Hybridized Timber Harvest – Horses and Fowarder

[Andy Carson]

Scott, I am glad that these slopes were well out of the range of most existing ground harvesting systems, as they definately (at least according to math) seem very very difficult. Earlier in this thread Carl mentioned on this particular job he had a 60-70 percent slope on the return trip for about 50 feet. In the woods around here (and probably in many places in the east), having some sort of techinique to tackle very steep but moderately short slopes like these would be useful. In alot of areas around here, “flatter” areas are excessable if one can get up and down a short steep slope. Using a counterweight on a sky-line (of sorts), I am essentially proposing a low-tech, low-cost hybrid between a cable logging system that is great for steep slopes and the horse drawn system, which is nice for flatter terraign. Both could be made to be low impact. I know the system doesn’t already exist, I am kinda thinking outside the box and doing a certain degree brainstorming. I do think the concept has merit though.

[Scott G]

Here is an old photo of a large load being belayed off the hill. A book I recently purchased titled “Woodsmen, Horses, & Dynamite” has a detailed sketch of a sophisticated belay device mounted on a mobile platform. I don’t have the book with me now but once I get my hands on it again I’ll scan the image and post it on here.

This is one of my favorite “back in the day” photos. The gentleman on the load seems quite contemplative. I would be too if I was trusting my & my team’s lives on that piece of well worn hemp/wire rope. Might even need to change my woolens’ during the course of the day… 😮

[Carl Russell]

@Scott G 29045 wrote:

Andy,

If you are working ground in excess of 50%, you are well out of the realm of a ground-based harvesting system.

I hope we all are in agreement in how we are measuring % slope.

Mathematically 100% slope is equal to a 45º slope. Rise of 100 feet over the run of 100 feet = 1.00, or 100%

A 60% slope has a rise of 60 feet in 100 feet, and is equal to about a 30º slope.

I realize there are some conventions that refer to a 45º slope as 50%, 1/2 way between straight up and level, but it is not accurately represented mathematically when using measurable features on the ground.

I know that if we multiply 75% x 90º we can get a number of 67.5º, which many would consider to be how to calculate % slope.

When I used the figure 60-70% slope I was referring to a rise of 60-70 feet over a 100 foot distance. In this case it is a rise of about 35 feet in about 50 feet level distance, or a 30-35º slope.

My methods are based on what I was taught in forestry school, and plane surveying. I also use a Suunto Clinometer that is calibrated to % slope with a conversion table showing 100% = 45º.

To calculate º slope from % use Tangent = Opposite/Adjacent
60% = 60′ rise (opposite) over 100′ run (adjacent) = .60
The inverse Tangent of .60 = 30.98º

With this in mind a 50% slope, while pretty good uphill is not as excessive as a 45º slope.

Carl

[Carl Russell]

@Scott G 29047 wrote:

Here is an old photo of a large load being belayed off the hill. A book I recently purchased titled “Woodsmen, Horses, & Dynamite” has a detailed sketch of a sophisticated belay device mounted on a mobile platform. I don’t have the book with me now but once I get my hands on it again I’ll scan the image and post it on here.

This is one of my favorite “back in the day” photos. The gentleman on the load seems quite contemplative. I would be too if I was trusting my & my team’s lives on that piece of well worn hemp/wire rope. Might even need to change my woolens’ during the course of the day… 😮

This was called a “Snub Line”, and was basically a rope wrapped around a stump, like a capstan. There was a “Snub Man” that would manage the tension of the snub line as the team descended. It was his job to make sure that the line was tight enough to slow down the team, while keeping it free enough so that the line wouldn’t grab and break. This was one of the most stressful jobs in the camp, as if the line were to break, the sled would be sluiced and both team and driver would be seriously injured or killed. There is one tale from northern NH where such an accident occurred. By the time the team came to a stop, hanging from their harnesses halfway up a bent over spruce tree, the snub man was already gone, and running for the Canadian border.

