Merkava Main Battle Tank
One of Jane's Fighting Nodes. Resources: Jane's, Israeli Defense Force material, interviews with IDF tank crew
The Merkava MBT is an Israeli-designed and built tank. It is an instructive look at the strategy and doctrine of the Israeli army; its particular design supports the hypothesis that strategy drives doctrine. It was developed beginning in the late 1960s; the first prototype was available in 1974 with the first low-rate production vehicles coming off the line in 1979.
The design of the tank emphasizes battlefield survivability. Its components all serve to maximize the crew's chances of escape in case their tank is disabled or even destroyed. The primary reasoning for this can be fairly simply deduced from Israel's strategic situation. Crews are far more valuable, in combat, than tanks are. Since the IDF must fight using reserves which compose a significant fraction of the available population, several factors apply:
- The economy essentially halts while the reserves are called up.
- There is no time to train replacements in such a war, and more importantly there are no available personnel.
- Tanks can be stockpiled during peacetime against future need. Personnel, in the Israeli case, cannot, in direct contrast to nations with large standing forces (such as the U.S.).
All of these factors contribute to making personnel an extremely scarce resource, and tanks a (relatively) abundant cheap one. Thus, personnel are given every possible chance at survival, even if it lowers the chances that the Merkava will be usable after a hit.
How is this done? The Merkava is of an unconventional design in that the engine compartment is in the front of the tank, ahead of the driver. This has two main consequences: One, the engine block and gearing serve as an additional buffer between the crew and the glacis plate, with its exposure to the frontal arc of fire. Two, the crew compartment has access doors at the rear of the tank, where crew or passengers can mount or dismount the vehicle while protected from frontal arc fire. This is extremely useful for escape in case of a medium or long range hit on the Merkava; it also allows the Merkava to act as a limited-capacity APC, carrying infantry along on quick driving advances. Finally, it means the Merkava can be emplaced with additional shieldingand/or camoflage in front of and alongside the tank while still allowing the crew protected entry and egress.
The Merkava has an almost vertical hull front just below a well-sloped glacis plate. There is a bulge on the right side of the glacis (vehicle right) to accomodate the engine. The turret is mounted slightly to the rear of the hull's midpoint, with a long, horizontal rear extension on the turret called a turret bustle fitted with stowage racks. The front of the turret is pointed with the main gun emerging at the triangle's apex; there is a thermal sleeve around the main gun and a fume extractor, visible as a short cylinder around the gun barrel near the rear of the gun.
Bring on the specs! Here we go:
Specs from Jane's Armor and Artillery
- Crew: 4 (driver, gunner, commander, loader/radioman.
- Armament: 1 x 105mm (Mk. 1, Mk. 2) or 1 x 120mm (Mk. 3) smoothbore cannon, 1 x 7.62mm coaxial mount machine gun, 2 x 7.62mm machine guns (anti-aircraft), 1 x 60mm mortar.
- Ammunition: 62 x 105/120mm, 10,000 x 7.62mm
- Length, gun forward: 8.63 meters
- Length, hull: 7.45 meters
- Width: 3.7 meters
- Height to commander's cupola: 2.75 meters
- Ground Clearance: 0.47 meters
- Power-to-weight ratio: 14.28 horsepower/metric ton
- Weight, combat load: 61,000 kg
- Ground pressure: 0.9 kg/cm^2
- Engine: Teledyne Continental AVDS-1790-6A V-12 Diesel developing 900 (Mk. 1 & 2) or 1,200 (Mk. 3)horsepower
- Maximum road speed: 46 km/hr
- Max. range: 400 km
- Fuel load: 900 liters
- Glacis gradient: 70%
- Side armor slope: 38%
- Armor: Classified
- Fording: 1.38 meters, 2 meters with preparation
- Vertical Obstacle: 0.95 meters
- Trench Crossing Width: 3 meters
- NBC System: yes
- Night vision equipment: yes
has kindly pointed out to me, the Merkava Mk. 4
has arrived (July 2002). Since there are a raft of changes to the vehicle, I offer the following quick impressions based on available information. Comparisons with its predecessors are offered where appropriate.
Although I have not yet had a chance to examine one firsthand, the first sight of pictures of the Merkava Mk.4 (M4 hereafter) brings a few quick conclusions. The chassis looks essentially unchanged on the exterior; the engine pack is still forward, with exit doors in the rear. The turret, however, looks noticeably different, and there are a few reasons for this. According to Defense International, Jane's Defense Weekly and the Israeli Government, we can expect the following changes (at least):
- New 120mm main gun, modified to sustain higher barrel pressures for higher velocity kinetic ammunition and longer range
- Ability to fire the upcoming Lahat ATGM
- Modular hybrid armor, with various type available and mission-configurable (reactive armor, spaced armor, depleted uranium?, etc.)
