Dueling Cranes – 4 Steps to Avoiding a Crane Collision

Posted by Mike Parnell on Nov 11, 2011 10:24:00 AM

4 Steps to Avoiding a Crane Collision

In a fabrication or assembly facility there can be a host of material handling that occurs during the general nature of work. The delivery of steel plate, beam, tubing and other raw materials or equipment is often performed in a variety in ways.

Typically a forklift or telehandler will move material from a storage yard or building into a fabrication bay. The material often needs to be sorted for initial fit-up and assembly. That’s when the cranes get involved. In bays with open ends, it may be inviting to integrate the use of a small mobile crane to assist the overhead bay cranes for material sorting and assembly.

When a boom type crane is tasked to work in a shop bay, the opportunity for accidental contact with obstructions is ever present. An even greater risk is at hand, with an overhead crane and mobile crane attempting to work in the same area. The overhead crane operator may not see the mobile crane boom due to fabrication obstructions. The mobile crane operator and assigned rigger/welder may not be looking up to ensure continued clearance with an approaching overhead crane. In both cases, the machines may be moving towards one another simultaneously with almost potentially disastrous results.

If one crane strikes another in this situation, the suspended load(s) can be easily dislodged and dropped, the load(s) can swing violently or there may be a crane derailment or tip-over. Nothing good can come out of this ticking time bomb.

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If a mobile crane or other high reach machinery (aerial work platform, telehandler with mounted boom, high-mast forklifts, etc.) is working in a crane bay, the site management needs to ensure certain precautions are in place. The following are options that management can take to minimize the risk involving “dueling” cranes:

  1. De-energize the overhead crane closest to the mobile crane. Make sure that additional cranes in the bay respect the de-energized crane and do not strike or push the tagged out machine. Instruct all personnel about the temporary work restrictions.
  2. Place rail clamps onto the runway rails so that they provide hard stops, in order to limit the travel of the bridge crane nearest the mobile crane. These aren’t designed as bumper stops, but are only for accidental over-travel. Hang warning tape or install floor level barrier cones to help highlight the maximum allowable travel distance of the bridge crane nearest to the mobile crane. Instruct all personnel about the temporary work restrictions.describe the image
  3. A somewhat less desirable method of protection is to have an “umpire” stationed between the two machines. The first rule is that neither crane can move horizontally without the umpire’s approval. The second rule is that the cranes cannot move horizontally at the same time. His approval is only granted when he can ensure that the opposing crane is stationary, while the other crane is in motion. Caution should be expressed to the overhead crane operator to compensate for crane “coasting” after the travel controller moves to neutral. Instruct all personnel about the temporary work restrictions.
  4. All personnel should be aware that lifting and handling long loads like I-beam can potentially contact any obstruction, exposed electrical bus-bar, or particularly the nearest crane. Don’t assume that vertical handling isn’t a risk in a congested work area as described in this article. Instruct all personnel about the temporary work restrictions.

There are some in our industry who would strictly prohibit the use of high reaching machines in overhead crane bays, but that doesn’t seem very practical. The secret is to have a game plan in place that minimizes the risk and have employees follow the approved procedures while adhering to the imposed operational restrictions. The ideas proposed here don’t represent an exhaustive list. There may be a number of other approaches that can be taken to avoid an incident related to high reaching equipment in an assembly bay. The best approach generally includes a combination of mechanical or electrical restrictors, visible barricades and trained personnel who are actively respecting the existing operational conditions.

Happy trails,

Mike Parnell

P.S. For more information about crane operations refer to ASME B30.5 Mobile and Locomotive Cranes and ASME B30.2 Overhead and Gantry Cranes. Both ASME Volumes are available at the iti.com/bookstore or asme.org.


Cranes, Rigging and the Peter Principle

Posted by Mike Parnell on Nov 10, 2011 12:11:00 PM

ITI trainingOur industry depends on cranes, rigging and other load handling equipment. The big key to success is having folks who are competent, qualified and capable at multiple levels to be able to safely and effectively get work done.

If you have a solid knowledge base in the rudimentary operations and practices of load handling, you should get ready for the next step. Why? You are the future of our industry. You may well be appointed to the next level of oversight that incorporates the use of the equipment and the procedures related to project execution.

mike parnell ITIIf you are being considered or have been appointed as a foreman or supervisor to manage any size crew who uses cranes and rigging, you will want to further your education in the subjects of your profession. In the 1968 book called “Peter Principle”, by Laurence J. Peter (1919-1990), Mr. Peter observed that in some cases, people tend to be promoted until they reach their level of incompetence. Their advancement to a new job is based on their previous successes that demanded a limited set of skills. Their new assignment may incorporate some of their existing skills but also demand competency in areas that they may not be prepared for. Don’t be a living example of the Peter Principle.

