Your favorite high-rise building wouldn’t exist if it weren’t for construction cranes. Imagine what your city’s skyline would be missing if these powerful industry staples didn’t exist. The whole world would be much lower to the ground. That must be why these machines have earned a reputation as the backbone of the construction world.
You’re probably no stranger to construction cranes. Today, lifting gear is a huge part of most urban landscapes. But have you ever wondered how they’re able to move such heavy materials around? If so, you’ve come to the right place. Read on to learn more about these impressive machines.
Construction Crane History
The use of cranes in construction dates all the way back to ancient Greece. Historians believe that crane-like machines first came into use somewhere around the year 700 B.C.E. This millennia-old invention played a massive role in the erection of most architectural wonders throughout human history.
Another group of renowned crane users in the early days of civilization were the Egyptians. Although their remarkable building precision still has some experts scratching their heads, one thing’s certain: they used cranes. Their version consisted of wooden beams attached to a rotating base and a cylindrical drum. This contraption also had a rope and pulley system that obtained the necessary tension with a bit of help from animal strength.
The Middle Ages fueled the evolution of construction cranes. Cathedrals and other monumental stone buildings called for more robust machinery. Those in charge of building these architectural gems used jibs to make their work easier. With the ability to pivot, these unparalleled tools provided the machines with a more comprehensive motion range.
During the industrial revolution, steam-powered engines gave humans and animals a much-needed break. Later on, with the introduction of the electric motor, cranes became more powerful than ever before. The pinnacle of crane technology came when steel substituted wood in crane manufacturing. This significant change permitted an increased lifting capacity that ancient Greeks could only dream of.
Today, cranes come in all shapes and sizes. There are static and mobile alternatives suitable for a myriad of purposes at a construction site. It’s hard to imagine how this essential invention could ever get any better. However, construction crane manufacturers might still surprise us in the future.
Manufacturing Construction Cranes
Crane manufacturing requires more skill than you might think. These weightlifting champions are physics and engineering marvels. They can endure remarkably high pressures on a regular basis, able to handle all the heavy lifting while balancing their own weight at the same time.
The materials involved in construction crane manufacturing also influence each machine’s lifting capacity. Most crane producers use high-strength low alloy steel (HSLA) to ensure durability and longevity. HSLA steel is lightweight and uses a vast amount of hardening and corrosion-resistant agents in its manufacture. Such qualities allow for heavy-duty cranes to be virtually indestructible and energy-efficient.
To build a crane, manufacturers follow a lengthy process to ensure quality and functionality. They create each piece separately using precision cutting tools, heavy presses, and rollers. Once each steel sheet is good to go, the assembly can begin. Putting all of the pieces together requires bolting and welding. Once the process is complete, the crane is put through a barrage of safety tests.
Anatomy of a Construction Crane
There are many types of construction cranes on the market. Some of them might have parts that others don’t. That said, here’s a quick rundown of the essential pieces in a construction crane:
- Concrete foundation: Allows the operator to anchor the crane to the ground, providing extra support to the entire machine
- Crane tower: Also known as the mast — consists of a steel lattice-like pillar attached to the base
- Turntable: Gives the crane a wider motion range and allows for full rotation
- Operator’s cab: The compartment from which the machinist can control the crane
- Jib: An arm that lies horizontally in front of the cab
- Trolley and hook block: Allow the operator to move materials back and forth along the crane’s arm
- Counter jib and counterweights: Stabilizing parts that sit behind the cab and stop the crane from giving in to the lifted weight
- Main winch and motors: Let the operator manipulate the long cable, allowing them to raise and lower it when needed
- Tower peak or apex: The highest section of the crane, providing an attachment point for the support pendants
Lifting Power of a Construction Crane
All cranes construction workers operate follow the same principles. Each lift they perform involves a series of basic moves that allows them to displace all sorts of materials at a construction site. Construction cranes are not almighty, though. Depending on their size, they can only lift so much weight before tipping over, bending, or breaking.
These numbers may vary, as they depend on different factors. One constant, however, is that the amount of weight a construction crane can safely lift is directly proportional to the mast’s distance to the load. Put simply, the closer the load is to the tower, the more weight the crane will carry. Most cranes have two limit switches that indicate the maximum load and the load movement to prevent overloading.
Control Systems for Cranes in Construction
A crane in construction is much more than meets the eye. Most varieties have a sophisticated control system that assists in their operation. There are three main types of control systems for heavy-duty lifting gear.
