Bulkheads are structures built to retain sand or soil and protect the land from erosion. They are used to construct reclaimed areas, port basins, and natural shorelines. Collision bulkheads in ships are positioned as per rules given by classification societies, normally based on flood-able length calculations. However, they are prone to damage due to accidents at sea or wear and tear over time. To learn more, check out Bulkheads Construction Charleston SC.
The bulkheads of ships are a vital component that provides the structural rigidity for the entire vessel against forces in both transversal and longitudinal directions. They are also designed to subdivide the ship into a number of watertight compartments. They also act as a safety feature to protect the passengers and crew from potential danger at sea. They are positioned in the ship based on flood-able length calculations and are also used to define the boundaries of fuel, water and other tank spaces.
There are many types of bulkheads that can be found in ships. Some are made from metal and others are constructed from wood. The steel ones are normally welded together and insulated with materials that prevent the spread of fire for a specific amount of time. These are known as Class A bulkheads.
Another type of bulkhead is a collision bulkhead. This is used to prevent the full-on collision of the ship with other vessels or segments of land. They are shaped with alternative grooves and ridges to prevent the impact from spreading in a straight line. The stiffeners of these bulkheads are usually connected to the plating at various intersection points and are reinforced with internal structures such as longitudinal ribs and shear webs.
In the case of waterfront property, bulkheads serve as a boundary between the natural and reclaimed shorelines. They also function as a separation wall between marina basins and the surrounding water. These walls can be constructed from a variety of materials, including concrete, galvanized steel and even timber. They are often anchored to the ground using soldier beams and lagging or can be freestanding.
The front wall of a bulkhead can be built from any material as long as it is sufficiently strong to resist the lateral pressure. In the case of granular soils, it is recommended to use a screening platform. This reduces the lateral pressure on the front wall and allows for the use of lighter sections of sheet piling.
Unlike a seawall, which is designed to limit erosion and frontline waves, a bulkhead is more of a shoreline stabilization structure. It retains surcharge loads and limits soil movement. However, it does not protect the waterfront property from storm surges and wave overtopping. It is important to hire a marine construction company to design these structures for the local conditions in order to maximize their strength and performance.
Materials
Bulkheads can be constructed from a variety of materials. Some types are made from steel, vinyl sheet piles, timber piling and concrete, all of which can provide a strong and sturdy structure to hold back water and protect shoreline areas. Bulkheads are typically stationed parallel to and close to high water marks in land areas to prevent coastal erosion of beach and shoreline areas. They also prevent the movement of soil in ocean currents and waves and help to create a distinct separation between land and water.
The biggest difference between a bulkhead and a retaining wall is that a retaining wall has two sides and is designed to hold soil while a bulkhead is one side, is built to hold back water and helps to prevent the movement of soil from a shoreline. A bulkhead is also usually a little taller than a seawall, but it can be shorter depending on its location and purpose.
There are three classifications of bulkheads according to SOLAS (International Maritime Safety Organization). Class A is the incombustible bulkhead and is used to keep fire from spreading to unaffected areas. Class B is a non-incombustible bulkhead and can be insulated to prevent the passage of flame, smoke or heat for up to 60 minutes following a fire. Class C bulkheads are not required to meet SOLAS fire resistance requirements and can be any material that is non-combustible.
When choosing the right bulkhead materials for your project it is important to consult a professional engineer to ensure that you are making the most efficient choice for your specific needs. There are many factors to consider, including the desired length and height of the bulkhead, the intended use, the climate and weather conditions where it will be installed, as well as local ordinances and zoning restrictions.
The foundation for any bulkhead is the pilings or sheeting that are anchored in the soil to hold back the water and prevent erosion of shoreline areas. Poles, or deadmen are then driven or buried and connected to the bulkhead with tie rods. Often the bottom of the wall is lined with rocks and wales are added to add protection to the area.
Installation
Bulkheads are important for the safety of both people and animals, as well as protecting a shoreline against erosion. They can be constructed of wood, stone, concrete or other materials and range in size from small sandstone cribs to massive concrete seawalls. Their construction, maintenance and inspection require a high level of skill and knowledge. They may be anchored or free-standing. Some are designed to contain loads, such as roadways, while others have a protective function, such as beach dunes, groins or jetties.
In a marine setting, bulkheads are used to control flooding in a compartment and are normally installed between a ship’s deck and the waterline. The number and position of a vessel’s bulkheads is determined by the classification society, usually based on the length of the ship and its function. Collision bulkheads are the forward most bulkheads, and are designed to withstand the collision of other ships or segments of land. They are located so that the collision does not flood other areas of the ship, and also so that the ship is not towed backward by the bow due to excessive trim caused by flooding of the forward compartments.
The collision bulkhead is designed to withstand the maximum forces that would be generated during a collision and must be built to the highest standards, including a special design for the flange and gasket material. To ensure the integrity of the collision bulkhead during a collision, the flange material is welded to the shell, and the gasket is sealed by a bead of silicone sealant. The flange and gasket material must be clean, dry and free of any particles or dirt that could cause a leak.
When installing a PVC bulkhead fitting, always install the gasket on the flange side and place the nut over the gasket. Use a bead of silicone or lap sealant to keep the liner from bunching up, and make sure the nut is tightened enough to crush the gasket against the flange. When installing a threaded bulkhead, always clean the excess flashing off both the flange and threads and use a thread lubricant that is safe for marine applications.
Inspection
Bulkheads, like seawalls, are often inspected on a regular basis to determine their condition. These structures are critical to coastal properties because they prevent erosion from pounding surf and keep land from collapsing into the water. When a bulkhead or seawall has been damaged, it can have significant impacts on the structure and the surrounding property. Performing a bulkhead inspection is important to identify damage before it becomes a major problem. If you are thinking about purchasing waterfront property, it is a good idea to have the bulkhead or seawall inspected before making the purchase. This can uncover hidden hurricane damage that the current owners may not be aware of.
In general, bulkheads are designed to be waterproof and structurally sound. However, their performance is dependent on the materials they are made of. Different materials will deteriorate differently in the marine environment. Proper inspection and maintenance can extend the life of a bulkhead. Bulkheads that are built of pile/panel or sheet piling may need to be reinforced on a periodic basis in order to maintain their strength. Bulkheads that are constructed of corrugated metal panels should be inspected for signs of corrosion on a regular basis as well.
Watertight bulkheads are subjected to pressure tests after installation in order to verify their structural integrity. The test is normally done by filling a compartment with water to the desired level and ensuring there are no leakages. Bulkheads that form tank boundaries are typically hose tested from the forepeak and aft peak. Other types of bulkheads are air-pressurized to check for any possible leakage.
Aside from subdividing the hull of a vessel for storage and habitability purposes, watertight bulkheads can also be used to create fire-resistant compartments. These compartments help to contain fires and prevent them from spreading to the rest of the ship, thus limiting potential catastrophic damages. For this reason, all passenger vessels are required to have a certain number of fire-resistant bulkheads. On aircraft, bulkheads are also used to physically divide cabins for passengers and cargo. In addition, they are inserted into the aircraft to protect electrical cables from fire.
