How Tower Cranes Work
Tower cranes are extensively used for lifting materials in construction sites. Most construction sites are very confined and close to public. Tower crane accidents not only hazard workers in construction sites, but also pedestrians. This paper investigates tower crane safety in related to the understanding and degree of executing statutory requirements and non-statutory guidelines for the use of tower cranes in the Hong Kong construction industry. A questionnaire survey and structured interviews are conducted. It is found that human factors are attributed to tower crane safety. Indolent performance of requirements or responsibilities of practitioners in tower crane operations is found. Inadequate training and fatigue of practitioners are one of the main reasons causing unsafe practices of tower crane operations. Recommendations for improving safety performance in tower crane operations are also discussed.
Research highlights
This paper investigates tower crane safety in related to the understanding and degree of executing statutory requirements and non-statutory guidelines for the use of flat top tower crane in the Hong Kong construction industry. It is found that human factors are attributed to tower crane safety. Indolent performance of requirements or responsibilities of practitioners in tower crane operations is found. Inadequate training and fatigue of practitioners are one of the main reasons causing unsafe practices of tower crane operations.
Tower cranes are a common fixture at any major construction site. They're pretty hard to miss -- they often rise hundreds of feet into the air, and can reach out just as far. The construction crew uses the tower crane to lift , concrete, large tools like acetylene torches and generators, and a wide variety of other building materials.
When you look at one of these cranes, what it can do seems nearly impossible: Why doesn't it tip over? How can such a long boom lift so much weight? How is it able to grow taller as the building grows taller? If you have ever wondered about how tower cranes work, then this article is for you. In this article, you'll find out the answers to all of these questions and more!
Weather monitoring in construction sites is important, but especially when luffing jib tower crane are used. A strong gust of wind can destabilize the load and structure, causing a collapse. Project managers should constantly check weather forecasts, and avoid lifting operations with unfavorable weather. A weather monitoring system at the project sites can warn about dangerous wind conditions that are not covered in forecasts.
Tower Crane Support System
One of the first questions that may be asked by someone looking at a tower crane is these structures stand upright. There are several elements that contribute to the tower crane’s stability. The concrete pad is a concrete foundation made by the construction company several weeks prior to the crane’s arrival. Typical measurements for the pad are 30x30x4 feet (10x10x1.3 meters), with a weight of around 400,000 pounds. Large anchor bolts are deeply embedded in the concrete pad, and these elements support the base of the crane.
Tower cranes are delivered to construction projects in parts, which are then assembled on-site. Qualified installers assemble the jib and the machinery section, these horizontal elements are then positioned on the mast, which is only 40 feet tall initially. Once this assembly is completed, the counterweights are placed by a mobile crane. The mast rises from the concrete pad, and it remains upright thanks to its triangulated structure. To increase the crane height, the crew adds sections to the mast with a climbing frame:
A weight is hung on the jib to balance the counterweight.
The slewing unit is detached from the top of the mast and hydraulic rams in the top climber push the slewing unit up 20 feet.
The crane operator uses the crane to lift another 20 ft mast section into the gap and then it is bolted in place.
These steps are repeated continuously until the desired height is achieved. Once it is time to remove the tower crane from the construction site, the crane disassembles its own mast and smaller cranes are used to disassemble the rest.
Tower crane accidents frequently occur in the construction industry, often resulting in casualties. The utilization of tower crane spare parts involves multiple phases including installation, usage, climbing, and dismantling. Moreover, the hazards associated with the use of tower cranes can change and be propagated during phase alternation. However, past studies have paid less attention to the differences and hazard propagations between phases. In this research, these hazards are investigated during different construction phases. The propagation of hazards between phases is analyzed to develop appropriate safety management protocols according to each specific phase. Finally, measures are suggested to avoid an adverse impact between the phases. A combined method is also proposed to identify hazard propagation, which serves as a reference and contributes to safety management and accident prevention during different tower crane phases in the construction process.