Improper use or care of shackles can result in serious accidents that not only injure employees but damage property as well. To avoid this, shackle inspection is critical. In accordance with ASME B30.26, shackles should be visually inspected before every use.

If any of these six conditions are apparent during shackle inspection, the shackle should be discarded and replaced.

shackle inspection

Example of a Worn Shackle

Condition 1:

Any part of the shackle is worn more than 10 percent of the original dimensions. If this happens, it typically means that the physical size of the shackle is smaller, therefore it cannot handle the rated load and becomes dangerous to use.

Condition 2:

The shackle has excessive pitting, corrosion, nicks or gouges. If a shackle has excessive pitting, that is usually a sign of corrosion. When this happens, material is being lost and the shackle dimensionally becomes smaller. Therefore, it cannot handle its rated capacity. Similarly, nicks and gouges are an intrusion on the original dimensions of the shackle and create a stress raiser on the shackle. Material is moved or removed from the shackle, making it smaller in size and unable to handle the rated load.

shackle inspection

Example of a Bent Shackle

Condition 3:

Load bearing components are bent, twisted, distorted, stretched, elongated, cracked or broken.

Condition 4:

Indication of heat damage. When shackles are manufactured, they go through a heat treatment process. Therefore, being exposed to heat in the field can reverse that process and weaken the shackle. Heat damage can be difficult to see, but there are a few key items to look for:

  • Blue or straw discoloration of the shackle material
  • Weld spatter. When weld spatter lands on the shackle, the heat from that molten dot of metal is immediately transferred to the shackle, changing the properties of that shackle.

Condition 5:

Missing or illegible manufacturer’s name or trademark, working load limit or size. Every CM shackle is forged with the CM logo, its body or diameter size, trace code, USA, “Forged” and its specified working load limit. These markings should be visible on the shackle.

Condition 6:

Load pins are bent or have visibly damaged threads. When load pins are bent, the pin has gone past its elastic limit. If the product continues to be used, there is a higher chance of a dropped load, which can injure operators and cause property damage. Damaged threads mean that the pin is not making 100% engagement with the shackle. This can lead to a failure of the shackle.

For more information on shackle inspection and safe shackle use, check out the following:

Nine Important Rules to Follow When Using Shackles
Shackle Markings, Materials, and Appropriate Standards
New CM Shackle Markings and Pins Lead to Improved Operator Safety
Customer Concerns over Recommended Shackle Pin Length


rail systems
At Ealing Common Depot, a railway service workshop of the London Underground, the tube subway trains used on the District Line will now be maintained with the aid of a lifting system from Pfaff Verkehrstechnik GmbH located in Kissing, Germany. On account of its futuristic design, the maintenance staff has nicknamed the versatile and unique system the “Transformer.”

The dual-purpose system is comprised of a total of 28 stationary hybrid lifting jacks from Pfaff Verkehrstechnik with bogie lifting beams and body supports that raise and hold the trains, which measure up to 384 ft (117 m) long and 4.7 ft (1.44 m) high. This design gives engineers ample and safe access underneath the train when performing service.

Precision and Versatility

rail systemsThe versatility of the lifting system from Pfaff Verkehrstechnik lies with its ability to lift the tube trains as either a complete unit or as individual carriages to infinitely adjustable, ergonomic heights. The 28 jacks can lift up to 308 tons (280 metric tons), and the supports can carry a load of up to 218 tons (196 metric tons). This is a task that requires utmost precision. If a complete train is lifted, the lifting process of the Pfaff-silberblau jacks runs in precise synchronization with a deviation of less than ± 2 mm. The worm gear screw jacks achieve this precision through a series of frequency converters, which also permit different lifting speeds within the system.

Once the vehicle has been lifted, the next set of system components is ready to go into action. The jacks feature additional motor-driven supports for holding up the carriage bodies. This, in turn, makes it possible to lower the individual bogies back down onto the rails and roll them out from underneath the raised vehicle. Large, bright LED lights integrated into the lifting beams ensure illumination of the work area under the raised vehicle.

Once the Pfaff Verkehrstechnik system is lowered, the lifting beams mesh together with the main rail and sit flush with the floor. As soon as the lifting beams go up, they are followed by gap covers, thereby resealing the recesses, which would otherwise remain open, such that they can be stood on.

The lifting system and the work processes are controlled by an easy-to-use touch display, which also enables the maintenance staff to check the status of all major system components at all times.

New and Cost-Efficient Concept

Pfaff Verkehrstechnik’s hybrid lifting jack system is a new concept and will serve as a cost-effective alternative to established underfloor lifting and support systems. It is an excellent value for our customers due in part to the fact that extremely shallow pit depths require significantly less foundation work.

The motion technology for the lifting system from Pfaff Verkehrstechnik GmbH was developed by Pfaff’s sister company also based in Kissing – Columbus McKinnon Engineered Products (CMEP). Working together, they were able to provide a sophisticated system that will meet the ongoing needs of the London Underground.



The 57th annual USITT Show kicks off next week.

The USITT show is the largest full production trade show in America, featuring 200 exhibitors and special exhibits from around the industry. USITT is the leader in life-long learning opportunities for the entertainment design and technology industry. The conference focuses on various workshops that help educate attendees on several aspects of theater.

This year’s conference will be held in St. Louis, Missouri, at America’s Center Convention Complex on March 7-11.

You can find CM Entertainment Technology (CM-ET) at Booth #731.

Stop by and see everything we have to offer, including new and industry-favorite products such as the:

Our sales and training teams will also be available to address your questions about any of our products.

While You’re Visiting USITT, Get Trained.

Check out this training opportunity during USITT. You still have time to register:

CM Lodestar RTC Motor Technician Certification School
taught by David Carmack, 
Entertainment Product Trainer, ETCP Recognized Trainer, IATSE TTF Recommended Trainer
This course counts toward 12 renewal credits for ETCP Certified Riggers.

Date & Time: March 7-8 (9:00 am-5:00 pm)
America’s Center Convention Complex
Location: TBD

Don’t miss an annual favorite “Stump the Rigger” featuring Herb Hart & Bill Sapsis on Saturday, March 11, from 11:00-12:30.


Please don’t be a stranger. Tell us what you enjoyed most about USITT this year by posting your comments and photos on our FacebookInstagram, and Twitter and using the hashtag #cmlodestar. Some of our new followers during the show will get a free CMET beanie cap! We would love to hear from you!


Columbus McKinnon Holds Hoist Workshops in Russia

by Dmitry Smirnov February 16, 2017

To showcase Columbus McKinnon and its products for the entertainment industry, the company presented two hoist workshops in Russia last year. Held at the Global Show Trade (Coda Audio) in Moscow, the first workshop was on January 20 and the second on May 12. More than 30 guests from leading Russian rental, installation and rigging companies took part in each session. The workshops were conducted by Columbus McKinnon Associates, […]

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Our Most Popular Blog Posts of 2016

by Gisela Clark February 2, 2017

As we look back at 2016 and are busy planning for 2017, it’s interesting to see which of our blog topics were the most popular with our readers last year. With all of our blog posts, we look to provide you with valuable information to help keep you safe and make your job easier. We […]

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Tips for Rigging with Eye Bolts

by Peter Cooke January 17, 2017

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 […]

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3 Safety Tips When Installing Your CM Trolley

by Peter Cooke January 7, 2017

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 […]

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Does the Age of a Crane Prevent Installation of a Collision Avoidance System?

by Jon Walters November 17, 2016

Al, 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 […]

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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, […]

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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 […]

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