[Tanks 101] Armor Protection 1920-1980 - Features and Characteristics

time to talk about the basics of tank armor after all we want to know the basics when we're diving into tank designs in upcoming videos note that this video is limited in scope and mostly deals with the development of the interwar period up to the 1980s anyway let's get started with armor materials the usual material for armor was and is steel but they're different techniques of producing steel and also automate errors let's take a look rolled homogeneous steel armor was for quite some time the standard steel armor for tanks rolled steel means that the hot steel was ruled for one or several pairs of rolls can be easily produced in large quantities but can only be bent to limit the degree usually disused for armor plates Germany involve the tool used for the most part rolled armor thus the tank hulls and turrets have boxy features in contrast to cast steel turret for the Sherman round features now a few words about the terminology rolled steel plates are usually welded together hence the term valid Armour is usually used instead of rolled armor although this can be a bit misleading since cast Armour is also welded together unless the part is completely cast the scarce turret on how implies that large parts of the elements are made from cast steel now the other main method for producing tank Armour is steel casting in this case the liquid hot metal is poured into a mold this has a main advantage because the armor can be molded into various shapes easily allowing for curved areas and specific thicknesses initially this technique was rather rare but it was already used involved with one for several versions of the French Renault ft to red and while the to the British solids and u.s. used various cast turrets but it isn't so straightforward for example the Churchill mark 3 had a welded turret where's the mark 4 had a cast turret and for certain variations of the t-34 they exist both welded and cast turret as you can see it can get quite complicated even up to this day certain tanks some variants with cast and welded turret like the t90 but back to World War two in Channel the Allies used more cast duritz than the Germans as the war progressed after the Second World War cast turrets became almost universal for main battle tank turrets since the 1950s it is also common to cast complete house nevertheless as mentioned before even current tank models used also welded elements now let's take a look at the advantages and disadvantages the disadvantages of cast armor is that heat treatment and auto refining techniques are complicated or not possible thus it is not as tough and shock-resistant as raw nama a manual from the US Army Materiel Command from 1963 states in general rolled armor is about 15% pattern resistance to shock and penetration and cast ammo however disadvantages offset to some extent by the varying angles of oblique rickety and irregular shapes possible in castings these variations in shape considerably decrease the penetrating ability of certain types of or check does note that I don't know if this value is also correct for Volvo - steel or currency now one way to improve the hardness of armor was to process the surface of the arm this process creates face hardened homogeneous steel armor in this process called carburizing the armor is heated in a furnace of a considerable amount of time usually rolled armor plates were used for this the advantage is to increase the hardness thus increasing the chance that protect does shatter on impact but increased hardness also increases the brittleness additionally the welding of such armor plates could often lead to cracking during welding or afterwards furthermore the process is quite expensive and not suited for mass production during the 1960's the problem of cracking could be overcome and high harness armor was used on light armored vehicles mostly only in the 1980s the technology was suitable to Bruce tool hardness still thick enough for main battle tanks there was a various non iron-based almost like titanium aluminum magnesium alloys nylon fiberglass and others probably one of the most notable non iron armored vehicles is the armored personnel carrier m113 which has aluminum armor and is also one of the most produced armored vehicles outside of the Soviet Union although other aluminium armored vehicles were built like the M 114 m 108 and m109 although aluminium is lighter for the same amount of protection about three times the thickness is needed compared to rolled steel there are various advantages and disadvantages for aluminium as pointed out by the offer or Gogebic in addition to savings in weight aluminum armor is also easier to machine and grade the thickness of its plates makes it possible to step joints which provide a partial interlock between plates and required therefore less welding all this has helped to reduce the cost of producing vehicles with aluminium armor but its cost per tonne has been significantly higher than that of rolled homogeneous Armour there are various armored vehicles that use aluminium and aluminium alloys to a large degree like the m551 sheridan the British Alva scorpion French AMX 10 and also the m2 Bradley infantry fighting vehicle now the Bradley also has a composite armor so let's take a look at it the wide adoption of shaped or hollow charge is like the Panzerfaust Apache and heat channels allow the penetration of thick monolithic steel armor quite easily this led to the development of composite armour to spare you and me some complicated mafia basically hollow charges are not too much affected by the density of the material thus certain lower density materials provide better protection for a mass in comparison to steel and the term for this is also called mass effectiveness which almost sounds like a really cheesy title for computer game problem is that the resulting thickness usually makes those materials impractical to protect again shaped charges furthermore there was a quite useless against regular anti-tank ammo or to use the technical term kinetic energy projectiles yet the combination of low and high density materials can provide effective armor protection the u.s. started to develop composite armor at the end of the Second World War there were flying tests of Sherman's later on different versions of composite armor were developed for the m48 and m60 Patton but didn't see mass production the cost and difficulty in production yet the British developed the so-called Topham armor which is already used by the US and Germany in the design since the early 1970s since then almost all new battle tanks have been built with some form of composite or multi-layered armor instead of monolithic steel armor there are various materials like glass ceramic and aluminium oxide that offer greater protection against shape charges then the density might suggest yet those materials often have the disadvantages the most effective approach is to use multi layered armor consisting of steel and set materials the effectiveness can also be improved by spacing those layers although this makes the armor more bulky another protection against shape charges is explosive reactive Armour it was developed in the 1970s and was first used by the Israelis in the operations in 1982 in Lebanon for British Centurions and USM 60s a few years later the solid t-64 and other soviet tanks also give with reactive armour now to properly explain reactive armor we need some basic understanding of shaped charges to put it very simply a shaped charge creates a jet of molten metal to burn through armor reactive armor solves this problem by exploding when it gets hit of course it's a bit more complicated than that reactive armor is basically a hollow brick consisting of an explosive charge between two metal plates now if the brick is penetrated by shaped-charge the explosive goes off and the brick expands towards the shaped charge there are two effects that reduce the effectiveness of the shaped charge first its velocity and angular and second the expansion of the plates requires mold Chett to go through more space of course reactive armor must be designed resistant enough to be unaffected by artillery fragments and small arms fire also it can be a potential