## 1 Introduction  
With the rapid change in climate conditions, the phenomena associated with strong winds are becoming more dangerous. Moreover, early wind prediction is also becoming more difficult. An example is the category 5 Hurricane Otis [1], which devastated Acapulco city in Mexico on 25 October 2023. At the very beginning, this hurricane was estimated as only a tropical storm, but unexpectedly, it became an unusually strong hurricane. The wind blew at 265 km/h. Sudden gusts of wind were even stronger. The observed wind gust speed was equal to 330 km/h. Equally dangerous weather phenomena also occur in previously moderate climate zones. At the beginning of November 2023, Europe was hit by Hurricane Ciaran [2]. The wind gust speed exceeded 200 km/h. In such conditions, all types of lifting equipment, such as scissor lifts, elevating work platforms of different kinds, and cranes, including tower cranes, are particularly vulnerable to destruction [3, 4, 5, 6, 7, 8, 9, 10, 11]. This paper examines the problem of the wind load acting on the gantry crane, particularly how strong the wind must be to cause the whole structure to tip over. Gantry cranes seem very stable and resistant to strong gusts of wind. However, cases of this type of structure overturning due to strong winds have been known to occur [12, 13]. The wind load is considered one of the most important loads in the design process. It is found in many codes, such as [14; 15; 16; 17; 18; 19]. The European Standard ISO-4302 [14] (like the other cited standards) concerns wind loading in cranes. According to the standard, if the wind blows at a constant speed from any horizontal direction, it will cause a quasi-static uniform load (pressure) on the investigated structure. This approach should be treated as a relatively simple method. The calculation method also considers redundancy qualities, considering the effects of gusts (rapid changes in wind speed) and the dynamic response of the crane structure. When calculating wind for cranes, two load states are considered. The first is the wind load for cranes in the working state. This is the highest wind load that acts on the crane during its operation and for which it was designed. The wind load is assumed to act from the least favorable direction in combination with other operating loads. According to the code [14], the operating state wind speeds and corresponding pressures are as follows: if the crane manufacturer has not adopted and specified other values in the crane's operating instructions, then, in the case of normal cranes working in open space, the design wind speed is equal to \(V=20\) m/s, and the corresponding wind design wind pressure is \(p=250\) N/m\({}^{2}\), whereas in the case of cranes that must work in high winds, the design wind speed and design wind pressure are equal to \(V=28.5\) m/s and \(p=500\) N/m\({}^{2}\), respectively. The second crane load condition, according to [14], is the wind load on cranes in the non-working state. This is the strongest (storm) wind gust load from the least favorable direction that acts on the crane in the non-working state and for which the crane was designed. The wind speed is variable and depends on the geographic location and the degree of exposure of the crane to the wind. Regardless of the code, however, the following equation is used to calculate wind load \(F\) of the entire crane, its parts, and individual structural elements [14]:  
\[F=A\cdot p\cdot C_{f}, \tag{1}\]  
where \(A\) is the effective frontal area of the part under consideration in m\({}^{2}\), i.e., the area of the projection of all elements on a plane, which is perpendicular to the wind direction; \(p\) denotes the wind pressure; and \(C_{f}\) is the streamlining coefficient of the part under consideration in the direction of the wind action. When calculating the wind load of a crane in a non-swinging state, the wind pressure is assumed to have a constant value in each 10 m vertical height interval of the crane.