Carl

[Scott G]

I’m talking rise over run, as measured with my clinometer. I was always taught, and have witnessed, that working a 45% (not 45 degree) slope with a ground system was usually the upper limit. Granted, that is going to vary with surface conditions, but as a guideline that is what we typically stick to. Mastication equipment such as self-leveling Timbcos’ will work steeper ground fairly well but they are not forwarding material off the hill. Shovel yarding is fairly popular out here and can work well but can still be messy on adverse ground. Any steeper than ~ 50% and you are either contouring a road and pulling line down or up from the skidder or using a yoder, jammer, or skyline. Not that you can’t run steeper, I’ve taken rubber-tired skidders and a dozer down grades (fall line) up to 60% but I felt that reupholstering the seat on certain occasions might be needed due to the fabric being soiled…

The major/primary issue is tearing up the site. With grades like that you are spinning tires & churning up ground pretty consistently. Trails/temp roads with a straight line descent on that type of grade are nearly impossible to adequately mitigate surface drainage issues and ultimately will cause eroision and possible BMP adherence issues as well. About 25-30% is the top end, for very short runs that we will go with, even on temp roads. Drainage structures/diversions just don’t work well when you exceed 25-30%.

But…, I’m coming at this from the Rocky’s, not New England. A few work in steeper ground with skidders out here, but they really shouldn’t be doing so from a resource damage perspective.

If I’m coming down a really steep stretch with a horse I’ll skid tree length, often with two trained together or I’ll do a lousy job of limbing to create a bit more resistance.

My personal preference is to use a block in a spar with a rope.

[Andy Carson]

Carl, you and I are figuring slope the same way. Maybe 60-70% does seem impressive to you, but I think it is quite a feat and it seems very demanding. Scott, this snub line is pretty close to what I’m proposing, except with a counterweight (perhaps a large loag or group of logs) attached to the other end of the line so that it raises as the horses fall. This live counterweight reduces the amount of downward force and if properly chosen could move it into a range that the horses (and some supplemental braking on the wagon) could control. On the return trip, the counterweight would fall and assist in pulling the horses and wagon up. If the counterweight is picked well, if could provide enough brake and power assist to allow the horses to supply a large percentage of the work, with no snub man needed to control braking. You just tie of the line at the bottom and tie off the line at the top. You would want to make sure the line doesn’t break, that would be terrible. Of course, if your brakes on a wagon went out going down a hill like that you’d likely be toast too. I am not sure which I would prefer… I suppose if you have brakes on the wagon and a line then both would have to break… It would probably be better if the path the counterweight takes is different than the path the horses/wagon takes, that way, there wouldn’t be logs falling on you if the line broke.

[Tim Harrigan]

@Carl Russell 29050 wrote:

…By the time the team came to a stop, hanging from their harnesses halfway up a bent over spruce tree, the snub man was already gone, and running for the Canadian border. Carl

My guess is the snub man was the fastest guy in the camp! 😮

[Tim Harrigan]

@Countymouse 29052 wrote:

..counterweight (perhaps a large loag or group of logs) attached to the other end of the line so that it raises as the horses fall…

I saw a video of something similar of harvesting hay in Europe, probably mountains of Switzerland or Germany where they loaded a sled at the top of the hill, pulled it down with the team, the sled being pulled down was attached by cable to a sled at the bottom of the hill which was pulled up the hill as the load descended. If I find the video sometime I will provide the link.

[Scott G]

@Tim Harrigan 29054 wrote:

I saw a video of something similar of harvesting hay in Europe, probably mountains of Switzerland or Germany where they loaded a sled at the top of the hill, pulled it down with the team, the sled being pulled down was attached by cable to a sled at the bottom of the hill which was pulled up the hill as the load descended. If I find the video sometime I will provide the link.

I have a visual of a horse-drawn tram…

[Carl Russell]

@Scott G 29051 wrote:

… I was always taught, and have witnessed, that working a 45% (not 45 degree) slope with a ground system was usually the upper limit. ……

But…, I’m coming at this from the Rocky’s, not New England. A few work in steeper ground with skidders out here, but they really shouldn’t be doing so from a resource damage perspective.

