Client Experience

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- North Sea
Brown & Root
ETAPS (Eastern trough Area Project)
EX Mechanical Handling Package

Technical Data

Crane Gantry Tolerances

BS466 Gantry Tolerances

  1. Track joints, wheel running and guidance surfaces
    • Any misalignment of running faces or gaps occurring between sections of track will have an adverse effect on the performance and life of the crane.
    • Joint arrangement should ensure accuracy in the alignment of running faces or guidance faces to provide a smooth transition path for the wheel between sections of track.
    • Track running and guidance faces should be free of obstruction and should be left unpainted. These faces should be free from damage and pitting or other surface defects.
  2. Dimensional and geometrical tolerances of tracks for top running and underslung cranes
    1. General - Tracks should be within the tolerances given in 2.2 to 2.5 when not supporting the crane.
      • Note : The tolerances shown for underslung cranes apply to single span, i.e. running on one pair of tracks.
    2. Tolerance on Span - The tolerance on span should be as follows (see Fig. 4)
      • ∆S ≤3mm where S≤15m
      • ∆S ≤3 +0.25 (S-15mm where S>15m)
      • ∆S max. =15mm
      Fig 4 Tolerance on Span
    3. Misalignment of track running surfaces in the vertical plane. - The tolerance on track misalignment should be as follows (see Fig. 4).
      • ∆H ≤0.001 S
      • ∆H max. = 10mm
    4. Tolerance on Track Width (underslung only). - The tolerance on track width (underslung only) should be as follows (see Fig. 5).
      • ∆W = 0.025 W
    5. Track Straightness Tolerances
      1. Permissible deviation in the lateral plane. For the total length of track, the maximum lateral deviation from the straight line mean datum should not exceed 10mm (see Fig. 5).The straight-line mean datum is the line about which deviations of track on each side will be equal, when summated over the whole length of the track. Local lateral deviation at any point of the track should not be greater than L/2000, measured over a length of not less than 2m on a line parallel to the straight line mean datum. Fig 5 Permissible Deviation in the Lateral Plane
      2. Permissible deviation in the vertical plane. For the total length of the track, the maximum vertical deviation from the theoretical datum line should not exceed 10mm (see Fig. 6). The theoretical datum line may be the true horizontal line or a theoretical camber line. Local vertical deviation at any point of the track should not be greater than L/2000. measured over a length of not less than 2m on a line parallel to the theoretical datum. Fig 6 Permissible Deviation in the Vertical Plane
  3. Running surface permissible traverse inclination from the horizontal datum position. The maximum permissible traverse inclination from the horizontal datum position should be as shown in Fig.7. Fig 7 Running surface permissible traverse inclination from the horizontal datum position
  4. Measurement of Crane Tracks
    • When measuring crane tracks, calibrated steel measuring tapes should be used. It is important that the readings obtained are corrected to allow for sag in the tape and for temperature variation. All track measurements for a particular crane should be made with the same measuring tape and the same applied tension force.