Jubal, an entertainment rigger from Local One IATSE and recent safety webinar attendee, asked the following rigging question about eye bolts:

Is it necessary to use only one washer when securing eye bolts or can the washers be stacked if necessary?

Peter Cooke, Columbus McKinnon Training Manager and Safety Webinar Presenter, answers:

If more than one washer is necessary, the eyebolt may need to be turned to align with the rigging. Please see the example below.

eye bolts
A shim can be added to reposition the orientation of the eyebolt. Most importantly, you must maintain proper engagement or tightness. A shim can vary in thickness depending on how you need to align the eyebolt, as when a 3/8  eyebolt with 16 thread per inch is used.  With 16 threads per inch, one turn would relate to .062” of movement into the mounting plate. If we divide this by 4 to get .0156” for our shim, the result will be a change in rotational position of the eyebolt of 90 degrees, which can be used as a reference dimension for adjusting the spacer on the eyebolt to achieve the proper orientation with the load.

Want to learn more? View our recent safety webinar!

{ 1 comment }

Whether it’s a hoist, trolley or rigging equipment, proper use, inspection and maintenance is important to ensure operator safety at all times. Operators of material handling equipment should adhere to the manufacturer’s installation, inspection and maintenance requirements outlined in the product’s operation and maintenance manual (O&M manual).

Beam clamps and trolleys are critical components of a complete lifting system and demand the same attention to safety as hoists and below-the-hook rigging. The following three safety tips are important to consider when installing and inspecting a CM Series 633 Trolley.

1. Consider the flange and shape of the I-beam to ensure proper fit and clearance. Measure the I-beam flange and check the distance between track wheel flanges. This distance should be 1/8 to 3/16 inch greater than the beam flange width for a straight runway. Additional clearance may be required for the trolley to negotiate track sections with curves. This clearance should be kept to a minimum to ensure the trolley operates properly on both the straight track sections and the curved track sections.

CM trolley
2. Ensure the equalizer pin nuts have been installed properly, in accordance with the O&M manual recommendations. The pins should be tight and locked into position. These nuts should be regularly inspected to ensure they are tight and secure during your periodic inspections, which can be monthly or yearly depending on service. Refer to your O&M manual and ASME B30.17.

CM trolley

Ensure the equalizer pin nuts have been installed properly.

3. It is recommended that the trolley is mounted to the hoist prior to final installation onto the beam.
Follow the washer and spacer instructions in your O&M manual to properly set the trolley based on the application’s beam flange width.

Please note: washer and spacer arrangement recommendations shown in the O&M manual are affected by structural variations. The accuracy of the final adjustment should be verified by the installer to ensure proper clearance is achieved between the trolley wheel flanges and the toe of the runway beam.
CM trolley

Remember, any trolley installation should always be done in accordance with the manufacturer’s instructions or the recommendations of a qualified person. Improper installation can cause unequal loading on the trolley and side beam and, as a result, can cause the trolley to fall from the beam. It is also recommended that a load test is performed to 100-125% of the rated capacity of the crane after installation.

At Columbus McKinnon, the safe and proper use of material handling products is important to us. We encourage all operators to periodically review the manufacturer’s operation and maintenance manuals for any equipment that they use. You can find the O&M manual for the CM Series 633 Trolley, as well as other hoist and rigging products, at www.cmworks.com/library.


collision avoidance systemAl, a CMCO distributor salesman, trainer and recent safety webinar attendee, asks the following question about applying a collision avoidance system:

Does the age of a crane prevent it from having a collision avoidance system installed? 

Jon Walters, Magnetek trainer and safety webinar presenter, answers:

No. The age of a crane has no impact on whether a collision avoidance system can be incorporated, but there is some basic information that should be considered to ensure it is applied correctly.

