What Are Cranes Used For?
Cranes are used to lift, lower and move heavy loads such as building materials, goods and machinery. Due to their versatility, they can be used for a wide variety of applications including construction, manufacturing, warehousing, shipbuilding and freight transfer. A crane consists of a number of key parts including:
- Boom – The long arm that bears most of the weight and is used to lift and lower materials. Booms can be fixed or telescopic (they can elongate as needed).
- Jib – A latticed structure attached to the end of the boom to prevent the load from banging into the boom while it is being moved.
- Rotex Gear – The mechanism that allows the cab and boom to rotate.
- Outriggers – Balancing legs that distribute the load of the crane in order to make it more stable.
- Counterweight – Weights that are attached to the opposite side of the crane from the boom in order to counteract the weight from the load and prevent the crane from tipping over.
- Cable – The steel rope which lifts the material.
- Hook – Attached to the load in order to pick it up.
A mobile crane is any type of crane that is self-propelled, meaning it can be driven around the lifting site and doesn’t need to be set up in a static position. Some of the key benefits of using mobile cranes include their ability to navigate tight spaces, lifting capacity, relatively low cost and ease of transport and set-up.
A crawler crane is a type of mobile crane, which is mounted on an undercarriage with tracks as opposed to wheels. This provides stability and mobility over a range of terrains. They can move easily over challenging terrain and within compact areas. This makes them very useful for lifting jobs on construction sites. They also require minimal set-up and can travel with a load. The main disadvantage of crawler cranes is that their heavyweight and large crawler cranes must be dissembled and transported, which can be costly and time-consuming.
Rough Terrain Cranes
Rough-terrain cranes are specially designed for use on uneven surface sites and are typically used on off-road job sites. The crane is mounted on an undercarriage with four oversized tires and equipped with four-wheel drive and multiple steering modes. This allows them to safely navigate complex terrain including slopes, uneven surfaces and large obstacles while carrying a load. The main benefit of rough-terrain cranes is their superior traction and stability, which allows them to navigate difficult to access and uneven areas. They also offer a great lifting capacity for their compact size, making them a good option for any site where space is an issue. The main disadvantage of rough terrain cranes is that they cannot be driven on public roads and must be transported between jobs.
An all-terrain crane has all the benefits of a rough-terrain crane, but with the added bonus of being able to drive on public roads. This makes them an ultra-versatile option for any construction job, particularly projects with multiple sites. They can be used to lift and transport loads between sites and can reach much higher speeds than rough-terrain cranes. They can also lift heavier loads than many other on-road cranes such as Franna and city cranes. The main disadvantage of all-terrain cranes is that they are often heavier than rough terrain cranes.
A truck crane is essentially a truck that has a crane attached either to the rear or just behind the cab, which is used to load and unload items from the truck’s deck. They provide a convenient solution for transporting small quantities of heavy items without the need for a larger crane. Truck cranes are often used on construction sites for delivering and transporting materials. The main disadvantages of truck cranes are that they are not suitable for unstable terrain and have a relatively low lifting capacity compared to other mobile cranes.
A Franna crane is quite similar to a truck crane in terms of its design however, the key difference is that the boom of the Franna crane is inbuilt into the vehicle chassis. Franna cranes are able to lift and transport heavy loads around worksites and on public roads. They are also known for their ability to be set up in tight spaces quickly and used to pick and carry materials from different areas. The main disadvantage of Franna cranes is that they can only be used to pick and carry items within a small radius because they have no stabilising legs.
Static cranes are permanent or semi-permanent structures that are fixed to the ground or building. They must be transported to the lifting site by truck and assembled on-site, often by smaller mobile cranes. Once they are assembled, they remain in the same location until they are packed down and removed from the site. The main advantage of most static cranes is their ability to lift very heavy loads and reach very high heights. There are a number of different types of static cranes each with its own purpose.
An overhead crane is designed to move heavy materials horizontally from one location to another. It consists of bridge girders, ends trucks, a trolley with a hoisting mechanism and an operator cab, which allows it to lift heavy items and transport them through the overhead space. The benefits of overhead cranes include improved safety (fewer accidents), freeing up floor space and ease of lifting. The main disadvantage is that compared to alternative lifting methods (forklift), an overhead crane is significantly more costly.
A tower crane consists of a vertical tower (for height) and an outstretched jib (for lifting and moving items). The tower crane has the largest lifting and loading capacity of any type of crane and can also reach the highest heights while maintaining stability. This makes them ideal for use in the construction industry or projects that have lifting height requirements. The disadvantages of tower cranes include the cost of set-up, installation and maintenance.
Level Luffing Cranes
A level-luffing crane is a static crane that is designed so that the crane hook stays at a constant level when lifting. The raising and lowering of the boom move the jib arm towards or away from the base of the crane. The clear advantage of a level luffing crane is its ability to move items horizontally through space while remaining at a fixed level relative to the ground. This allows it to move loads near ground level with maximum precision and care and makes it ideal for freight loading and construction projects. The main disadvantage of level luffing cranes is the time it takes them to lift and move objects.
Bulk Handling Cranes
Bulk handling cranes are used to grab and move large and bulky materials that cannot be moved by a crane with a standard hook design. Its key distinguishing feature is that it has a two-piece hinged bucket known as a shell grab or shell bucket. They are commonly used to lift materials like coal or mineral ore or for other applications such as dredging or stevedoring. The main disadvantage of bulk handling cranes is that they are not appropriate for lifting all types of loads (e.g. long, thin loads such as beams or building materials).
Stacker cranes are a type of fixed overhead crane system that is used to lift up and place items into stacks. They use a mast suspended from a bridge trolley, with a fork or gripper attached to the end to pick up items. These cranes are predominantly used in commercial and industrial warehouses for storing and retrieving stock. While stacker cranes have the benefit of being completely automated, they are also very expensive to install and not suitable for moving smaller items.
Cranes fulfil an important role in a wide range of industries. While static cranes are great for performing very heavy and extremely high lifting tasks, mobile cranes offer more versatility and are much more affordable. If you’re looking to hire a mobile crane in Sydney, contact St George cranes today.