Slide 1. Slide 2. Slide 3. The Knack. Background Information

Transcription

1 Slide 1 Prepared by: Ian Humphrey, P. Eng. Paul Henderson, P. Eng. Slide 2 The Knack Slide 3 Background Information Began my career in the lifting industry in 1994 as a draftsman and returned to school to graduate from the University of Alberta as a Civil Engineer in Since that time I have worked as a Rigging and Transportation Engineer servicing the heavy lift and heavy haul industry in Western Canada. In 2007, I co-founded 2H Engineering, a firm specializing in engineered rigging, lifting, and transportation plans.

2 Slide 4 Introduction This presentation will identify some common criteria for defining a critical lift. There are several reasons that lifts are categorized as critical and one method to mitigate risk is through the use of an engineered lift plans. This session will address components that should be included in lift plans and the advantages to critical lift planning. Slide 5 Definition of Critical Lift Lifts in congested areas where power lines, structures, and obstructions are present. Lifts where ground is poor and potentially unstable. Lifts with potentially unstable loads (ie offset center of gravity, uneven lift points). Lifts using multiple cranes. Lifts over a defined percentage of crane capacity, often 75%. Lifts with difficult rigging arrangements. Lifting equipment that is irreplaceable, monetary value is high, or hazardous. Lifts where the load cannot be seen by the operator (blind lift). Lifts where the load is transferred between cranes (ie tailing a vessel to vertical). Lifting personnel with a crane (ie manbasket). End users have different criteria for a critical lift and therefore we need to be flexible in the definition, although there is often common ground when defining. Ref: Slide 6 My Critical Lift

3 Slide 7 Critical Lifts by Definition Slide 8 The Law in Alberta See excerpt below from the Alberta OH&S (2009) Code. It is now law in Alberta to produce lift calculations for loads exceeding 75%. This is one important component of the critical lift plan. Ref: Alberta OH&S 2009 Slide 9 Sample Lift Calculation from Alberta OH&S for Mobile Cranes Ref: Alberta OH&S 2009

4 Slide 10 Sample Lift Calculation from Alberta OH&S for Overhead Cranes Ref: Alberta OH&S 2009 Slide 11 Critical Lift Plan Critical lift plans should be prepared by the personnel completing the work, this includes the supervisor, crane operator, or rigger. This is often done thru a critical lift form. It is key that all field personnel completing the work be involved in the plan (ie pre-lift meeting). The next few slides will show a couple of sample critical lift planning forms, used by site personnel to document the lift. Slide 12 Critical Lift Form Sample 1 Ref: Iron Ore Company of Canada

5 Slide 13 Critical Lift Form Sample 2 Ref: Work Place BC Slide 14 Mitigate Risk on Critical Lifts Ways to mitigate risk: All critical lifts should be documented by a critical lift form or an engineered lift plan. Key personnel involved in the lift (ie crane operator, supervisor) should review and approve the documentation. More than one person to approve lift plan. Some owners will have a third party review of the engineered lift plan. Pre lift meeting prior to hoisting. Trial lift or dry run to ensure clearances and radii are acceptable (no load on the hook block). Ensure all crane and rigging inspections are up to date and documented. All crane mechanics and functions are properly working (ie anti-two block, LMI) Slide 15 Engineered Lift Plan An engineered lift plan may be required due to the complexity of the lift. These plans shall be prepared by a qualified engineer with suitable experience. The engineered lift plan should always be reviewed and approved by the field personnel. Five basic areas on an engineered lift plan: 1) Plan view (Crane placement details) 2) Elevation view (boom clearance details) 3) Rigging Details 4) Lift Chart Details 5) Lift Procedure

6 Slide 16 Sample Engineered Lift Plan Slide 17 1) Plan View Plan view should contain the following information: X, Y dimensions for placement of the crane Initial lift & final set position of equipment Footprint of the crane identifying orientation and size of load spreading mats North arrow Swing path (if complicated) Surrounding obstructions Tailswing to show area required for crane Maximum lift radius Minimum lift radius (if required) Slide 18 Sample Plan View

7 Slide 19 2) Elevation View Elevation view should contain the following information: View of the crane lifting at maximum radius View of the crane lifting at minimum radius Maximum equipment height to be lifted Surrounding obstructions Boom clearance to load and adjacent equipment Worst case clearance with load or specify that the load cannot be swung under boom Headroom, distance between hook block and boom tip sheaves, otherwise known as anti-two block Slide 20 Sample Elevation View Slide 21 3) Rigging Details Rigging can be one of the more critical elements on a lift study. Rigging page should contain: Sling lengths and WLL for synthetic and wire rope Identify position of lifting attachments (ie lugs, trunnions, basket hitch, choker hitch) Sling angles Spreader bar length and capacity Size of hook block and required parts of line Total weight of all rigging Identify specific uses on rigging components (ie sling saver shackles on round slings) Note the load distribution for the rigging / cranes if required

