Moving a redirecting sheave changes support reactions even when the load mass is unchanged. Review the whole winch, rope, sheave, anchor and landing system for the new arrangement before lifting.
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
1. Singapore legal and technical basis
Singapore lifting controls require the actual lifting duty, complete load path and suitable competent team to be established before use. Confirm the equipment category, registration applicability and current examination requirements with the Authorised Examiner where applicable. MOM distinguishes required load/functional tests from the removed periodic overload tests; neither a nameplate nor an exemption claim proves this installation safe.
| Source category | Task application and limit |
|---|---|
| MOM - Risk management | Assess lifting, recoil, landing and dismantling changes. Official explanation of WSH Risk Management duties, not a complete consolidated statutory text. |
| WSHC - Planning a Lift | Plan actual load, route, personnel and change control. Official guidance. The plan and permit requirements must be determined for the actual lifting operation; this page is not a universal permit rule. |
| MOM - Test and examination circular, 29 August 2025 | Resolve the applicable test and examination schedule. Table extraction has merged cells; no model-specific test scope or detailed interval is certified here. Consult the original schedule with the Authorised Examiner. |
| MOM - Lifting equipment examination FAQ | Distinguish overload testing from continuing examination and functional checks. Removal of periodic overload tests does not remove examination, functional testing or required load tests. The actual altered crane needs AE determination. |
| WSHC - Safe Use of Machinery | Control guarded drum access, unexpected starts and stored energy. Official guidance with a summary of statutory duties; not a machine-specific safeguard design or full review of current legislation or paid standards. |
Use Singapore requirements and SI units. Manufacturer limits apply to the actual model. Foreign technical examples do not establish Singapore statutory duties. A job safety analysis or completed checklist is not a permit or approval.
2. Scope and required inputs
Included work
Lifting material with a winch specifically permitted for that lifting duty and an engineered arrangement of anchors, sheaves, rope and rigging, followed by stable landing, tension release and dismantling.
Separate assessment
Converting a vehicle-recovery-only winch to a lifting device, personnel lifting, forced extraction of stuck loads and unreviewed load-path changes are excluded.
| Required input | Evidence to obtain |
|---|---|
| Review lifting duty and load | Model and lifting duty; Load weight and centre; Layer capacity; Speed and duty limits |
| Review anchors and route | Sheave location and angle; Anchor reaction basis; Revised layout; Recoil and fall boundary |
| Inspect rope and controls | Rope and attachment; Brake inspection; Stop and restart response; Supply and protection |
| Rig and trial lift | Rigging and centre; Trial position; Brake holding; Anchor sheave movement |
Singapore application
Verify a lifting-permitted winch and the actual duty/layer chart. Vehicle-recovery-only winches, personnel lifting and forced extraction are excluded. Record the equipment category and applicable examination evidence with the asset owner; no blanket registration exemption or universal rope-wrap number is assumed.
3. Eight-stage JSA
| Job stage | Hazards and effects | Failure factors | Controls | Site verification | P | S | R | A |
|---|---|---|---|---|---|---|---|---|
| 1. Review lifting duty and load | 1. Dropped load2. Winch failure3. Insufficient line pull4. Brake loss | 1. Recovery-only tool used2. Weight unknown3. Layer capacity ignored4. Duty misunderstood | 1. Verify lifting-permitted model2. Confirm actual load3. Review layer chart4. Match duty and brake limits | 1. Model and lifting duty2. Load weight and centre3. Layer capacity4. Duty and examination status | ||||
| 2. Review anchors and route | 1. Anchor pullout2. Sheave drop3. Side-load failure4. Rope recoil | 1. Redirect reaction omitted2. Support unreviewed3. Sheave moved4. People in bight | 1. Review complete force path2. Match support directions3. Reassess layout changes4. Exclude rope and load zones | 1. Sheave location and angle2. Anchor reaction basis3. Accepted revised load path4. Recoil and fall boundary | ||||
