The marine industry is wide-ranging and constantly evolving. Just cruise by any port city and you’ll be awed by the massive infrastructure on display, all of which allows for the efficient, speedy transport of virtually every type of product and material. Go further out to sea, and you’ll find offshore drilling sites and critical military and defense outposts and vessels. To put it simply, the marine sector powers a huge range of applications and keeps modern industry running smoothly.
While a variety of material handling equipment is used in the marine sector, cranes, in particular, are especially important. Marine cranes can vary both in design and function to meet specific application needs while ensuring optimal performance and safety.
Common Marine Crane Applications
Marine cranes are used to facilitate heavy lifting, moving tons of material and cargo from one to place another. Whether dealing with ship-to-shore work or erecting oil platforms offshore, cranes are critical machines in all types of marine jobs. Common marine crane applications include:
- Submerging or recovering equipment from the ocean; transporting equipment on the seabed
- Moving equipment and materials around the deck
- Transferring equipment and materials to and from other platforms and vessels
The engineering expertise required to construct these behemoths — some of which are several stories high — while ensuring safe, efficient operations is remarkable.
But what options are available, and how can users be sure they’re employing the right type of crane for the particular marine application at hand?
Types of Marine Cranes
Gantry Marine Cranes
Gantry cranes are used to move cargo on and off ships dockside. These cranes are several stories tall and are the largest type of crane used in loading/offloading shipping applications. These cranes are unique in that the operator’s cabin is on the top end of the crane, suspended from the trolley. The cabin is 80% transparent, providing operators with a clear view of loading and unloading operations. This approach contrasts with the design of conventional models, where the crane operator remains at the base of the equipment.
Overhead cranes also make use of a spreader, rather than a hook. The spreaders move out in four directions, latching onto a container ship’s corner castings and lifting the cargo from there.
Today’s sophisticated overhead cranes can lift as many as four cargo containers at a time, speeding up the process for vessel unloading. However, the tradeoff for the additional lift capacity is that loading cargo onto the vessel requires more care, as the weight of the cargo and its addition to the deck or cargo hold can create dangerous movement or listing on the ship.
Overhead Jib Cranes
Jib cranes, meanwhile, use a horizontal piece — a jib or boom — that supports a moveable hoist. These pieces are permanently fixed to a stable surface, such as a wall or a floor pillar. In the marine industry, jib cranes are often used in offshore drilling industries. In addition to marine applications, jib cranes are commonly used in construction sites on the tops of buildings, lifting materials to different floors within the structure. Various types of jib cranes are available to meet specific application needs and headroom requirements.
In addition to these common crane types, monorail and based-mounted hoists, gantry cranes, and below-the-hook devices are often used in marine environments.
Key Factors to Consider When Selecting a Marine Crane
Because the marine industry is inherently unpredictable, it’s crucial to carefully consider all variables before selecting a specific type of crane. The behavior of the ocean itself, for instance, can have a huge impact on crane functioning and material handling capabilities. Ocean conditions are especially relevant when constructing offshore drilling platforms, as there are a number of volatile factors to contend with, such as weather and bottom suction, which result in an extremely unstable environment.
And when dealing with dockside operations, it’s important to consider the impact each piece of cargo will have on a ship’s listing behavior. Great care and experience are needed to operate these cranes safely and efficiently while also minding the waters.
To ensure smooth, safe operations in the marine industry, it’s critical to partner with a crane supplier who understands the unique needs of the sector and will work with you to select a model well-suited to your specific needs. Whether working in shipping or offshore sectors, take the time to weigh your options and carefully consider all application-specific requirements.