Crane barges are specialized vessels that have cranes mounted on their deck for loading and unloading purposes. While other types of cranes are used for construction and more purposes, crane barges are limited in terms of usage and are mostly used in industries like transportation and heavy machinery moving from one shore to another. They are not used at construction sites. So, let’s dig deeper and try to understand how crane barges differ from other types of cranes out there.
Types And Construction Of Crane Barges
As mentioned previously, crane barges have an open deck with mounted cranes that are designed to load, shift and unload extremely heavy weights. However, crane barges come in several different types and configurations as well.
For instance, simple cranes are flat, full-form barges with one or a maximum of two lifting cranes installed. Furthermore, these cranes are either rotated or fixed and can also lift up to 1000 to 2000 tons if the configurations are both heavier and larger.
Another popular type is Derrick cranes. These cranes are capable of lifting a batch of extremely heavy loads at the same time as they operate on a fully rotating crane system. While smaller Derrick cranes have a lifting capacity of 50 to 500 tons, larger Derrick cranes can lift somewhere around 1000 to 1500 tons.
However, modern Derrick cranes have become so advanced that they are able to lift loads weighing more than 10,000 tons. A common problem experienced by the this type is the tendency of listing. As a result, a counterweight is usually placed during partial or no-load conditions to keep the barge in balance.
Then, comes the Sheerlegs crane. These cranes are identified by their A-Frame made using truss-like or tubular structural members. These are capable of lifting extremely heavy loads as well. However, they lack the ability to rotate.
In addition to that, large sheerleg cranes are self-propelled, while the smaller ones need to be manually towed from one place to another.
And finally, comes the Heavy Lift Crane Barges. These cranes are used for heavy loads for offshore installations and construction. These cranes are characterized by mostly twin-hull configurations, while the lifting device or crane rests on both hulls in a symmetrical position.
How Are Crane Barges Designed?
Now that we have discussed the most popular type of crane barges, it is time to shift our attention toward the design philosophy behind crane barges. When it comes to designing crane barges, the first factor designers keep in mind is strength and integrity. Since the crane is being designed to lift and shift heavy loads, it should be able to do so without breaking down or threatening the people on the ground.
Next, the lifting system or carnage is more or less the same as any traditional crane. The lifting system or carnage is for handling the lifting mechanism. The designers need to ensure that the lifting mechanism is able to safely lift loads within the maximum limits set.
Once the details of the carnage along with the expected loads are decided, it now comes to designing the hull structure of the barge. The hull is constructed using suitable steel materials and reinforced to offer strength.
The most important aspect here is the deck plating. Since most of the weight will be absorbed by the deck, the deck plating needs to be thick and able to withstand extreme weight.
In addition to that, floatation and stability are also great causes for concern. The reason is that lifting at sea is very different from lifting on land and if the vessel is to lift weights that exceed its limit, it can run into a problem. That said, the designers ensure the hull is in a state of equilibrium during the lifting operation in both the longitudinal and transverse directions.
To achieve this state of equilibrium, the designers consider two important factors i.e. placement of the lifting system and the stability of the hull. This helps the vessel load and unload weights without having to trip over.
In the end, crane barges play an important role in installations and constructions at sea and which is why they are used around the world. So, if you are out there looking for one, make sure that you keep the features and types mentioned above in mind to when going to cranes services VA to make the right decision.