Take a pro-active approach today and get the proper tools for your new and expanding assignment. These tools involve skills and knowledge of the subject matter. In our world that may mean exposure to a few subjects like:

            1. Advanced Rigging Inspection and Trouble Shooting

            2. Intermediate and Advanced Rigging

            3. Mobile Crane Operations and Load Chart Interpretation

            4. Lift Director Responsibilities

            5. Lift Planning

            6. Accident Investigation

            7. Crane and Rigging Audits

            8. Crane Inspections

            9. Safety Procedures, LOTO, PPE and HazMat

            10. Crane Assembly/Disassembly

            11. Contingency Planning

            12. Emergency Response

Others in your organization are depending on your current and future work skills and operational knowledge. Make sure your competency grows with your assignments. If you are ready for the next step, visit our website (www.iti.com) and see which of our programs can help you avoid the Peter Principle.

Happy trails,
Mike Parnell

P.S. Believe me when I tell you that at ITI, all of our trainers and consultants are asked to live by an axiom that reflects this article; “Be a student first and a trainer second”. I get up each morning and wonder what will I learn today? What questions can I ask, who can give me insight that I don’t have, and what situation can I learn from, that will make me better prepared for tomorrow?  Would you forgive a seasoned veteran (old man) for being a little preachy?

Proverbs 4:7 Wisdom is the principal thing; therefore get wisdom: and with all thy getting get understanding.

Topics: crane & rigging training, Industrial Training, rigger training, ITI, mike parnell

Video - A World Leader in Crane & Rigging Training - ITI

Posted by Mike Parnell on Sep 8, 2011 11:12:00 AM

Learn why Industrial Training International is a world leader in crane and rigging training.


Topics: ITI

5 Items to Consider When Installing Welded Pad Eyes for Rigging

Posted by Industrial Training International on Jul 11, 2011 8:19:00 AM

Structural Connection Points for Attaching Chain Hoists (load drifting)

welded padeyes4riggingIn power plants, refineries, aboard ships, in paper mill and other industrial settings, equipment must be installed or removed to accommodate the facility’s operation. Often riggers must be creative when rigging loads in tight quarters where there are no existing overhead cranes.

If the proposal is to use existing structural beams or columns for chain hoist connections prior to a load drifting activity a number of things should take place.

  1. Ensure that the facility engineering team has approved the rigging point based on the anticipated loading. Obtain the maximum allowable working load limit in writing.
  2. Identify the proper connector for the beam; welded pad eye, bolted swivel hoist ring, beam clamp, etc. Get a qualified engineer to approve the connector, and in the case of weldments get the details of the required material type, size, shape, thickness and shackle pin hole size and its location. If the desired connector is a pad eye also get a listing of the engineer’s minimum “removal criteria” based on wear, deformation and weld condition.
  3. Have a qualified welder, install the pad eye and inspect the welding using the recommended non-destructive examination method (dye penetrant, magnetic particle, etc.). A documented load test may be required.
  4. Mark the pad eye for its maximum rated capacity and angular limitations as provided by the engineer. The pad eye can be serial numbered (RFID identifier) so that it can be referenced on a site plan for original data, limitations and the name of the approving engineer. Maximum capacity and angular markings should be stenciled near the pad eye for future “quick reference” by all rigging personnel.
  5. Inspect all rigging pad eyes before and after use to ensure their integrity.

Chain hoist information can be obtained by reviewing ASME B30.16. This document can be obtained at www.iti.com/bookstore or through www.asme.org.

Happy trails to my crane and rigging friends.

Mike Parnell
ITI – Field Services

Topics: overhead cranes, rigging safety

Synthetic Slings vs. Harsh Hooks

Posted by Mike Parnell on Jul 6, 2011 6:26:00 AM

A variety of industries use synthetic slings to move equipment and product on a daily basis. Like most other sling types, synthetic web slings and synthetic roundslings serve to help provide acceptable rigging methods for load handling. In the same locations, loads may be rigged using steel slings made from wire rope and alloy chain. Spreader bars and lifting beams get used on certain loads to help avoid sling-to-load contact, and increase sling angles thereby lessening the individual sling tensions.

soft riggingEspecially when a mix of rigging equipment is used at one location, the rigger should pay special attention to the crane hooks in use. Multiple lifts (hundreds and thousands) with steel rigging can result in peening, gouging and displacement of the material in the hook bowl or saddle. Though not exceeding the removal criteria established by the hook manufacturer, this phenomenon can result in sharp edges towards the outer face of the hook.

