The Army is planning to bulk up its lightweight Infantry Squad Vehicle with a heavier, hybrid-powered variant, according to a federal contracting notice.

The service wants to add 606 ISV-Heavy vehicles to its existing fleet of roughly 1,105 ISVs through a three-contract effort, signaling a shift in how it intends to use the platform.

While the original ISV was designed to rapidly move a nine-soldier squad across rugged terrain, the ISV-H is built to do more than just transport troops. Instead, it emphasizes onboard power generation and mission system support.

According to a GM Defense factsheet, the ISV-H is designed for “a myriad of mission areas to include command and control, counter UAA, medical evacuation, loitering munition and drone deliver launch and recovery.”

The hybrid-electric design also enables “silent drive” and “silent watch” modes, allowing for “stealthy ingress and egress for high threat zones, while powering equipment needed.”

The biggest change to the vehicle is its exportable power capability. In the solicitation, the Army said it wants the vehicle to generate and export 60 kW of continuous high-voltage DC power, 15 kW of 28V DC power and 4.8 kW of 120V AC power — effectively turning the ISV-H into a mobile energy source for small units in the field.

Despite its name, the ISV-Heavy is not an armored version of the original vehicle (though, it is “add-on armor capable”). Instead, it is built on the commercial Chevrolet Silverado 3500 HD platform, with “heavy” referring to its heavier-duty chassis rather than added protection.

That change comes with tradeoffs. The ISV-H weighs roughly 9,000 pounds more than the original and carries fewer troops. Early mockups show configurations ranging from two to six seats, compared to the nine-seat capacity of the baseline ISV.

The Army completed the first phase of the solicitation — collecting industry white papers — on April 13. Timelines for the remaining phases, including presentations and final proposals, have not been released.