Arch Logging with Dozer

California Barrel logging with Fred Slanger and Denny Olsted
California Barrel logging with Fred Slanger and Denny Olsted
California Barrel road between Jewell and Olney, Denny Olstedt on one cat and Fred Slanger on the other 1951 Epson Logging
Arch.jpg - 16.9 K
1940's D8
As found in the Caterpillar Museum
1940's D8 arch
Bdozera.jpg - 5.6 K

The first two frames are actually the same photo enlarged a bit differently. They date to 1951 and show Fred Slanger and Denny Olstedt operating a pair of D8's recovering an oldgrowth log along what was known as the California Barrel -- between Jewell and Olney. Special thanks to the Baker General Store for providing this frame.

Beginning with the 3rd frame down, we have a classic track laying arch of the 1940's. This writer is uncertain as to the dozer but assumes that it is probably a D-8. In the 1940's and 1950's tractor logging with an arch proved less expensive on favorable ground than cable logging. The keyword, of course, is 'favorable ground' which implies ground level enough that a dozer can operate. This equipment was doing salvage logging in the Tillamook Burn as is obvious from the background. I should note that what we generically call the Tillamook Burn, was actually a series of fires between 1933 and 1945. My estimate is from what information I have is that this is clean up from what is formally known as the the "Wolf Creek Fire of 1933" which started about the same time as the first Tillamook Burn of unknown causes 50 miles to the north of the more famous Tillamook Burn of the same season, and burned westward in two fingers---one through the Vine Maple area and the other south of Elsie--but actually sparing Elsie.

The small frame on the right here reflects one of the hazards of logging with a dozer. It is reported that a large log tumbled off the hillside in front of the dozer crushing it. The operator was alerted and escaped, but as you can see the dozer is in need of general repairs. Judging from the extend that this dozer is dismantled, some pretty bad things must have happened to it.

The third frame is courtesy of Bob Sharp, and was taken in the Spruce Run area.

The colored photos to the left are taken at the Caterpillar Museum at Brooks Oregon. They are included here because of their uncanny similarity to the equipment shown on the job in the Sharp Photos. Note that the D-8 has 3 modifications all of which are Oregon specials related to Oregon's early adoption of a logging safety code.
The Canopy or metal roof over the operator was intended to protect the operator from falling objects. There were no strength requirements at that time so they were often made of a water pipe frame and 1/8th or 3/16's steel sheet.
The sweeps were added as a requirement defined as something from the top of the radiator to the front of the canopy intended do deflect the brush over the top of the machine.
Safety screen
The wire mesh on the back was the third requirement. It was intended to stop flying rigging in case the winch line broke.

The Arch

Many styles and shapes of arches have been used to assist in moving logs. The tracked arch shown here is a classic, though arches with rubber tires were often used with smaller dozers. The winch line was threaded through the the arch. It provided two distinct benefits. First by pulling 'up' on the logs a little you could help free them from hang ups and obstacles that might be in the way (stumps for example). Secondly, logs drag a lot easier if they are partially lifted off the ground. This means that with an arch you can pull a lot more wood than if you are dragging the logs on the ground.

The downside of the arch is that you are pulling a trailer around and you can never forget that. Also a trailer that wants to upset on the corners. If for example you turn a short corner will pulling a turn of logs, the arch will tip over. While it is easier to 'right' one than you might think it is still a nuisance. What you do to turn one right side up is to disconnect the turn of logs, and reconnect the winch line (which is still through the fair lead) to the arch frame somewhere. Then you wind up the winch. Because the winch is above the hitch winching on the fairlead will pull the fair lead up, and with the tracks being the heavy part---they will drop down, and presto the arch is rightside up.

arch1a.jpg - 19490 Bytes
Hyster Winch with integral arch

Integral Arch

Towed arches were common in the middle of the 20th century, but then came the log skidder with an integral arch built in, and finally it occurred to folks that you could integrate an arch on a dozer as well. Now days dozer logging is only used in special cases, and often when a dozer is used is is really just a tracked skidder often with a grapple. However the photo that follows is that of a Hyster powershift winch on the back of an Fiat-Allis 16B. This is a classic integral arch on a classic logging size dozer. Although you can probably pull more with a towed arch, a towed arch is a perpetual headache to keep right side up. The limiting factor here being how much you can pull before the dozer rares up. The dozer only weighs around 50,000 lbs so what you can pull is limited, but when it comes to brute force dragging the only thing that will do better is a bigger dozer.

Though convenient, the downside of the integral arch is that they won't allow you to pull as much as you can with a trailer arch. They have two limitations: they are not as high as a trailer arch and secondly they disrupt the balance of the dozer, and if you try to pull to much the fair lead goes down and back, and the front of the dozer goes up, and the logs don't move. By contrast the trailer type arch carries the load, and the limit of capacity is really when you can't pull the load instead of when the dozer stands on end.

- - Updated 12/11/2012
- - Updated 11/13/2012
- - Updated 06/08/2008
- - Updated 04/15/2008
- - Updated 2/4/01
- - Updated Sunday, August 5, 2007
- - Updated Wednesday, March 12, 2008
- - Updated 3/16/2008