid of the generator and pressure flasks, saving some space inside, at the expanse of some added projectile disturbance downbarrels. Some tanks used both, breech and barrel mounted bore evacuators. These fume extractors made the guns safer to use and improved rof.

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    1. AFAIK the Shillelagh actually had some issues with smoldering crap in the breech being sucked into the fighting compartement, which was obviously A Very Bad Thing given the alarmingly flammable character of its caseless (or rather "consumable cased") shells nevermind now being less than pleasant for the crew...
      Pretty much a markedly worse level of the fume problem. (This wasn't a terribly successful weapon system in general.)

      Exact same operating principle, anyway.

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  7. High powered guns in service after end of ww2 created some problems with consumption of large amounts of propellant in firing for the enclosed turret space. There were also cases with backlash injuring people.

    The CBSS did not work exactly similar as the german "Rohrausblasvorrichtung". A decided difference in both system is that the latter worked with open breech while the former had the breech closed. Closed breech operation is (much) more efficient but detracts from rof (not much of an issue with 155mm systems, I guess).

    http://tankarchives.blogspot.de/2015/03/tiger-ii-trials-ergonomics.html

    Gives some deteails on bore evacuator performance trials on Tiger Ausf. B.

    The 1943 bore evacuator was less efficient than post war designs but in combination with the fan kept the concentration of CO in mg/L low. I have a GDR report on T54A trials conducted 1955 without and with bore evacuator and after 3 and 4 shots in a minute respectively, the concentration was 1.08 mg/L and 1.38mg/L, requiring the adoption of the system to extract fumes from the space.

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    1. The Shillelagh had stupidly low RoF to begin with due to the glacial working speeds of the breech mechanism, so not like adding the CBSS changed things any. A rather bigger issue was that the small Sheridan's ammo load was pretty pitiful already before the bulky air bottles were shoehorned in...

      Less of a problem when the weapon was adapted for the considerably larger and roomier M60 I understand.

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  8. The picture of the modernized "Tiran 5s" on parade in Tel Aviv clearly shows they're not Tiran 5s, but Tiran 4s.

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