Cage armor

Slat armor (or slat armour in British English), also known as bar armor, cage armor, and standoff armor, is a type of vehicle armor designed to protect against high-explosive anti-tank (HEAT) attacks, as used by anti-tank guided missiles (ATGMs) and rocket-propelled grenades (RPGs).

Operation

Slat armor takes the form of a rigid slatted metal grid fitted around key sections of the vehicle, which disrupts the shaped charge of the warhead by either crushing it, preventing optimal detonation from occurring, or by damaging the fuzing mechanism, preventing detonation outright. Although slat armor is effective against incoming missiles, it does not offer complete protection – as many as 50% of missile impacts are unimpeded by the slat design. Slat armor is more likely to be effective if the cage spacing is less than the diameter of the incoming RPG round, which is commonly 85 mm.

Combat history

World War II

The German Wehrmacht was the first employer of cage armor during World War II, using ''Drahtgeflecht-Schürzen'' (English: "wire mesh skirts") to fortify its tanks against shell fire. It was found to be just as effective as the steel plate '' Schürzen'' also being utilized. In March 1943, Adolf Hitler ordered all new Sturmgeschütz, Panzer III, IV, and Panthers be outfitted with ''Schürzen'' of either the wire mesh or steel plate type. However, the wire mesh was not as easy to mass-produce as steel plate ''Schürzen'' or armored skirts. Soviet Red Army tanks, faced with the new and highly effective German Panzerfaust, were similarly outfitted with "bedspring" armor made from expanded metal mesh grating panels.

However, Schürzen were designed to stop Soviet PTRD-41 anti-tank rifles, and proved ineffective against Bazooka and Panzerschreck anti-tank rockets in US and German tests.

Cold War era

In the Vietnam War, slat armor was commonly used on the sides of American patrol barges and boats. The CCB-18 is a surviving example of the Mobile Riverine Force which used such armor. Wire fencing was also placed on vehicles such as the M113 to defeat Vietcong RPGs. The Swedish Stridsvagn 103 of the same era employed a much heavier front-mounted metal grid to protect against incoming projectiles.

Modern era

In modern times, slat armor has seen use on the Israel Defense Forces (IDF) Caterpillar D9R armored bulldozer, the Force Protection Buffalo MPV MRAP vehicle, the General Dynamics Stryker, Ukrainian BTR-4, the Warrior infantry fighting vehicle,"The MRAP Cage Fight"
DefenseTech.org. 18 July 2007. Retrieved 4 October 2012. the M113 APC, the British Challenger 2, the Leopard 2A6 main battle tank, and Russian T-62 tanks. Slat armor is favored over traditional plate armor not only due to its effectiveness against shaped-charge warheads, but also due to its much lighter weight, which improves vehicle maneuverability."Slat Armour for Stryker"
Defense-Update.com. 2005. Retrieved 12 February 2013.

Slat armor was first used on the Israeli IDF Caterpillar D9R armored bulldozer in 2005, and was installed in large numbers in 2006. Around the same time in 2005, slat armor was first proposed for the Stryker by a team of experts from the Army Research Laboratory (ARL), the Developmental Test Command, and the Aberdeen Test Center (ATC) to protect the vehicle from RPGs. Within seven days, the ARL and ATC designed and produced the first prototype, which was later mass produced at the Lima Army Tank Plant in Ohio and implemented in different variants of the Stryker. The design of the slat armor has the cage placed 50 cm ahead around the vehicle, allowing an RPG warhead to explode at a safe distance. Also, the slat armor on the Stryker vehicles is reportedly effective against HEAT rounds.

In 2007, BAE Systems developed a very lightweight aluminum slat armor system named ''LROD'', which was initially used on the Buffalo MPV, and which was claimed to weigh half the amount of comparable steel designs. BAE later equipped several US Army RG-31s with a variant of the LROD system, and also developed the system for its RG-33 vehicles, the Caiman and the JERRV. Slat armor is also fielded on the American M1 Abrams as part of the Tank Urban Survival Kit (TUSK) urban warfare series. In the Syrian Civil War, Islamic State of Iraq and the Levant (ISIS), the Free Syrian Army and Syrian Army equipped their armored vehicles with homemade slat armor to protect them from RPG impact.

In August 2016, Russia introduced bar-slat armor developed by NII Stali and Uralvagonzavod to increase protection of Russian armored vehicles against RPG and recoilless rifle HEAT rounds by 55-60%. The armor can be integrated with a variety of old-Soviet and Russian vehicles including the BTR-50, BTR-60, BTR-70, BTR-80/82, BTR-90, BMP-1, BMP-2, BMP-3, BRDM-2, BRDM-3, and T-14 Armata, with the full kit adding of weight.

Top-mounting

In 2021, various Russian tanks were observed with top-mounted improvised slat armor made from steel grilles; these were nicknamed ''kozyrek ot solntsa'' (russian: козырек от солнца, lit. "sun visors") by Russian tank crews, and the Russian Ministry of Defense stated in mid-2021 that they were intended to enhance protection against "various weapons". In December 2021, the Ukrainian Army released video of a military exercise in which an armored fighting vehicle (apparently a BTR fitted with a T-64-like turret) carrying such equipment was destroyed by a Javelin missile. These implementations add weight to the tank, increase its visual profile, and make it more difficult for the crew to enter and exit the vehicle. In 2022, during the Russian invasion of Ukraine where they saw combat usage, they were pejoratively termed "cope cages" by English-language online communities, western military analysts, and British defence secretary, Ben Wallace, expressing scepticism over their real-world effectiveness, based on the assumption by these analysts that the armor was most likely designed in an attempt to mitigate the threat of top-down anti-tank missiles such as the FGM-148 Javelin, and other top-attack munitions.

Other analysts have proposed that they may instead be used as a countermeasure against HEAT warheads from weapons such as RPG-7s fired from above during urban combat, loitering munitions, or against drone attacks, as a response to lessons learned from the 2020 Nagorno-Karabakh war and First Chechen War. The lack of uniformity between the makeshift cage variants made from different meshes and iron fences suggest that they are largely improvised by the tank crews, and are not standard issue. In May 2022, it was reported in Russian media interviews with Russian tankers who have returned from Ukraine that their crews eventually removed the cages, as they obstructed the use of machine guns and radios, and prevented timely evacuation if the tank caught fire.

Gallery

File:USAF M113 in Iraq2.JPG, Slat armor on an upgraded M113 armored personnel carrier in 2008
File:Abrams(rear) en.jpg, Slat armor protecting the engine exhaust port at the rear of the hull of an M1 Abrams
File:Polish Rosomak in Afghanistan.jpg, Lighter netting type fitted to a Polish KTO Rosomak in Afghanistan, 2010
File:Viking BVS10 ATV - Warthog (7527870668).jpg, Slat armor on a BvS 10 Viking ATV in 2012
File:D9R--Natan-Base-Independence-Day-2018-IZE-052.jpg, Slat armor of an IDF Caterpillar D9 armored bulldozer
File:Bangladesh Army upgraded T-59G 'Durjoy' MBT. (33659625935).jpg, Slat armor protecting the rear of the turret of a Type 59G Durjoy tank
File:Buffalo Vehicle Part of Talisman Suite in Convoy in Afghanistan MOD 45153768.jpg, Buffalo vehicle with attached slat armor in Afghanistan

See also

*Reactive armour
* Spaced armour
*V-hull
*Vehicle armour

References

External links

*{{commons category-inline, Slat armor

Vehicle armour
Armoured warfare