The Forestry Forum is sponsored in part by:

iDRY Vacuum Kilns

Forestry Forum
Sponsored by:

TimberKing Sawmills

Toll Free 1-800-582-0470

LogRite Tools

Norwood Industries Inc.

Your source for Portable Sawmills, Edgers, Resaws, Sharpeners, Setters, Bandsaw Blades and Sawmill Parts

EZ Boardwalk Sawmills. More Saw For Less Money! sponsored by Northeast STIHL

Woodland Sawmills

Peterson Swingmills

 KASCO SharpTech WoodMaxx Blades


Sawmill Exchange

Michigan Firewood, your BRUTE FORCE Authorized Dealer


Council Tool

Baker Products


iDRY Wood Lumber Vacuum Drying for everyon

Baltic Abrasives Technologies Nyle Kiln Dry Systems

Author Topic: A log's wave amplitude magnification  (Read 1622 times)

0 Members and 1 Guest are viewing this topic.

Offline PatrickG

  • member
  • *
  • Posts: 39
  • Age: 75
  • Gender: Male
    • Share Post
A log's wave amplitude magnification
« on: April 08, 2004, 07:33:55 PM »
So, nice guy that I am I offered to top a sycamore tree for a friend.  I loaded the "top" stripped of branches into my pickup with my tractor's pallet forks.  Later unloading the "log" which was about 8-10 inches in diameter at the big end, 15 feet or so long, and about 2 1/2 inches in diameter at the small end, it was full of water and heavy so I levered it up onto the side of the pickup bed and rolled it off by twisting the small end.  As the big end began to fall I turned lose of the small end.

When the big end hit the ground a wave of motion went up the log with amplitude of the wave increasing as the diameter of the log decreased.  So it did a "crack the whip" sort of motion and flew up and the tip drove a stop about an inch in diameter and 3 inches long into my right hand between the thumb and fore finger.

It opened up a right angled tear in my hand big enough to drop in silver dollars if I were of a mind to do so.  I looked in and could see all the moving parts, which is kinda spooky.  I wadded up a paper towel and grasped it to hold the hole closed, finished unloading my chainsaw, extension ladder, etc. and announced to my wife that I was going to drive to the clinic.  about 12-15 stitches later it was closed up and a week later the stitches wre removed.  Two more weeks and it is healed sufficienty that if I cover it with a LARGE band aid and wear gloves that it doesn't tear open anymore or leak.

It all makes perfect sense from a physics point of view but it didn't come to me at the time that the log would transmit a wave of motion that woujd grow in amplitude and strike me like a cobra.

Completely preventable, just take a step back as the log won't jump endwise, just wave the business end at you.

I hope none of you ever get tagged like this as I was just very lucky and had a near miss of the "important parts."  I will have a full recovery and a scar that looks like a small shark tasted me.

:P :P :P Pat  :P :P :P

Offline Jeff

  • Fearless Leader
  • Administrator
  • *****
  • Posts: 47581
  • Age: 57
  • Location: Harrison MI
  • Gender: Male
  • I know that I do not know.
    • Share Post
    • THEE Forestry Forum
Re: A log's wave amplitude magnification
« Reply #1 on: April 08, 2004, 08:07:28 PM »
Just call me the midget doctor.
Forestry Forum Founder and Chief Cook and Bottle Washer.

Commercial circle sawmill sawyer in a past life.
Ezekiel 22:30

Offline Fla._Deadheader

  • Senior Member x2
  • *****
  • Posts: 10366
  • Age: 75
  • Gender: Male
  • Linda Vista, Costa Rica
    • Share Post
Re: A log's wave amplitude magnification
« Reply #2 on: April 09, 2004, 06:48:33 AM »
That's weird. Messed with my share of Sycamore, and never had anything like that happen.  Glad yer OK ;D
All truth passes through three stages:
   First, it is ridiculed;
   Second, it is violently opposed; and
   Third, it is accepted as self-evident.

-- Arthur Schopenhauer (1788-1860)

Offline PatrickG

  • member
  • *
  • Posts: 39
  • Age: 75
  • Gender: Male
    • Share Post
Re: A log's wave amplitude magnification
« Reply #3 on: April 09, 2004, 07:29:10 AM »
Don't know if what happened to me was something everyone else knew about or not but wouldn't want to remain silent and let someone else get hit.

Being sycamore and spring it was really full of water and heavy for its size.  I guess being the top of the tree it may have been considerably more limber. I assume something like this could happen with other species as well.  Easy to prevent! Just take a step back as the log won't jump endwise

I'm just glad it only nicked the important internals and there is likely to be little residual effect beyond a scar which isn't that bad. As a right handed guy and it is my right hand AND right where a chainsaw gives it a workout, I haven't been chainsawing for 3 weeks. Tomorrow I am leaving to go to Mexico with a friend to resurect an RV and drive it back to the states and then from California to Oklahoma.  By the time I get back I should be as fine as fiddle dust.

8)  Pat   8)

Offline Tom

  • In Memoriam
  • *
  • Posts: 25839
  • Age: 76
  • Location: Jacksonville, Florida
  • Gender: Male
    • Share Post
    • Toms Saw
Re: A log's wave amplitude magnification
« Reply #4 on: April 09, 2004, 09:59:24 AM »
Good story, glad your hand is OK.  It's good advice to stand back. I've seen logs do things that I would never suspect. Good to keep a little clearance. :)

Share via delicious Share via digg Share via facebook Share via linkedin Share via pinterest Share via reddit Share via stumble Share via tumblr Share via twitter

sawmillers wave, almost.

Started by amberwood on General Board

9 Replies
Last post January 24, 2010, 05:11:40 PM
by ErikC
Edge of boards have a wave?

Started by WoodChucker on Sawmills and Milling

24 Replies
Last post May 10, 2003, 09:56:58 AM
by WoodChucker
wave and lines in lumber

Started by Gary_B on Sawmills and Milling

6 Replies
Last post December 17, 2004, 10:34:00 AM
by Gary_B
Snake and wave in boards cut.

Started by Noobsawyer on Sawmills and Milling

41 Replies
Last post January 22, 2014, 09:16:04 AM
by LittleJohn

Powered by EzPortal