A crawler crane should be used in lifting huge and heavy structures such as tower crane located at the center of the building, huge steel structure, huge chiller to be lifted up to the 16th floor of a high-rise building project.
The construction manager will make sure that the material or structure to be lifted are in safe and can be laid to its final location without any hassles and unsafe conditions. A method statement engineer should make sure to develop a good method statement.
So without further ado.
Here is the following method statement that you should consider following.
Method Statement for Assembly, Rigging, and Deregging of 200 Ton Crawler Crane
The purpose of this method is to define the specific tasks to be performed by Company relating the assembly, rigging, and de-rigging of the 200-ton crawler crane and to make sure the quality of the output including the safety of the works.
• Crawler Frame Assembly
• Car body
• 9 meters boom trap
• Upperside counterweight
• 12 meters boom insert
• 6 meters boom insert
• Lower body counterweight
• Load block
4. Equipment and Tools
• Lifting web slings/chain
• Tower lights
5.1 Delivery of crawler crane components to the site
5.1.1 The crawler crane components will be dispatched to site from the supplier warehouse and transported to the site through the night.
5.1.2 The crawler crane components will be offloaded at the designated assembly area the following morning using the third party certified mobile crane with adequate capacity. Plant/equipment and operators will have valid 3rd party testing and competency certificate respectively available for review and approval upon request.
5.2 Establish assembly area for the crane
5.2.1 Assembly area for the crawler crane will be near to Hangar 6 Box truss area. Proper barricade and signage will be provided and show the limit of the area.
5.3 Assembly procedure for crawler crane
Prior to the commencement of any works, the following requirements will be obtained from the main works contractor:
- Lifting permit and lifting plan to be completed and signed-off by (company) appointed person and supervised by the third-party certified and competent lifting supervisor during assembly.
- All lifting plants and equipment are certified by approved (municipality) Third-Party Testing Body. Lifting supervisor and rigger will inspect the lifting equipment prior to use and color-coded based on (company) safety color scheme for the current month.
- Third-party inspection and certification of the crawler crane after the function test to be submitted for review and records.
5.3.1 Offloading the crane car body from the trailer:
188.8.131.52 Jack down the car body (superstructure + crawler mid-section + SA-frame + winch I & II) on four built-in jacks of the crane from the trailer to the ground. The car body will be leveled by adjusting the 4 support jacks. Weight of Car body = 39.7 Ton. When the car body is completely balanced on four jack support and is free from the trailer bed, move the trailer slowly away from the car body.
5.3.2 Assembling the crawler carried
184.108.40.206 Make sure that the crane is level on all four support jacks.
220.127.116.11 Select the SA-operation program on the crane.
5.3.3 Assembly of Main Boom
18.104.22.168 Hang the S-pivot section (14 TON) onto the auxiliary crane and swing into the pinning points on the turntable.
22.214.171.124 Establish the hydraulic connection to the pin pulling device via two quick couplers.
126.96.36.199 Hang the pin pulling cylinder into the receptacle support and the screw on the pin.
188.8.131.52 Connect the pin pulling cylinder on quick couplers, hydraulic turntable.
184.108.40.206 Lock the pins on both sides of the S-pivot section with the hydraulic pin pulling a cylinder.
220.127.116.11 Actuate key on the control console and “hold down”, finally actuate the key until the pin is fully pinned in.
5.4 Procedures for unloading materials from the trailer using a forklift
5.4.1 The trailer truck should be in complete stopped (engine off) before loading/unloading activity starts.
5.4.2 Wheel choke will be provided on the trailer truck at both front and end tires.
5.4.3 The unloading area will be demarcated and provided with plastic red / white chain and safety signage will be in place. Only authorized personnel will be allowed in the work area.
5.4.4 The flagman and lifting supervisor will inspect the material for any displacement from its original configuration or stacking on the trailer bed. If there is no displacement, then unloading can proceed. Otherwise, the materials will be rejected and send back to the supplier to rectify the stacking onto the trailer bed.
5.4.5 Maximum working radius with the SA-frame to lift the crawler carrier is 5.5mts as per SA load chart.
5.4.6 Secure the trackpads with the chains provided on the sides of the crawler carrier.
5.4.7 Move the SA frame down till the lifting hook on the SA frame is centralized with the crawler carrier.
5.4.8 Connect the lifting tackle onto the two lifting links provided on the crawler carrier and assembly cylinder provided on the SA frame; make sure that the lifting link is swung between the trackpads. Lift the crawler carrier and move it carefully towards its attachment points on the crawler center section. Use the pin pull/push cylinder to insert the crawler pins and secure it with the retaining pins.
5.4.9 Release the lifting tackle and similarly lift and assemble the second crawler track
5.5 Installation of counterweight
5.5.1 Total central counterweight is 30 Ton.
5.5.2 Lift the base plate of central counterweight using an auxiliary crane and swing it to its attachment points on the car body. Insert the pin and secure it with the folding pin. The weight of the base plate section is 5Te – 02 Nos.
5.5.3 Stack the required number of counterweights. blocks =< 30 Te, distributing equal numbers of plates on the right and left side. Use receptacle stud to lift the counterweight. blocks (max. cap. is 10 ton).
5.5.4 Make sure that the counterweight. difference between the right and left counterweight stack should not exceed 5 Ton.
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6. Functional Test:
Once the assembly of the crane is completed, check properly for all the hydraulic, electrical, guy rod connections, pin connections.
Anemometer and aviation light will be fitted and functional for day/night operation.
7. De-rigging procedure:
The de-rigging procedure of the mobile crane will be the exact opposite procedure of the assembly of the crawler crane.
8. Demobilization of the crawler crane:
The demobilization will follow once the crawler crane has been successfully de-rigged. (Company) logistic management will be notified once the crawler crane components are ready to be demobilized from site.
- Hard physical segregation will be in place around any/all steel materials being lifted and/or temporary work areas.
- Appropriate signage will be in place.
- Traffic routes and closures will be authorized by (company) Logistics Manager, clearly defined with barriers & signage and communicated to all.
- Ground conditions to site will be assessed by a competent engineer to ensure suitability for forklift, load, away from any overhead or ground hazards such as other plant and equipment, erected steel, excavations.
- All plant/machinery and operators to be 3rd party certified. Third-party training will also be given to banksman.
- Pre task briefing to be completed daily by the site/project engineer prior to any task starting. Foremen to conduct a pre-task briefing for teams every morning clearly outlining the safe work method steps, roles, and responsibilities.
- Full PPE to be worn at all times and inspected prior to use.