Bunker Busters
Written by SCOTT R. GOURLEY
WHETHER TAKING OUT ARMORED VEHICLES OR KNOCKING A HOLE IN A WALL, HIGH CAPACITY LAUNCHERS DELIVER THE PUNCH. PART 1 OF THIS ARTICLE LOOKS AT SEVERAL OPTIONS AVAILABLE TO THE SOF WORLD.
One of the key lessons of 21st Century battlefields has long been known to special operations forces; specifically, the value of bunker buster capabilities in asymmetric combat operations. From Fallujah to Takur Ghar, military forces long trained and equipped to defeat a range of sophisticated armored vehicle threats now face an increasing need to defeat an enemy fighting from urban and battlefield bunker fortifications.
LEARNING THE LESSON
For example, in presenting some of its own lessons learned during initial Operation Iraqi Freedom combat operations in 2003, the U.S. Army’s Third Infantry Division (Mechanized) after action report (AAR) noted, “…The armor-piercing fin-stabilized discarding sabot (APFSDS)/high explosive anti-tank (HEAT) mix was adjusted in the ammo basic load (ABL) at the outset and was continually refined as the target array of trucks, BMPs bunkers and buildings became better known. Toward the end of offensive operations, ABLs consisted of about 60 percent HEAT and 40 percent APFSDS…”
While the optimum mix of round types may have come as a lesson to some, the fact is that for many years military planners have recognized the need to retain—and in some cases reintroduce— bunker busting capabilities for modern forces.
The evolution of the Army’s Stryker Brigade Combat Team (SBCT) provides an excellent example.
Early Army architectures for the SBCT included the presence on 105 mm mobile gun system (MGS) platforms. Among other things, the MGS would satisfy the SBCT key performance parameter (KPP) of providing the units with a bunker busting capability against urban masonry and battlefield earthen structures—specifically masonry walls (minimum 24-inch diameter through hole in 8-inch double reinforced concrete wall) and also defeat an earth and timber bunker.
Delays in the MGS development and fielding effort, however, forced Army planners to adopt an alternate near-term solution to satisfy the KPP in its early SBCTs. The solution adopted was to provide the Stryker anti-tank guided missile variant vehicles with TOW missiles that would be specially modified to provide those bunker busting capabilities until sufficient quantities of MGS could be fielded.
Due to the urgencies surrounding the fielding and equipping of the SBCTs, the TOW bunker buster program was conducted as an accelerated one-year joint government/contractor development effort under the auspices of PEO—Tactical Missiles. Initial industry participation primarily involved Primex (Hi-Tech) loading the new warheads and Raytheon doing modeling, simulation and missile retrofit through an engineering services contract.
Government participants have publicly described the technical approach as developing a fragmenting HE bulk charge warhead (6.25 pounds of PBXN-109 explosive) that leveraged the Hellfire missile blast-fragmentation effort.
The bunker buster modification program utilized existing TOW 2A missiles, maintaining the same flight algorithms, flight accuracy and range. Approximately 600 missiles were modified under the initial one year effort: 50 missiles for qualification testing; 50 for additional testing; and retrofit/fielding of 500 missiles for the SBCT.
According to one industry source close to the program, the idea was to provide the SBCTs with a breaching round able to create holes that soldiers could pass through. They added that the modified rounds provided “the capability of blowing a hole over a meter wide through the concrete wall and rebar” at the full range of TOW.
JAVELIN
But not all units possess TOW launchers. Another weapon system that has demonstrated its 21st Century bunker busting capabilities is the Javelin missile.
Javelin is manufactured by the Javelin Joint Venture, which is owned by two stockholder companies: Raytheon and Lockheed Martin, with the basic system work share arrangement tasking Raytheon with producing the command launch unit (CLU), the guidance electronics unit and the software; while Lockheed Martin produces the seeker, the common electronic safe/arm, the guidance integration and the all-round integration (missile assembly).
The Javelin missile played a critical part in OIF combat operations.
The 3ID(M) AAR, for example, effuses, “…The Javelin missile was an invaluable weapon in defeating enemy armored forces and reinforced positions to include bunkers, building and revetments. There is no other weapon that can support dismounted infantry in fighting against these types of engagements. The CLU provided day and night capability with the Javelin missile as well as provided vehicles without LRAS3 [Long Range Advanced Scout Surveillance System] and dismounted infantrymen with a means of thermal observation out to four kilometers…”
As of October 2005, combat missile expenditure totals reflected that Army elements had fired 1,058 Javelins in Iraq while the Marine Corps had fired 548 of the missiles.
In addition to providing conventional forces with the ability to defeat armored forces and bunker complexes, the Javelin missile also supported special operations elements during OIF, ranging from Australian SAS operations conducted deep inside the deserts of western Iraq to the battle of Debecka Pass, which was conducted by U.S. special operations elements on April 6, 2003.
In the latter case, service representatives explain that, as the initial phases of OIF major combat operations were commencing, a Special Forces team was inserted north of Baghdad to hold a major avenue of approach called Debecka Pass. The team, which faced the equivalent of a motorized rifle company in open formation, fired 19 Javelin missiles and completely destroyed the company, which included tanks, BMPs and BRDMs while the Special Forces team reportedly wasn’t even fired on.
