http://www.military.com/soldiertech/0,14632,Soldiertech_Merkava,,00.html
The Israelis know their tanks, and the Merkava Mk. 4 is no exception -- behold a tank bristling with weaponry and advanced digital systems, not to mention extra protection for its operators, and enough space to hold an infantry unit, to boot.
World's only MBT with a forward mounted engine
World's only MBT capable of carrying an infantry squad or performing crew/ casualty extrication under battlefield conditions
Fully integrated digital battlefield information recording and distribution system
Capable of launching LAHAT 120mm thru-tube laser guided ATGM
No country in the world is more synonymous with armored warfare than Israel. And with good reason: no country is more dependent for its very survival on the quality of its armored formations. Thus armed with the experience of almost 30 years of tank warfare, and with full knowledge of its needs, the Israeli Defense Force (IDF) has come up with a marvel of tank engineering that boasts firsts in a number of categories: the world's only Main Battle Tank (MBT) with a forward mounted engine, and
the world's only MBT capable of carrying an infantry squad or performing crew/ casualty extrication under battlefield conditions, to name a few. And that's not mentioning its impressive array of weaponry, and its fully integrated battlefield information recording and distribution system. Meet the Merkava, a tank that truly belongs in the digital age.
As is often the case, the problem for Israel's "home-grown" tank program in the past has been ponying up enough cash. Through the late 1970s, Israel had to content itself with upgrading and improving the surplus American M4, M48, M60, British Centurions, and the captured Soviet T55 and T62 tanks it had in its inventory. Unfortunately, the Yom Kippur War of 1973 came as a rude awakening to the IDF. During the war, Russian-made, man-portable anti-tank guided missiles (ATGMs) decimated Israeli tank formations, and with their destruction came the hard truth that tanks may be replaceable, but crews are not. Logistical issues associated with supplying and servicing several dissimilar vehicle types also brought the issue to a head. What was needed was an "in house" tank that would be well-suited for crew protection and the type of urban, built-up combat environments Israel found itself in. Enter the Merkava.
The driving factor in the Merkava's development was crew survival, followed by firepower, and then mobility.
The engine for example, is mounted in front, where its mass serves as additional armor. While a penetrating hit to the front might disable the tank, the crew will survive (it takes several weeks to fabricate a new engine; it takes several years to fabricate a new tank crew). All main gun ammunition is stored in the hull, below the turret ring (where it is protected not only by the thicker hull armor, but by earth as well, when the tank is "dug in" in a hull down defensive position).
Not only does the Merkava carry more tank ammunition than any modern MBT (the Merkava MK1 carried 85 rounds of 105mm ammunition), but the ammunition is also stored in removable modules. This, coupled with the fact that the Merkava comes with a rear access hatch in the hull means that ammunition modules could be removed to create space to enable a Merkava to safely recover a tank crew stranded in a disabled vehicle. Alternatively, Infantry can be carried in the Merkava's expanded crew compartment, thus providing the tank with an added measure of protection in urban or built-up areas.
The turret of the Merkava is also uniquely sloped; where most tanks slope the turret armor vertically (i.e., the M1, Challenger, and new Leopard II series) the Merkava's armor slopes horizontally. This not only provides a smaller forward aspect, but also presents a greater realized depth or armor to frontal direct fire threats. This configuration gives the tank greater armor protection through a smaller amount of actual armor.
As for the guns themselves, suffice it to say that the Merkava is one of the most heavily armed tanks in history. In addition to the main gun, Merkavas are also armed with a 7.62mm COAX machine gun, the loader and commander each have a 7.62mm machine gun, and a .50 caliber MG is often mounted directly to the gun mantlet for use by the gunner as a light vehicle weapon. Finally,
the Merkava is also one of the only MBTs to mount a 60mm infantry mortar, capable of firing both HE and illumination rounds.
Carrying on the Tradition
The Merkava MK4 is the latest installment in the Merkava tradition. Entering service in 2004, the Merkava MK4 continues the tradition of meeting the IDF's specific requirement for crew survivability. In terms of armored protection, the Merkava MK4 offers one of the most sophisticated, non-DU (depleted uranium) based packages available. In addition to the more traditional steel and composite armor of the turret and hull, the MK4 features an extensive suite of configurable bolt on armor packages for the turret and hull. These packages increase the armor protection of the hull top as well as the turret top and sides, and can also be specifically tailored to meet specific anti tank threats. Since these packages are bolted on, they are easier to repair or replace than more conventional integrated armor. The MK4 is also equipped with an Amcoram LWS-2 laser warning system which detects incoming laser designation or ranging beams, with a threat warning display installed at the commander's station. Lastly, the Merkava's role as a battlefield taxi continues, as the MK4 is capable of internally carrying an 8-man infantry squad, a battalion-level battle staff, or 3 litter patients.
