BS/EN 16851-2017 pdf download.Cranes – Light crane systems.
5.4.9 Trolleys
Trolleys shall incorporate features to prevent unintentional derailment, accidental fall or climbing on the rail. This requirement can be fulfilled by the use of devices such as guide rollers and / or wheel flanges. The trolley shall be prevented from falling or overturning in the event of a single-wheel failure.
5.4.10 End stops and motion limiters
Any motion that has a designed restriction of movement and those motions that have a restriction shall be provided with motion limiters. A motion limiter can be. for example. an electrical switch or a mechanical end stop. End stops shall be capable of stopping the movement from the maximum speed without overloading the crane.
The ends of bridges and tracks shall be equipped with mechanical end stops. End stops of the parallel runways for crane or track shall be aligned. Where provided, the electrical motion limiters shall be in accordance with EN 12077-2.
Where end stops for the crane or the trolley are fixed by a bolt tightening friction grip joint relying only on friction, to provide the possibility of adjustment of the travel range, there shall also be:
— a positive locking provided behind the end stop as a back-up means or
— the end stop construction shall be designed with a risk coefficient y = 1.6.
Where the design permits only limited rotation of a jib crane, end stops for the rotation movement shall be provided.
5.4.11 Power supply
The electric power supply shall conform to EN 60204-32.
Means to shut off the pneumatic power shall be provided.
In some cases, the power supply may be able to move the lifting device by itself, e.g. due to weight of festoon cable. Where this is not an intended feature, the lifting device or bridge shall be equipped with a braking system.
5.5 Tandem operation of cranes/trolleys from a single control station
When two or more cranes/trolleys are used for handling a single load from a single control or control station, the control systems of the individual cranes shall be interconnected to ensure that during tandem operation:
— the hoisting speeds are the same within the tolerances required for the particular application;
— the horizontal speeds are the same within the tolerances required for the particular application;
— any interruption of the operation on one crane/trolley shall have a corresponding effect on the other. This requirement does not apply to fully pneumatic or hydraulic powered and operated cranes/trolleys with horizontal speeds less than 15 rn/mm and hoisting speeds less than 2 rn/mm.
At horizontal speeds exceeding 60 rn/mm or hoisting speeds exceeding 20 rn/mm, the relevant motion control shall provide self.correcting synchronization and any interruption in the operation on one crane/trolley shall have a corresponding effect on the other.
Where the cranes can be used separately and in tandem, the controls shall be clearly marked accordingly.
5.6 Use of multiple lifting devices
Where use of multiple hfting devices may overload any component in the crane, measures shall be taken to prevent overloading by mechanical or electrical means. Examples of such overloading cases are
— crane bridge capacity Is less than the combined capacity of the lifting devices;
— several adjacent lifting devices loading one suspension of a monorail;
— several adjacent bridges loading one suspension of a track;
— telescopic system and cantilevered beams of tracks/bridges with several lifting devices;
— the crane has permanent access ways for maintenance and inspection, designed in accordance with
EN 13586;
— access is through external access ways on the surrounding building or siniilar permanent construction;
— access is from a mobile elevating work platform.
In the two latter cases, the access relies on external means, which are not part of the crane. However, those means shall be specified and their use described in the maintenance instructions of the crane.
Where maintenance or inspection requires access to enclosures, the openings shall conform to
EN 13586.
For requirements not covered by EN 13586, the following clearances are generally recommended as minimum values:
— clearance above the crane with access ways to the interrupted roof: 500 mm;
— clearance between two cranes mounted above each other with access ways in either of the cranes:
500 mm;
— If it is foreseeable for personnel to access the top of a permanent obstacle, then clearance under the crane to that permanent obstacle: 500 mm;
— clearance between the end carriage and the building taking into account the maximum skew position and allowable wear and there is no permanent access: 50 mm.
NOTE Guidance is also given In ISO 11660.5.
Some maintenance and inspection work may require the use of a safety harnesses. Where such
equipment is required attachment points in conformity with EN 795 shall be provided.
5.7.3.2 GuardIng
To avoid crushing and shearing hazards the minimum distance between moving parts within the crane shall be in accordance with EN 349 unless equivalent safety is provided by other means, for example a person detector and motion limiter system.
Where there Is a danger of a shearing or falling hazard occurring on the access way, the transfer points shall be provided with gates. These gates shall be fitted with an interlocking device that disables the relevant motion.
Where the running surfaces are exposed and they are at a lower level than 2,5 m above the access level, the hazard zone shall he guarded in accordance with EN ISO 13857. The clearance between the running surface and the guard shall be a maximum 6 mm.BS/EN 16851-2017 pdf download.