A Tower crane is a special crane that gets attached to a tall tower with a massive horizontal extension. Its main purpose is to achieve high lifting capacity for large-scale construction and manufacturing.
With simple, but incredibly effective design, construction workers use tower cranes to generate incredible work output. The first tower cranes have directly contributed to building the first skyscrapers in the world. With the help of levers and pedals, a crane operator controls the hoisting system and the jib.
For such gigantic machines, tower cranes are very flexible, and can adapt to many situations due to simple but effective operating mechanisms. Because it is such a formidable object, full of structural components and electrical equipment, a tower crane is one of the biggest and most expensive heavy equipment machines.
The best tower cranes can cost as much as 200,000 to 400,000 EUR. With such high price tags, experienced construction companies hire a competent person to ensure that all workers strictly adhere to the manufacturer’s instructions before using the infamous machine.
In this comprehensive guide, you will learn about the importance of maintenance requirements and procedures that keep a tower crane in top condition. A tower crane must receive particular attention and maintenance to preserve its structural integrity and prevent any physical damage to nearby objects. Keep reading to learn about key components of a tower crane, and how to identify visual signs of equipment damage
How does a tower crane work?
Tower cranes are extremely powerful helpers for big projects in the construction industry. Unlike many other heavy equipment machines, a tower crane is one of the hardest machines to use. Most employees need years of proper training and experience to meet the expected operator qualifications.
Most tower cranes are powered by electric engines that drive hydraulic pumps, but there are cheaper options that use diesel. The operator’s control panel opens the valves on command to transform the incoming pressurised fluid into mechanical force in the hydraulic cylinders. If the station is working properly, the exchanged power is used to control the jib for lifting heavy loads.
Before focusing on repairs, structure damages, and other essential maintenance procedures, one must understand the necessity of main tower crane components and what factors contribute to their damages.
Tower crane components
Although massive, tower cranes come in many different shapes and sizes, and there is no better tool for learning about a specific machine than the manufacturer’s manual. Still, with a brief overview of the main parts, you can better understand the moving parts, as well as identify unusual cracks and damages and inform equipment managers about the need for repairs.
A mast is a big metal construction upon which the tower crane stands. It is responsible for the support and structural integrity of the machine and houses the operator’s cabin on its top. The mast is often attached to concrete or other materials that provide extra stability.
The jib is the horizontal extension that latches onto the top of the mast. It is the section responsible for heavy lifting on the construction site and is operated by a skilled worker.
A counterweight is just a simple weight that hangs on the opposite side of the jib. Without it, the entire tower would topple over or become extremely unstable when lifting heavy loads.
A trolley and a hook block
A trolley is an attachment that moves parallel to the jib by latching onto its underside. The work performed by a trolley is also generated through pressurisation in the hydraulic system. Operators control the trolley via the control panel, moving the load either closer or further from the mast.
A hook block hangs off of the trolley and serves as a component hanging off of the trolley. It is the part that connects to the load to lift it.
The main electrical components in a tower crane are electric motors that empower the machine’s massive lifting capacity, and the control panel that controls other machine parts and enables work output. Wires, safety devices, warning systems and communication tools are complementary parts that help the operator ensure safe working conditions and inform equipment managers about the overall state of a tower crane.
Types of tower cranes
While tower cranes may look the same to an untrained eye, they have different types with unique strengths that shine bright in niche use cases. This section explains 4 main types of tower cranes and their biggest strengths:
Luffing jib tower crane
Luffing jib tower cranes are perfect for building large buildings and structures of varying sizes. It comes with one big strength – a jib with an adjustable height for extra control and flexibility. While this type is expensive, luffing jib towers have the most moving parts, which makes them a lot more adaptable to many use cases, even in an unorthodox job site.
Hammerhead tower crane
Hammerhead tower cranes are the most common type of tower crane. While their jib is built at a fixed height, the reduction of moving parts reduces the necessity for maintenance and repair. Hammerhead towers are easy to set up and disassemble, which makes them great for tight spaces and urban areas.
Internal climbing tower crane
An internal climbing tower crane is a niche type that is purposefully designed for the erection of tall skyscrapers. Their biggest strength is the ability to grow alongside the constructed object. Internal climbing towers can be used for both the outside, and the inside of big structures, which is essential for structuring the interior with much greater efficiency. These cranes are more expensive than hammerhead towers, but they can adapt to more situations, although frequent restructuring can take up a lot of time.
Self-supporting tower crane
Self-supporting towers fall into the high-end of tower cranes. Their biggest strength is mobility, as, unlike other types, it does not have any grounding mechanism. Instead, it relies on its robust frame for stability. While self-supporting cranes do not have the biggest lifting capacity, their easy transportation, and multiple mechanisms for extra stability make them the best crane for massive construction projects, where constant crane relocation greatly accelerates the completion of essential tasks.
