A fender in port is a device that protects a vessel from colliding with a dock, pier, or another vessel near the shore. Fenders function as buffers or absorbers, absorbing kinetic energy with elastic action. This reduces the impact of reciprocal interaction. Therefore, harbor fenders are helpful in preventing structural damage to vessels.
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Why Do We Need Fenders in Port?
All vessels must berth at authorized sites. During this operation, the vessel must place itself in a precise spot to complete its mission. At the same time, the crew must consider the available space and other aspects of the pier, harbor, dock, piers, shoreline, and so on. When a vessel is anchored, it can be secured by mooring buoys.
As a result, even if the vessel is moving at a glacial pace, there is a significant risk of contact or collision with the harbor or other structures. When a vessel is anchored at a mooring, the chance of contact remains significant. However, a ship’s speed is zero after docking or mooring. However, the nature of the waters is extremely dynamic.
Currents, tides, and waves all contribute to continuous motion. As a result, even non-floating vessels may occasionally make touch with shore buildings. Furthermore, different vessels fulfill distinct functions at breakwaters, piers, docks, harbors, or ashore. As a result, individual boats are more likely to make direct contact with one another.
In contrast, as a vessel enters a port or harbor with heavy traffic, the danger of colliding with another vessel increases. Furthermore, two vessels can be moored together for a variety of purposes, including refueling or cargo transshipment, often known as ship-to-ship transfert (STS).
Thus, harbor fenders arose from this need. You can see these rubber fenders in a variety of ports. Common fenders in port include arch rubber fenders. For the same reason, there are many different types of marine fenders that can be utilized for small speedboats to enormous cargo ships. These rubber maritime fenders shield the hull structure from localized crashes and impact.
Factors To Consider When Selecting A Fender
A fender built for one use may not be suitable for another. It is consequently dependent on the type and purpose of the vessel. As a result, the selection of fenders for a specific site and operation is determined by a number of factors.
Type of Vessel
This is the most important consideration. Fender methods designed for fishermen’s ports are completely ineffective for large cargo ships entering the harbor. In addition, the vessel’s kind, size, and design are significant. For example, arch fenders are appropriate for small to medium-sized vessels.
Similarly, bulk carriers and ordinary cargo ships must be moored close to the quay or trestle with restricted clearance. This ensures efficient cargo transfer via maximum crane reach. Similarly, passenger ships require this to enable the safe and easy boarding and disembarkation of passengers.
As a result, large flat fenders of the appropriate size and shape, which are strong and require little clearance, are frequently utilized.
In addition, current fender systems offer advanced features, including parallel motion, sliding, and retractable extrusion. They can absorb significant ship momentum over lengthy periods of time while simultaneously adapting to external influences. This narrows the gap between the ship and the port terminal. Berthing energy is directly related to ship type.
Structure And Environment
Coastal infrastructure and ecology are crucial. The conditions around a breakwater, pier, or jetty determine the danger of collision and the forces involved in the impact. Examples include tidal levels, wave factors, currents, and so on.
Similarly, the type and configuration of the structure are taken into consideration. For example, open pile breakwaters, which are popular in deep ocean operations, are load-sensitive and have a small fender area. Large, effective fendering devices are therefore necessary. These devices can not only handle the heavy loads of huge vessels, but they can also work under changing external conditions, such as high tide or large wave loads.
Mooring Configurations and Methods
Vessels can be moored alongside in a variety of ways, depending on their requirements and construction. Side berthing is the most prevalent method, followed by end berthing (bow or stern). There are also uncommon ways, such as dolphin berthing or lock-berthing. Thus, when a vessel must berth from the bow or stern, the berthing arrangement on the vessel and structure differs from the side berthing method.
This element is directly related to the first point (kind of vessel). For example, consider a ship with a spherical bow that must berth from the front. Then, its fenders differ from those of a ship without a spherical bow. Other important considerations are approach speed, angle, and so on.
