As the metaphorical grandfather of all construction equipment, cranes have a long history of simplifying heavy lifting tasks, and have revolutionised our ability to construct buildings of all shapes and sizes. If you’re looking to hire a crane for a construction project and aren’t sure where to get started, or if you’re even just curious to know more about how cranes actually work, we’ve answered some of the questions we get most frequently asked about this essential type of machinery below.
What are the Basic Components of a Crane?
While there are many different types of crane (as we’ll discuss later on), there are a few basic components that are typically universal. The main parts that you’ll find on almost every crane include:
● Jib
● Boom
● Rotex gear
● Outriggers
● Counterweights
● Reinforced steel cable
● Hook
The Boom
The boom is perhaps the most instantly recognisable part of a crane. As the long arm you find on all types of cranes, the boom’s main purpose is to lift, transport and position heavy materials. They bear the majority of the load and are responsible for determining the reach of the crane. This arm can either be telescopic or fixed, and takes on a variety of roles depending on the type of crane and how it’s built. They are able to work without the help of the jib, and are sometimes even the main component of the crane.
The Jib
The jib is the long, lattice-type structure you’ll find attached to the end of the boom. Using this lattice build helps to reduce the weight it adds to the front of the boom. The jib has one primary purpose: to help keep the objects being lifted clear of the main support so that they don’t hit it during transport. Jibs are fixed in place and cannot be extended or retracted like booms can. They are also sometimes surplus to requirement, and are often looked at as an additional feature that can be used when necessary.
Rotex Gear
The rotex gear is the mechanism found below the cab of the crane. It allows the cab and boom to rotate - the simple motion of which is invaluable to the machinery’s operation.
Counterweights
As the name suggests, counterweights are designed to counter the weight on the front of the crane when lifting extremely heavy materials to increase stability and prevent tipping. Many cranes have adjustable counterweights so that they can fit the specific requirements of a job.
Outriggers
As one of the most important factors in ensuring crane safety, the outriggers work to provide additional support by distributing the load being transported over a large enough area that the crane doesn’t become unstable. All outriggers are required to meet or exceed the weight requirements of a crane or job.
Reinforced Steel Cable
In order for cranes to actually lift and move objects, a line or rope is required to do the actual lifting. In the case of modern cranes, this line is a reinforced steel cable. First used as mining hoists in the 1830s, today the wires used are highly reinforced, resistant to corrosion, force and motion-absorbent and have extremely high breaking points.
The Hook
Finally, the crane requires something to connect the materials to it, the most typical way of which is a hook. The lifting hook on a crane is generally equipped with a safety latch to prevent loads from slipping off the hook during transit. Hooks are usually made of steel or wrought iron, and in heavy-duty applications the hook will be heat-treated and forged to ensure maximum strength.
How Have Cranes Evolved Throughout Time?
Our most concrete historical evidence suggests that cranes date back as far as 500 B.C. in Ancient Greece. Based on archaeological findings of lewis tongs and lifting irons in stones, by 515 B.C. crane mechanisms were being used to construct Greek temples. However, some historians have suggested that cranes were in use even before this time, perhaps even as early as 650-700 B.C.
Regardless of the timeframe, it’s clear that crane technology originated way earlier that you might have initially thought. Unlike many other ancient civilizations, who used manual labour or ramps to shift materials and equipment, the use of a handy mechanism to simplify the task speaks to the innovative minds of the Greeks. After all, they were also responsible for the alarm clock, geometry, lighthouses, democracy and even central heating!
What are the Most Popular Types of Crane?
While there are countless functions, specifications and weight capacity for cranes, here are some of the most popular types that you’ll find used in the construction industry.
Mobile Cranes
A mobile crane is one of the most basic types of crane you’ll see used in construction. Fitted with a steel truss or telescopic boom that’s mounted to a platform, this type of crane can be moved to, from and around a site as needed - hence its name. The platform in question can be either wheeled, fitted on a rail or to a truck if needed.
Mobile cranes are typically used for general construction work and roofing jobs. They are powerful enough to move materials with ease while being less of a permanent fixture than a tower crane, making them much more convenient.
Tower Crane
When you think of cranes, a tower crane is often what your mind will conjure up. A form of balance crane, tower cranes are fixed to the ground and used to move heavy loads over a longer distance. They are most often used when constructing tall buildings, which is why they are such a common sight across skylines in areas with lots of new developments cropping up.
Because of their size and the fact that they are often used on more lengthy construction jobs, tower cranes are a more permanent fixture. A concrete foundation must be built about a month before the crane even gets erected, as the foundation needs time to settle and become strong enough to take its weight.
Rough Terrain Cranes
With an undercarriage that resembles that of a monster truck, rough terrain cranes are fitted with four giant rubber wheels to help the crane traverse difficult surfaces. Since they are portable, the undercarriage has vertical and horizontal extending outriggers to help provide stability and support during operation.
Naturally, rough terrain cranes are used for any project that requires material movement over uneven ground or off-road type terrain. Interestingly, they are single-engine machines, meaning that the same engine that powers the wheels also operates the crane. Because of this, they tend to be much more compact than other types of crane.
All-Terrain Cranes
Although similar to rough terrain cranes, all-terrain cranes can also be driven on the road. This means that they can conveniently be moved from one construction site to another, in addition to being able to traverse most ground types.
These cranes are mounted on trucks with anywhere from 6 to 18 wheels and can lift substantially heavier weights than rough terrain types. In order to achieve this however, sometimes additional measures have to be taken on site, including installing outriggers and boom weights.
Compact Cranes
Compact cranes, otherwise known as spider or telescopic cranes, are fitted with a boom that features a hydraulic cylinder, allowing it to change length. Although they are considered to be a fixed type of crane, many compact cranes are mounted on a truck to transport to and from different worksites.
Due to the unique nature of the boom being able to collapse and compact itself, this type of crane is highly adaptable for a variety of situations, including short-term construction jobs or fitting into spots where space is limited.
Where Can I Hire a Crane?
Virtually all construction jobs require the transportation of heavy materials, so having a crane to hand is a huge plus. Fortunately however, you’ll be pleased to know that you don’t have to go to the trouble of purchasing one outright, as there are a number of professional plant rental services that will provide you with the necessary machinery at a fraction of the cost. With this in mind, if your next project is based in Devon or Cornwall, Macsalvors Plant Hire Ltd should be your first choice when it comes to hiring a crane.
Whether you’re looking for Hiab truck hire or low-loader rentals, the expert team at Macsalvors can help you find the right lifting equipment to meet your needs. With a wide variety of crane hire services on offer, we’ll help you see your project through to completion. To get started with the hiring process, please get in touch with us today.
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