Now armed with a 2nd Generation high pressure 120mm smoothbore gun (first introduced on the MK3) the MK4 carries 48 rounds of ammunition in individually armored compartments, while the loader feeds the main gun from a semi-automatic 10 round armored magazine located in the turret. This magazine, like the ammunition storage compartments on the Leopard II and the M1 tanks, is blast-isolated from the crew to protect them in the event of an ammunition explosion.
While the MK4 is designed to be used with IDF manufactured ammunition, it is capable of firing any current American or German made 120mm munition. In addition, the MK4 is also capable of firing the 120mm thru-tube LAHAT duplex warhead ATGM. The LAHAT missile has an 8,000-meter range and can be guided by a laser designator. The gun tube itself is equipped with a thermal shroud to reduce the effects of thermal bending, while the turret itself is driven by an advanced all-electric drive. The fire control system is every bit as modern as the rest of the tank. Both gunner and commander are equipped with dual axis stabilized sights with both daylight and thermal channels. The turret is equipped with a laser rangefinder and the target tracking software allows for the engagement of rapidly moving targets such as helicopters and aircraft. Both the gunner and tank commander can scan independently for targets, with the TC having the same battle override and target handoff capabilities as are found on the M1A2 and the Leopard II. The 60mm mortar, now configured for internal operation, is capable of launching illumination rounds or HE projectiles a maximum of 2,700 meters downrange. The Merkava MK4 retains the 7.62mm COAX mounted MG, as well as the commander's MG (the loader's hatch and MG were eliminated) and carries 10,000 rounds of 7.62mm ammunition.
The MK4 is also one of the most digitally integrated tanks in the world. Every crew station is equipped with a color flat panel display which provides crew specific system status information. In addition, the driver is provided with 360o situational awareness through the use of the "Tank Sight System."
The TSS comprises 4 day/night video camera units, mounted in hardened armor shells, which the driver can use to observe conditions all around the tank. This system allows the driver to maneuver rapidly and efficiently in any direction without guidance from the TC. The tank is also equipped with a digital Battlefield Management System (BMS) that allows for the rapid exchange of information between units and individual vehicles. In addition, the BMS also incorporated a digital video recorder that allows for the "real time" capture of battlefield imagery, which can then be disseminated up and down the chain of command.
Pushing the MK4 is a brand new high output V-12 power plant. Developed by General Dynamics and the German company MTU, the GD833 is a liquid cooled, direct injection, turbocharged V-12 diesel engine generating 1,500 hp. Coupled to this is a 5 speed hydrostatic gearbox while the vehicle is stabilized by externally mounted, single position rotary shock absorbers.
The MK4 also features a positive pressure chemical and biological warfare overpressure system that not only sterilizes incoming air, but also provides climate control (in the form of air conditioning and heating.)
The Merkava series tanks are some of the most effective, purpose built tanks ever produced. Everything about the Merkava is designed to enhance not only crew safety, but crew recoverability as well. The layout of the tank's systems, from the forward mounted engine to the hull stowed ammunition, is specifically intended to dovetail with how the Israelis expect to defend themselves
(properly dug in, a 105mm Merkava MK2 with 85 rounds of ammunition would be all but indestructible, and sustain itself for days without having to withdraw in order to replenish its ammunition supply). The Merkavas have often been criticized for their relative lack of speed, compared with the M1 series or the Leopard IIs. Yet for Israel, speed is secondary to survival; the Israelis are concerned with defending their country, not racing across Eastern Europe.
Finally, as conflicts transition into low intensity, "bush war" affairs, where most combat takes place in urbanized or built-up areas, the Merkava may prove to be the most appropriate armored vehicle ever made. Heavily armed and armored, with a digitally integrated communications system, AND the ability to carry a full 8 man squad of infantry, the Merkava MK4 is quite possibly the best city tank ever built.
Hope that clears things up for you aimster