If synthetic slings are placed directly into a peened hook bowl, the edges can act like a razor and sever the sling during the rigging and lifting process. This same type of event can occur when rough shackles that are regularly used with steel rigging, are placed into service with synthetic slings.

Always look at the contact point to which synthetic rigging is connected. Sling protection used along the body can prevent friction or cutting damage. However, a peened hook or shackle can cause just as much devastation.

Inspect the contact points used with all rigging. If hardware or connection devices can cause damage or severing of a sling while under tension, tag out the component and get it repaired or replaced. Certain hardware manufacturers allow for hand filing and buffing of their components to help maintain smooth surfaces. Follow the manufacturer’s instructions about repair and maximum allowable loss of cross-section criteria when considering hardware repair.

Happy Trails to my Crane & Rigging Friends,

Mike Parnell
President - ITI Field Services

Topics: sling protection, synthetic slings, rigging operations, rigging safety

Rigging Training Workshop - Incline Planes: 3 Points to Remember

Posted by Industrial Training International on Apr 25, 2011 6:29:00 AM

When towing or pulling a load up an incline the effort increases with the slope. Here are three key points that the rigging crew should address to ensure a successful operation.

1. Know the load’s weight and the rolling equipment’s CoF (coefficient of friction). You’ll notice the formulas offered from ITI’s Master Rigger’s Reference Card provide the means to calculate the required force if faced with a pull on a Level surface, Uphill or Downhill. Synthetic wheels such as provided with a common 3-point industrial rolling system offer a CoF of about .02, while steel rollers like those produced by Hilman, Multi-ton and Heavy Haul typically have a CoF of about .05. Discovering the CoF while on a level plane is especially helpful to refine the calculation for an uphill pull. Using a dynamometer in the winch line during a level pull can help finalize the approximate CoF for a particular set of rolling equipment.

2. Correctly accounting for the height, run and ramp length will help determine the values needed for either the Uphill or Downhill formula. These significantly influence the winch pull required and the sizing of the equipment; winch, snatch blocks, slings and shackles.

3. We have all heard about “staying out of the bight”, which infers being clear of inside block angles and areas that can be in the line of fire if one experiences a sling or equipment failure. Some winches have controls immediately adjacent to the winch line, so the precaution is for non-essential personnel who aren’t critical to the load pull while the equipment is under tension. In many cases, essential personnel must be next to loaded winch lines during the operation. It is a matter of minimizing the risk to the lowest level, verifying the calculations, confirming the capacity of the rigging equipment, developing and following the proper procedure and adhering to all reasonable safety restrictions where possible. Having the right equipment, well maintained and inspected is a significant key to success.

Now, let’s have some fun. Try your hand at calculating the required force (tension in lbs.) by tackling the workshop below. It is based on the adventures of Stinker and Tinker, two brothers who always seem to be getting into a rigging challenge (from Mike’s Rigging Mysteries). (Truck winches are not officially covered by ASME or OSHA.) Answers can be found below.

Determine the amount of winch pull required to pull this truck out of a small canyon. Use the Uphill formula:

[CF×W×(R/L)]+[(H/L)×W] = F

incline plane workshop

Given: The truck weighs 5,200 lbs.
Given: The run is 7' and the height is 8'.
Given: The ramp length (L) is 10.6'.
Given: The coefficient of friction is .05.

  1. The required winch pull is _____ lbs.
  2. The winch and its mounting is rated at 5,000 lbs. Is it
    overloaded? Yes _____ No _____

Hint: Refer to the MRRC-P6. (While stump-jumping, Stinker ended
up sliding down into a small canyon and his truck doesn’t have the
horsepower to get out the same way he came in.)

Master Rigger Reference Card

Happy trails to all my crane and rigging friends,

Mike Parnell
ITI-Field Services

 P.S.  This article was originally published in The Professional Rigger Newsletter - Incline Planes: 3 Points to Remember.


1. Winch pull = [.05 x 5,200 x (7/10.6)] + [(8/10.6) x 5,200] = 172 + 3,925 = 4,097 lbs.
2. No

Rigging Training Workshop: Off-level Pick Points (uneven elevation)

Posted by Industrial Training International on Apr 20, 2011 8:11:00 AM

A special condition arises when lifting a load whose pick points are not on the same elevation. In determining the slings and rigging hardware necessary for the lift, the rigging planner needs to realize the affect of the load’s pad eyes at different levels.

