Lifting Plan for Tandem Lifting and Critical Lifting
Understanding Lifting Operations
Lifting operations involve moving heavy loads using cranes, hoists, or other mechanical equipment. These operations are common in construction, oil & gas, and heavy industrial projects. Without a structured lifting plan, accidents such as load drops, crane failures, and worker injuries can occur.
What is Tandem Lifting?
Tandem lifting refers to using two or more cranes simultaneously to lift a single load. This method is used when the load is too large or heavy for a single crane to handle safely.
When is Tandem Lifting Required?
- Moving large prefabricated structures
- Lifting long and heavy beams or pipes
- Installing heavy equipment in restricted spaces
What is Critical Lifting?
A critical lift is any lift that:
- Exceeds 75% of the crane’s rated capacity
- Is performed near obstacles or live equipment
- Involves lifting personnel or hazardous materials
Examples of Critical Lifting:
- Lifting reactors in refineries
- Handling nuclear components
- Installing offshore platforms
Key Elements of a Lifting Plan
A well-structured lifting plan should include:
- Load Calculations – Determining weight, center of gravity, and load stability.
- Crane Selection – Choosing the right crane type and configuration.
- Risk Assessment – Identifying potential hazards and mitigation measures.
- Personnel Roles – Defining responsibilities for operators, riggers, and supervisors.
- Emergency Procedures – Preparing for unexpected situations.
Step-by-Step Lifting Plan for Tandem Lifting
Step 1: Identifying the Load and Weight Distribution
- Calculate the exact weight of the load.
- Identify the center of gravity for balanced lifting.
Step 2: Selecting the Right Cranes
- Ensure both cranes have similar lifting capacities.
- Consider boom lengths and working radius.
Step 3: Coordinating Crane Movements and Communication
- Assign a Lead Crane Operator to control movements.
- Use radio communication and hand signals.
Step 4: Ensuring Synchronization Between Operators
- Both cranes should move at the same speed.
- Operators must follow a synchronized lifting sequence.
Step 5: Conducting a Trial Lift
- Lift the load slightly off the ground to check stability.
- Adjust rigging if necessary before completing the lift.
Step-by-Step Lifting Plan for Critical Lifting
Step 1: Understanding Load Characteristics
- Identify the shape, weight, and stability of the load.
Step 2: Verifying Equipment Load Capacity
- Check load charts to ensure the crane can handle the weight.
Step 3: Checking Environmental Factors
- Monitor wind speeds and ground stability.
Step 4: Appointing a Competent Lift Supervisor
- The supervisor oversees all aspects of the lift.
Step 5: Implementing Emergency Procedures
- Prepare for load swings, equipment failure, or power loss.
Sample Example of a Lifting Plan for Tandem Lifting and Critical Lifting
Project Overview
- Project Name: Installation of a Heat Exchanger in a Petrochemical Plant
- Location: Saudi Arabia
- Lifting Date: April 5, 2025
- Lifting Type: Tandem Lifting & Critical Lifting
- Equipment Used:
- Crane 1: 250-ton mobile crane
- Crane 2: 200-ton mobile crane
- Lifting Accessories:
- Wire rope slings (rated capacity: 50 tons each)
- Shackles (rated capacity: 75 tons each)
- Lifting beam
Load Details
- Load Type: Heat Exchanger
- Weight: 120 tons
- Length: 15 meters
- Center of Gravity (COG): Slightly off-center, requiring load balancing
Lifting Plan – Step by Step
Step 1: Risk Assessment & Safety Planning
✅ Conducted a Job Hazard Analysis (JHA) to identify potential risks.
✅ Established a Restricted Lifting Zone to prevent unauthorized access.
✅ Verified crane ground conditions and confirmed stability.
Step 2: Crane Selection & Load Calculation
✅ Crane 1 (250-ton) will take 65% of the load (78 tons).
✅ Crane 2 (200-ton) will take 35% of the load (42 tons).
✅ Load charts were checked to confirm each crane’s safe working load (SWL).
Step 3: Rigging & Load Balancing
✅ Used a lifting beam to distribute the load evenly.
✅ Connected slings and shackles to lifting points on the heat exchanger.
✅ Adjusted rigging angles to maintain the correct center of gravity.
Step 4: Communication & Coordination
✅ Assigned a Lead Crane Operator to synchronize movements.
✅ Used radio communication and hand signals between crane operators and riggers.
✅ Conducted a pre-lift meeting to clarify lifting sequences.
Step 5: Trial Lift & Final Execution
✅ Lifted the load 10 cm off the ground to check stability.
✅ Made minor adjustments to crane boom angles for proper alignment.
✅ Proceeded with a slow, controlled lift to the installation point.
Outcome & Lessons Learned
✔ Successful installation with no safety incidents.
✔ Improved load balancing by adjusting slings mid-lift.
✔ Enhanced coordination through real-time communication.
A structured lifting plan is essential for safe tandem and critical lifting operations. By ensuring proper risk assessment, crane selection, communication, and trial lifting, complex lifts can be executed safely and efficiently.
Safety Precautions for Tandem and Critical Lifting
✔ Inspect cranes, slings, and shackles before the lift.
✔ Ensure all personnel wear PPE (helmets, gloves, high-visibility vests).
✔ Establish clear communication between team members.
✔ Set up exclusion zones to keep unauthorized personnel away.
Case Study: A Successful Tandem and Critical Lift Execution
📌 Project: Lifting a 100-ton reactor vessel in a refinery
📌 Challenges: Tight space, high wind speeds
📌 Solution: Used two synchronized cranes, adjusted lift sequence, implemented a detailed contingency plan.
📌 Outcome: Safe and successful lift with zero incidents.
Conclusion
A well-structured lifting plan is essential for the safe execution of tandem lifting and critical lifting. By following proper procedures, conducting risk assessments, and ensuring strict supervision, companies can prevent accidents and complete projects efficiently.
Critical Lifting Risk Assessment
Tandem Lifting Risk Assessment
Tandem Lifting Vs Critical Lifting
Mobile Crane Safety Interview: 50 Questions and Sample Answers
Boom Truck Safety Interview: 50 Questions and Sample Answers
FAQs
- What is the difference between tandem lifting and critical lifting?
- Tandem lifting involves two cranes lifting the same load, while critical lifting involves high-risk conditions like extreme weights or hazardous environments.
- Who is responsible for preparing a lifting plan?
- A competent lifting engineer or supervisor is responsible for preparing and approving the plan.
- What are the main risks in tandem lifting?
- Uneven load distribution, miscommunication, and crane synchronization issues.
- Why is a trial lift important before critical lifting?
- It helps identify potential instability before the actual lift takes place.
