Canada’s Roshel develops mobile mortar system

A Canadian armored vehicle manufacturer and a Singaporean defense engineering giant unveiled a joint concept at Canada’s premier defense exhibition that could fundamentally change how infantry units deliver indirect fire: a light pickup truck carrying a fully automated mortar system that two soldiers can deploy in 15 seconds and stow just as fast before driving away.

Roshel, which has supplied more than 2,500 vehicles to Ukraine, presented the concept at CANSEC 2026 in Ottawa, integrating ST Engineering’s Ground Deployed Advanced Mortar System, known as GDAMS, onto the bed of its Senator Pickup, a militarized 4×4 truck built around a 6.7-liter diesel V8 engine producing 330 horsepower.

The mortar system at the heart of this concept addresses one of the oldest tactical problems in infantry warfare: how to deliver explosive firepower on targets that direct fire weapons cannot reach, without exposing a dedicated gun crew to counter-battery fire for long enough to get killed. Traditional mortar teams set up, fire, and must move before the enemy can locate and engage them through sound detection or observation. A vehicle-mounted mortar that can be ready to fire in 15 seconds and back on the road in another 15, driving at highway speeds to the next position, compresses that exposure window to a degree that conventional dismounted mortar operations cannot approach.

The GDAMS system that ST Engineering, the Singaporean defense conglomerate with land systems operations headquartered at 249 Jalan Boon Lay in Singapore, developed for exactly this kind of mobile application fires both 81mm and 120mm caliber ammunition, covering the two most common NATO mortar calibers in a single platform. The 81mm round is the standard light infantry mortar caliber, offering a maximum range of approximately 5 kilometers (3.1 miles) with standard ammunition and weighing enough to be carried in significant quantities by a light vehicle. The 120mm round is the heavier mortar caliber used by mechanized infantry and dedicated fire support units, with ranges exceeding 7 kilometers (4.3 miles) for standard rounds and considerably further with rocket-assisted or precision-guided variants. ST Engineering confirms GDAMS is compatible with precision-guided 120mm mortar bombs, which can achieve first-round hit probability against point targets that unguided rounds require multiple corrections to engage.

The system’s recoilless design is the engineering choice that makes the Senator Pickup integration possible. Conventional mortars transmit enormous firing forces into the baseplate and through the vehicle structure when fired from a platform, requiring heavy vehicles with reinforced frames to absorb the stress without damage. GDAMS directs those firing forces into the ground through its baseplate rather than into the vehicle chassis, which means the system can mount on a light commercial or military pickup without structural reinforcement that would add weight and cost. The Senator Pickup, with its 6,105 mm (240 in) length, 2,550 mm (100 in) width, 275 mm (10.8 in) of solid axle ground clearance, and 800 km (497 miles) operational range on a 251-liter (66-gallon) fuel tank, provides a mobile platform capable of reaching firing positions across the full range of terrain that Canadian and NATO operational environments demand.

The blast diffuser that ST Engineering has patented for GDAMS addresses a survivability problem that vehicle-mounted mortar crews face acutely: the acoustic signature of a firing mortar, which conventional systems produce at volumes that can cause hearing damage and which betray the firing position to adversary detection systems. The GDAMS blast diffuser reduces noise exposure by threefold compared to conventional systems, protecting the two-person crew from auditory injury and simultaneously reducing the acoustic signature that enemy sound-ranging systems use to locate mortar positions. For a crew operating from a light pickup that cannot absorb the casualties that a traditional mortar team might accept, that protection is not a comfort feature but a survivability requirement.

The digital fire control system integrated into GDAMS automates the laying process, meaning the crew receives target coordinates from any command center and the system automatically calculates and sets the elevation and traverse required to hit that target, without requiring the manual calculations and physical adjustments that conventional mortar operations demand. The system achieves elevation and traverse accuracy of less than 3.0 mils, equivalent to less than 3 meters (9.8 feet) of error at 1 kilometer (0.6 miles), which translates to first-round accuracy at practical combat ranges when combined with precise target coordinates. At maximum rate of fire, GDAMS can deliver 15 rounds per minute for three minutes, then sustain 4 rounds per minute for 20 minutes, giving a two-person crew a firepower output comparable to a conventional four-person mortar section.

Roshel’s Senator Pickup provides a platform whose specifications are matched to the GDAMS integration in ways that matter beyond raw carrying capacity. The vehicle’s 35-degree angle of approach and 30-degree angle of departure allow it to access firing positions across rough terrain, its 4×4 drivetrain with 10-speed automatic transmission ensures the crew can reposition rapidly after firing, and its seating capacity of up to five allows the vehicle to carry both a two-person mortar crew and additional ammunition handlers or security personnel. The 330-horsepower engine and 950 lb-ft (1,288 Nm) of torque at 1,800 rpm ensure the loaded vehicle can move at speed on roads and maintain cross-country mobility with the additional weight of the GDAMS system and its ammunition supply.

Canada’s CANSEC 2026 provided the right audience for this concept’s debut. The Canadian Army operates 81mm and 120mm mortars in its infantry battalions and has been exploring options for more mobile indirect fire solutions as it updates its force structure under the Future Army program. A domestically produced vehicle carrying a proven Singaporean mortar system, demonstrated by a Canadian manufacturer with an established track record of supplying vehicles to active conflict, offered CANSEC attendees something beyond a product brochure: a complete, integrated concept ready for evaluation.