Letters, Emails & Voicemails September 2022

Kudos on “Internal Customers” column

Your Outlook piece, “Internal Customers,” was excellent. In my experience, most companies in our profession consistently under-invest in professional (and personal) development for their teams. Going further, it’s my observation that many companies tend to view employees as “production resources” rather than people, and fail to provide a work environment that creates community and personal connection. The result is distrust, disconnection, high turnover, property damage and safety incidents.

At TCI EXPO this fall, I’ll be speaking on the subject of employee engagement and its fundamental role in the success of training and business in general. Your article stimulated a number of new thoughts about the evolution of our profession and the challenge of hiring, developing and retaining a great team.

Craig Bachmann, CTSP

Lead arborist & manager,

Tree133, LLC

Seattle, Washington

Question on the cow hitch

I hope you are learning as much as I am in life in a way similar to what our team does from your publication! I noticed some fact checking that needs to be done in the July 2022 issue, in the article titled “Knotting Really Matters,” by Anthony Tresselt, CTSP. The area in question is the description of the workings of the well-known and -used cow hitch. I believe this information could lead many into a dangerous situation.

First off, I do find the writing in this and other articles by the author to be well written and informative. In this article, the cow hitch that gets tied using a dead-eye sling is compared a few times to a basket configuration of a round sling or endless-loop sling.

“Take the cow or Stilson hitch, essentially a girth hitch with a half hitch. The half hitch keeps the knot stable and allows for multidirectional loading. A closer inspection of the hitch will show a ‘basket’ configuration. There are two legs of the sling around the object and also through the bight. Therefore, the cow hitch doubles the rope much like a basket configuration does on a round sling. This inherently adds strength.”

Unfortunately, this is not a fair comparison because of the way a load or hardware will always be attached to one eye; one leg of line in the cow hitch and the half hitch on the tail will not take a load (unless somehow you tie them directly into the hardware or load).

This next caption, under a photo of the cow hitch, again implies that the “two parts of rope” will increase strength.

“A knot such as this cow hitch puts the sling in a basket formation. Here, two parts of rope (green arrows) pass through the bight and around the anchor. This configuration uses twice the rope and can increase strength.”

I believe readers would conclude that this means the hitch will double or increase strength of the sling beyond its rated MBS (minimum breaking strength) or WLL (working load limit) of the dead-eye sling. The dead eye will not share a load and increase strength in the same way that a round sling in a basket configuration will. Besides, the true configuration of a cow hitch is more closely comparable to a girth hitch, which is maybe or maybe not well known to decrease strength.

I hope I have communicated my thoughts well and that they hold up to any fact checking that needs to be done. Again, thank you for the great response, it shows much care for our industry.

Benjamin Fedor, owner

Parkway Tree & Landscape Services, LLC

Ephrata, Pennsylvania

Anthony Tresselt replies: Years ago, in some very unscientific knot-breaking sessions, I noticed the cow hitch behaved when pulled to failure much more like a basket hitch than a true, choked configuration. I always attributed this to the amount of rope in the bight of the knot. This reminded me of how a bowline with a Yosemite finish increases the strength of the overall knot by roughly 10-15%.

From this observation and from many years in the field tying and untying cow hitches, I find the “basket-like” configuration to be the biggest difference between it and other possible knots; it affects its holding ability and ease of untying much like a choked sling.

Furthermore, years of teaching in the field have led me to describe the cow hitch as formed more “basket-like.” Seems students just seem to grasp it better when describing how to tie and, more important, how to load the knot. I would agree, in its truest form, it is a choking-type knot and not a true basket formation.

“Take the cow or Stilson hitch, essentially a girth hitch with a half hitch. The half hitch keeps the knot stable and allows for multidirectional loading. A closer inspection of the hitch will show a ‘basket’ configuration. There are two legs of the sling around the object and through the bight. Therefore, the cow hitch doubles the rope much like a basket configuration does on a round sling. This inherently adds strength.”

Perhaps I should have used the word “stability” as opposed to “strength,” but to surmise, “I believe readers would conclude that this means the hitch will double or increase [the] strength of the sling beyond its rated MBS (minimum breaking strength) or WLL (working load limit) of the dead-eye sling” is a bit of a leap. I would never make this assertion, nor feel it is implied with the observations I made in the article. All knots by their nature reduce ultimate breaking strength.

The materials we have access to are very strong, and “testing” numbers are often way more than a thoughtful arborist with good judgment would ever generate while rigging. Not to mention the weakest link is often the tree! I think of the stability and the similarities of the cow hitch to a choked-sling configuration more as an added safety factor with an appropriate size sling than an actual way to make or describe it as stronger.

It is always a challenge in writing articles trying to find a practical balance between theory and practice, data and in-field experience. I appreciate the comments/feedback and mostly the time you chose to spend with me and my thoughts vicariously through the medium of reading.

Comments

The following were comments made regarding articles on the TCI Magazine webpage, tcimag.tcia.org.

In response to: “National Mall and Memorial Parks Wood-Chip Project,” by Don Staruk, with Matthew Morrison, TCI Magazine, April 2022

Linda Kovary writes: “Thank you, Matthew Morrison, for taking such good care of the National Parks and your dedication to preserving the beauty of the Mall in Washington, D.C.”

In response to: “Transporting Wood Using Cross-Referenced Rigging Techniques,” by Chris Girard, TCI Magazine, July 2022

Derek (ddeweese@waukesha-wi.gov) asked: What happened to the rigging plate in photo 2? The lowest pulley looks bent.

Chris Girard replied: Please tell Derek he has a good eye. The aluminum pulley in the bottom actually is slightly bent from many hours of being used as a ground redirect and the upper cheek plates getting tweaked between the tree and brush/wood being hauled. However, our loads (while using this redirect) never exceeded the working load limit (WLL) and, with a breaking strength of more than 5,000 pounds, we were always within our safety parameters (we also reduced what we could haul when we found the bent plates).

With the light loads we were going to be using, I knew it would be safe to use with our highline system. Though, honestly, the full WLL would also have been fine, as there was nothing wrong with the sheave, stainless-steel pin or lower cheek plates.

In response to: “Arborist Forum: The Epicormic Conspiracy,” by Jeremiah Sandler, TCI Magazine, June 2021

Hannah (hannah@charlestontreeexperts.com) writes: “This article is so helpful for new tree workers and our customers! Thank you!”

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