What are the duties of a rigging supervisor on oil rigs?

Rigging Supervisor (Oil Rigs) — Duties and Role Definition

Leads and controls all rigging and lifting operations on drilling and production installations, ensuring safe, compliant, and efficient handling of equipment, tubulars, and cargo on deck and between rig and supply vessels.

I. Core responsibilities

• I.1 Plan and authorize lifts: develop task risk assessments, lift method statements, and permits; conduct toolbox talks and pre-lift briefings.
• I.2 Engineer rigging arrangements: select slings, shackles, spreader bars, lifting frames; calculate load weight, center of gravity, sling angles, and line tensions; verify working load limits (WLL) and dynamic allowances.
• I.3 Supervise execution: direct riggers/banksmen, coordinate with crane operators, enforce exclusion zones and line-of-fire controls, verify tag line use and pinch-point management.
• I.4 Manage rigging loft: maintain inventory, certification and color coding; quarantine defective gear; track inspections, proof-load tests, and NDT schedules.
• I.5 Oversee critical lifts: review lift plans for complex geometry, offset CG, tight clearances, personnel proximity, or vessel-to-rig transfers; approve contingency plans and stop-work criteria.
• I.6 Control deck logistics: sequence lifts with drilling and marine operations; prepare backload; ensure proper slinging of cargo units and load restraint for sea fastening.
• I.7 Compliance: ensure adherence to offshore crane and lifting standards (e.g., offshore crane RPs, lifting operations regulations), site procedures, and SIMOPS rules.
• I.8 PTW and SIMOPS: raise lifting permits, align isolations and barriers, schedule operations around drilling, well testing, and marine activities.
• I.9 Assurance and reporting: perform field audits, post-job reviews, incident/dropped-object reporting, and lessons learned; maintain lift registers and daily activity logs.
• I.10 Emergency readiness: plan recovery of stuck loads, suspended load abandonment, and weather stand-by; coordinate with emergency response for man-basket operations.

II. Required skills and physical demands

• II.1 Technical skills
  • Lift planning and calculations: multi-leg sling tensions, included-angle effects, dynamic amplification for vessel lifts, CG estimation and reaction distribution.
  • Rigging gear knowledge: wire rope/chain/synthetic slings, shackles, turnbuckles, swivels, lifting clamps, padeyes, spreader beams, tuggers, chain hoists, come-alongs, skidding systems.
  • Crane operations interface: load charts, radius effects, boom obstructions, wind limits, supply-vessel operations, heave considerations, landing area selection.
  • Inspection and certification: visual/NDT acceptance criteria, discard criteria, traceability, proof-load requirements, and color-code regimes.
  • Standards and governance: application of offshore crane practices, lifting regulations, and site lifting procedures.
• II.2 Soft skills
  • Leadership under pressure, clear radio/hand-signal communication, hazard recognition, and stop-work enforcement.
  • Planning and coordination across drilling, marine, maintenance, construction, and logistics functions.
  • Documentation rigor: producing concise lift packs, permits, and shift handovers.
• II.3 Physical demands
  • Offshore work in heat, cold, wind, and sea spray; 12-hour shifts; prolonged standing and walking.
  • Manual handling of rigging gear (e.g., shackles, slings) within safe limits; frequent climbing, kneeling, and work at height with fall protection.
  • Use of PPE, radio headsets, and intrinsically safe tools; certified for offshore survival, medical fitness, and working at height.

III. Typical tools, software, and equipment

• III.1 Rigging gear
  • Wire rope, chain, and synthetic round slings; softeners and edge protection; master links and subassemblies.
  • Shackles, swivels, turnbuckles, hooks, plate clamps; spreader beams and modular lifting frames.
  • Chain hoists, lever hoists, tirfors/come-alongs; tuggers, winches, snatch blocks, beam trolleys.
  • Load cells/dynamometers, inclinometers/angle finders, measuring tapes, calibrated scales.
  • Skidding/rolling systems, hydraulic jacks, tag lines, man baskets, cargo baskets rated for offshore service.
  • Rigging loft storage systems with traceability tags; color-coding and quarantine bins.
• III.2 Software and systems
  • Lift planning software and 2D CAD for sketches and rigging arrangements.
  • Rigging calculators and spreadsheets for sling tension, CG, and reaction loads.
  • Electronic permit-to-work, digital certificate repositories, and CMMS for gear inspection scheduling.
  • Crane monitoring displays and weather/marine condition dashboards.

