Dismantling Method Statement - Tower Crane

| Role | Responsibility | |------|----------------| | Appointed Person (AP) | Overall planning, risk assessment, method statement approval, lifting plan sign-off. | | Crane Supervisor | Supervise dismantling activities, ensure lift plan followed, stop unsafe acts. | | Tower Crane Operator (during dismantling) | Operate crane for last lifts if powered, then vacate cabin safely. | | Mobile Crane Operator | Operate assist crane for lowering mast sections, jib, counter-jib, slew unit. | | Riggers / Slinger Signallers | Attach slings, guide loads, communicate with crane operators. | | Ground Support Team | Receive and lay down components, secure against rolling. | | Safety Officer | Monitor compliance with PPE, exclusion zones, and permit-to-work. |

A tower crane dismantling method statement outlines a precise, top-down sequence designed to manage risks like structural stability and high wind conditions, typically involving counterweight removal, jib dismantling, and mast section removal via telescoping or direct lift. Key safety measures include establishing exclusion zones, verifying equipment, and ensuring qualified personnel strictly follow the manufacturer's procedures. For a detailed example, see the Tower Crane Dismantling Procedure on Scribd. Tower Crane Dismantling Procedure | PDF - Scribd

Method Statement: Tower Crane Dismantling The dismantling of a tower crane is one of the most high-risk phases of a construction project. Unlike installation, where the site is often clear, dismantling usually occurs when the building is nearly finished, leaving limited space and tighter logistics.

This method statement outlines the systematic approach to safely decommissioning a tower crane. 1. Project Overview & Scope

The objective is to dismantle the tower crane using a mobile crane or a derrick crane, ensuring the safety of personnel, the structural integrity of the building, and the protection of the public. 2. Pre-Dismantling Requirements Before any work begins, the following must be in place:

Permits: Valid local authority permits for road closures or sidewalk diversions.

Weather Monitoring: Dismantling must be suspended if wind speeds exceed the manufacturer’s limits (typically 38–45 mph).

Exclusion Zone: A physical barrier at ground level to prevent unauthorized entry into the "drop zone."

Equipment Inspection: All lifting gear (slings, shackles, chains) must have valid test certificates. 3. Personnel & Responsibilities

Appointed Person (AP): Responsible for the lift plan and overall safety. Crane Supervisor: Manages the dismantling team on-site.

Lead Rigger: Ensures all components are balanced and secured before disconnecting.

Slinger/Signaller: Communicates with the mobile crane operator via radio. 4. Equipment List

Assist Crane: A mobile crane with sufficient capacity and reach (e.g., a 250-ton or 500-ton crane). Hand Tools: Impact wrenches, drift pins, and sledgehammers.

Personal Protective Equipment (PPE): Safety harnesses (with double lanyards), hard hats, hi-vis vests, and steel-toed boots. 5. Step-by-Step Dismantling Procedure Phase 1: Preparation

Jib Positioning: The crane is rotated to the pre-agreed "parked" position to allow the assist crane access.

Trolley & Hook: The trolley is moved to the minimum radius and locked. The hook block is lowered to the ground or secured. Phase 2: Counter-Jib Weight Removal

The assist crane takes the tension of the first counter-weight. Riggers remove the retaining pins.

The weight is lowered to the ground. This process is repeated, usually leaving one weight in place to maintain balance until the jib is removed. Phase 3: Jib Removal

The assist crane hooks onto the jib at the manufacturer-specified lifting points. Riggers disconnect the jib pins at the tower head.

The assist crane slowly lowers the jib to the designated dismantling area. Phase 4: Counter-Jib & Tower Head Removal The remaining counter-weights are removed.

The assist crane supports the counter-jib while pins are removed. The tower head (apex) is disconnected and lowered. Phase 5: Mast Section Removal

If a climbing frame is used, the crane "telescopes" down by removing mast sections one by one.

If the assist crane has enough height, it simply unbolts and lifts each mast section directly from the top.

The slewing ring and cab are typically removed as one unit before the final mast sections. Phase 6: Base & Foundation The fixing angles or foundation anchors are released. The remaining base section is removed.

Any ballast weights at the base are loaded onto transport trucks. 6. Safety & Environmental Controls

Communication: All team members must use a dedicated radio frequency.

Working at Height: Riggers must remain 100% tied off to approved anchor points.

Traffic Management: Marshals must guide transport trucks into and out of the site to prevent collisions. 7. Emergency Response In the event of an accident or equipment failure: Cease all lifting operations immediately. Secure the load if possible. Follow the site-specific Emergency Action Plan (EAP).