- More powerful engine pack, a 1,500 BHP V-12 fuel-injected Diesel weighing in at 4.9 tons with its full systems pack
- Automated 10-round 'ready magazine' with autoloader (there is still a loader in the crew roster)
- CCTV cameras in hardened boxes around the turret (4 per tank) to offer the crew surround video while buttoned up
- Better battlefield information systems, including one that appears quite similar to the U.S. IVIS system
- Zoned NBC-protection air conditioning, with microcooling for each crew position, as well as a 'low power' mode when operating with the engine shut down
- Improved stabilization and automated gunlaying systems, allowing automatic target tracking even at high speeds and during rough handling
As far as I can tell, the M4 is an evolutionary change to the Merkava design. They have followed the tradition of the IDF of soliciting user feedback and tweaking the design to better suit the tank's particular combat environment. For example, there is is only one hatch on top (the Tank Commander's); the rest of the crew, driver included, exit through the rear doors. While this makes un-assing the vehicle more difficult, it also provides improved strength for the top armor, as fewer penetrations means better resistance. This is important not only to deal with newer top-attack weaponry, but because unlike many tanks the Merkava is expected to fight (often) in mountainous, constricted territory, where it will present a frequent and tempting target for dismounted opponents above it with grenades or ATGMs.
After a nasty incident involving a "huge" buried homemade explosive and a Merkava M3 in Feb. 2002, in which the turret was blown off the tank and only one crew member survived, the tank's underbody was afforded additional protection. There are limits, however; the Merkava is already one of the world's heaviest MBTs, since it doesn't usually have to deploy very far and is expected to go up against prepared ambushes more often than others.
The IVIS clone makes the Merkava a more effective team-fighting vehicle. One of the deadliest problems a tank crew can face is losing coordination with their cohorts - see Blackhawk Down for what happens when you lose situational awareness. The IVIS both allows better (faster, more accurate) coordination between tanks, and allows more realistic training, since scenarios can be piped directly into the tank's live displays.
The turret displays the hybrid armor system. Unlike many tanks, the Merkava has a particularly noteworthy design choice - the turret armor has slope on both the top and bottom of the turret. This means that incoming projectiles and missiles may be deflected down at the top of the chassis, near the turret ring. Normally, this would be considered one of a tank's most vulnerable points; however, the Israelis apparently have decided that they can better protect the tank against threats this way. Some possibilities: first of all, the all-electric drive of the turret means there are no hydraulics to suffer damage and fire around the base of the turret. Second, it's possible that the hybrid modular armor required the ability to angle in both directions to properly distribute or deflect incoming rounds or warhead plasma. Third, it does in fact reduce (slightly) the visual signature of the tank turret, meaning that if the tank is in hull down position, it will be harder to see. Finally, it may simply be a means of minimizing the weight of the turret - armor thickness removed in favor of better slope, increasing the effective protection.
Several of the modifications are clearly aimed at improving the tank's chances of surviving in an environment with many foot threats. The armored closed-circuit TV system allows the driver not only to maneuver in tight spaces more accurately, but also allows all crew members a chance to spot hostile activity. The perimeter defense system, in addition to sporting new sensors designed to warn against laser rangefinders and millimeter-wave radars, also has an antipersonnel skirt. The latter can, if activated, fire explosive charges placed around the tank's lower armor belt which drives claymore-like AP payloads.
The tank-on-tank capabilities, however, have improved even more. Better main guns, better stabilization for shooting on the move, ATGM capability, better armor and a more powerful engine pack all point to an even more lethal and fleet fighter. This is in keeping with Israel's strategic necessity for fast maneuver forces.
All this does not come cheap, however. The M4 weighs in at around $4 million US per tank, which is quite high. The 20 billion Israeli New Shekel development cost reflects this as well. The tank is heavy; although Israel can ensure that all bridges and roadways within its borders can handle the tank, it will be at a serious disadvantage if it finds itself needing to traverse older, smaller structures or needing to leave a road net in decent condition.
In any case, the M4 remains tightly coupled to Israel's strategic situation and local terrain. That's okay with them; while they'd like to sell the M4, the technologies inside it help support a thriving Israeli business in upgrading and refurbishing armored vehicles for other nations. Long-time users themselves of the U.S. M60, Israel offers a number of options for that platform, many of which can be found in the M4.