Construction cranes mainly refer to tower cranes, also known as "tower cranes" and "tower cranes", which are common lifting equipment on construction sites. From the beginning of this century, China's tower crane industry experienced "golden decade", and by 20 12, the sales volume of tower cranes began to decline at the peak, with an average annual decline rate of more than 15%. However, since 20 17, the tower crane industry has once again ushered in a rebound. The weight of the hoisted object exceeds the allowable range of mechanical properties, and lifting is not allowed; Unknown command signal, unknown weight and dim light. There are people standing on the working surface, or there are live animals floating on the working surface. Buried things don't hang; It is not allowed to lift inclined traction objects; The slings and accessories are not fastened tightly, which does not meet the safety requirements; When the crane is lifting heavy objects, it can be directly processed without lifting; Oxygen cylinder, generator B and other sexual goods are not hoisted; When the mechanical safety device is out of order or sick, it is not allowed to be hoisted; In bad weather, hoisting is not allowed in strong winds above level 6. What happens to the spreader should be handled in time? Answer: Cranes with deformation, distortion, open welding and cracks must be handled in time, otherwise they will stop. What should I do if the store is abnormal after suspension? Answer: In case of sudden abnormality after the operation is suspended, the commander should make a quick judgment according to the situation and urgently notify the personnel in the dangerous parts to evacuate. Command the tower crane driver to lower the crane slowly, and then lift it after eliminating the danger.

There are many types of tower cranes, because the lifting weight is different. The purchase price and rental price of each model are also different. The models commonly used in general construction sites are 56 10/3,5610,6012,6015. Of course, there are more subdivided models, smaller models and larger models. And like other commodities, tower cranes have different brands and different purchase prices. But the basic rental price of the same model is similar, unless the brand tower crane price is slightly higher. It is understood that the application fields of tower cranes are mainly infrastructure construction, including railways, highways and water conservancy. At present, China's infrastructure sector is vigorously promoting the PPP model, driving the construction of urban rail transit, railway trunk lines and feeder lines, and the demand for mine and farmland water conservancy construction is picking up. 20 17 1 1 year 10, the "13th Five-Year Development Plan for Railways" was issued, indicating that the total railway investment will increase by 800 billion yuan every year. Statistics also show that in 20 17, the national investment in fixed assets (excluding farmers) was 63168.4 billion yuan, an increase of 7.2% over the previous year. Among them, the planned total investment of newly started projects is 51909.3 billion yuan, an increase of 6.2% over the previous year. In addition to infrastructure, the tower crane industry is also highly related to the real estate market. * * * Figures show that in 20 17 years, the national real estate development investment was 109799 billion yuan, an increase of 7.0% over the previous year, and the growth rate was 0. 1 percentage point faster than the previous year. Among them, the newly started area was 6.5438+0.78654 million square meters, an increase of 7.0%. The land acquisition area of real estate development enterprises was 255.08 million square meters, up by 15.8%. In addition, the service life of construction machinery such as tower cranes is generally 6 years-10 years. At present, it has been six years-10 years since the last peak of the construction machinery industry (2007-20 10), and the industry has entered a concentrated release period of upgrading demand. In the next 2 -3 years, the demand for renewal will continue to expand. At the same time, there is still a big gap between the accessories, experimental verification and quality awareness of China's tower crane industry and international standards, and it is difficult for products to enter the international market. The overall intelligence level of the industry is still low, and there is still much room for improvement compared with the advanced * * *. Industry concentration is also at a low level.