Indian Army Upgrades FH‑77B (Bofors) Howitzers with Modern Cummins Engine to Enhance Combat Readiness

The Indian Army’s Corps of Electronics & Mechanical Engineers (EME) has started upgrading its FH‑77B (Bofors) howitzers by replacing the ageing Auxiliary Power Units (APUs) with new Cummins engines. The upgrade aims to improve the reliability, mobility, and operational efficiency of these artillery guns, which have been serving in the Army since the 1980s.

The existing Volvo B20 APUs used in the FH‑77B guns are no longer in production, and spare parts are becoming increasingly difficult to procure. The new Cummins engine, already used in the Dhanush howitzer, is expected to solve these problems by offering better availability of spares, improved fuel efficiency, and simplified maintenance.

The integration process involves reengineering the engine mounts and ensuring compatibility with hydraulic and control systems. After retrofitting, each howitzer undergoes a series of field trials to test mobility, fuel consumption, and performance in various terrains and weather conditions.

Officials stated that standardising the engines across artillery platforms would lead to significant logistical benefits. Mechanics’ training, maintenance schedules, and spare-part inventories can be streamlined, making support easier and faster in operational environments.

The APU upgrade also allows the howitzers to move under their own power for short distances, increasing their deployment flexibility in difficult terrains such as high-altitude areas or deserts.

The FH‑77B howitzer, with its 155 mm/39 calibre gun, has been a backbone of the Indian Army’s artillery force. However, with components becoming obsolete and operational readiness affected by spare-part shortages, modernisation has become essential. The Army plans to phase out the FH‑77B by around 2030, but upgrading them with new engines will extend their service life and keep firepower levels intact during the transition to newer artillery systems.

This move is part of a broader artillery modernisation programme that includes the induction of Dhanush and ATAGS (Advanced Towed Artillery Gun System), which promise extended range and greater precision.

Experts believe that this upgrade will significantly enhance the combat readiness of artillery units while allowing for cost-effective maintenance and standardisation across platforms.

With the Cummins engine upgrade, the Indian Army is strengthening its artillery capability by combining proven systems with modern technology, ensuring that legacy platforms remain relevant until the next generation of guns is fully operational.