The Israeli company Elbit Systems developed a new generation of 155mm SIGMA wheeled self-propelled howitzers to replace the M109 crawler self-propelled howitzers currently in service with the Israeli armed forces.
Today, with the advantage of being lighter and easier to deploy by rapid response units using military transport aircraft, self-propelled howitzers have become very popular with the militaries of many countries including Indian, China and Russia.
The wheeled artillery gun also has high strategic maneuverability and simplifies logistics due to less dependence on heavy transport vehicles. Like many militaries around the world, Israel wants to replace its crawler self-propelled howitzers with wheeled self-propelled howitzers.
The US Army has also launched a search to equip a new mobile artillery system for brigades equipped with Stryker wheeled armored vehicles, which are currently armed with the 155 mm M777 towed vehicle cannon. The Israeli company Elbit Systems with its 155mm Truck Mounted Artillery System (ATMOS) is one of the candidates for this program of the US Army.
In May 2019, the Government of Israel announced a $125 million contract under a planned 12-year, $280 million program to replace the M109 crawler self-propelled howitzer in service of the Israeli armed forces.
In August 2021, Army Recognition reported that the Israeli company Elbit Systems had developed a new fully automated, truck-mounted 155 mm self-propelled howitzer to meet the needs of the Israeli military, to replace the M109 155 mm cannon system around 2023 and will be codenamed “Roem”. According to Janes, the new 155 mm SIGMA will use the LVSR 10×10 military truck chassis manufactured by the American company Oshkosh Defense.
The LVSR is a family of trucks based on a conventional 5-axle 10-wheel drive 10×10 chassis that can be configured to mission requirements. SIGMA is expected to compete directly with the Caesar artillery system of the French company Nexter in the tender to supply 36 155 mm self-propelled guns to the Brazilian Army.
According to an analysis by Army Recognition, the SIGMA 155 mm self-propelled gun is based on an improved US military truck chassis with an armored cabin in front that can protect against mines. The vehicle has a crew of three.
The photo released by Janes shows the crew’s cabin located at the front of the truck, which is armored to protect against small arms and shrapnel and has a defense system against nuclear, Biological, and Chemical threats (NBC) and air conditioning. The armored compartment can accommodate the crew.
All firing operations can be performed from within the vehicle cabin. The rear part of this complex is equipped with a turret and a 155 mm cannon with a length of 52 times the caliber.
Elbit Systems said that the SIGMA 155 mm self-propelled howitzer is equipped with a remote-controlled weapon station that includes a modular automatic reloading system (Uni-Modular Artillery Charge System (UMACS)), with a high rate of fire.
According to press published by Elbit company, The Systems Awarded $106 Million Contract to Supply SIGMA Self-Propelled Howitzer Gun Systems to a Country in Asia-Pacific. The contract will be fulfilled over a five-year period.
So far, SIGMA is a 155mm/52 calibre self-propelled howitzer capable of automatic loading and laying of the gun system, rapid in-and-out action times and high rate of fire. It offers a protected cabin for a crew of three. Depending on the mission, SIGMA is capable of automatically selecting and loading the required projectile, propellant and fuze and laying the gun to optimally engage targets.