The Puzzle of Israeli Add-on Armor

This amide andphotographs are reprinted by special permission from Defence Attache; No. 4. 1982. Copyright Diplomatist Associated, Ltd. Ed.

One of the more fascinating, if by press day wholly unproven, aspects of the Lebanon operation is that it may have marked the first fielding by any army of a form of active armor to defeat shaped-charge attacks on main battle tanks. The alternative, that the add-on and readily detachable protective arrays seen on Israeli M60s and Centurions contain ceramic tiles (though not of a kind to be found in any bathroom), would also mark a fmt in terms of o p erational deployment. The possibility cannot be excluded that armor of both kinds is involved.

While no answers are to be found in external appearance, the configurations, as seen in the accompanyingDe-fence Attache' photographs, show obvious differences in the thickness and shape of the packs provided for M60 and Centurion respectively. The Centurion's additional armor is mainly in the form of quite shallow panels fitted to the brow of the turret and thicker pieces to the glacis and the mantlet either side of the main gun; a hole is included in the left-hand piece (looking forward) to permit the firing of the coaxial machinegun. Wedge-shaped packs are mounted on top of the storage boxes fitted forward above the track The M60, partly because it lacks whatever protective values come with the Centurion's storage bins, has been provided with a considerable amount of add-on armor around the turret. Here the packs are thick and vertically deep, with smaller and thinner sections patched in-with no great concern for aesthetics-to the upper surfaces which, because of the turret's m a -ture and varying angles to the perpendicular, not to mention obstructions such as lifting eyes, cannot be covered by the main boxes. As with the Centurion, panels are fitted to the front of the turret roof and to the glacis; in the lab ter case, because the M60's basic glacis is curved, it hasbeennecessarytofit a straightening frame to which the packs guards.

Upper left. Mine-clearing rollers on an M60.

Lower left. Sharply-angled mantlet add-on armor and wedge-shaped slabs on top of hull storage boxes show clearly on this Centurion.

Center. Note distinctive mantlet armor with port for coaxial machinegun and extra-capacity smoke grenade launchers The Puzzle of Isrl can be attached. TheM60's installation is completed by the fitting of wedge-shaped or angled sections either side of the driver's hatch to help protect the vulnerable area where turret meets hull, with further angled sections each side of, and thinner plates above, the mantlet.

Although it can be stated with a fair degree of certainty that the add-on arrays are intended to help defeat shaped-charge high-explosive antitank (HEAT) attack, any discussion of what the packs and panels consist of must, in the absence of any word of guidance from the Israeli-who on the contrary are happily watching, if not promoting, the circulation of a number of often fanciful and frequently mutually exclusive "solutions" to the puzzle-fall short of a definitive answer. While one source suggested that the boxes were empty (and the large ones on the M60 do sound quite hollow when thumped) the probability is that there is more to 26 ARMOR on each side of turret on this Israeli Centurion.

Upper right. Wedge-shaped side add-on armor blocks, distinctive mantlet add-on slab and frontal slabs show clearly on this Centurion. Gaps probably indicate displacement.

Lower right. Esthetics had no part in this arrangement of add-on armor slabs to this M60 rli Add-on Armor it than that. In view of solutions that have been adopted elsewhere, though usually in the context of new-build tanks, it seems quite likely that the Israelis have developed their own ceramic tiles and that the boxes are partially filled with them. The alternative of a form of active armor is suggested more by the vehemence with which several sources in Israel stated this to be the case than by any objective evidence. A number of different types and configurations of active armor are possible. An example is a sheet of explosiv-laid on top of a steel plate, with a covering for environmental protection on top-which detonates when hit by the incipient jet of a shaped-charge warhead and in the process disrupts the jet's further formation. If the Israelis are indeed deploying a form of active armor, such a fact would carry the implication that they have sufficiently overcome the formidable difficulties that seem to have pre-L vented larger and better-endowed countries from doing likewise; the United States and Soviet Union are among the nations that are known to have been engaged in related research and experimentation for many years. Not the least of these difficulties lies in ensuring that the explosive is not detonated by hits other than a shaped charge, e.g., by a bullet. The explosive must therefore embody an adequate energy strike threshold while remaining sensitive enough to be activated without the involvement of a separate detonating agent. The panels in the array must also be so designed that when one or perhaps two detonate in response to a shaped-charge jet, the others in the array do not go off too. Other kinds of active armor have this difficulty and additional ones. Among the earliest kinds experimented with (and one offering considerable attractions in theory) was an array of miniature shaped-countercharges. A major problem here is that unless the shaped countercharge detonates on the axis of the incoming jet, it will not have much ARMOR more effect than a flat sheet of explosive.

Other points observed on [Israeli] Centurion and M60 tanks include the addition of banks of smoke dischargers either side of the turret. These appear to be fixed and forward-facing, thus indicating a probability that they are intended for offensive rather than defensive use. Many M60s and Centurions were seen with a.50 caliber machinegun, mounted on the mantlet above the barrel of the 105-main armament and in alignment with it, for ranging, though doubtless it can also be used separately. As the.50 caliber machinegun appears, certainly in the case of the M60, to be out of comfortable arm's reach (and would be extremely hazardous to operate in battle) it is assumed that it is remotely fired by the gunner. A similar arrangement has been applied to the M109A1 for aiming in direct-fire engagements. An addition to some M60s deployed in builtrup areas was alight mortar (52-mm or 60-mm) fitted to the right of the turret and o p erated by the commander. 27