“With top attack mode, the Javelin goes up somewhere between 200 and 300 feet in the air before coming down in attack,” notes Roy Adams, Raytheon business development manager for the Javelin Joint Venture. “So if somebody gets hit they will probably look for an airplane somewhere, because the attack came in from the top. And even at Debecka Pass, the SF guys will tell you that they saw the other guys get out of their tanks and start putting camouflage tarps over their tanks, thinking that they were being hit from the air. And our guys were firing at them from the pass.”
“And Javelin is a soft launch,” he added. “So you can fire it from inside enclosures; inside buildings; out of a window. It’s a smokeless motor also so there’s no signature going back to the launch site and that’s another thing that I think special ops guys find to be pretty effective.”
In reviewing the technical operations of the missile, Adams explained, “All the software for the Javelin resides in the CLU. And when you activate the seeker on the missile it cools down the seeker and uploads the software at the same time. And when you cool the seeker down you’re still looking through the eyepiece of the CLU but you’re looking through the missile seeker. It switches from the afocal [view] to the missile seeker [view]. Lock-on is with the seeker.”
He continued, “The CLU can also be used as a surveillance device, independent of the missile. And that’s what most of the units are using it for now, because they’re not launching missiles. For dismounted guys, it’s the best surveillance device that they have on the battlefield. It runs on a [BA] 5590 [lithium battery], with the power consumption probably six to eight hours on one battery. We have had Rangers reporting to us that they have had a CLU running for 90 hours straight, and the only time it was shut off was to change the batteries, so you can maintain surveillance without worrying about it overheating.”
According to Adams, the most significant new program activities center on production of the “Block I” Javelin missile and CLU, which began in September 2006. All missiles are now being produced in the new configuration. Adams observed that the most visible improvement in the Block I Javelin is an increase from 9X to 12X in the a focal assembly.
“Also, the missile itself has now increased in range to ‘in excess of two kilometers’,” he said. “The British have reported to us that they have been able to ID at a greater range than that [with the 12X]. The missile has the motor that will reach out that far and then the key is to be able to ID out that far.”
Reiterating that British users have reported identification ranges in excess of two kilometers, Adams added, “As far as the U.S. Army’s specification, two kilometers is the range that we will be able to stand behind.” “The other thing about Block I involves software improvements that ‘helps the identification and helps the lock-on’,” he noted.
CARL GUSTAF
Another battlefield system being enhanced with expanded tactical capabilities is the M3 Multi-Role Anti-Armor Anti-Personnel Weapon System (MAAWS) Carl Gustaf 84 mm recoilless rifle system from Saab Bofors Dynamics AB. The system is employed by the U.S. Army’s 75th Ranger Regiment as well as other special operations elements around the world.
In U.S. SOF applications, the spring of 2004 saw USSOCOM reveal its interest in a new multi-target (MT) round for the MAAWS “that will incapacitate personnel protected in the line-of-sight of the projectile detonation inside of man-made or natural protective structures/confined spaces. The MT round must be capable of defeating urban structures constructed using three-inch reinforced concrete or 12-inch triple brick walls where no openings exist…”
“We are upgrading the system all the time,” states According to Leif Jilsmo, product director for ground combat systems within Saab Bofors Dynamics AB. “When the need comes up we bring in new capabilities. For example, at the moment we are in the final phase of the development of a multi-target round for [USSOCOM].”
Jilsmo explained that the new multi-target round is being developed from a modification of the current 751 tandem anti-tank round for the Carl Gustaf.
“We are modifying that to meet the USSOCOM requirement of a multi-target round,” he explained. “The MT is a round that had an effect behind walls—the precursor makes a hole and then the main/ follow-through charge goes through and detonates on the rear side. That has now been demonstrated and we will deliver test articles for qualification in the U.S. by the end of 2007.”
In addition to the new round, Jilsmo said that the company is involved with enhancements to the Carl Gustaf sights, including better capabilities for the telescopic sight and adding night capabilities for the system. “It’s possible to put on different types of existing night vision scopes already,” he observed, adding that AN/PVS-17 was one popular choice.
“We are now bringing a small laser rangefinder together with the sight and that will increase the hit probability for the gunner, when he can measure the distance himself and not ask for that information from an assistant gunner,” he said. “And we are in cooperation with another company on that sight.”
He added that Saab Bofors Dynamics is also working with SPA Simrad on the IS2000 laser gun sight. “We have ‘different steps on the ladder’,” he explained. “The first step is the existing [system sight]. The next is the day scope with the laser rangefinder. He will still use the mechanical brackets and everything but the gunner can get the range and then adjust the elevation. Then we have the Simrad IS2000, together with the [Simrad] KN250 [image intensifier] to give it a night capability. In my view, that is the only existing fire control for a shoulder-fired weapon today. There are many prototypes in the world but no one that has passed the qualification.”
He added that the IS2000 is currently fielded in Norway, and “is also being evaluated by a number of different users.” ♦