DSEI 2023 – GDAMS, a lightweight vehicle deployable 120 mm from ST Engineering

Paolo Valpolini

ST Engineering of Singapore unveiled at DSEI 2023 its GDAMS, a 120 mortar system that can be installed on small vehicles, providing heavy indirect fire support to light infantry formations

While long range fires have proved their key importance in recent times, shorter range system also maintains a key importance at tactical level. The Singaporean defence industry champion already had in its portfolio an automatic heavy mortar solution, installable on heavy armoured vehicles, the Super Rapid Advanced Mortar System, SRAMS in short, however this could not be deployed by light infantry units.
To fill that gap ST Engineering worked on a new programme, the Ground Deployed Advanced Mortar System, GDAMS its acronym, which was shown in public for the first time at the 2023 edition of the London exhibition.

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The GDMS leverages the work done by the company in the mortar sector, exploiting of course the fire control system which is interfaced with the battalion battle management system to reduce as much as possible the sensor-to-shooter time.

When travelling the mortar barrel is carried in a nearly horizontal position on the vehicle flatbed, at DSEI the GDAMS was installed on a commercial pickup 4×4, ammunition being stored on the sides or at the front of the flatbed. When the unit receives a fire mission it quickly finds a suitable deployable area and the vehicle comes to a stop. The system actuators rotate the mortar backwards until the baseplate touches the ground. This allows discharging all recoil forces on the terrain, which in turn permits to install the GDAMS on a light vehicle, as suspensions will not be affected by those forces. The baseplate is designed to absorb part of the recoil forces in order to avoid the system to sink in the ground even when the soil is not particularly hard. The whole deployment operation takes less than 25 seconds.

The weapon is manually load and can shoot 16 rounds per minute for three minutes, then the barrel must be cooled. This is not however a problem, as it is well time to redeploy to avoid any possible counterbattery fire, hence in less than 25 second the vehicle fitted with the GDAMS quickly leaves the deployment area ready to reiterate its firing action from another position.

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The system shown at DSEI was fitted with a 120 mm smoothbore barrel, however the GDAMS can also be fitted with a medium calibre 81 mm barrel. In the 120 mm configuration the GDAMS weighs 700 kg. Once deployed on the ground, it can be traversed on a ±90° sector, while elevation is between 45° and 80°. A two-man crew is required to operate the system.

ST Engineering considers its system having a TRL 6/7, first qualification firings being planned for Q1 2024. EDR On-Line understood the Singaporean Army has no immediate interests in this system, which has been developed on company funds aiming mostly at the export market. The launch of the GDAMS at DSEI let understand that ST Engineering is eyeing the British Army 81 mm replacement programme, the service looking at new solutions to provide its light forces with medium-calibre indirect fire support with a modern system that will take the place of the legacy L16 mortar, another potential customer being Saudi Arabia.

Photos courtesy P. Valpolini