Below is a detailed method statement for Installation of EOT Overhead Gantry Crane. EOT crane installation shall be in accordance with the project requirements and crane manufacturer installation instructions.
This method statement also describes the installation of overhead gantry crane for the pump rooms, cooling plants and maintenance and erection workshops etc.
Project manager is overall responsible for the implementation of the approved method statement, specifications, drawings, and ensure that his team of engineers and foremen are aware of it; He shall also ensure that all resources, humans, materials, and equipment are available to carry out the work as planned without any delay.
EQUIPMENT USED FOR INSTALLATION
- 50 ton capacity Mobile Crane (as per the site requirement), lifting gears & / shackles.
- 2 Tons Pallet Truck/Trolley
- Chain Block 2 Ton
- Lifting Slings
- Hand Tools
- Welding Machine
- Cutting Machine
Pre Installation Requirements
The following points shall be taken care before the erection of the rail & E.O.T crane at project site.
Check that all the trenches / pits are covered with proper steel covers inside the building.
Suitable ramp should be provided for the building entrance for the material access if necessary.
The truck routing shall be planned properly and any possible obstructions should be avoided.
All other activities inside building near the specified erection area shall be stopped until the erection is completed.
Make sure the Floor is build to take specified loads and is covered with proper steel plates/hard wood ply woods to move the loads smoothly over it.
Ensure that right size of unifix is being used and holes made accordingly on the rail.
Make sure that rail of proper size i.e. width and thickness is being used.
EOT Crane Rail Welding Method
Upon site readiness i.e. aligned crane runway beam survey report to be forwarded to crane installer for review. If ok proceed with the rail installation.
Fall protection & working platform (platform to be built on the corbel level from outside the building parallel to the crane span & extended inside the building and which has got the holding capacity of 2 Tons – refer to relevant sketches.
Obtain all the necessary hot work permits to secure prior to any hot works (welding, grinding, gas cutting etc.)
Rails will be lifted using mobile crane from ground outside & placed on the platform, then skid the rails inside the building on the runway beam using pallet truck.
Marking is done to required crane span.
Welding of rails done as per manufacturer crane standards
Deflection to be within limits.
Ensure that MEP services already installed at high level are not disturbed / damaged.
EOT Crane Erection Using Tower Crane:
The long travel rails will be thoroughly inspected for the level, straightness and alignment before starting erection of the crane.
Once the long travel beams found OK, before erection of the crane measure the rail spans at various locations and confirm it matches with crane span.
Transport, mobile crane access routes and erection method to be agreed with the client.
Weight of crane is as per approved technical submittals and slab load calculations.
The area near to the lift will be inspected for access / positioning of the crane and make sure it is as per the requirement before getting the equipment’s on site.
Mark the approximate location of the mobile crane near building.
Unload the crane girder, Endcarraiges, hoist machinery & bridge panel from the trailer one by one, in presence of manufacturer representative.
Fix at least 2 numbers of long tag lines at the extreme end of the crane girder to control the load from swinging.
By using safe access attach the slings to box girders of the E.O.T by choker hitch in the center.
Provide proper packing at sharp edges to prevent slings from damaging.
Lift the load up to 1 ton and make sure everything is O.K.
Slowly lift the load ton by ton till it comes off the base by about 100mm and check for level of lift.
Adjust the level by shifting the slings if necessary.
Once the load is up in the air check for the level of the load is OK.
Keep raising the load gradually to the required height.
Once load reaches to the required height, slowly swing the crane girder to required position.
Crane girder will be placed outside the building on the platform, then Crane girder will be skidded inside the building on the platform using pallet truck.
Once Crane girder secured over the platform, release the slings from the mobile crane.
The above procedure is repeated to lift the Endcarraiges, hoist machinery & bridge panel.
Remove the slings and remove all other lifting tackles.
Assembly the EOT Crane on the platform.
Lift the girder above the LT beams and align the Endcarraiges on to the rails and place over the rails.
Dismantle the platform.
Now EOT gantry crane is ready for final commissioning work.
Once the crane erection is done, installation of the long travel power supply system will be carried out at site by using standard clamp on brackets using scaffolding.
Power supply connections shall be made to the main isolator.
Power supply connections shall be made to the crane through power collector trolley.
Now the EOT crane is ready for final testing.
After the power connection, the crane shall be checked for operation by operating the crane slowly in all the directions.
Limit switch shall be set for hoisting up/down and cross travel left/right directions.
Crane shall be run in long travel direction throughout the length of the building slowly to cross check the rail installation.
Long travel limit switch strikers shall be fitted at the extreme ends of the building and limits shall be set for the crane.
Now the crane is ready for final load testing.
ALTERNATE PROCEDURE OF EOT CRANE INSTALLATION:
- The complete EOT Crane shall be supplied and erected by competent personnel representing the Manufacturer of the crane.
- The crane girder and the components are brought near to the Tower Crane on a trailer.
- Using the Tower Crane, crane girder and the components are lifted one by one through Entrance Vestibule Skylight Void and placed on the pallet trolleys and brought below the runway beams.
- The EOT crane will be assembled mechanically and electrically.
- Total weight of the assembled crane will be 1130 Kgs.
- Using a 2T chain block hanging from the Cross beam connecting the RCC Columns, the EOT Crane is lifted and the wheels of the cranes are placed on the bottom flange of the runway beams.
- Make sure that all the wheels are seated properly before removing the slings then remove the chain block
- Power supply bus bar will be installed along the runway beam.
- The crane shall be tested for proof load
- The crane shall have identification.
- The parts catalogs, factory test certificates, operation manual, as well as the on-site load testing certificate, shall be given to the Engineer in original plus copies as may be required, upon completion of the works.