Toolchain Snapshot

• Lift planning suite; 2D CAD; spreadsheet templates.
• Digital PTW; lifting gear certificate database; CMMS.
• Load cells/dynos; inclinometers; radios; tag/ID systems.

Key rigging calculations (used in daily duties)

• Two-leg sling tension (symmetric): let total load be \(W\) and sling angle to vertical be \(\theta\). Tension per leg: \(T = \dfrac{W}{2\cos\theta}\). If angle to horizontal is \(\beta\), then \(T = \dfrac{W}{2\sin\beta}\).
• n-leg sling (equal angles/tension): \(T_{\text{leg}} = \dfrac{W}{n\cos\theta}\) (practically, only two legs may share when geometry is uneven—apply conservative assumptions).
• Included angle relation: if included angle between two legs is \(\gamma\), then \(\theta = 90^\circ - \dfrac{\gamma}{2}\).
• Load share from CG offset (two pick points): with distances to CG of \(a\) and \(b\), reactions are \(R_1 = W \dfrac{b}{a+b}\), \(R_2 = W \dfrac{a}{a+b}\).
• Dynamic amplification (vessel lifts): effective lifted weight \(W_d = W \times \text{DF}\), where \(\text{DF}\) (dynamic factor) typically \(1.1\text{–}1.3\), or \(W_d = W \left(1 + \dfrac{a}{g}\right)\) using vertical acceleration \(a\).
• Sling angle reduction factor: capacity factor \(F_\theta = \cos\theta\); effective WLL of each leg \(= \text{WLL}_{\text{rated}} \times F_\theta\).
• D/d effect (wire rope over shackle/bending): apply manufacturer efficiency factor \(E(D/d)\); effective WLL \(= \text{WLL}_{\text{rated}} \times E\).
• Design factor: \(\text{SF} = \dfrac{\text{MBL}}{\text{WLL}}\) (use per equipment class); ensure \( \sum V_i = W\) for vertical components of all legs.

IV. Work environment

• IV.1 Location: Offshore jack-ups, semisubmersibles, drillships, or fixed platforms; occasional onshore yards during shipyard/upgrades.
• IV.2 Rotations: 14/14, 21/21, or 28/28; 12-hour shifts, day or night; overtime during critical lifts and weather windows.
• IV.3 Conditions: Exposure to wind, rain, salt, vibration, and noise; vessel motions during deck transfers; restricted visibility at night.
• IV.4 Travel: Helicopter or crew boat to/from installation; safety/induction requirements at heliports and quaysides.
• IV.5 Constraints: Weather and sea-state limits, SIMOPS with drilling/well ops, crane availability, deck congestion, red-zone management.

V. Reporting lines and cross-functional interfaces

• V.1 Reporting lines (estimated): typically reports to the Deck Foreman/Crane Supervisor or Maintenance/Construction Supervisor; functionally accountable to the Offshore Installation Manager for lifting operations.
• V.2 Direct reports: riggers, banksmen/slingers; may have rigging loft attendants.
• V.3 Key interfaces:
  • Crane operators and assistant operators (lift execution and radio comms).
  • Drilling (toolpusher/driller) for tubular handling, BOP/subsea spares, and red-zone alignment.
  • Marine/barge operations for vessel approach, heave limits, and deck landing plans.
  • Maintenance/construction for equipment change-outs, scaffolding/rope access coordination.
  • Materials/logistics for cargo manifests, backload prep, and certification of cargo units.
  • HSE for permits, audits, dropped-object prevention, and incident reporting.

Deliverables & Interfaces

• Lift plans, sketches, risk assessments, and permits issued to crane operations and area authorities.
• Rigging loft registers, inspection reports, and certificate packs handed to maintenance and HSE.
• Shift handovers and post-lift reports provided to supervisors and planning teams.

VI. Career ladder

• VI.1 Next-step roles (role-specific): Crane Supervisor, Lifting Superintendent, Construction Supervisor, or Lifting/LOLER Focal Point.
• VI.2 What’s needed to move up:
  • Track record leading critical lifts (complex geometry, high loads, vessel interfaces) with zero LTI/TRIR.
  • Advanced rigging/lifting qualifications and assessor/competent person status; authorization to sign off lift plans.
  • Demonstrated cross-discipline coordination (drilling, marine, construction) and improvement of lifting procedures.
  • Capability to manage multi-rig lifting campaigns and mentor junior rigging personnel.
• VI.3 Progression Trigger: typically promoted after 12–24 hitches or completion of 15–30 critical lift campaigns plus advanced rigging competency and examiner/competent person certification (estimated).