Control voltage:

Confirm the necessary control voltage needed so the collision avoidance system can be matched to the existing control voltage. This ensures major changes will not be needed to existing crane control logic.  Magnetek’s collision avoidance systems are designed to operate with control voltages of 12-240 VAC or VDC.

Type of existing crane control:

Is it a contractor control, static stepless control or a variable frequency drive? Determining the existing control scheme defines how the output(s) from the collision avoidance system will be incorporated into the existing control logic. Older cranes may be operating with contactor controls, but still permit the installation of collision avoidance systems.

Type and number of crane motions:

What crane motions will collision avoidance be applied to?  Motions may be:

  • Bridge to obstruction (such as a wall or no-go area)
  • Bridge to bridge
  • Trolley motion to end of travel on bridge
  • Trolley to trolley

The number of motions, along with any “no fly” zones, will determine the number of collision avoidance systems needed.


The distance at which a collision avoidance system will “trigger” is determined based on the distances and speeds of the traverse motions in accordance with what is deemed safe for a slowdown and stop function.

The above factors will help determine the configuration of a collision avoidance system that can be added to your crane, which, again, may be implemented regardless of crane age.

Want to learn more? View our recent safety webinar!


Chain Inspection: Hoist Chain vs. Rigging Chain

by Perry Bishop November 3, 2016

We recently received the following question on chain inspection from Slade, a utility crew supervisor working for a water district: “I was wondering if you carry a “no-go gauge” for Columbus McKinnon chain to inspect gouges, nicks and stretching on the links. Our warehouse personnel struggle to determine the correct gauge for your chain.” Perry Bishop, […]

Read the full article →

Going to LDI? Stop by and Visit Columbus McKinnon

by Gisela Clark October 13, 2016

The 29th annual Live Design International (LDI) Show kicks off next week. This year, LDI show organizers are expecting more than 12,000 attendees – representing 80 countries – who work in theater, concert halls, outdoor production venues, houses of worship, theme parks and a variety of other live entertainment venues. They are coming to LDI to […]

Read the full article →

Does the Age of a Crane Prevent Installation of a Radio Remote Control?

by Jon Walters October 6, 2016

Al, a CMCO distributor salesman, trainer and recent safety webinar attendee, asked the following question about applying a radio remote control: Does the age of a crane prevent it from having a radio remote control installed? Jon Walters, Magnetek trainer and safety webinar presenter, answers: No, the age of a crane has no impact on […]

Read the full article →

CM-Entertainment Mega School now 10 day Event

by Dave Carmack September 30, 2016

Each year Columbus McKinnon hosts a 5-day CM-Entertainment Mega School, to train up new entertainment riggers. This year’s mega school, held in Orlando, Florida, was extended from the normal 5 days to a 10-day event. This one-of-a-kind class combined our 5-day Mega School with a 5-day Rope Access Certification course giving participants the chance to earn a […]

Read the full article →

Are Your Shackles Safe for Overhead Lifting?

by Christie Lagowski September 21, 2016

When determining the best shackle for your lifting application, there are many options to choose from. Shackles are typically available in two styles: chain style and anchor style. Chain shackles are best-suited for straight line, single connection pulls because of their U-shape. Anchor or bow shackles have a more generous loop. This allows them to be side […]

Read the full article →

What is a Ramshorn Hook?

by Tim Lewis September 8, 2016

A Ramshorn hook is a shank hook with two throat openings, sometimes called sister hooks, double hooks or twin hooks. They are used in applications with shipyard cranes and container cranes. Ramshorn hooks can be used on any type of crane block. Why Use a Ramshorn (Double) Hook? Ramshorn hooks offer many benefits to the user. […]

Read the full article →

Load Securement: Don’t Take it for Granted

by Henry Brozyna August 11, 2016

In many cases, the importance of tying down a load on or in a truck is underestimated. It’s interesting to talk to trucking people and find out that they are very in tune with what is expected of them with regards to the vehicle they drive and the maintenance of that vehicle. But when it […]

Read the full article →