8 Slide 22 Sample Rigging Details Slide 23 4) Load Chart (Part A) Load chart shall contain: Configuration of the crane(s) Boom length and sequence Jib length and offset angle All counter weights (ie super lift, central, track) Lift radius Crane capacity Outrigger or track spacing Slide 24 Sample Load Chart (Part A)

9 Slide 25 4) Load Chart (Part B) Load chart shall contain: Load information and crane deductions Weight of load Weight of main hook block Weight of aux block (if installed) Weight of aux head (if installed) Weight of rigging Weight of load line Weight of stowed or erected jib Weight of misc stowed attachments (ie jib lines on Demag crawler, TA or TY bracket on a Liebherr all terrain) Slide 26 Sample Load Chart (Part B) Slide 27 4) Load Chart (Part C) Load chart shall contain: Percentage of crane capacity factoring in weight of load and deductions. Ground bearing pressure (GBP) under the outriggers and tracks of crane. Identify the GBP under the mats or pads and specify sizes. General notes for the engineered lift plan that specify assumptions and identify limitations. It is important for all parties to be aware of the notes.

10 Slide 28 Sample Load Chart (Part C) Slide 29 Sample Load Chart (Part C) Slide 30 5) Lift Procedure All engineered lift plans should contain a lift procedure to clarify execution of the lift. Some procedures can be very simple and straight forward, but can be very detailed if required (often due to space restrictions). Procedures are helpful when placed with the plan view since they complement each other (ie procedure puts in writing what the plan view illustrates).

11 Slide 31 Sample Lift Procedure Slide 32 Engineering Lift Plan Additional Information Additional information may be required due to complexity of the lift. Provide weight distribution for two crane lifts. Details for specialized rigging to be shown (ie tailing frames, snatch blocks, lift links). Identifying items that need to be removed on the equipment for safe lifting (ie platforms). Any load transfer between cranes (ie tailing vessel to vertical). Slide 33 Engineering Lift Plan Additional Information

12 Slide 34 Supplemental Information not Provided on Engineered Lift Plan Lift plan should always be accompanied with a field level risk assessment to determine site specific hazards. Crane and rigging inspections should be current and accessible for personnel performing the lift. Operator and supervisor qualifications to be accessible. Slide 35 Lift Deviation Form Lift deviations can be useful to approve minor changes to the drawing in a timely manner, but you need to make sure it is a viable alternative to revising the drawing. When are they ok, when should the drawing be revised instead? If your in doubt, it is better to revise the drawing. Lift deviation should be approved by all parties, same as the engineered lift plan (operator, supervisor, engineer, and owner). Sketches should be added, if required, to clarify changes. Often, sketches will be less ambiguous than written words. If the lift deviation causes confusion, it would be advisable to revise the engineered lift plan instead. Slide 36 Sample Lift Deviation Form

13 Slide 37 3D Vs 2D Lift Plans Both 3D and 2D engineered lift plans are suitable. There are some minor advantages and disadvantages to both. The key to an engineered lift plan is ensuring that all lift details are presented in a clear and concise manner, this way it avoids any confusion. Slide 38 Critical Lifts Knowing When to Stop All work personnel have the right to refuse any work that is deemed unsafe, this includes hoisting. If there are concerns it might be advantageous to reassess the methodology or equipment utilized. Accidents often happen when there are multiple mistakes. If there is more than one area that is concerning to the group, then it should be reassessed to find a better alternative. Slide 39 Engineered Lift Plan Key to Success Information given by the client can often be minimal. Ensure most up to date information is supplied. Too much information is generally better than not enough. Field personnel to have input and approve final lift plan. Client or end user to approve lift plan. Drawing to be sealed by a qualified professional engineer. Lift plans should be completed numerous days in advance to allow for proper planning. Engineered drawings and critical lift forms are great planning tools, but the operator and supervisor must always be aware of other hazard during the lift, items that may not have been identified in the planning process. Lift drawings should provide all the necessary information required for execution in a clear and concise manner (as stated earlier in presentation). Follow all local, provincial, and national codes on cranes and rigging.

14 Slide 40 Engineered Lift Plan - Conclusion There is inherent risk when using cranes and the use of critical lift forms and engineered lift plans are an excellent way to document and mitigate risks associated with these lifts. For critical lifts to be completed successfully all parties need to be involved in the critical planning, and work together to meet the common end goal of a safe, incident free lift. Slide 41 Critical Lifts Questions? Clarifications?