Swedish Aerospace Company Saab Keen to Develop Warhead Advantage

One main reason Saab purchased RUAG Warheads in 2007 was the NLAW missile (Next generation Light Anti-tank Weapon). Thun-based company is located 25 kilometers southwest of Bern, the Swiss capital. This is where they developed and manufactured the missile.

Saab has been able to exploit synergies in the Swedish group’s research and technology facilities since then because SBDS (Saab Bofors Dynamics Switzerland Ltd) has been integrated. As a result, Saab can swiftly adapt its designs to customer demands because of the ever-expanding and increasing technologies that form the foundation for new designs.

According to Christopher Leitner, Head of Marketing and Sales at Saab Bofors Dynamics Switzerland, the focus has shifted from multipurpose warheads to anti-tank weapons at present since the current situation does not allow for the development of multipurpose warheads.

However, though anti-tank warheads have long been the company’s specialty, Saab will not forego the multipurpose concept, as it is currently working on lightweight anti-tank warheads for loitering munitions or other weight-sensitive applications.

Saab provides a wide range of products to suit every requirement. Anti-tank, anti-air, anti-bunker, and multirole devices are just a few examples. In addition, unguided shoulder-fired systems are available at a reasonable price, and the most advanced warheads are available for the finest missile systems in both the anti-tank and air defense sectors.

Several missile manufacturers have outsourced their warhead production capability, resulting in a small community of companies responsible for developing and manufacturing these warheads. Due to the limited number of systems produced, the Thun-based company sends warheads to many OEMs (Original Equipment Manufacturers). Although small caliber systems are manufactured and designed by Saab in Europe, the shaped charge remains the dominant player.

Creating New Records Around Charge Performance

In anti-tank weaponry, the hollow charge is the most significant factor. Penetration capability against the diameter of the main hollow charge, known as CD, is one of the most important parameters. The CD 10 limit (penetration 10 times the charge diameter) has already been surpassed in the past, as evidenced by Saab’s Milan ER warhead, which had a CD of 12 in early 2000.

“The tendency is to go for CD 15,” Christopher Leitner says. If a missile can destroy more targets while maintaining or reducing weight, fragmentation elements can be added, resulting in a rocket with a logistics footprint and reduced training costs.

New explosives and materials are obviously included in the CD increase. New materials and explosives are definitely part of the rise in CD. In addition to the fact that missiles are manufactured to Insensitive Munition (IM) standards today, the most significant element is IM explosives. Mortar bombs, a large market share requiring non-IM ammunition loaded with COMP B or TNT in Western Europe, are not produced in this manner.

An IM explosive has “less energetic density, as part of it is made of non-explosive” material, which provides it with its non-sensitivity characteristics.

“One of the most used IM explosives is the PBXW-11 of which 96% is made of HMX with only 4% of non-energetic materiel, and it is quite easy to compensate that small energy loss by optimising the warhead design,” Christian Herren, the company Director Development and Quality said.

PBXW-11 is accepted in most European nations, except for Germany, where the Bundeswehr requires higher sensitivity features, and it is at the base of Saab products such as the 5th generation MMP developed by MBDA.

“We have proven that using that explosive we can reach CD 11-12 by improving the warhead design, and we are pushing further.”

“However, things change when some nations, or some services, mostly navies, need higher IM properties. To reach this objective, only 86-87% of the fill is made of energetic materiel [sic], and optimising the design allows to recover around 10% of the loss, hence we only have a 5-7% reduction in performance,” Herren added.

EDR On-Line asked Herren, an expert in chemistry and explosives, to comment on recent developments in the volatile sector. According to him, two trends are occurring. Research institutions are working on new explosive formulas, but we are just at the end of the line in that regard. There are, of course, specific molecules that might improve penetration efficiency, but in terms of a few percentage points, and some of these substances cost thousands of Euros per kilogram, they will never be used in mass-produced items. They will, in all likelihood, be used only in nuclear devices. We currently have PBXW-11 and PBXW-17, and we must work with them,” he says. “We can, however, better comprehend the complicated physical chemistry behind those explosives, as well as other things.

Quantum mechanical simulation provides many surprises and opportunities for increasing efficiency and lowering costs in the production process. The standard manufacturing process for high-end warheads, isostatic pressing, is an example. Machining explosives results in lost explosives, which are a high cost. We are researching how we may use the material more efficiently and whether we might recycle scrap material, which would ultimately make warheads cheaper.”

Herren sees the replacement of non-IM explosives such as TNT or COMP B with NTO (Nitrotriazolone) explosives becoming increasingly popular internationally. As previously mentioned, cost prevented many nations from adopting non-IM ammunition in specific categories, and these new explosives may bridge the gap for mass production rounds.
Leitner says that simulation is critical to the optimization process: “We are working on artificial intelligence to design the liner profile, and we are using neuronal networks.”