- Sway control system: To reduce the strain that swaying motions cause on the electrical and mechanical parts, this system reduces the load oscillations. The SCS is great for keeping high maintenance costs at bay.
- Intuitive boom operating system: This system gives the operator the crane’s stats. An IBO system increases productivity by providing reliable insights into the crane’s overall performance, allowing the contractors to stay on schedule.
- Load monitor indicator: This control system helps the operator with the math behind the crane’s functionality. It provides relevant calculations regarding weight and other data while accurately tracking the crane’s stability in the process.
Having a comprehensive understanding of all three types of systems makes a crane operator’s job much easier. It also contributes to a safe environment on the construction site. That’s why having only qualified machinists handling all heavy machinery is a must.
How to Operate a Construction Crane
Operating cranes for construction for the first time might seem daunting — the weight of the whole project rests on the crane’s jibs and beams — but experienced operators make it seem so easy. They spend their days at the construction site sitting inside the cab and pushing buttons. However, their work is a lot more complex than it looks.
Crane operators begin their day by performing the proper safety checks. If they don’t, the consequences could be fatal. Before getting to the best part of the work, operators must:
Ensure They’re Using the Correct Crane for the Job
A crane for construction is not a one-size-fits-all lifting instrument. The characteristics it must have depend entirely on the project the crane is needed for. It’s not uncommon to see several different crane styles at the same construction site. While their primary purpose is to help move heavy materials and pieces of equipment, they can serve many more. These are the most commonly used crane types:
This widespread type of crane is mounted on a mobile platform — hence the name. It offers several advantages on a construction site, allowing for easy transportation and requiring virtually no setup effort. A mobile crane features a hinged boom that can be raised using cables or hydraulic cylinders.
This style offers a versatile alternative to much heavier — and costlier — construction cranes. It comes mounted on the rear side of a heavy-duty rubber-tire vehicle, which enables mobility. Truck-mounted cranes are incredibly beneficial when dealing with narrow spaces larger cranes can’t have easy access to.
This type of crane is the one dotting your city’s skyline. It features a vertical mast and an outstretched arm, remarkably useful when constructing tall buildings. In a motion known as slewing, a tower crane can rotate a full 360 degrees. This modern-age balance crane comes in three different styles: hammerhead, luffing, and self-erecting
Rough Terrain Crane
Built atop a truck-style body with four large rubber tires, a rough terrain crane can climb uneven ground where traction is challenging. This single-engined machine is compact and can easily access narrow spaces. It uses the same motor to power both the crane and the undercarriage. This crane type uses a boom and a hoist to lift heavy loads higher than some other mobile options can manage.
A crawler crane consists of an upper carriage mounted on a crawler type undercarriage. The upper deck and attachments rotate 360º. A crawler crane features either a box or a lattice type straight boom and it may be equipped with an optional jib (boom extension). The unique undercarriage makes crawlers an ideal crane to do the extra heavy lifting on a construction site.
Perform a Pre-Start Check
Guaranteeing a crane’s optimal functioning is a crucial step that should never be overlooked. The operator must always check oil levels, seat belts, air reservoirs, pressure gauges, fuel levels, and battery performance before starting the engine.
For suitable communication with the construction team, the turn signals, horn, suspension, and control systems should be working perfectly. Lastly, the machinist should always test the anti-two-blocking system, rated-capacity limiter, and outriggers.
Understand Construction Site Protocols
Crane operators are responsible for following specific rules to guarantee safety. They can ensure a safe lift by communicating via radio and paying attention to hand signals from other staff members to avoid potential hazards. Keeping track of all information provided by the control systems is vital.
A machinist should have sound knowledge of how to use the joysticks and other controls in the cab to perform all maneuvers correctly. Monitoring the load and wind speeds is imperative. The operator must also never leave a loaded crane unattended — no exceptions.
By taking suitable precautions, the operator can significantly reduce the risk of accidents at the construction site. Once through with all pre-start checkups, the machinist can start the crane’s engine and carry out their daily tasks.
Construction cranes are incredibly powerful pieces of equipment with the ability to make the impossible possible. They allow construction workers across the globe to lift and transport the heavy loads needed to transform our cities’ skylines into modern metropolises.
Having more knowledge about jibs and winches certainly allows us to look at these lifting powerhouses from a different perspective. Perhaps reading this article won’t prepare you to successfully operate a tower crane, but at least you’ll get to show off your newfound knowledge.
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