RIG DOWN
Complete Mast Lowering Procedure & Safety Protocol
🛢️ Oil & Gas Drilling Operations
Phase 1: Mast Semi-Vertical — Initial Lowering
Phase 2: Mast Inclined — Ongoing Lowering
Phase 3: Mast Near Horizontal — Advanced Lowering
🔍 What is Rig Down?
Rig Down is the systematic process of dismantling and lowering a drilling mast (derrick) from its operational vertical position to a horizontal or transport-ready state. This procedure is critical for rig relocation, maintenance, or decommissioning. The images above capture the three key stages of mast lowering in a desert drilling site, showing workers in full PPE coordinating the controlled descent of the massive steel structure.
📊 Key Facts
4
Main Phases
15+
Critical Steps
12+
Tools & Equipment
6
Major Hazards
Phase 1: Preparation & Inspection
1Pre-Task Meeting (Toolbox Talk)
Conduct a JSA (Job Safety Analysis) meeting. Assign clear roles to all crew members. Review the rig down procedure, identify hazards, and ensure everyone understands their responsibilities.
2Hydraulic Unit Startup & Testing
Start the hydraulic power unit. Test all control levers and hydraulic cylinders. Verify smooth operation of mast raising/lowering cylinders.
3Lubrication & Service Loop Check
Lubricate mast cylinders. Ensure service loops (cable bundles) are free from tangles and properly secured.
4Comprehensive Mast Inspection
Check for loose bolts, tools, or debris on the mast. Inspect all cables and wires for breaks or tangles. Verify brakes are functioning correctly. Never proceed with lowering if any defect is found.
Phase 2: Disassembly of Attachments
5Break Down High-Pressure Area
Disconnect the Stand-pipe Manifold and all High-Pressure (HP) Lines. Cap all open connections to prevent contamination.
6Break Down Setback Area
Using cranes, carefully remove the setback area (pipe racks). Ensure tag lines are used to guide loads away from personnel.
7Remove Rig Floor
Lift and remove the rig floor platform using cranes. Verify all personnel are clear before lifting operations.
8Remove A-Frames & Support Structures
Dismantle the A-frame support legs and any secondary bracing. Store bolts and pins in labeled containers.
Phase 3: Mast Lowering
9Attach Snub Lines to Heavy Trucks
Secure snub lines (guy wires) to heavy trucks positioned at safe distances. These lines control the descent speed and direction of the mast.
10Feed Raising Lines Through Sheaves
Thread the raising lines through the sheaves located on the mast side frames. Verify proper reeving and no line crossover.
11Pull Frame Raising Pins
Remove the frame raising pins from the mast side frames. Ensure the Bridle line is slack with no tension before proceeding.
12Initial Pull by Heavy Truck (5 meters)
A heavy truck pulls the mast approximately 5 meters to initiate the lowering sequence. This overcomes the initial static friction.
13Release Truck Line & Engage Magoo Brake
Release the truck line and continue lowering using the Magoo brake system for controlled descent. Two brake operators must be present at all times.
14Monitor Weight Indicator
Continuously monitor the weight indicator. Weight should increase as the mast lowers. Any unexpected drop indicates a problem — stop immediately.
15Stop at 10 Meters Above Ground
Halt the lowering when the mast crown is approximately 10 meters above ground level. This is the critical positioning phase.
16Position Crown Stand
Place the Crown Stand in its designated position. Ensure it is level and stable before lowering the mast onto it.
17Lower Mast Onto Crown Stand
Carefully lower the mast until it rests securely on the Crown Stand. Verify stability before releasing tension on all lines.
18Place Catwalk Under Traveling Block
Position the catwalk beneath the traveling block and secure it with chains. This provides safe access for further disassembly.
Phase 4: Dismantling
19Dismantle Mast Sections
Break down the mast into sections: Lower Section (ODS & DS), Middle Section (ODS & DS), Upper Section (ODS & DS), Crown Block, Rig Support Beams, Setback Area, A-Frames, Drawworks & Sub-base.
