Floating cranes are a remarkable feat of engineering that play a crucial role in heavy lifting and maritime operations. They can lift enormous loads while remaining buoyant, a feature that is often baffling to the observer. In this blog, we will take a look at the floating crane and attempt to understand how this remarkable bit of machinery operates.
What is a Floating Crane?
They’re also known as crane vessels or crane ships, and are specialised watercraft equipped with powerful cranes designed for heavy lifting in marine environments. Yes, this includes lifting 1000-tonne objects in choppy waters. Unlike conventional land-based cranes, floating cranes are self-propelled vessels with a large deck area and a sophisticated ballast system that enables them to operate in water bodies such as harbours, rivers, and oceans. A ballast is a tank in the hull of a ship that allows water to flow in and out to maintain stability and take pressure off the hull. We’ll examine this more in-depth later.
Key Components and Working Principles:
Crane Boom:
At the heart of a floating crane lies the crane boom, a massive, extendable structure that provides the necessary reach and lifting capacity. Typically made of high-strength steel, the boom is hinged to the ship’s deck and can be rotated in various directions to facilitate precise positioning of the load. We often see the crane boom being used to lift cargo from vessels, or construct ports and bridges,
Turret:
Floating cranes incorporate a turret, a rotating platform located at the centre of the vessel. The turret supports the boom and allows it to rotate freely, ensuring maximum flexibility during lifting operations. This feature enables the crane to access a wide range of angles and positions, enhancing its adaptability in different working scenarios.
Winches and Cables:
To lift and manoeuvre heavy loads, floating cranes utilise powerful winches and cables. These winches are located on the deck and are connected to the boom and lifting hooks. By winding or unwinding the cables, the winches can control the movement and elevation of the load with exceptional precision and safety.
Ballast System:
One of the most crucial aspects of floating crane operation is its ballast system. Floating cranes have ballast tanks strategically positioned throughout the vessel. By filling or emptying these tanks with water, the crane can adjust its buoyancy and stability. This capability is vital for maintaining equilibrium during lifting operations, compensating for changes in load weight, and counterbalancing external forces such as wind and waves. This is how they remain stable in chop and adverse weather conditions.
How Do They Operate?
The working process involves the arrival and positioning of the ship, after the floating crane navigates to the desired location and anchors itself using mooring lines to maintain stability. Then, the ballast tanks are adjusted to achieve desired buoyancy. The crane boom is then extended, and the loan is secured using winches and cables. The crane operator carefully manoeuvres the load through rotating the boom. Finally, the load is gently lowered into its intended destination with utmost precision. The process is reversed by carefully releasing the tension in the cables, allowing the load to settle on the target surface.
Floating cranes are marvels of engineering that have revolutionised heavy lifting operations in marine environments. Through their remarkable components, such as the crane boom, turret, winches, cables, and ballast system, these versatile vessels are capable of handling immense loads with exceptional accuracy and stability.
