Navigating Tall Ships Under Bridges: Challenges and Solutions

The Challenge: A Tall Ship

One of the more unusual aspects of life at sea can be the challenge faced by tall ships when navigating under bridges. I was stationed on a ship with a mast that was too tall to pass under certain bridges without taking a significant step. Specifically, we had a stub mast, a section of the mast that could be lowered by hand, to ensure our vessel could clear the bridge.

The Procedure: Manual Mast Lowering

The process of lowering the stub mast required a meticulous and precise procedure. It began with locking out the radar and UHF/VHF transmitters to minimize interference. Then, a crew member would ascend the mast to remove two critical bolts that secured the mast in its raised position. With the bolts removed, a signal would be sent to the crew on the winch to safely lower the stub mast.

Special Considerations

The stub mast, which was approximately 15 to 20 feet tall, housed essential UHF antennas, necessary for communication. Care had to be taken during the lowering and raising process to avoid damage to the antenna and ensure the mast remained in excellent condition. Safety was the top priority throughout this procedure, ensuring the ship and crew remained unharmed.

Bridge Clearance Types of Bridges

Not all bridges pose the same challenge to tall ships. In fact, many bridges are designed to accommodate tall vessels such as those found in major waterways. However, certain bridges are not movable and do not provide clearance for ships with tall masts. These immovable bridges can present significant obstacles for ships trying to navigate through them without first addressing the mast issue.

There are several types of bridges that ships may encounter. Fixed bridges, which do not move, are the most challenging. Basque and drawbridges can be raised to allow ships to pass underneath, making them more accommodating for high-mast ships. However, raising and lowering these bridges takes time and coordination, which is why they are not always the best solution for frequent deep-draft shipping traffic.

Alternative Solutions: Mast Design Modifications

In some cases, the solution to the problem of navigating tall ships under bridges is not just in the immediate action of lowering the mast, but in the design and construction of the ship itself. Some ships are constructed with redundant mast sections, meaning they can have two or more masts that can be independently lowered. This allows for greater flexibility in navigating under bridges without posing a risk to the ship's critical equipment.

Additionally, some ships are designed with a drop mast system, where the mast can be quickly deployed and lowered or raised using hydraulics. This system eliminates the need for manual labor and reduces the risk of damage to the mast and antennas during the process.

Conclusion

In conclusion, the challenge of navigating tall ships under bridges is a complex issue that requires careful planning and execution. Whether through manual mast lowering, alternative mast designs, or the use of drop mast systems, the goal is always to ensure the safety and efficiency of the vessel while maintaining communication capabilities.

For more information on ship design and maritime navigation, continue reading below or consult with maritime experts.