Cranes
Lifting and removing heavy mast sections, rig floor, and setback area
Heavy Trucks
Pulling snub lines to initiate and control mast lowering
Snub Lines (Guy Wires)
Controlling descent speed and directional stability during lowering
Raising Lines
Threaded through sheaves to guide mast movement during raise/lower
Magoo Brake System
Primary braking mechanism for controlled mast descent
Hydraulic Cylinders
Extending/retracting mast cylinders for positioning
Pins & Bolts
Securing and releasing mast frame connections
Weight Indicator
Real-time monitoring of load during lowering operations
Crown Stand
Support structure for the mast after lowering
Hand Tools
Wrenches, hammers, pliers for bolt/pin removal and assembly
Power Tools
Pneumatic/electric tools to speed up disassembly
Tag Lines
Guiding suspended loads away from personnel
Before Operations
Toolbox Talk / JSA Meeting
Conduct a thorough Job Safety Analysis. Explain all hazards, assign roles, and ensure every crew member understands the procedure before starting.
Equipment Inspection
Inspect all tools, cables, brakes, and hydraulic systems. Do not use any equipment showing signs of wear, damage, or malfunction.
Personal Protective Equipment (PPE)
All personnel must wear: Hard Hat, Safety Glasses, Safety Gloves, Steel-Toe Boots, High-Visibility Coveralls. No exceptions.
During Operations
No Personnel Under the Mast
ABSOLUTELY NO ONE is allowed beneath the mast or within the swing radius during lowering. Establish a clear exclusion zone and enforce it strictly.
No Climbing During Movement
Climbing on A-Legs, mast structure, or any part of the rig is PROHIBITED during raising or lowering operations.
Dual Brake Operators
Two trained brake operators must be present at all times. One primary operator and one backup ready to assist immediately if needed.
Use Tag Lines for Guiding
Never stand under suspended loads. Use tag lines to guide equipment and loads from a safe distance.
Secure All Loose Lines
All lines must be clear of personnel before lowering. Ensure no cables are tangled or under tension unexpectedly.
Tool Tethering
All tools suspended from the mast must be secured with lanyards/safety lines to prevent dropped object incidents.
Clear Communication
Maintain continuous communication between all crew members using hand signals or two-way radios. Confirm every command before action.
After Lowering
Secure Mast on Crown Stand
Verify the mast is stable and secure on the Crown Stand before releasing tension on any lines. Double-check all support points.
Post-Operation Maintenance
Clean, lubricate, and apply protective coating to all disassembled parts before transport or storage.
⚡ Ensuring Smooth & Efficient Rig Down Operations
Follow these 7 principles to eliminate delays, reduce risks, and maintain crew coordination throughout the entire procedure.
1
Pre-Planning: Develop a detailed step-by-step plan before starting. Every crew member must know the sequence, their role, and emergency procedures.
2
Clear Role Assignment: Assign specific tasks to each person with zero ambiguity. Use a role board if necessary. Everyone must know who does what.
3
Continuous Communication: Use standardized hand signals or radios. Confirm receipt of every command. No assumptions — verify everything.
4
Controlled Speed: Lower the mast SLOWLY and under full control. Never rush. The Magoo brake must be engaged properly. Speed kills — patience saves lives.
5
Dedicated Weight Monitor: Assign one person exclusively to watch the weight indicator. Any abnormal reading means STOP immediately and investigate.
6
Emergency Readiness: Have an emergency stop plan ready. All crew must know the emergency signals and evacuation routes. Conduct a dry run if possible.
7
Team Coordination: The Drawworks operator and ground crew must work as one unit. Synchronized actions prevent accidents and ensure smooth transitions.
| Hazard | Risk Level | Control Measure |
|---|---|---|
| Struck by Moving Equipment Cranes, trucks, mast swing |
CRITICAL | Maintain safe distance from all moving equipment. Establish exclusion zones. Use spotters. |
| Falls from Height Working on mast, A-frames |
CRITICAL | Use fall protection (harness, lanyard). No climbing during lowering. Secure work platforms. |
| Line Snagging / Whipping Cables, snub lines, tag lines |
HIGH | Clear all lines before lowering. Never stand in line-of-fire. Use proper reeving. |
| Dropped Objects Tools, bolts, debris |
HIGH | Tether all tools. Barricade areas below work zones. Wear hard hats at all times. |
| Crushing / Pinch Points Mast sections, hydraulic cylinders |
HIGH | Keep hands clear of pinch points. Use push sticks. Wear steel-toe boots and gloves. |
| Equipment Failure Brake failure, cable snap |
CRITICAL | Pre-operation inspection. Dual brake operators. Never exceed rated capacity. Replace worn parts. |
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