Perhaps what is not being properly perceived is the fact that one smart weapon is highly likely to do its job a lot better than ten dumb rounds and that, therefore, fewer would be needed.

The Bazalt RBK-500 uses the same submunition as the 300 mm Smerch rocket launcher. It carries 15 in an arrangement of five clusters of three. Each dual-spectrum infrared submunition weighs 15 kg.

Recent artillery demonstration firings of 155 mm rounds on a windy day to a range of between ten and twenty kilometres left the observers with mixed feelings. Granted, the heavy shelling of a wide area would result in a total disorganisation of an attack on the enemy side, but the demonstration also proved that a direct hit against a hypothetical tank would have been just plain, fat luck. Indeed, the blast effect of a high explosive warhead will stop the action of anything short of heavy armour in its near vicinity, and the blowing off of antennas and various sensors from their stems will temporarily put a tank out of action, but if the ultimate aim is to prevent a tank from seeing another day, then a direct kill is a necessity. Furthermore, if, at the same time, reduction of the famous "collateral damage" has to be thrown into the equation, there is a clear dichotomy in the term "modern battlefield warfare" if the aspects of guidance and homing are left out.

Then of course, there is the emergence of really quick and accurate counter-fire radars and artillery. These totally preclude readjustment of fire. Therefore, a first round must hit what it is supposed to hit. If the target is a bunker, the round (ideally a penetrator-high explosive combination) will require terminal correction; if the target is armour (therefore mobile) the answer is a homing device. This discussion is primarily concerned with the latter variety, which can be air or surface launched.

	A Textron BLU-108 shown here with its four "skeet" submunitions deployed as they would a split second before being spun out into the air (diagram on right shows the kinematics).

Air Launched

While the basic design of a self-forging projectile warhead triggered by a sensor (whether it be infrared or electromagnetic) is the same for air-launched or barrel-launched applications, there is a world of difference in construction standards. And yet, with time and technological advances the gap has narrowed, simply because of mechanical constraints: the air-released, and incidentally rocket-launched, varieties do not have to sustain the shattering G forces of both linear and spin accelerations imparted by rifled barrel charges. Unsurprisingly, therefore, the air-launched variety was the first to see operational status. On the other hand, the unexpected element here is that the Russians appear to have pioneered the field.

As Armada reported back in 1994, the Bazalt 500 kg RBK-500 bomb housing 15 SPBE-D submunitions was claimed to have been in service for a while by Russian officials. These declined to be more precise, so to assume that it is a Soviet era weapon would not necessarily be overspeculative. Dropped from an altitude of between 1200 and 15 000 feet at speed of 500 to 1200 km/h, it is said to be able to simultaneously turn up to six running tanks into good tanks. Unlike all other Western Word equivalents, the SPBE-D submunition descends under three parachutes.

The World’s next guided anti-armour submunition is the Textron Systems BLU-108 submunition designed to fit (in two clusters of 5) inside an SUU-66 Rockeye tactical weapons dispenser which is then known to the Air Force as the CBU-97. Each BLU-108 is in fact also a subcontainer, as it itself contains four warheads. The sequence of events is as follows: the aircraft releases a CBU-97 (for sake of clarity, we say one, but it can be several) which flies in the general direction of the threat, i.e. a formation of armoured vehicles. The container then opens up and radially ejects the two clusters of BLU-108s. These each deploy a parachute that not only brakes them, but also gives them a vertical attitude. At a predetermined height above the terrain, the parachute is released and a rocket motor spins the tube container and at the same time thrusts it upwards. The effect of this is that the four submunitions will be ejected out radially in four opposite directions, but with an upward movement which will cause them to nutate, resulting in their downward looking dual-band infrared seekers having the required conical search pattern (see box, Principle). As soon as the target and the sensor cross paths, the explosively formed projectile dashes down. When all 40 warheads are released, they simultaneously "look down" at an oblong pattern of 250 x 500 metres. A single BLU-108 thus has the theoretical capability to destroy forty armoured vehicles – the term "force multiplier" here takes all its significance. What is more, it can be used by any aircraft cleared to release the Rockeye. It can be released by day or night at an altitude of 200 to 20 000 feet at speeds of up to 650 knots

The Sensor Fused Weapon went into low-rate initial production in 1992, then into full-rate production in 1996 under a $ 157 million Air Force contract for 500. A third production contract for 550 units came in February 1998, followed in 1999 by what is now know as a "full rate production 4" worth $ 100 million for 300 scheduled for delivery in July 2000. Interestingly, the latter contract includes provisions for the supply in September 1999 of 144 submunitions (BLU-108s, thus 576 warheads) for the Jsow programme. The Jsow (see brilliant missiles in this issue) can carry six BLU-108s.

Barrell Launched

As said above, the barrel-launched types first have to fight an initial battle, that is to say, they must overcome both the roughly 18 000 G initial acceleration and 5 000 G rotation imparted by the rifling. In barrel applications, one cargo round typically carries two submunitions.

