Pre-installation inspection covers five critical areas ensuring platform safety from the moment of first use.

 

Roof anchor point inspection: Verify anchor point structural integrity—concrete anchors require minimum C25 strength withembedment depth per manufacturer specification (typically 80-120mm for M16 anchors). Confirm anchor positions match installation drawings—incorrect spacing invalidates load calculations. Test 25% of anchors with calibrated torque wrench to 110% of specified installation torque. Document test results with anchor identification numbers. For suspended platforms exceeding 500kg capacity, structural engineer confirmation letter should be obtained before installation.

 

Counterweight verification: Confirm counterweight quantity matches calculated requirement—typically 500-1000kg per side for standard platforms. Verify counterweight blocks are actual weight—documented cases show counterfeit counterweights weighing 30-40% below marked weight. Inspect counterweight attachment hardware—U-bolts, shackles, and safety pins must be present and undamaged. Confirm counterweight trolley wheels function freely and brakes engage properly.

 

Wire rope inspection: Unwrap and visually inspect all wire ropes before installation—check for kinking, birdcaging, broken wires, or corrosion. Measure diameter at multiple points—diameter must be within manufacturer tolerance. Verify rope length sufficient for planned working height plus 2-3 wraps on drum. Confirm wire rope end terminations (sockets or swages) are factory-installed with certification documentation.

 

Electrical system check: Verify control panel seals intact—no signs of moisture intrusion. Test all control functions including emergency stop. Confirm limit switches function correctly at full and minimum platform positions. Verify ground fault protection functional—test with fault indicator button. Inspect cable management—no damaged cable sheathing, proper support, and appropriate bends.

 

Safety device verification: Confirm overspeed safety devices are installed, calibrated, and show ready status. Check safety harnesses and lanyards—in-date for inspection, no visible damage. Verify platform guardrails, toe boards, and access gates function properly. Confirm communication system (radio or hard-wired) operational between platform and ground supervision.

 

 

 

Installation follows a sequential procedure ensuring each step is completed before proceeding to the next.

 

Site preparation: Establish exclusion zone below installation area with warning signs and barriers. Position mobile elevated work platform (MEWP) or scaffolding at roof anchor points for installation access. Clear debris from rooftop and ensure clean working surface. Position counterweight trolleys at designated anchor points.

 

Anchor point preparation: Install suspension rigging (outriggers, beams, or anchor frames) per manufacturer drawings. Tighten all bolted connections to specified torque using calibrated torque wrench. Install safety pins and secondary retention devices on all load-bearing connections. Verify anchor points are level—height differential should not exceed 10mm across suspension points.

 

Wire rope installation: Route wire ropes from platform drum to suspension points avoiding sharp edges—use edge guards where rope contacts building surfaces. Install temporary guide ropes for handling rope during raising. Ensure rope enters drum grooves correctly—spiral grooves must match rope diameter. Wind minimum 3 wraps of rope on drum before releasing platform from ground.

 

Platform assembly: Assemble platform sections on ground if not pre-assembled. Install all guardrails, toe boards, and safety gates. Connect electrical connections following color-coding—verify all connections secure and weatherproof. Install counterweights onto trolleys in calculated quantity. Attach safety harnesses and lanyards to designated anchor points on platform.

 

Initial raising: Raise platform slowly (approximately 5m/min initial speed) while observing wire rope winding on drums. Watch for rope displacement from grooves, unusual noises, or platform tilting. Stop immediately if any abnormality detected. Raise to minimum working height and inspect suspension points while platform is occupied.

 

Load testing: With platform at minimum height and occupied by test crew, conduct no-load test: raise and lower platform through full range, test all limit switches, verify emergency stop function. Conduct rated load test: add calibrated test weights to rated capacity; raise platform 1m and hold for 5 minutes—platform should not descend; check for structural noise or abnormal deflection; lower and inspect all connections. Document test results in installation certificate.

 

 

 

Analysis of installation-related accidents reveals predictable error patterns that systematic procedures can prevent.

