Crosscut Saw Underbucking Safety Photo Gallery by bchw at pbase.com

Crosscut Saw Underbucking Safety

This gallery is about underbucking with a crosscut saw. The gallery was put together after reviewing photos of a recent wilderness trail cleared job. Maybe it will encourage crosscut saw users to keep safety in mind at all times and especially get them to be aware of the placement of an underbuck (or underbucker) when underbucking.

The question is, what side of the cut should the underbucker be placed to provide the safest condition for the sawyer when the log separates? Should it always be placed on the section that is likely remain stationary after the cut? Or should it be placed on the part that is likely to drop after the cut?

I think that in most cases that it is safest for the sawyer to place the underbucker on the section that is most likely to drop. In a rare condition where one section of the log is likely to raise after the cut then I would set the underbucker on the section that is likely to remain stationary. Note that this is not what is recommended in text and a picture in the US Forest Service Guide "Saws That Sing". In the end it is up the the sawyer to assess each condition and make a decision that will provide the safest condition for all involved.

Additional thoughts; In this case a heavy 6' Royal Chinook bucking saw was used so the underbucker was firmly set to hold the saw into the cut. If we had been using an axe handle to hold the saw, it is likely that the axe would have come loose or the handle just broke off of the axe head when the log dropped. In either case it would have been better for the equipment and safer for the sawyer if the underbucker would have been placed on the section of log that dropped.

Your comments are welcome (select "post a comment" at the bottom of this page).

Jim Thode, Lewis County Chapter of the Back Country Horsemen of Washington
More general pictures of this day a: https://pbase.com/bchw/packwood_lake_trail_5_22_10

The 44" fir log to be cut to clear the wilderness trail	View from above the trail, the trail is on the right	View from below the trial looking up hill	The underbuck is started after single bucking the top as far as possable
Close up of underbucking	Underbucking	Undercut was offset 1/2" to allow the right log to fall away without hanging on the left log	Falling log 1
Falling log 2	Falling log 3	Falling log 4	Falling log 5
Falling log 6	Video	The crew	The cleared trail
Saws That Sing - Underbucking	Homemade Underbuck or Underbucker	Underbucker closeup	Another Underbucking No No
Underbucker Drawing

comment |

bchw		29-Apr-2014 05:08
Smitty, Thanks for the comments. Part of the idea of posting this is just to get folks to think about it. If you mean by moving the under buck uphill that the saw be rotated form vertical so that the saw is cutting the log perpendicular to the log, then that would help to prevent the dropping log from rubbing on the fixed log. However, crosscut saws do not work well when not cutting in line with the pull of gravity and this especially true when single bucking. Jim

Smitty		19-Apr-2014 17:30
Please dismiss my last comment, not only" not" an expert, but a dyslexic idiot as well. Sawyer is in correct position. Did not watch video close enough. Could the under buck been placed a little further uphill so that the falling side would not have caught bottom of saw? My apologies for jumping in without looking. thanks

Smitty		19-Apr-2014 16:39
Hi Jim, I do not consider myself an expert at cross cutting but have had over 30 years in landscape arborist work. Much of the work involved removing and also planting huge trees with cranes. There was something about this video that struck me as odd but could not pin it down right away. I think the under buck was done correctly but the sawyer was in an unsafe position. He should have been working from the other side of the saw, on the down hill, to allow himself another step away from the log and the saw in case of un-predictable drop. He was standing in a "pinch point" between the saw and the weight of the uphill log. yes it is true that the saw might take a higher risk of damage but saws are replaceable and people not so much. Just my two cents worth.thanks

Dan		03-Oct-2010 01:10
We seldom get such big timber out east, so I hesitate to be critical. Like you said, all ended well, and I will use your example when I instruct new sawyers on unexpected dangers. On several occasions when I've had to cut big green blowdowns, I've used hanging wedges to hold (or slow) the drop. I also block my cuts so the drop isn't so severe. I prefer the axe handle as an underbuck though, as its springiness gives me more bite into the undercut, though that may just be my familiarity with the technique. As for breaking an axe handle, I can rehandle my axe for 10.00. If my underbucker holds fast and twists my saw, I'm out a good crosscut. You were fortunate not to have damaged your saw. Had that been a modern saw it probably would have twisted like a pretzel and held that bend/kink forever.

Chaz		02-Oct-2010 05:17
Oh, also, I don't ever have another person to run the other end of the saw, so I'm probably more used to single bucking than most. (I use one of the one man saws I have filed to fell with; the 5 1/2' Chinook will take a bit more practice, it's a bit "clumsy" at that, to say the very least...)

Guest		02-Oct-2010 04:59
Hi Jim, Actually, I was talking about crosscut's. I tried a similar angle of cut with my 5 1/2' Simonds 520 and it had no trouble. A very little bit of sag, but not much, and I could saw fine without the tip vibrating as long as I didn't try to cut too fast. A bit slower, but well worth it for the safety. To be honest since the cut was already angled a bit I thought it was just a mistake that it was not perpindicular. Happy sawing, Chaz

Jim Thode		29-Sep-2010 05:32
Chaz, Thanks for the comment and you bring up a good point about the difference between using a crosscut and a chainsaw. With a chainsaw there is no problem with cutting at any angle to be perpendicular with the axis of the log. However, crosscuts do not do well when cutting at an angle not in line with the pull of gravity. They need to cut vertical. This is especially true in this case where the top of the log was about 7 feet above the ground and the log would have to be single bucked. If we had tried to cut perpendicular with the axis of the log the upper end of the saw would have flexed to the down hill side and caused the cut to be curved. We did angle the cut in the horizontal direction to allow clearance for the log to be moved away from the sawyer after the cut. The alignment of the log did shift as it dropped with the left section moving away from the sawyer and the right section moving a little toward the sawyer. Once the cut was completed and the log dropped the wedges held the cut open enough for the saw to be easily removed. It was not stuck or damage in any way. Jim

Flip		27-Sep-2010 21:09
Several of us with the San Gorgonio Wilderness Association (SGWA.org) have been certified by the Forest Service for crosscutting. We always learn more with every project and we learned a lot from your underbucking video. Thank you very much for the time and effort in putting together these photos and the video. Commenter Chaz provided a very good reminder also. On large difficult projects like you had on this big fir we spend almost as much time sizing up the situation and discussing alternate approaches as we do sawing. :-) Our primary objective is never about the trail or the tree - it is always to get everyone home without a scratch. Wishing you all continued safe fun in clearing trails out there.

Chaz		01-Jul-2010 20:32
Good points! But, I have to say that I see another issue with the cut made, as well. It was several degrees less than perpendicular to the log that was to remain stationary, so as it fell it pinched the saw. I say this as even if the underbucker was placed on the side that should fall, it would still pinch in the best case, and could damage the saw as it fell, or have the log cut through, but still hanging dangerously in the air. By the way, how did you go about removing the saw? (Very nice saw, by the way.)

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