| 3. Inspect rope and controls | 1. Brake failure2. Entanglement3. End slip4. Unexpected restart | 1. Rope damaged2. Guard missing3. Termination wrong4. Power-loss control defective | 1. Inspect rope and drum2. Check guards and stops3. Verify approved termination4. Test required control features | 1. Rope and attachment2. Brake inspection3. Stop and restart response4. Supply and protection | ||||
| 4. Rig and trial lift | 1. Eccentric rotation2. Rigging release3. Support deformation4. Load collision | 1. Center unreviewed2. Hook connection incomplete3. Movement ignored4. Path obstructed | 1. Use approved lift points2. Inspect complete rigging3. Trial low by accepted method4. Watch support and balance | 1. Rigging and centre2. Trial position3. Brake holding4. Anchor sheave movement | ||||
| 5. Lift and watch spooling | 1. Overlap damage2. Sudden load drop3. Flange interference4. Crushed rope | 1. Layer unchecked2. Signals lost3. Fleet angle excessive4. Rope hand-guided | 1. Maintain permitted spooling2. Stop on lost contact3. Observe actual lead angle4. Keep hands off moving rope | 1. Layers and wrap conditions2. Signals and sightline3. Rope lead angle4. Drum and rope condition | ||||
| 6. Land and transfer load | 1. Support collapse2. Sudden movement3. Hand crush4. Stack overturn | 1. Rope slackened early2. Contact mistaken for support3. Hands adjust gap4. Restraint absent | 1. Land on accepted supports2. Verify full load transfer3. Keep pinch zones clear4. Restrain before tension release | 1. Support and contact2. Movement restraint3. Hand-clearance check4. Tension-release sequence | ||||
| 7. Hold fault or outage | 1. Brake-release drop2. Residual-energy recoil3. Unexpected motion4. Temporary-support failure | 1. Repair under load2. Stuck load overpulled3. Power alone isolated4. Residual load unknown | 1. Stop and exclude area2. Use reviewed load support3. Control power and tension4. Follow separate recovery plan | 1. Load and tension state2. Support plan3. Isolation verification4. Repair and restart authority | ||||
| 8. Dismantle and transfer | 1. Tensioned-rope strike2. Damaged gear reused3. Falling anchor parts4. Lost defect history | 1. Anchor released loaded2. Defect untagged3. Order confused4. Gear ID absent | 1. Verify unloaded condition2. Follow removal sequence3. Segregate damaged gear4. Transfer inspection history | 1. Load transfer and no tension2. Dismantling order3. Rope and equipment defects4. Recipient and use limits |
P/S/R/A and actual measurements, checks, names and signatures remain blank for the site assessment. A score cannot waive a required control.
4. Hypothetical scenario and failure mechanisms
This illustration provides educational context. It is not an actual incident photograph or evidence of equipment suitability; any AI-generated depiction is illustrative only.
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
| Stage | Fictional situation |
|---|---|
| Initial situation | A fictional winch lift uses a redirecting sheave. |
| Changed condition | The sheave is moved to clear a walkway. |
| Failure path | The crew relies on unchanged load weight and winch rating and omits a new anchor review. |
| Possible outcome | The changed reaction could deform the support, release the rope and drop the load. |
| Prevention barrier | Hold the lift, record actual angles and positions, verify the revised support and rope arrangement and complete the accepted trial before release. |
Failure mechanisms
A winch nameplate does not rate the whole lifting system. Drum layer changes the effective radius and may change available line pull. Brake holding, rope, attachments, duty cycle and anchor capacity must all suit the actual lifting configuration.
A redirecting sheave support carries the vector sum of the rope forces acting on it, with the actual geometry and relevant friction/dynamic effects considered. Moving the sheave can change the force direction and reaction even when material weight and winch are unchanged.
Touching a landing support is not complete load transfer. Verify the intended contact and restraint against movement before releasing rope tension. Power isolation also does not support a suspended load or remove stored rope energy.
Work sequence: Review lifting duty and load → Review anchors and route → Inspect rope and controls → Rig and trial lift → Lift and watch spooling → Land and transfer load → Hold fault or outage → Dismantle and transfer. This is a teaching flow, not a device drawing or a complete operating procedure.