 

Counterweight miscalculation (15% of installation accidents): Counterweight calculation errors include forgetting dynamic coefficient (EN1808 requires 1.4 factor), mismeasuring lever arm distance, and using incorrect counterweight block weight. Prevention: Use standardized calculation forms with built-in formulas; verify block weight against shipping documentation; require second-person verification of all calculations. Physical check: after loading counterweights, verify platform does not float (rise without load) by more than 50mm when all weights are on trolleys.

 

Wire rope termination failure (20% of fall accidents): Socket or swage termination not properly seated, missing safety clips, or incorrect installation sequence. Prevention: Factory terminations only—field terminations prohibited without specialized equipment and certification. Verify safety clip installation per manufacturer diagram—missing or incorrectly installed clips are common. Implement torque verification on all connection bolts.

 

Anchor point failure (25% of structural accidents): Inadequate embedment depth, concrete strength below specification, or incorrect anchor type for substrate. Prevention: Core drill inspection of 10% of anchor positions before installation to verify concrete strength. Verify anchor type matches substrate—some anchors require specific concrete thickness. Use anchor pull-out tester on first installation day to confirm holding force.

 

Electrical system errors (10% of electrical incidents): Incorrect wiring sequence, damaged cables during installation, or missing grounding connections. Prevention: Use pre-installation wiring continuity checks; protect cables with appropriate conduits; verify grounding connections with multimeter before energizing. Never bypass safety interlock circuits for troubleshooting convenience.

 

Personnel qualification errors (30% of accidents): Installation by unqualified personnel, inadequate supervision, or insufficient communication. Prevention: Verify installer certification before assigning work; require minimum 2-person installation teams; implement formal pre-installation meeting to review procedures; require supervisor sign-off at each step completion.

 

 

 

Dismantling follows reverse sequence of installation but with specific differences addressing safety during removal operations.

 

Personnel positioning: During installation, personnel work from above (roof level) for suspension rigging and from platform level during testing. During dismantling, personnel work primarily from platform level to remove counterweights and disconnect components, plus roof level for suspension rigging removal. This requires more personnel and careful coordination between roof and platform teams.

 

Counterweight removal sequence: Counterweights must be removed from the trolley that has been moved to the designated unloading position—not while platform is at height. This requires lowering platform to minimum height, moving trolley to edge, unloading counterweights to ground, then repositioning trolley for next removal cycle. Never remove counterweights while platform is suspended at working height.

 

Wire rope unwinding: During dismantling, wire ropes must be unwound from drums in controlled manner—excessive speed causes rope to pile on drum or tangle. Use brake to control descent speed. Maintain minimum 3 wraps on drum until rope is completely free from suspension points. Never allow rope to run free during unwinding.

 

Suspension rigging removal: Remove suspension rigging after platform is fully lowered to ground and disconnected. Maintain stability during removal—progressive disassembly rather than removing all connections simultaneously. Final disconnection should be last step with only one person at roof level after platform is grounded and confirmed empty.

 

Dismantling sequence: (1) Clear all materials, tools, and debris from platform. (2) Lower platform to minimum working height. (3) Remove counterweights to ground level—never while platform is suspended. (4) Move platform to ground level and disconnect electrical connections. (5) Disconnect and remove wire ropes from platform, coiling carefully for storage or inspection. (6) Lower platform to ground and secure. (7) Remove suspension rigging from roof anchor points. (8) Document condition of all components for return-touservice inspection.

 

 

 

Pre-installation checklist: roof anchor points, counterweight quantity, wire ropes, electrical system, safety devices

Counterweight calculation: total counterweight greater than or equal to (max load x safety factor 2)/lever ratio; usually 500-1000kg per side

Installation acceptance: must conduct no-load and rated load tests (gradual loading)

Dismantling sequence: first installed, last dismantled; last installed, first dismantled

Common error #1: insufficient counterweight causing overturning (15% of accidents)

Common error #2: wire rope anchor points not double-locked (20% of fall accidents)