§354 過負荷及び転倒の防止

The requirement set out in section 4.2.2 applies to lifting machinery in the strict sense and interchangeable equipment for lifting with a maximum working load of not less than 1000 kg or an overturning moment of not less than 40 000 Nm and to safety components fitted to such machinery to prevent overloading and overturning.

The purpose of the requirement set out in section 4.2.2 is to prevent machinery from being used, intentionally or unintentionally, to lift loads in excess of the maximum working load specified by the manufacturer or in such a way that the overturning moment is exceeded. Overloading of machinery can lead to immediate failure of load-bearing components or to the collapse or overturning of the machinery. Repeated overloading of the machinery may also cause excessive wear of load- bearing components, leading to failure after a certain time.

Section 4.2.2 takes account of the fact that, in the foreseeable conditions of use, the operator may not correctly evaluate the weight of the load to be lifted, he may attempt to lift a load that is too heavy or lift the load to a position that would lead to loss of stability. This requirement thus aims to prevent such foreseeable misuse of the machinery – see §173: comments on section 1.1.2 (a).

The choice of protective devices depends on the category and characteristics of the machinery concerned. For most categories of lifting machinery, the devices to be fitted are specified in the relevant harmonised standards. In general, load and moment control devices must be able to measure or calculate relevant parameters such as, for example, the weight of the load, the position of the load and the overturning moment created by the load. The devices must transmit a warning to the operator before the maximum working load or the overturning moment is reached, in order to enable him to take action to avoid overloading the machinery or moving the load to a position that would lead to overturning. The protective devices must be integrated into the control system in such a way as to prevent dangerous movements of the machinery or the load if the maximum working load or the overturning moment is exceeded. Non-dangerous movements of the machinery can be permitted.

It may be necessary to provide a means of overriding a load or moment control device, for example, in order to carry out overload tests or to bring the load back to a safe position. In that case, the necessary measures must be taken to prevent misuse of the override facility, for example, by means of a mode selector – see §204: comments on section 1.2.5 - or by locating the override control out of the reach of the normal operating position. For machinery intended to be used by emergency services, it may also be necessary to permit trained operators to override a load or moment control device, for example, to deal with a threat of fire or explosion.

Loading control is not required if it does not contribute to the safety of the machinery. For example, for machinery fitted with load holding device, such as a casting ladle, that makes it impossible to lift a load greater than the maximum working load of the machinery, the requirement for loading control may not be applicable.