hazard to unbuttoned crew and nearby supporting infantry and before we look at the ballistic properties let's take a look at the physical properties because dollar determining the ballistic ones and the most important physical properties are a hardness the ability of armor to resist indentation B toughness the ability of armor to absorb energy before fracturing C soundness the absence of local flaws cavities or weaknesses in the armor unsoundness is not so often found in rolled armor as in cast armor because of the mechanical working which has been done during your hot rolling process note that a high hardness which is measured by the Brinell hardness number usually makes armor quite brittle and easier to break thus reducing the toughness rating thus increasing one value can also lead to reduction of another value hence the proper balance is more important than one local maximum so let's move on to the ballistic properties that are most important for armor the necessary ballistic properties which are required of armor consist of resistance to penetration resistance to shock and resistance of spalling resistance to penetration is quite simple it is the ability of the armor to resist partial or complete penetration next the resistance of shock which means the ability of the armor to absorb energy without cracking or rupturing note the resistance to shock is referring to energy thus it includes both projectiles as also explosions also atmospheric conditions can change this property low temperature makes most materials more brittle and thus more likely to crack something you should consider especially if you want to in with Russia Canada or Finland finally resistance to spoiling which is the property of armor resisting to partial cracking flaking and breaking away of smaller elements especially on the opposite side of the penetration usually spoiling results in an expanding hole from the to the exit of the armor plate or to put it another way resistance of spoiling is the property of the armor plates preventing themselves from transforming into a shotgun blast the turns your crew into Swiss cheese now while reading I encountered a very interesting distinction it seems that most of us use the term penetration not quite precisely to quote the term penetration is reserved for the entry of a missile into Armour without passing through it the term perforation implies the passage of the missile completely frulliamo now one things in more biological terms this actually makes quite a lot of sense but in case you want to go full penetration perforation nazi here's a list of sub reddits that will really enjoy your comments where's the word enjoy is used rather loosely here next the overall surface design of tank Armour should be focused on providing appropriate protection in relation to the expected direction of attack for instance strong frontal armor and weak rearm furthermore the tank should have an overall convex surface and as a short reminder this is what the concave looks like in context with armor design convex is reached by the absence of reentrant angles these so-called shot traps would often occur between the turret and the hull what makes them so dangerous is that the deflected projectiles could strike weak spots in the armor that we're usually hard to hit like the top of the hull probably best known shot trap of World War 2 is the early panther as you can see here a shot that the bounces from the gun mantlet will deflect into the upper side of the hull which is weakly armored this was the reason why the gun mantlet was changed as you can see here the lower pant is a later variant here the same shot will not be directed towards the hyung if it ricochets reentrant angles are also relevant when attacked by high-explosive shells because they will also redirect the explosive blasts and fragments into the lesser protected areas now another aspect that is less obvious is that the surface should be as regular as possible basically every irregularity the brakes the uniformity of the armor will restrict the uniform observation of energy and as a result could damage the r-mo thus a flat smooth wall of constant thickness offers the best resistance to severe attack principally because the shock of impact can be uniformly absorbed over the entire area probably one of the best-known armor features is sloped armor which was one of the features the Russian t-34 is well known for sloped armor is basically armor that is not angled at 90 degree sloped armor increases the effectiveness of armor in two ways first it increases the distance the projectile has to perforate in this case an arm of the thickness of one point two has an effective armor thickness of 1.7 if it's angled at 45 degree and secondly due to the angle deflections and shattering of projects becomes more likely another way to improve the armor is by using spaced armor one of the first tanks the possibility of spaced armor was the laid pants of 3 in 1942 after the Second World War spaced armor was not used commonly until the 1960s it nowadays spaced armor is not so obvious than in Volvo - for instance the leo part to a5 uses spaced armor at the frontal part of the turret pro the best known use of spaced armor was two German ships and/or armor scrubs in World War two these were originally introduced to protect the sides of German armored vehicles against Soviet anti-tank rifles that fight conventional kinetic grounds why do I mention it because there's an ongoing myth out there that the skirts were introduced to protect against shaped charges yet at the time of the introduction of armor scripts in 1943 shaped charges weren't common on the battlefield yet almost words were not common the first decades after the Second World War but they were reintroduced with the british centurion and other tanks in the 1960s and 70s although this time in order to protect against shaped charges there are also other forms of spaced armor namely sled cage or bar our mo which is also used involve a tool with wire meshes instead of metal plates for the skirts it usually consists of steel paths that are located at certain distances to the main arm of the vehicle afterward the two slit Olmos or reintroduction 1960s and recently it was used by the Israelis and US troops in the Middle East to protect against shaped charges also since it is relatively easy to produce when heat is used in the current conflicts in Iraq and Syria equipped with all kinds of sled and chain armor for some interesting pictures you might check out the galleries the block tank and armored fighting vehicle news put up as always the link is in the description as a final remark one important aspect that we need to consider when it comes to armor is the visibility in terms of industry cost and resources which is probably very well expressed with this remark from 1963 the elders of certain light metals should future promise for use as aircraft armor but importance of weight saved would offset the disadvantages of substituting a more expensive strategically critical material in place of steel to summarize steel was and is a common material for armor in tanks once it was used almost exclusively it has a high density and is quite easily to produce in large quantities the interaction of shape challenges although allowed to penetrate even very thick steel plates easily to counter shape charges various measures were introduced like spaced composite and explosive reactive armor thus nowadays the tank is usually armored with multiple layers of different materials and/or additional armors like spaced and reactive armor although steel was the main material for main battle tanks for light armored vehicles aluminium Allah is not uncommon since the 1960s armor design is a complex topic because many factors affect each other for instance the key physical properties of tank Armour are hardness toughness and soundness with increased hardness usually decreases toughness furthermore certain materials and techniques are quite expensive the Sarma design is not only influenced by military and engineering aspect but also by the feasibility in terms of industrial capabilities and resources of the producing country thank you for watching please like comment share and subscribe and see you next time you