Dismantling a tower crane requires a meticulous, top-down sequence—involving hook block removal, counterweight reduction, and jib disassembly—to maintain structural balance. Key safety requirements include comprehensive risk assessments, strict adherence to manufacturer manuals, and mandatory site exclusion zones. Read the full method statement at Scribd. Method Statement Dismantle Tower Crane - Scribd

Tower Crane Dismantling Method Statement tower crane dismantling method statement

Introduction

Tower cranes are commonly used in construction sites to lift and move heavy loads. However, when a construction project is completed, the tower crane needs to be dismantled and removed from the site. Dismantling a tower crane is a complex process that requires careful planning, specialized equipment, and trained personnel. This method statement outlines the steps and procedures for safely dismantling a tower crane.

Scope of Work

The scope of work includes the dismantling of a [insert type/model] tower crane, located at [insert location], to a height of [insert height] meters. The crane has a lifting capacity of [insert capacity] tons and consists of [insert number] sections.

Pre-Dismantling Activities

Before dismantling the tower crane, the following activities will be carried out:

Dismantling Procedure

The dismantling procedure will be carried out in the following stages:

Stage 1: Preparation

Stage 2: Dismantling of Crane Sections

Stage 3: Removal of Crane Components

Stage 4: Final Activities

Safety Measures

The following safety measures will be implemented during the dismantling process:

Equipment and Tools

The following equipment and tools will be used during the dismantling process:

Quality Control

The following quality control measures will be implemented during the dismantling process:

Environmental Considerations

The following environmental considerations will be taken into account during the dismantling process:

Conclusion

The dismantling of a tower crane is a complex process that requires careful planning and execution. This method statement outlines the steps and procedures for safely dismantling a tower crane. By following this method statement, the risk of accidents and injuries can be minimized, and the dismantling process can be completed efficiently and effectively.

A tower crane dismantling method statement is not merely paperwork – it is a life-saving operational blueprint. Every bolt removed represents a high-risk engineering challenge. By following the systematic, step-by-step approach outlined above – including rigorous pre-planning, clear roles, weather monitoring, and emergency contingencies – project managers and dismantling crews can complete the job safely, efficiently, and in compliance with regulatory standards. Always remember: if the method statement does not adequately address a specific site condition, stop work and revise the document before proceeding.

Final note: This article is a general guide. Always consult your crane manufacturer’s specific manual, local legal requirements (OSHA 1926.1400, BS 7121, etc.), and a qualified appointed person before any dismantling operation.

You should adapt the site-specific details (crane model, load capacities, access constraints, weather limits, etc.) before use.

A tower crane dismantling method statement is the final safety-critical document on a construction project. It transforms a high-risk, complex operation into a controlled sequence of verifiable steps. Never rush this process. The crane that took three days to erect may only take eight hours to dismantle, but those eight hours demand greater vigilance.

Before any pin is pulled or sling attached, ensure:

When in doubt, stop. Re-evaluate. Then proceed. Stage 2: Dismantling of Crane Sections

Disclaimer: This article is a generic template for informational purposes. Always consult the specific crane manufacturer’s manual and employ a qualified Appointed Person to prepare a site-specific method statement. Regulations vary by jurisdiction.

METHOD STATEMENT FOR THE DISMANTLING OF A TOWER CRANE

1. PROJECT DETAILS

2. SCOPE OF WORK This method statement outlines the procedures for the safe dismantling of the tower crane described above. The scope includes the recovery of the crane components from its erected position, lowering them to ground level, and loading them onto transport vehicles for removal from site. The dismantling will be performed using a mobile crane (assist crane) and the tower crane’s own climbing system where applicable.

3. RESPONSIBLE PERSONNEL

4. EQUIPMENT AND RESOURCES

5. PRE-DISMANTLING PREPARATION

6. SEQUENCE OF OPERATIONS

Phase 1: Jib and Counter-Jib Dismantling

Phase 2: Tower Dismantling (Climbing Down or Section Removal) Option A: Internal Climbing (if applicable)

Option B: Section Removal by Mobile Crane

A Tower Crane Dismantling Method Statement is a critical safety document that outlines the step-by-step procedure for removing a crane from a construction site.

Below is a standard framework for this document. Note: This must be tailored to the specific crane model, site constraints, and local safety regulations by a qualified engineer. 1. Project Overview & Scope Project Name/Location: [Insert Details]

Crane Specifications: Make, model, jib length, and current height under hook.

Objective: To safely decommission and remove the tower crane using a mobile assist crane. 2. Personnel & Responsibilities

Appointed Person (AP): Responsible for the lift plan and overall management. Crane Supervisor: Oversees the dismantling team on-site.

Slinger/Signallers: Responsible for attaching loads and directing the assist crane.

Crane Technicians/Erectors: Skilled team performing the mechanical disassembly. 3. Equipment & Tools

Assist Crane: [Insert Capacity, e.g., 200-ton Mobile Crane] with sufficient boom length.

Hand Tools: Torque wrenches, impact drivers, drift pins, and sledgehammers.