5. Hold and proceed decisions
| Situation | Required action | Evidence | Proceed when |
|---|---|---|---|
| Sheave relocated | Review whole force path | Angles, anchor and reaction review | Layout accepted |
| Rope overlaps or crushes | Stop safely | Layer, rope condition and recovery | Spooling restored |
| Brake slips | Use planned safe load support | Brake repair and test evidence | Equipment accepted |
| Dismantling requested | Verify unloaded state | Landing, restraint and tension | Load fully transferred |
Similar observations, different decisions
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
| Observation | Insufficient conclusion | Required distinction |
|---|---|---|
| Same load weight | Mass unchanged | Sheave reaction may differ |
| Load touches support | Contact observed | Complete transfer unproved |
| Power switched off | Drive isolated | Suspended load remains |
6. Roles and supervision
| Role | Responsibility |
|---|---|
| Work supervisor | Confirm model and lifting duty and the task scope, resources, interfaces and stop authority. |
| Qualified technical reviewer | Review sheave location and angle, model limits, compatibility and unresolved technical conditions within assigned competence. |
| Work crew | Apply the listed controls, report changes and stop when evidence or safeguards are missing. |
| Inspector / assessor | Record actual layers and wrap conditions and other relevant checks; do not mark unverified conditions as accepted. |
| Handover authority | Reconcile load transfer and no tension, restrictions and outstanding actions before the next task. Role labels do not establish a legal credential. |
Supervision and handover focus
| Stage | Management action | Evidence |
|---|---|---|
| Review lifting duty and load | 1. Record model and lifting duty2. Record load weight and centre3. Record layer capacity | 1. Model and lifting duty2. Load weight and centre3. Layer capacity |
| Review anchors and route | 1. Record sheave location and angle2. Record anchor reaction basis3. Record revised layout | 1. Sheave location and angle2. Anchor reaction basis3. Revised layout |
| Rig and trial lift | 1. Record rigging and centre2. Record trial position3. Record brake holding | 1. Rigging and centre2. Trial position3. Brake holding |
| Lift and watch spooling | 1. Record layers and wrap conditions2. Record signals and sightline3. Record rope lead angle | 1. Layers and wrap conditions2. Signals and sightline3. Rope lead angle |
| Hold fault or outage | 1. Record load and tension state2. Record support plan3. Record isolation verification | 1. Load and tension state2. Support plan3. Isolation verification |
| Dismantle and transfer | 1. Record load transfer and no tension2. Record dismantling order3. Record rope and equipment defects | 1. Load transfer and no tension2. Dismantling order3. Rope and equipment defects |
Singapore application
The responsible lifting lead and engineer accept the actual anchor/sheave arrangement and load reactions. The operator follows model braking, spooling and duty limits. The receiving team verifies stable support and restraint before tension release; maintenance isolation does not by itself support a suspended load.
7. Hold points and record quality
| Hold point | Evidence before release | Actual approval |
|---|---|---|
| HP-0 Scope | Lifting material with a winch specifically permitted for that lifting duty and an engineered arrangement of anchors, sheaves, rope and rigging, followed by stable landing, tension release and dismantling. | |
| HP-1 Review anchors and route | Sheave location and angle; Anchor reaction basis; Revised layout; Recoil and fall boundary | |
| HP-2 Rig and trial lift | Rigging and centre; Trial position; Brake holding; Anchor sheave movement | |
| HP-3 Hold fault or outage | Load and tension state; Support plan; Isolation verification; Repair and restart authority | |
| HP-4 Dismantle and transfer | Load transfer and no tension; Dismantling order; Rope and equipment defects; Recipient and use limits |
Hold points are internal project checks. They are not universal statutory permits and do not grant work permission. Reassess after defects, changed conditions and shift changes.
Record comparison
The scenario and record comparisons are fictional teaching examples, not records of real incidents, measurements, inspections, signatures or approvals.
The boxes are static record prompts, not interactive or saved approvals. A tick does not establish suitability or permission to restart. Record the evidence, person, time and unresolved issues; retain the change history.
| Record | Insufficient record | Record checklist |
|---|---|---|
| Review lifting duty and load | Only marked “OK” | □ Model and lifting duty□ Load weight and centre□ Layer capacity□ Speed and duty limits |
| Rig and trial lift | Only marked “OK” | □ Rigging and centre□ Trial position□ Brake holding□ Anchor sheave movement |
| Hold fault or outage | Only marked “OK” | □ Load and tension state□ Support plan□ Isolation verification□ Repair and restart authority |
| Dismantle and transfer | Only marked “OK” | □ Load transfer and no tension□ Dismantling order□ Rope and equipment defects□ Recipient and use limits |
8. Pre-work checks and emergency response
| Site check | Actual result | Person / action |
|---|---|---|
| Review lifting duty and load: Model and lifting duty; Load weight and centre; Layer capacity; Speed and duty limits | ||
| Review anchors and route: Sheave location and angle; Anchor reaction basis; Revised layout; Recoil and fall boundary | ||
| Inspect rope and controls: Rope and attachment; Brake inspection; Stop and restart response; Supply and protection | ||
| Rig and trial lift: Rigging and centre; Trial position; Brake holding; Anchor sheave movement | ||
| Lift and watch spooling: Layers and wrap conditions; Signals and sightline; Rope lead angle; Drum and rope condition | ||
| Land and transfer load: Support and contact; Movement restraint; Hand-clearance check; Tension-release sequence | ||
| Hold fault or outage: Load and tension state; Support plan; Isolation verification; Repair and restart authority | ||
| Dismantle and transfer: Load transfer and no tension; Dismantling order; Rope and equipment defects; Recipient and use limits |
Stop work
Stop for rope overlap/damage, anchor movement, brake slip, abnormal resistance, lost signals or entry into rope/load zones. Do not repair under an unsupported load or increase force to free a stuck object.