Channel: Military History Visualized

Views: 506,520

Rating: 4.9238768 out of 5

Keywords: History, Education, Visualized, Tanks 101, Armor Protection, Sloped Armor, Effective Armor, Cast Armor, Welded Armor, Resistance, Aluminium, Documentary

Id: f0IbZGfTgUM

Length: 18min 37sec (1117 seconds)

Published: Fri Aug 19 2016

Reddit Comments

[u/murkskopf]

I think the problem of this video is relying too much on old sources and doesn't take into account different forms/types of armor while making a few other mistakes.

• For example it is claimed that aluminium armor (density 2.7 g/cm³) has to be three times as thick as steel (density of 7.85 g/cm³) for the same protection level. If this was true, nobody would utilized aluminium armor, as it wouldn't offer any weight savings thanks to a higher areal density (2.7 x 3 = 8.1 g/cm²). Maybe the "three times thickness" statement is correct for pure aluminium, but instead aluminium alloys are used on modern armored vehicles for saving weight. Alloys of the Al-5000 series (such as the Al-5083 used on Bradley and M113) is claimed to have a thickness efficiency of about 0.6 compared to steel (instead of 0.33 as previously proclaimed). This would then reduce the weight required for armor protection by about 45% compared to steel. Alloys like Al-7017 (used for the hull of the Warrior and sloped parts of the Bradley) and Al-7039 (used on the British Scorpion) supposedly provide even better protection, but are harder to machine and more expensive.

• No shaped charge jet is molten metal, it is instead a solid metal rod/jet/sting. Shaped charge jets do not penetrate with a kinetic effect (or barely at all), most of their penetrating power is the result of the extremely high dynamic pressure at their extremely small tip: under huge pressure metal will essentially behave like liquid. ERA doesn't defeat shaped charge jets by reducing the jet velocity or increasing the space that it has to travel through, instead the converse movement breaks the solid metal rod apart and moves more mass into the path of penetration.

• The suggestion that shaped charges jets are not much affected by the material density is wrong. The density law is directly affecting the penetration of shaped charges (although as noted by US researches in 1993, the penetration is about 15% lower than implied by the density law). However non-metallic materials aswell as special armor layouts allow to provide higher protection at a lower density.

• "There are various materials like glass, ceramic and aluminum oxide"... aluminium oxide is a ceramic.

• The surface desgin and riccochet statement on concave/convex shapes aswell as the shot traps only matter with pre-APFSDS ammunition or extremly old APFSDS designs. Given that the 1970s timeframe already includes APFSDS with little to no chance to riccochet, one should clarify this.

• The Leopard 2A5 has NERA for it's turret front, it is only including empty space, because the NERA needs to be sloped for maximum effectiveness. The T-90's ERA is also requiring slope for maxmimum effectiveness, but I have never seen anybody describe the ERA at the turret front with the resulting hollow section as spaced armor.

• Cage, slat, and bar armor are not based on the same working mechanism as spaced armor and shouldn't be considered to be sub-forms of spaced armor. They work by crushing the warhead or the fuze of a rocket-propelled grenade, before the main warhead fuzes. This is a lot different from spaced armor, which works after the shaped charge liner has already formed a penetrating jet.