In the United States, Aerojet Ordnance and Alliant Techsystems are in charge of developing a weapon known as the Sadarm for the US Army. The exact status of this weapon – other than "in production" - is not known, data having not been received on time by the author. There had been persisting rumours about submunition separation difficulties, but Armada has since been told that they have been resolved. Details on the exact status will be published by Armada as soon as they are received. Like the German Giws Smart, the Sadarm submunition has both infrared (one) and electromagnetic (two) sensors, and descends under a parachute.

Each BLU-108 produces this kind of search pattern, meaning that a full CBU-97 would produce this (right).

The most advanced 155 mm in Europe – and possibly in the world - is the German Smart, a 155 mm submunition specifically developed for the PzH 2000 armoured howitzer by a consortium made up of Rheinmetall and Diehl. In 1994, the company said that initial live firing had been successful and that entry into service was planned for 1999. Well, the proverbial Germanic sense of precision seems to remain firmly established, for Giws has confirmed to Armada that 9 000 rounds (i.e. 18 000 submunitions) were being produced for delivery to the German Army by the end of 1999 (the contract, worth more than DM 550 and announced in 1997, actually covers the delivery of those rounds between the end of the year and 2002). However, a "pilot lot of 32 rounds" will have already been delivered by the time these lines are printed. The Smart is designed to offer a range of 27 kilometres, carries an infrared sensor and an electromagnetic sensor as well as an explosively formed tantalum projectile warhead.

As regards exports, the Smart has apparently attracted keen interest from a couple of countries, including a European nation that is said to be very close to a decision. The Smart is of course Nato compatible, has been fired from the M109, the FH-155 and the PzH 2000, from an unspecified 47 calibres gun and there is "no reason why we shouldn’t fire from a G6," according to the company.

A rare cross-section drawing of the Giws Smart warhead revealing the tantalum lens. Top and just off centre to the right is the sensor section which swings out and folded in the back on the right is the parachute.

Europe’s second artillery smart round is the Franco-Swedish Bonus – also intended for 155 mm howitzers (initially a Bofors project, the Bonus meant BOfors NUtating System). The subsystem is now fully qualified, and the official qualification of the full system is scheduled for completion by mid-1999 (full systems tests, needless to say, have already been successfully performed. For qualification, several "tens" of rounds will be fired both in France (mainly from a special test 52 calibres gun and AUF-F1s) and in Sweden from FH-77s, up to maximum charges. The industrialisation phase is already underway, a contract for this having been received in 1998. A production contract is expected during the second half of 1999. Total requirement is classified, but production will be spread over a period of 10 to 15 years. Interestingly, a Giat official informed Armada that new generations might slip into the production line in about seven years from now, as improvements in seekers – particularly as regards processing capacities- are available. The Bonus distinguishes itself from its counterparts in having only one dual-band infrared sensor and no parachute: the submunition deploys two offset winglets that provide its nutating motion. Maximum range, if fired from a 52 calibres gun, is 34 kilometres. As for production, two integration lines are envisaged, each fed from single-source sub-component suppliers. In other words, Bofors is in charge of the canisters (a thin skin that contains the submunitions within the cargo round), the submunition-canister separation mechanism, sensor (in fact supplied by Intertechnique in France), and the assembly of the submunition into the canisters. Giat is in charge of the cargo round, the cargo-canister extractor, the base-bleed system and the warhead.

Rockets

Mention of the Splav Smerch was made at the beginning of this article. This is a massive 12-tube rocket launcher that was displayed at Idex in 1997, has a range of 70 kilometres. This rocket usually releases large submunitions that are parachute-braked which, when in a vertical position dive downward onto their targets. Since, Splav has integrated the air-launched RBK-500 submunition into the Smerch rocket and renamed it the A-349 Motiv-3M.

The Bofors-Giat Bonus 155 mm round should be fully qualified by mid-1999 and enter production shortly after for both Sweden and France (see text).

Another noteworthy Russian rocket launcher is the twelve-tube Splav 122 mm Grad. This lighter equipment has recently been demonstrated with a substantially upgraded rocket, which boosts the range from the original 20 kilometres to 40 kilometres, and increases its payload capacity from 18 to 21 kg. Splav has now also integrated another product from Bazalt, the 9M55K1 submunition. The system is now being offered on the export market.

	Pictured at Idex in 1997, this rather hefty Bazalt A-349 Motiv-M submunition (it requires three parachutes) was announced as a submunition for Splav Smerch rockets.

Hand-emplaced

The Bazalt 9M551K can now be used in conjunction with the Splav 122 mm rocket launcher.

The Hornet is a much smarter weapon as it also determines what it needs to attack, and even which vehicle in a column. A development of the Textron Systems Sensor Fused Weapon, it is mounted on its own small gimballed platform that enables it to cant itself from vertical into any direction. That direction is determined by a set of four microphones and a processor. The Hornet is hand-emplaced and can be activated or de-activated by radio. When a target generates an acoustic or seismic signature that corresponds to the information stored in memory, it cants its warhead in the direction of the target and ejects its warhead so that it over-flies its intended victim. The rest of the sequence is known.

Mortar

Like the Smart, the Textron Hornet seen here uses a tantalum lens in its explosively formed progectile for better armour penetration. The melting point of tantalum is 2700 °C as opposed to 1083 for copper.