BS EN 13001-2:2011 pdf download
BS EN 13001-2:2011 pdf download.Crane safety -General design Part 2: Load actions.
4.2.3.3 Loads duto temperature variation
Where relevant, local temperature variation shall be specified and taken into account.
4.2.3.4 Loads caused by skewing
Skewing loads occur at the guidance means of guided whee4-rnounted cranes or trolleys while they are travelling or travei-smg at constant speed. These loads are induced by guidance reactions which force the wheels to deviate from their free-rolling, natural travelling or traversing direction,
Skewing loads as described above are usually taken as occasional loads but their frequency 01 occurrence varies with the type, configuration, accuracies of wheel axle parallelism and service of the crane or trolley. In individual cases, the frequency of occurrence will determine whether they are taken as occasional or regular loads. Guidance for estimating the magnitude of skewing loads and the category into which they are ptaced is given In the European Standards for specific crane types.
The lateral and tangential forces between wheels and rails as well as between guide means and guidance caused by skewing of the crane, can be calculated by a simplifd mechanical model. The crane is considered to be travelling at a constant speed without anti-skewing control.
The model consists of n pairs of wheels transversally in line, of which p pairs are coupled. A coupled pair of wheels (C) is coupled mechanically or electrically. Independently supported non-driven or also — in approximation — single-driven wheels are considered as independent wheel pair (I). The latter condition is also valid in the case of independent single drives.
The wheels are arranged in ideal geometric positions in a rigid crane structure which is travelling on a rigid track. Differences in wheel diameters are neglected in this model. They ace either fixed (F) or movable (N) in respect of lateral movement
The different combrnations of transversally in-line wheel paws that are possible are shown in Figure 8.
4.2.4.6 Loads caused by emergency cut.out
Loads caused by emergency cut-out shall be calculated in accordance with 4.2,2.4 taking into account the most unfavourable state of drive (i.e. the most unfavourabie combination of acce4eration arid loading) at the time of cut-out.
4.2.4.7 Loads caused by antlclpat.d fallur. of mechanism or components
Where protection is provided by emergency brakes in addition to service brakes, failure and emergency brake activation shall be assumed to occur under the most unfavourable condition
Where mechanisms or components are duplicated or secured by other means for safety reasons, faure shall be assumed to occur in any pan of either system.
Resulting loads shall be calculated in accordance with 4.2.2.4. taking into account any resulting impacts.
4.2.4.8 Loads due to external excitation of the crane foundation
Examples of crane foundation excitation are seismic or wave-induced movements. Where relevant, loads
caused by such excitations shal be specified and taken into account.
4.2.4.9 Loads caused by erection, dismantling and transport
Depending on the crane type it may be necessary to take into account the loads caused by erection, dismantling and transport, including specified wind loads during these processes
In some cases these loads could be occasional.
4.2.4.10 Loads on means provided for access
Loads acting on means provided for access are considered to be local, acting only on the facdities themselves and on the mirnediate supporting members, The following perpendicular loads shall be taken into account:
3000 N where materials can be deposited:
1 500 N on means provided for access only,
300 N horizontally on railings at least, depending on location and use.
4.3 Load combinations
4.3.1 General
The proof calculation based on the ‘Limit state method’ requires to multiply the selected loads of a load combination with partial safety factors (see Tables 10 and 11).
