Dual Crane Spreader Beam

Relevant Codes & Standards

ASME B30.20 Below the Hook Lifting Devices

Materials and Components

G40.21 Gr. 44W Structural Channel

A516 Gr. 70 Pressure Vessel Plate

Project Brief:

Lift and maneuver a lead pot using two overhead bridge cranes in tandem. Lead pot must be tilted and rotated during installation/removal.

Challenge: 

  • Minimum distance between cranes sets the length of beam and positions the pot lift points.
  • Weight of lift beam must be minimized to allow for a reasonable buildup of lead remaining in pot to be safely lifted.
  • Weight of lead pot (20,200 lb) must be distributed between both cranes to avoid exceeding 7.5 Ton crane capacities during lifting, tilting, and rotating operations.
  • Pot hood must also be removed using same lifting beam, extremely low headroom available for remotely engaging with hood and maneuvering during lift.

Solution:

Field measurements of the minimum crane distances along with a review of the existing lead pot installation drawings aided in developing a conceptual arrangement of the lead pot and hood lift points that allowed for the necessary maneuvering to be safely achieved.

I/O optimized the lift beam construction to achieve the strength required based on the position of the loads while minimizing the weight of the fabricated lifter. This was achieved by selecting a structural steel channel size and joining it together to form a rectangular box-section.

A set of custom hooks were designed to be fabricated from plate steel to achieve a low headroom engagement mechanism for lifting the pot hood without requiring a worker to attach rigging while exposed to a potential fall hazard.