Emergency response
Maintain exclusion from the suspended load, rope bights and recoil paths. Use the planned competent load-stabilization and emergency response arrangements. Do not release anchors, brakes or rope connections until the actual load and residual energy are controlled.
9. Sources and review limits
Public-source review: 14 October 2026. Only the material and limits identified below were reviewed.
| Source | Reviewed material | Task application |
|---|---|---|
| MOM - Risk management | Responsibilities; routine and non-routine work; hierarchy of control and risk assessment team. Official explanation of WSH Risk Management duties, not a complete consolidated statutory text. | Assess lifting, recoil, landing and dismantling changes. |
| WSHC - Planning a Lift | Main guidance on lifting plans, load, equipment, crew, method, communication, environment and changed conditions. Official guidance. The plan and permit requirements must be determined for the actual lifting operation; this page is not a universal permit rule. | Plan actual load, route, personnel and change control. |
| MOM - Test and examination circular, 29 August 2025 | Three-page text extraction, revised regime effective 12 September 2025, equipment categories and test definitions. Table extraction has merged cells; no model-specific test scope or detailed interval is certified here. Consult the original schedule with the Authorised Examiner. | Resolve the applicable test and examination schedule. |
| MOM - Lifting equipment examination FAQ | Questions 1-6 and 15: overload versus load/functional tests, changed requirements and Authorised Examiner discretion. Removal of periodic overload tests does not remove examination, functional testing or required load tests. The actual altered crane needs AE determination. | Distinguish overload testing from continuing examination and functional checks. |
| WSHC - Safe Use of Machinery | Printed pages 4, 27, 37-39: dangerous parts, maintenance training, hazardous-energy isolation, verification, group/shift continuity and restoration. Official guidance with a summary of statutory duties; not a machine-specific safeguard design or full review of current legislation or paid standards. | Control guarded drum access, unexpected starts and stored energy. |
Selected public official sources were reviewed on 14 October 2026 within the recorded scope. No full consolidated legal audit, paid Singapore Standard, actual model manual, site inspection, engineering calculation or professional approval is claimed. Verify current detailed requirements and actual equipment/site records before use.
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
10. PDF use and frequently asked questions
PDF A covers basic task controls; B focuses on technical failures; C covers supervision, records and handover. The article has eight stages with four items per main cell; each PDF has six key stages with three items per main cell. P/S/R/A, measurements, confirmations and signatures remain blank for actual site assessment.
PDFs are complementary six-stage extracts. Apply all eight body stages and the actual equipment/site procedure.
Can a recovery-winch rating authorize lifting?
No. Verify that the actual model and installation are permitted for this lifting duty.
How many rope wraps must remain?
Meet the applicable equipment requirements and the exact manufacturer minimum-wrap, attachment and layer conditions; do not use a generic number.
Can the anchor be removed when the load touches down?
Only after complete stable support, movement restraint and verified tension removal under the approved sequence.
Has a professional verified or approved this document?
No. Public sources and editorial, layout and consistency checks were reviewed using AI. No site inspection or professional technical approval has been performed. Obtain appropriate professional review before use.
Singapore application
Read A, B and C together with all eight JSA stages and the approved work procedure. The sheets are complementary extracts, not separate work authorisations.
11. Authorship and revision history
AI-generated reference material. It has not been verified or approved by a professional. Before use, a qualified person must review and adapt it to applicable Singapore requirements, the actual equipment and site, and approved safe work procedures.
| Date / edition | Authorship and scope | Professional approval |
|---|---|---|
| 2026-09-19 / Korean source | Original topic and educational illustration retained as references. Source content is unchanged. | Not asserted |
| 14 October 2026 / Singapore 1.0 | Added Singapore lifting-equipment classification/AE gate and changed-load-path acceptance without generic wrap or proof-test numbers. | Not performed |
Source topic: https://smartjsabridge.com/ko/case-study/jsa-winch-lifting