An Otto 76mm naval gun system is being hoisted onto the ship, with a rare ammunition supply system located beneath the hemispherical turret. The practice of installing artillery and ammunition supply systems as a whole began with the Otto 76mm naval gun. Since its birth in the 1960s, the Otto 76mm naval gun has undergone continuous improvements and upgrades, forming a huge family of artillery. The naval gun system is small in size and light in weight, and can be easily installed not only on large and medium-sized ships, but also on patrol boats and missile boats weighing less than 100 tons. Good adaptability is attributed to the application of modular naval gun technology. Before the appearance of the Otto 76mm naval gun, the installation of large and medium caliber naval gun systems on board was relatively complex. The large and medium caliber naval gun system consists of a cannon and a ammunition supply system. The cannon is installed on the deck, while the ammunition supply system consisting of a hoist and a drum/magazine is installed below the deck and needs to penetrate several layers of the deck. Before installation on board, these complex systems are first docked and debugged on land at the production plant, then disassembled and transported to the shipyard for installation on board, and finally docked and debugged after installation. The entire process is not only time-consuming and laborious, but also difficult to ensure the stability of the naval gun performance. To address this issue, Europe took the lead in developing modular naval guns, such as the Otto 76mm naval gun. Through modular design, the cannon and ammunition supply system of the naval gun system are combined together. When it completes production and final assembly debugging at the production plant, and is transported to the shipyard for installation on board, it only needs to hoist the naval gun system under the gun position, and connect it with water, electricity, and gas circuits through simple mechanical connections to complete the installation and debugging of the naval gun system on board. The entire construction period not only significantly shortens the time, but also ensures the stability of the technical status of the naval gun system. In addition, the lower part of the naval gun's ammunition supply system has good integration and often only occupies one deck, making it easy to install on light ships. In recent years, modular naval gun technology has further developed. For example, the latest upgrade of the Otto 76mm naval gun, the "Sofrapente" type gun (meaning a deck mounted gun), eliminates the lower feeding system and places the automatic feeding system entirely inside the turret. In this way, the installation of naval guns does not require penetrating the deck, not only achieving "plug and play", but also reducing the total weight of the system by nearly 40%. The corresponding cost is only a reduction from 80 rounds of ammunition storage in the lower drum in the past to 76 rounds of ammunition storage in the inner drum. Modular design not only enhances the compactness and adaptability of naval gun systems, but also makes them easier to replace and upgrade. During installation and modification, there is no need to "open the barrel" of the ship, which has become the development direction of naval gun design. (New Society)