A redesigned General Dynamics [GD] Stryker wheeled vehicle outfitted with a potent 30mm cannon passed its critical design review this week, clearing the way for an initial contract to retrofit the vehicles next month.

The Army in summer 2015 declared an urgent operational need for a Stryker with more punch in Europe as a show of force to deter Russian aggression and reassure NATO allies that the U.S. military has their back.

“We have been asked to provide a long rifle to the brigades,” said Col. Glenn Dean, the Army’s Stryker Brigade Combat Team program manager. “Can we give them more lethality and the ability to fight and destroy vehicles with greater overmatch and provide greater support at longer range?”

Stryker lethality upgrades
Stryker lethality upgrades

Because of the urgent need in Europe, the program is progressing on an abbreviated timeline. The urgent need for a larger Stryker offensive weapon was generated in June 2015 followed by the selection of the Kongsberg turret and Orbital ATK [ATK] XM813 30mm cannon in December. Full funding and detailed engineering work began in January.

An initial production contract will be awarded in April with deliveries to begin in December, Dean said. Preliminary testing will occur in the middle of fiscal 2017 with the first production Strykers delivering before the end of fiscal 2017.

Initial fielding to Germany and in-theater operational test of the upgraded vehicles should begin halfway through fiscal 2018 with an entire brigade’s worth fielded by the end of fiscal 2018.

The Army’s intent is to field a brigade with a mix of conventional Strykers and some with lethality upgrades-–every other vehicle will have a 30mm cannon while the rest retain the remote weapon station with a .50 caliber Browning M2 machine gun.

“This program is not one that has been held up by bureaucracy, or process,” Dean said. “The only thing that slowed us up is the authority to fund the project.”

“That will significantly enhance 2nd Cavalry Regiment’s lethality capabilities and will be the precursor for the Army’s future strategy that grows the lethality of all of its Stryker brigades,” he said. “That will include similar, but not necessarily the same capabilities of this integration.”

Future additions to the vehicle likely will include integration of a Javelin missile launcher, he said. Javelin is made by the Javelin Joint Venture formed by Raytheon [RTN] and Lockheed Martin [LMT].

The current program calls for a XM813 cannon mounted on an MCT-130 unmanned, remotely operated turret built by Kongsberg. A forward-looking infrared (FLIR) sensor is integrated into the turret and provides full-motion video for the weapon operator inside the vehicle.

Adding the hefty cannon and turret to the relatively light wheeled vehicle required chassis and suspension upgrades, and integration of fire-control systems to the Stryker interior. The turret and gun together add between 5,000 and 6,000 pounds to the vehicle, Dean said.

Each Stryker will receive a complete mobility system upgrade to “Gen 5.5” standards, including new drivetrain, suspension, brakes, steering and hull components. The vehicle’s eight tires are replaced with wider versions and rims that improve stability, prevent rollover and increase purchase in soft soil.

Existing Strykers will be shipped to Anniston Army Depot in Alabama where the hulls are stripped of all common components. The hulls are then shipped to the Lima Tank Plant in Ohio where they are machined to accept the turret.

A hull riser is installed between the original upper hull and the turret that allowed for integration of the weapon system interfaces. It includes an armored liner, hatches for the turret and to the exterior and the vehicle commander’s periscopes.

Stowage capacity is reconfigured and expanded to hold 30mm ammunition and tools that were stored topside are relocated inside the vehicle.

A standard load is 156 rounds and 78 in each of several “ready boxes” of ammunition. Officially, the requirement is to carry a total 450 rounds of 30mm ammo.

“We’re actually still working on where you can fit all those stowed boxes because, as you can imagine, a 30mm ammo box has quite a bit of volume and you don’t sacrifice the squad’s equipment capacity, we’ve lost our stowage on the roof of the vehicle, so there’s not a lot of space.”

After arriving back at Anniston, the turret will be integrated, the cannon and fire-control systems and then the reassembled Stryker will be shipped to Germany for operational testing.

“As you can see, it is a relatively significant change in the platform,” Dean said. “This is fundamentally a new vehicle.”

“We’re doing it very rapidly for this level of effort,” he said. “I would be underselling the challenge and risk in doing that if I were to merely state that we think we have it under control.”

Dean’s caution stems from recognition that the Army is rusty at mounting big guns on vehicles. The last time the U.S. Army successfully integrated and fielded a new direct-fire weapon system on a ground vehicle was the M256 120mm main gun on the M1 Abrams tank in the 1980s, Dean said.

The Army isn’t entirely reinventing the wheel, however. Some work that was done in development of the now-defunct Future Combat Systems (FCS) and the failure-to-launch Ground Combat Vehicle (GCV) was applied to the Stryker lethality effort, he said.

The cannon itself originated in the GCV program while the ammunition-feed system resulted from FCS, he said. The ammunition suite was initially developed for use on Marine Corps vehicles.

“This builds on a legacy of work that has been done in the past, which has allowed us to do the work more quickly,” Dean said.

Not included in the upgrade package are improvements prescribed in the Stryker engineering change proposal (ECP) program designed to address deficiencies in space, weight and power-cooling so that the Army’s new battlefield network can be installed on the vehicles. That suite of upgrades is in testing and would not allow the lethality upgrades to field within the schedule outlined in the urgent needs statement, Dean said.

Another hitch is that the lethality upgrade package is being installed on “extra” flat-bottomed Strykers that can be removed from theater for maintenance without affecting operations. ECP is being performed on Strykers with the Double-V blast-mitigating hull, of which there are no extras, Dean said.