If I’m coming down a really steep stretch with a horse I’ll skid tree length, often with two trained together or I’ll do a lousy job of limbing to create a bit more resistance.

My personal preference is to use a block in a spar with a rope.

Just couldn’t be done out here. Possibly our soils are less sandy, and therefore more stable. I know your slopes are certainly steeper than ours as a rule. We don’t harvest on these slopes without creating contoured trails.

With animals using a sled on these slopes is ideal. Bridle chains for breaks. Of course horses can handle the slope much better than machinery, as they are naturally self-leveling, so are the teamster cutters.

I have yarded to the top of steep slopes and rolled the logs down to pick them up again at the bottom. Hand logging on steep slopes can be pretty dangerous, but gravity can be used to one’s advantage, keeping the animals and machines in safe circumstances.

As far as the counterweight system…. I’m having a tough time remembering the specific details, but I remember seeing an old film of cattle being used to move a revolving cable system. The teams were worked on a flat section in the loop. Several teams were employed, hooking on to the cable and traveling some distance to a place where they unhooked and walked back to their starting place. There were usually several teams hooked at once. The other, downhill side of the cable ran along a sluice-way and had logs attached to it at the same intervals that the oxen were hitching into on the other side. It ran kind of like a fair ride with animals stopping to unhitch while choker setters were hooking logs in. Obviously this was a system they used after they started clearcutting big wood out west, as the time required for this set-up would need to be justified by sending a lot of wood down it.

Carl

[Scott G]

These are illustrations from WSU’s Timber Harvesting Primer. It’s a great forest op’s reference that I often forward to folks. If you want a copy you may go to my GoogleDocs site:

https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B2DO8YkfkhPLYWQwYjllZWYtMjYyNi00YjhiLWJjNjktZWE0ODBiYzZmODM0&hl=en_US

Although this pub is directed towards western forests, it can have applicability across all regions.

As has been mentioned, sites differ as far as what you can get away with. We can definitely operate over the reccommended slope % but, in our western forests, potential site damage usually negates that option.

Just goes to show you can never have too many tools in the toolbox.

[Scott G]

Click on the following links to view illustrations.

Timber Harvesting Systems Slope/Distance Operability

Ground-Based Systems Slope/Impact

These illustrations are from WSU’s Timber Harvesting Primer. It’s a great forest op’s reference that I often forward to folks. If you want the full copy you may go to my GoogleDocs site: Timber Harvesting Primer

Although this pub is directed towards western forests, it has applicability across all regions.

As has been mentioned, sites differ as far as what you can get away with. We can definitely operate over the recommended slope % but, in our western forests, potential site damage usually negates that option.

Just goes to show you can never have too many tools in the toolbox, …and thinking outside of that box is a good thing as well.

[Scott G]

@Carl Russell 29056 wrote:

I have yarded to the top of steep slopes and rolled the logs down to pick them up again at the bottom. Hand logging on steep slopes can be pretty dangerous, but gravity can be used to one’s advantage, keeping the animals and machines in safe circumstances.
Carl

Skidding to the top of a temporary sluice, dry or wet, and then rocketing the material down the hill to where it was picked up again on moderate terrain to be skidded/forwarded was pretty common out here back in the day. I guess you could call it an early form of swing yarding.

I bet the “snub men” were heavy drinkers…:eek:

[Jim Ostergard]

Thanks for the thoughts on electric Carl. I pretty much figured it was better to go with gasoline especially if the wagon stayed on the job. Lugging batteries is not my idea of an evening chore.

[Baystatetom]

They used sluices back here in New England to. But not nearly as often. While we do have steep land it is not usually that long a run before it flattens out a bit. Those areas that are that steep often have poor soils and poor timber so nobody ever wanted to risk their life for the timber. I still see cut bank roads zig zagging hill sides with with mature trees growing in them and they are half as wide as even a small machine needs. They must have pulled log length wood around switch backs in the trails to get access. Unfortunately those old trails often lead down rivers and/or have a ton of avoidable stream crossings.

[Author]

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