Using the formula in the Level vs Off-level Pick Points on Master Rigger's Reference Card Panel 10 below, identify the tension for Slings 1 and 2 in the problem below. Then identify the wire rope slings and shackles needed to rig the beam using the Journeyman Rigger's Reference Cards, also pictured below.

Determine the tensions and rigging selections below based on the illustration. Answers can be found below.

  1. Sling 1, tension = _______ lb
  2. Sling 1, load shackle (SPA) = _______" @ _______ lb WLL
  3. Sling 1, wire rope sling = _______" @ _______ lb WLL
  4. Sling 2, tension = _______ lb
  5. Sling 2, load shackle (SPA) = _______" @ _______ lb WLL
  6. Sling 2, wire rope sling = _______" @ _______ lb WLL
  7. Rigging shackle = _______" @ _______ lb WLL

rigging workshop

mrrc p10

rigging reference cards


Happy trails to all my crane and rigging friends,

Mike Parnell
ITI-Field Services

 P.S.  This article was originally published in The Professional Rigger Newsletter - Off Level Pick Points.


25 2 answers

Topics: industrial training international, Professional Rigger, rigging workshop, rigging safety, mike parnell

Rigging Training Workshop - Rigging Selection: Tension & Sling Size

Posted by Mike Parnell on Apr 19, 2011 9:21:00 AM

Some loads can be single point picked, and the rigging is selected based on suspended weight.

Other times, a rigging task will require that we use a few steps to get to the solution. Note that in some cases the distribution of weight is required, then the sling tension is discovered as a 2-step process. In the assignment below, we can determine the sling tension in the 9.2’ leg and the 6.7’ leg by using the formula on the Master Rigger Reference Card, Panel 10 (left side of the panel).

Once we find the tension of side 1 (TS1) and then tension of side 2 (TS2), we can select the correct size of alloy chain for the lift.

In the assignment below, the ADOS stands for “Adjustable, Double (leg), Oblong (link at the top), Standard or Sling (hook at the bottom)”.

Let’s see how you do.

Determine the tension and the alloy chain sling size necessary to make the lift.

Leg 1 (9.2') Tension    =     ___________ lb
Leg 2 (6.7') Tension    =    ___________  lb
Sling Description:  ADOS    ___________"  ×  10'

rigging workshop


master rigger reference card

Happy trails to all my crane and rigging friends,

Mike Parnell
ITI-Field Services

 P.S.  This article was originally published in The Professional Rigger Newsletter - Rigging Selection.



25 1 answers

Topics: Professional Rigger, rigging workshop, rigging quiz, mike parnell

Rigging Training Workshop - Rigging Selection (sheave blocks)

Posted by Mike Parnell on Apr 13, 2011 6:42:00 AM

Circle the best answer for each system which matches the illustrations at the right.

Information: All winches have a maximum capacity of 2 tons. All single sheave rigging blocks are rated at 3 ton WLL, and triple sheave rigging blocks are rated at 10 ton WLL. All load and wall anchor pulling lugs are rated at 8 ton WLL each. All shackles are rated at 12 tons each.

Panels from ITI Bookstore's Journeyman Rigger's Reference Card and Master Rigger's Reference Card have been provided to assist you in your calculations.

(Answers below)

24 3 riggingSelection1

System 1, no blocks
B) No, high potential for overload if the winches are not synchronized

System 2, single sheave blocks

B) No, it would not tend to pull square and would require constant attention to rollers

System 3, triple sheave blocks
B) No, it would overload the load’s pulling lug

Caution: Don’t stand in the bight.

24 3 riggingSelection2

24 3 riggingSelection3

Happy trails to all my crane and rigging friends,

Mike Parnell
ITI-Field Services


P.S.  This article was originally published in The Professional Rigger Newsletter - Rigging Selection.



System 1 = B, System 2 = B, System 3 = A

Topics: industrial training international, ITI Bookstore, rigging workshop, rigigng safety, mike parnell

Rigging Training Workshop - Load Control

Posted by Mike Parnell on Apr 11, 2011 8:59:00 AM

Identify the rigging method below which provides the best load control of the two hitch systems illustrated. Answers below.

load control workshop

Happy trails to all my crane and rigging friends,

Mike Parnell
ITI-Field Services

P.S.  This article was originally published in The Professional Rigger Newsletter - Load Control.


24 2 loadControl answers

Topics: Professional Rigger, rigging workshop, Load Control, mike parnell