B-55A

U-FRAME TWISTLOCK 55°

B‑55A U‑frame Twistlock

The CONTECH® dovetail or U‑frame twistlock B‑55A is a bottom twistlock designed for securing ISO containers on board vessels. It is used in combination with a dovetail or U‑frame foundation such as FR‑34, FR‑34BQ (elongated), or a double FR‑35B/A set at 55 degrees. Together, these components lock into the container’s corner castings to ensure safe and stable stacking during maritime transport.

The B‑55A features reduced wings, specifically engineered to make removal from the dovetail or U‑frame quicker and easier—especially beneficial during fast turnaround operations or when access is limited. Despite the compact wing design, the twistlock maintains a strong mechanical engagement with the corner casting, ensuring reliable load‑securing performance in demanding sea conditions.

Key Characteristics

• Application: Bottom twistlock for container securing in ship holds or on hatch covers
• Compatible fittings: FR‑34, FR‑34BQ, FR‑35B/A (55°)
• Design advantage: Reduced wings for faster insertion/removal
• Function: Prevents horizontal and vertical movement of containers during sea transport
• Use environment: Suitable for vessels operating with dovetail or U‑frame securing systems

Typical Use Cases

• Securing single or stacked containers on vessels equipped with U‑frame or dovetail foundations
• Operations requiring quick release during unloading
• Situations where conventional twistlocks are difficult to remove due to limited clearance

‍