The core of selecting a crane that meets the requirements is to match it around three dimensions: operating parameters, environmental conditions, and economy, in order to avoid insufficient performance or resource waste.
一、 First, clarify the core homework parameters (selection basis)
This is the primary basis for determining the crane model, which must be accurately calculated and a safety margin of 10% -20% must be reserved.
1.Maximum lifting capacity: Confirm the weight of the heaviest object to be lifted, not the average weight. For example, if the total weight of the lifting equipment including the lifting device is 50 tons, a model with a rated lifting capacity of not less than 55-60 tons should be selected.
2.Assignment radius: Measure the horizontal distance from the center of rotation of the crane to the center of gravity of the lifted object. The larger the operating radius of the same crane, the smaller the rated lifting capacity, which needs to be confirmed by comparing its "lifting capacity radius curve".
3.Lifting height: Calculate the vertical height that an object needs to be lifted, including the distance from the ground to the bottom of the object, the height of the object itself, the height of the lifting device, and the reserved safety distance.
二、 Match the working environment conditions (to avoid equipment discomfort)
The environment directly affects the safety and operational efficiency of cranes, and the following three points need to be focused on:1.Site space: Narrow construction sites (such as indoor renovations and old factory areas) should prioritize the use of crawler cranes or small truck cranes; Tower cranes or gantry cranes can be considered for open areas such as new construction sites and ports.
2.Ground bearing capacity: A crawler crane must be selected for soft ground (such as muddy construction sites and farmland), as its grounding ratio is small and not easy to sink the vehicle; Hardened ground (such as cement ground, asphalt road) can be lifted by a truck crane or a tire crane.
3.Special environmental factors: Wind speed should be considered for high-altitude operations (operations are prohibited beyond the specified wind speed); Explosion proof cranes should be used in flammable and explosive environments; Night or indoor work requires confirmation that the equipment is equipped with sufficient lighting and limit devices.
三、 Balancing economy and practicality (controlling costs)
Choose the most cost-effective solution based on project duration and usage frequency, rather than simply pursuing high performance.
1.Job cycle: For short-term projects (1-3 months), it is recommended to lease to avoid idle equipment; Long term projects (over 1 year) can be considered for purchase, with lower long-term costs.
2.Operating costs: Compare the fuel consumption, maintenance costs (such as crawler cranes having higher maintenance costs than truck cranes), and operator salaries of different models, and choose the type with lower overall costs.
3.Transition requirements: frequent replacement of work locations (such as municipal emergency repairs, multi-point equipment installation), priority should be given to using a truck crane, which can drive and transition on its own; Fixed site operations (such as factory workshops, port yards), tower cranes or gantry cranes are more suitable.