A Picture Is Worth …
I have been going through the article “An Analysis of Wood-Chipper Nonfatal Injuries: Us Versus Them” (TCI, July 2021). The information is on point. However, the pictures are not. This is not the first instance of this, either.
If we are to lead the industry in knowledge and technology, then all the related material used in the magazine should represent just that.
Some of these pictures (illustrate) improper PPE for use with a chipper, and equipment left out that should be stowed before the chipping commences, such as the chipper winch line. Simple oversights such as these lead the industry as a whole to not heed proper practices.
We, as TCIA, need to set and lead by the example set forth in our instruction materials.
Bill Burley, foreman
Warwick Tree Service
Coventry, Rhode Island
Editor’s note: Dear Bill, thank you for your comments. First off, John Ball did not provide the images, they are TCIA file photos (including the one from Santoro Photography). These three images were taken of different crews at different times, so the PPE “styles” vary, but all workers depicted are wearing proper head, eye and hearing protection. The guidance about wearing chaps while chipping isn’t definitive in the standards and is left to the discretion of the employer to determine if it constitutes an unreasonable catch hazard in a given situation. We all know and should acknowledge that workers wrestle with the dilemma of having to put the chaps back on to make “just one cut” if they have removed the chaps to chip brush. It would be unforgivable if the bucket operator shown staging brush was actually feeding the chipper while wearing a full body harness, versus helping the chipper operator, and we assure you that all he was doing was providing a small assist.
A winch line is out in two of the three pics, but there is no evidence that the chipper is running in either pic, i.e., there are no chips coming from the chute. We agree with you: the Z133 standard says the winch line “shall be stowed” before chipping commences. The first image, on page 68 in the print issue of the magazine, depicts the operator complying with the spirit of the rule by holding the line well out of the way of the incoming tree section while being very attentive to the piece’s movement. But again, the chipper does not appear to be running. The operator may actually be reeling the winch in, as the next photo in the sequence, displayed here, shows the winch line fully retracted.
In the third photo, on page 70, the winch obviously is still in use, and it appears the chipper is not running. Even so, anything short of full compliance with rules such as these places one on a slippery slope. Going forward, we will continue to try to use illustrations that do not require explanations or apologies.
Rigging: What About the Tree?
In Lawrence Schultz’s article, “Rigging Wood in Tight Quarters,” (TCI, July 2021), he correctly states, “Your rigging system is only as strong as its weakest link.” He then goes on to crunch a bunch of numbers in regard to blocks, ropes and log charts. Not once does he acknowledge the role of the tree in that rigging system.
More than one climber has suffered the consequences when the tree itself was the weakest link. In fact, the working load limit (WLL) of a tree is never known, and there does not have to be an obvious defect for a tree to be compromised. And, as I’ve pointed out in the past, it is also impossible to know the maximum breaking strength (MBS) of anything but a brand-new line or sling. Taking the biggest piece we can based on our rigging calculations and log charts may not be the safest way to approach a cut. If you are approaching the safe limits of your rigging system, you are probably going too big.
That being said, it is also appropriate when there is no target under the tree to test the limits of what your rigging can take. How else do you really know?
Kurt Woltersdorf, owner
Lawrence Schultz responds: You are absolutely correct, sir. I was entirely focused on the finer points of the rigging itself. I was remiss not to have touched on wood, its fibers and the biomechanics involved in negative rigging. It is something that can be discussed at great length on its own, however, and could be an excellent topic for a follow-up article.
On the topic of MBS, using the high-end percentage for rope-strength reduction by knots along with the maximum force calculation, and sticking to weights below the WLL, all help pad the situation. I was somewhat attempting to steer readers in the direction of more involved techniques, like double-block rigging. I hope that was conveyed, because they bring the forces down and spread the load over more rope and components. This will keep people more safely away from those working load limits, peak forces and MBS. Thanks for your comments. Be safe out there.
Kudos for Rigging Article
This article (“Rigging Wood in Tight Quarters,” TCI, July 2021) is fantastic. It is gripping and full of information. This is the sort of thing that excites me about writing for your magazine. Good writing, good editing and great photos!
I just want you to know I am not always a malcontent when it comes to content.
Jack O’Shea, BCMA, TRAQ,
crew trainer (and occasional
contributor to TCI Magazine)