Some liner profiles are impossible to produce, while others have become possible, and they’re often very similar to those designed by Saab scientists. Furthermore, to penetrate a Main Battle Tank’s primary armor, the jet generated by the shaped charge must first be able to reach it.

The Explosive Reactive Armour (ERA) installed on most MBTs must be dealt with first. We developed various technologies to evacuate ERA without detonation that can be utilized in multiple ways, including detonative and non-detonative manners. This can be done in a kinetic or an energetic fashion, according to Leitner.

Multipurpose Missiles Are the Future

The advantage of non-detonating solutions is that they do not create a lot of havoc ahead of the main charge. We don’t know how the non-detonating energetic solution works, but it appears to be based on a shaped charge. The Modular Explosive Penetrator (MEP) created by Thun in the past and now developed by RUAG Warheads was used in an RPG prototype to penetrate sandbags and walls in order to penetrate walls and sandbags.

The MEP is shaped in a conical way, with its surface material remaining undisclosed. Furthermore, it should have some ability to penetrate walls, making it a potentially multipurpose solution.

The multipurpose solution shown in Thun includes a series of elements designed to neutralize ERA and then the armor, while maintaining multirole functionality. Before firing, the operator may choose the mode most suitable for the target, which adds much flexibility to the missile. All technologies involved are at TRL 9.

A multipurpose missile can be produced by combining fragment generation with anti-tank capabilities. MAPAM (Mortar Anti Personnel Anti Material) is a mortar round that causes personnel casualties, for example, as well as material damage.

The Skjoll belt is an anti-tank technology that consists of a strap surrounding the warhead that generates fragments with adjustable energy and adjustable spray angles. It is capable of targeting soft targets. The tungsten balls are small in diameter and are used in a variety of shapes and materials to accommodate customer demands. These technologies have been patented and have already been used in some of Saab’s warheads. The third SBDS fragment technology, named Thor, is an improvement on MAPAM (Mortar Anti Personnel Anti Material) that uses multi-materiel and multi-geometry features.

While this SBDS technology is currently not in production, one more patent has been issued. ExploStrain is an SBDS technology that starts with multiple initiation points; the detonation can be initiated via smart fuses available on the market in a way that concentrates debris on one side at an angle, producing a 40% increase in warhead effectiveness. It is currently at TRL 4-5 and would either increase the missile’s effectiveness or reduce its weight while maintaining the same effectiveness as a conventional missile.

Because the warhead can be triggered in the best location relative to the target with the ExploStrain technology, air defense missiles are particularly suitable, as they will orient most of the fragments towards the intercepted airframe. It is relatively simple to do, as many missile seekers provide not only the target’s relative position relative to the missile but also the missile’s rotation, according to Herren.

A still-unnamed technology exploits two initiation points to concentrate fragments. When a detonation starts in a single location, the resulting shock wave produces a cone of fragments that spreads from 7° away, reducing fragment density and compromising performance.

Working on shrapnel focusing’s initiating points is one of many ways to increase fragmentation concentration.

“Diffgeo refers to differential geometry, a mathematical procedure for optimising shrapnel focusing based on fragmenting surface geometry alone,” So Saab has already developed and tested a variety of systems relying on this technology.

Herren feels that this technique is much simpler than the dual-point initiation process, which requires more effort.

Dual-point initiation is a technological innovation that combines with Diabolo geometry to create a very concentrated jet of fragments. This technique is used to overcome tough aerial targets such as maraging steel tubes that must be cut, according to Herren. Because the Diabolo shape is a symmetric shape, it is spearheading what future air-to-air battle looks like.

Blast Shield is an enhanced blast solution that mixes into a multipurpose warhead and is used when the main impact desired is a pressure wave rather than fragments; ExploStrain may be combined with it to focus the blast in the same way as when it is coupled to a fragment creation technology.

Scientists and engineers in Thun, however, are not exploiting those technologies solely to improve warhead effectiveness. They also want to know more about the inner workings of warheads in order to determine which parts require the greatest precision and which are less important. Leitner emphasizes that “at CD 14-15 charges, 40% of the cost” will be based on manufacturing quality, and therefore we’ll be able to reduce costs by 15-20% in order to maintain a great performance-to-price ratio.

In addition to missiles and mortar shells, the SBDS company is looking at novel applications such as Loitering Munitions (LM) or Unmanned Ground Vehicles (UGV). The SBDS company is looking at two primary geographical markets, Europe and North America, where many nations have employed LM in their military. In the next five to ten years, this might change drastically. LM firms will probably invest in warheads that can handle many target types, one of Saab’s specialties, as the quantity of LMs increases. This will leverage the technological progress made up until now.

Saab believes that the LM business will have a more unified approach than missile warheads regarding UGVs. As for effectors, the goal is to create a range of less-than-lethal to lethal solutions, even for firefighting situations, to avoid putting human beings in dangerous situations.