Tower crane use cases
Unlike some industrial machines, tower cranes serve a primitive purpose, but at an unprecedented scale. Here are the main use cases where the tower crane’s load-lifting capabilities get utilised the most
The quality and efficiency of a construction site greatly depend on heavy equipment machines. Tower cranes are constantly used for the construction of buildings, bridges, power plants, and other massive buildings.
Tower cranes are also present in docks to speed up loading and loading processes, and even in the assembly of massive tankers and other ships. With such big machines, even their separate components are too heavy to lift with most heavy-duty equipment. The careful operation of a tower crane provides the necessary assistance in shipbuilding and industrial manufacturing.
When floods, tornadoes, hurricanes, and other disasters destroy homes and even towns, Tower cranes are quickly deployed for fast removal of rubble. They can clean up the most problematic areas a lot faster, while conventional machines deal with areas with potential survivors.
Tower cranes can be used in non-underground mines or underground structures with high ceilings. If the area is big enough, tower cranes accelerate the transportation of raw materials and management of heavy equipment.
How do you maintain a tower crane?
A tower crane’s maintenance requirements can vary greatly from one machine to the other, so it is always better to follow the servicing instructions provided in the manufacturer’s recommendations. Still, here are the five main procedures that keep them in top condition.
While cleaning such a machine is not easy, it is recommended that the trolley and the hook block receive thorough cleaning at least once a week. A tower crane must not have any buildup of contaminants in these components, as they come in direct contact with the lifted load.
Visual inspections are at the core of all maintenance schedules. Operators and certified technicians inspect the tower crane’s structure and carefully document any signs of minimal damage. If a big crack goes unnoticed, the operation of a faulty machine can lead to a big disaster
For complex machines that transport big weights, the tension and friction between their components can slowly damage the entire tower crane. Thankfully, we have lubrication solutions that grease the connection between the jib, mast, trolley system, and other parts.
Once every few weeks, a certified technician schedules the replacement of tower crane parts that experience gradual failure. While the machine could probably continue working with a faulty component, repair work always takes precedence with massive heavy-duty equipment. For a modern crane tower, these tasks are much simpler, because the entire structure is full of sensors sending recommendations and warning signals to heavy equipment software.
After daily inspections, the operator tests the machine and its control panel, carefully searching for signs of faulty movement and operation. Workers perform every test carefully and always wear personal protective equipment, as well as follow the manufacturer’s recommendations.
How often does HSE require cranes to be inspected?
The Health and Safety Executive (HSE) provides guidelines for the safe operation of heavy equipment in the United Kingdom. On top of recommended daily, weekly, and monthly servicing, it requires companies to perform thorough annual inspections on tower cranes. While daily procedures are carried out by operators, bigger tests need certified third-party technicians to determine the machine’s health.
In addition to servicing requirements, HSE provides tower crane operation tips that prioritise the health and safety of fellow employees. To keep them safe and in good condition, the cranes should only be operated by qualified operators with multiple years of experience. They must follow the manufacturer’s requirements and avoid excessive load on the crane. Playing by the book is the best way to avoid injuries and death on a construction site.
Tower crane maintenance requirements
This section covers the basic maintenance requirements for an average tower crane. Keep in mind that the recommended order of servicing tasks and inspections can vary greatly based on the model of your machine. That being said, this method structures maintenance procedures by evaluating their priority and needs in specific time intervals, so feel free to add or remove tasks for your unique use case.
Daily inspections focus on visually scanning the tower crane for obvious signs of damage. After that, the operator inspects the hydraulic oil, levels of essential fluids, and lubrication of gears,
Weekly servicing focuses on cleaning reachable components to minimise the influence of dirt, dust, debris, and other contaminants. A clean tower crane handles lifted materials with greater accuracy, while motors and engines burn fuel more efficiently.
For a complex machine like a tower crane, monthly maintenance procedures need skilled technicians and electricians for inspection of the control panel, and internal components, and identification of electrical hazards. Any damages to even the smallest equipment parts get logged, where preventive maintenance procedures focus on bringing in replacement parts ahead of time
The annual tower crane inspection follows the same principles as a monthly maintenance plan, but with even more attention to detail and inclusion of HSE safety requirements.
Tower cranes are among the biggest and most useful heavy equipment machines, and the importance of their maintenance should not be taken lightly. With extremely high repair costs and pricing for new tower cranes, modern construction companies focus on the efficient execution of crane maintenance procedures. Careful operation and high maintenance standards are the main criteria that will push your tower cranes beyond expected operation hours.