Safety Gear: Full-body harnesses, fall arrest lanyards, radios, and standard PPE (Hard hats, boots, hi-vis). 4. Pre-Dismantling Requirements

Exclusion Zone: Establish a physical barrier around the radius of the crane and the loading area to prevent unauthorized access.

Weather Check: Confirm wind speeds are below the manufacturer’s limit for dismantling (typically <10 m/s).

Ground Conditions: Verify the mobile crane standing area is compacted and capable of bearing the outrigger loads. 5. Step-by-Step Dismantling Procedure Phase A: Preparation

Position the mobile assist crane and set outriggers on spreader mats.

Trolley the tower crane to the minimum radius and engage the slew lock.

Disconnect the main power supply and switch to the assist crane’s auxiliary power if required. Phase B: Counterweights & Jib

Counter-Jib Weights: Remove the specified number of counterweight blocks as per the manufacturer's manual to maintain balance.

The Jib: Attach the assist crane to the jib at designated lifting points. Remove pins and lower the jib to the ground for further disassembly. a hammerhead or luffing jib crane)

The Counter-Jib: Remove the remaining counterweights, then rig and lower the counter-jib. Phase C: Tower Head & Cab

Rig the tower head/apex and disconnect it from the slewing ring. Lower to the transport vehicle. Disconnect and lower the operator’s cabin. Phase D: Slewing Assembly & Tower Sections Unbolt the slewing ring/gear assembly and lower it.

Systematically unbolt and remove tower sections (masts) one by one. If a climbing frame was used, dismantle and lower it last. 6. Safety & Environmental Controls

Fall Protection: 100% tie-off policy for all technicians working at height.

Communication: Dedicated radio channel for the lead signaller and mobile crane operator.

Waste Management: Ensure no hydraulic fluids leak during hose disconnection; use drip trays where necessary. 7. Emergency Procedures

Contact details for the nearest hospital and site first aid station. Rescue plan for a technician stranded at height.

A Tower Crane Dismantling Method Statement is a critical safety document that details the sequence, equipment, and precautions required to safely take down a crane. It typically follows a reverse order of erection, starting from the hook and moving down to the foundation. 1. Preliminary Preparations

Before any physical work begins, specific site conditions and administrative checks must be met:

Site Survey & Risk Assessment: A full site survey is conducted to identify hazards like adjacent buildings, power lines, or street furniture.

Weather Monitoring: Dismantling must stop if wind speeds exceed specific limits (typically 25 km/h or 14 m/s).

Exclusion Zone: A safe zone must be barricaded, with warning signs and guards to prevent unauthorized entry.

Permit to Work (PTW): Ensure all necessary permits and third-party certifications for equipment and personnel are in place. 2. Equipment & Personnel

Personnel: Only qualified professionals (erectors, riggers, and signalmen) who are medically fit should be involved.

Mobile Crane: A larger mobile crane (e.g., 150T or 160T) is often used to lower heavy sections like the jib and counter jib.

Communication: Continuous radio or hand signal communication must be maintained between the operator, ground crew, and safety officer. 3. Standard Dismantling Sequence While specifics vary by crane model (like the Potain MCi 85 or Zoomlion 6517 ), the general top-down steps are:

Hook & Hoist: Remove the hook block and reeve the hoist rope back onto the drum.

Counterweights: Use a mobile crane to remove the rear counter ballast blocks one by one to maintain balance.

Front Boom (Jib): Sling and dismantle the jib in sections, often using the mobile crane to lower them to the ground.

Operator's Cabin & Slewing Unit: Dismantle the cab, turntable, and slewing mechanism.

Mast Sections: Remove tower/mast sections one by one. If using a climbing frame (telescoping cage), it is used to lower the top sections within reach of a mobile crane.

Chassis & Foundation: Finally, dismantle the base frame, outriggers, or bogies and clear all debris from the site. 4. Safety Checks During Work

Balance: Always ensure the crane is in balance before unpinning major components. Use trolleying to fine-tune balance if needed.

Stored Energy: Safely release any stored energy (e.g., hydraulic pressure or tensioned cables) before disassembly.

Lifting Accessories: Inspect all slings, chains, and shackles—the 3-3-3 rule suggests taking 3 seconds to inspect before every lift. Tower Crane Dismantling Procedure | PDF - Scribd

The method statement serves as the operational playbook. Its primary purposes are:

Scope typically covers: The complete dismantling of a specific tower crane model (e.g., a hammerhead or luffing jib crane), including the removal of the jib, counter-jib, tower mast sections, slewing unit, and base/foundation plates.

The purpose of this method statement is to define the systematic procedure for the safe dismantling of a [Insert Make/Model] tower crane (e.g., Potain MDT 289, Wolff 355B) from the [Project Name] site. This document ensures all personnel understand their duties, the sequence of operations, and the hazard controls required.

Using the auxiliary mobile crane.

Critical: Never stand under the jib during pin removal. Use tag lines.