ZSU-37-2 Yenisei

The ZSU-37-2 Yenisei was a Soviet self-propelled anti-aircraft gun prototype developed during the same broad period as the ZSU-23-4 Shilka. It mounted two 37 mm guns and was intended to provide mobile air defense with heavier shells than Shilka's 23 mm armament. The Soviet military ultimately selected Shilka for service, leaving Yenisei as an important but cancelled development path.

Yenisei's twin 37 mm guns promised greater shell weight and reach than 23 mm weapons, but at the cost of rate-of-fire density, ammunition size, and system complexity. Like other advanced SPAAGs of its era, it sought to combine tracked mobility, radar-assisted engagement, and high-volume gunfire against low-flying aircraft. Its cancellation indicates that Soviet planners valued Shilka's denser short-range fire and practical fielding prospects more.

Because Yenisei did not enter serial service, its operational importance is mainly comparative. It shows the design choices Soviet engineers explored before settling on Shilka as the standard mobile gun air-defense system. The vehicle remains useful for analysis because it highlights a recurring air-defense tradeoff: heavier shells and longer reach versus rate of fire, mobility, reliability, and cost.