Fender Type, Design, And Arrangement
Consider the type, design, and arrangement of fenders in high-interaction areas. Harbor fenders are often organized in a line at more or less regular intervals. These fenders are found on the furthest reaches of the harbor, wharf, or trestle. There, they could come into contact with the ship’s hull. Rubber fenders are also installed on the side hulls of boats and ships, along the waterline and deck edges.
Thus, for harbors, fenders can be put as needed. Fenders, for the most part, are optional for big seagoing boats on the move. This is due to the absence of low-scale collisions in deep waters, as well as the effects of ship fenders on weight, stability, and speed.
Types of Fenders
Fenders in port vary significantly in size, shape, type, and style. Common types of fenders by shape include the following:
- Cylindrical fenders
- Spherical fenders
- Square fenders
- Corner fenders
- Round Fenders
- Conical fenders
- Circular fenders
- Arch Fender
- D-shaped fenders
Depending on their movement, there are many kinds:
- Fixed the fenders
- Floating fenders
Fixed fenders, as the name implies, are attached to a structure like a ship or a harbor platform. A floating fender is suspended in the water and left to float. It serves as a buffer between two items, such as a vessel or a fixed structure.
Furthermore, fenders can be generically categorized into the following types based on their structure and design:
- Flatbed fenders
- Pneumatic fenders
- Foam fenders
Application Scenarios
Flat plate fenders are exclusively used on land structures such as breakwaters, bridge piers, and ports. They are mainly made of rubber and have a high stiffness index. In addition, they do not compress considerably and are hence ideal for low-momentum collisions. They are often circular, ring, square, or D-shaped.
Fixed fenders are most commonly used on land. Pneumatic fenders, on the other hand, are often utilized between ships. However, they are also utilized on land when larger ships are present.
Pneumatic fenders are larger and contain pressurized air. As a result, they can absorb a large amount of energy while deflecting very little. Pneumatic fenders provide greater flexibility and are perfect for mooring between two floating vessels with a wide range of motion. Furthermore, it is ideal for docking huge vessels at high speeds. Pneumatic fenders are typically cylindrical or spherical in shape.
Because of their pneumatic qualities, they are commonly classified as floating fenders. Foam fenders, like pneumatic fenders, can float because of their construction. They have an interior foam core and an outside shell made of synthetic polymer or elastomer. Another advantage of foam polymers is that they do not deflate when punctured.
Mechanized fenders that adjust and retract in response to loading pressure are also widespread today. Fenders are commonly classified as legged, extruded, sliding, or parallel motion.
Design Factors
Berthing Energy is the most significant characteristic in fender design. Berthing energy is the kinetic energy of an impact load when it travels from a vessel to a berth or between two boats.
Fender spacing is the distance between two nearby fenders. This is determined by the type of vessel, the surrounding environment, and the mooring method.
Fender contact is the force that each fender shares. This is connected to mooring configuration and vessel type. As previously stated, when the vessel is moored sideways, the forces on the fenders are more or less constant. This is because the entire loading cycle is extremely dynamic.
Materials
Materials vary depending on the type of fender. For example, with foam fenders, the inner core is foam, and the outer core is elastomeric. Flatbed fenders are typically reinforced with polyethylene, rubber, and occasionally steel.
Inflatable fenders are made of ordinary rubber (like tires) and monomers. Additionally, polyvinyl chloride is a commonly utilized substance. Mechanical fenders are primarily constructed of steel and filled with rubber at the point of contact. Thus, the material used for the fender is determined by its strength and functional requirements.
Conclusion
In conclusion, fenders in ports safeguard ships and harbor structures. Fenders protect the hull and docking structure by absorbing a ship’s kinetic energy during berthing. As a result, harbor fenders can help to guarantee that marine operations run smoothly and safely.
Additionally, the design and selection of fenders are crucial. This is because they must be customized to accommodate a wide range of vessel sizes, types, and environmental conditions. It is critical to understand the various types of fenders and their intended applications. This is because it improves the safety and longevity of port facilities.