Scope of Work:
Disconnect and remove 40,500# Kato Synchronous AC Generator from Solar Taurus 70 7.5MW combustion turbine generator for emergency repairs. Unit needed to be rigged from a 2nd floor wall penetration and loaded onto truck. Following generator repairs, rig the unit back into place.
- Remove air intake louvered wall panels
- Disconnect generator from Solar 70 turbine
- Remove Kato 40,500# synchronous AC generator
- Load onto truck
- Reinstall repaired generator in same manner at later date
- Reset/level on shims
The 2nd floor wall penetration from which the generator needed to be removed was only accessible from a narrow alley. This required a crane selection based on half-outrigger charts and a positioning of the crane outriggers safely adjacent to sub-grade concrete vaults. This left the crane with virtually no swing radius.
Because the combustion turbine generator package was elevated from the floor, getting the generator into a position for the crane to pick it from the 2nd floor required a 20’ plated pathway from the module to the wall penetration on 48” of cribbing to match the height of the generator within the module from which it was being removed. This difficulty was compounded by less than 1.5 inches of overhead clearance to remove the generator within the module. Since this was insufficient height to allow the use of typical skates or dollies under the generator, we designed and fabricated bearing lugs to mount on the back of the generator with an elevated bearing surface allowing the use of skates within these clearances. These designed lugs served an important secondary purpose in that it extended the weight bearing point beyond the rear of the generator and allowed us to ‘nose’ the generator further out of the building onto the supported plate plated path cantilevering out of the wall penetration. This gave us enough room to hook with the crane and a manual hoist and safely ‘drift’ the generator out of the building without interference between the upper penetration edge and the rigging connected to the rear of the generator. We also had to work around a hoist rigging beam centered within the penetration and extending beyond the wall.
After lowering the generator to the ground, the crane was removed and a Versa Lift 60/80 was used to pick the generator and load it onto a truck. The rigging activities required street closings which were limited from 7:00pm to 6:30am the following morning. We installed a temporary cover of the wall penetration until we reinstalled the repaired generator at a later date. After re-installation, we restored the penetration with the original air intake wall louver.