World War Photos

Erco 250 SH-3 nose turret

The Erco 250 SH-3 (Spherical-Hydraulic) turret, prominently featured in the nose of the PB4Y-2, was an advanced and innovative design for its time. The turret’s spherical shape and comprehensive coverage of the gunner and mechanical parts by Plexiglas gave it a distinctive and futuristic appearance.

Key Features of the Erco 250 SH-3 Turret:

1. Construction and Design:

   • Shape: The turret was spherical, providing a streamlined and compact form.
   • Materials: The upper portion was made of Plexiglas, offering clear visibility and protection.
   • Armor: The front of the gunner was protected by armor plate and bulletproof glass, which could be easily removed and replaced with wing nuts and lanyards.

2. Operation:

   • Controls: The gunner had access to electrical switches, triggers, and a control handle, all within easy reach.
   • Seat Adjustments: The gunner’s seat could be adjusted vertically and horizontally by two inches, with armrests, chest belts, and seat belts provided for stability and safety.

3. Mechanics:

   • Power: The turret was gear-driven and powered by hydraulic pressure from a hydraulic motor.
   • Control: Movement was controlled by a handle with a valve at its base directing hydraulic fluid to maneuver the turret.
   • Armament: It was equipped with two 0.50-cal Browning machine guns, mounted on Bell adapters type E-10, with manual charging. Each gun had four magazines holding 800 rounds of ammunition.

4. Movement and Range:

   • Rotation: The turret could rotate 85 degrees to either side of the aircraft’s longitudinal centerline.
   • Elevation: The guns could elevate 82 degrees above neutral and depress 83 degrees below neutral. Some PB4Y-2s had the turret installed with a 13-degree forward cant, which adjusted the elevation and depression angles accordingly.

5. Sight:

   • Reflector Sight: Positioned directly in front of the gunner at eye level, this provided accurate targeting.

The Erco 250 SH-3 turret was a sophisticated piece of military engineering that provided significant defensive capabilities to the PB4Y-2. Its combination of innovative design, comprehensive protection, and advanced control systems made it a crucial component in the aircraft’s operational effectiveness.