[Traveling Woodsman]

Looks fun! Is this on your property? And what are you gonna do with it?

[Traveling Woodsman]

@Carl Russell 15085 wrote:

I am considering a break down of the different energy centers, if you will, those points in the machine where the energy produced by the motor is reduced. Not so much a comparison of how efficiently horses or tractors utilize the intake fuel, but some comparison that can show the power apportionment.
Carl

Ok, I mistook what you said earlier. Although a fuel utilization comparison would be interesting. Power apportionment would be a lot smaller bit to chew, I think I will do some research on this.

Another random thought that I don’t think has been brought up yet. Horses become more efficient the more you use them, at least up to a point, because horses eat whether you use them or not. So the more you use them the lower the ratio of feed input to work output. Machines on the other hand are stuck with a certain efficiency, whether good or bad. This can be viewed as either an advantage or disadvantage, depending on the situation.

I think this has been said before, but many of the discussions I’ve seen all over seem to have an inaccurate understanding of what efficiency is. I am not referring to this board, but to research papers, books, discussions and other such things on any subject related to what we’re talking about. The most common statement is that equipment is more efficient than animals because it can get more done. I am not sure where these people get their understanding of the word efficient, because they are supposed to be college educated experts in their respective fields. Efficiency has absolutely nothing to do with how much work is done, but it has everything to do with the proportion of input to output. In other words, efficiency is a ratio, not a value. It really irks me when people make statements with the wrong use of the word. Part of what we’re saying here is that horses are more efficient, in terms of not using up power in the transmission of it. So that is just another way of saying what has already been said……

I’m sure that none of using horses for a livelihood made the choice based strictly on the mechanics of a horses output. Nobody would make a decision to use horses based solely on this, ’cause ultimately you can do more with motorized equipment. Part of the argument of the animal-powered community is that basing decisions on purely one aspect (or maybe fewer than the total), such as mechanics, will ultimately leave you with negative side effects. We are saying that the power choice decision process should involve as many aspects of the big picture, or “whole forest”, as possible, not just simply brute force production. Aspects such as the effect on the user, pollution, environmental impact, and many others. And this is really what our argument is in other areas as well, such as forestry and agriculture. When we make management decisions based on incomplete criteria, ultimately we will find some of our choices to be actually defeating our purpose. The choice to use animal power is (or should be) really a choice to look at and consider the “big picture” of whatever operation or field is being considered.

So there’s my few thoughts for the moment……

[Traveling Woodsman]

I totally agree with Tim, tongs are great ’cause you don’t have to dig around under the log, I use them regularly. I have never found that hundred dollar bill under a log! But they don’t have as much lift when used with an arch because you can’t hook as close to the log. And that’s just on a conventional top hitch, not even considering the extra lift you can get from a cradle hitch. So I have taken to using a combination system, if the chain doesn’t go under the log right away I slap the tongs on it and pull it out to a place where I can easily put a chain underneath. Then I put a chain with a full choker hook on it. This saves me the time and frustration of digging, but gives me maximum lift on most of the skid. I am a logger, not an excavator! But Tim is right that when ground skidding, tongs will give you a little bit of advantage. And tongs are also the fastest method for hooking and unhooking logs. I do like to use tongs in some situations when ground skidding.

Another tool for hooking to logs is the grab, also called a dog. The advantages this offers is that it will never come unhooked if there is ever slack in a chain, and is great for making a log train. More of a specialized tool, but when you need them they are really nice. So I actually keep tongs, chains, and grabs on my arch when I’m skidding. It’s not a matter of which method is the best, but of having an understanding of all the different methods and knowing when and how to apply them to maximum efficiency. And too, when ground skidding you may not find it worth it to drag around several chains, a set of grabs and tongs to every single log that you skid. Just another of the many advantages to using an arch. Of course this is more of a concern to professionals, part-time practitioners may not find it advantageous to keep lots of gear like this around.

And then there is the cable choker, which I have never seen an advantage to using in a horse operation. I have one that I have used once or twice, just concluded that they were intended for a choker setup on a skidder.

Looks like I broadened the discussion…..

[Traveling Woodsman]

@Carl Russell 15058 wrote:

This is in part becoming a discussion that I have been trying to have with the “Alternative Energy” crowd for several years. Our culture has become so dependent on the internal combustion motor that we just take for granted the advantages that they provide, without really looking at the efficiency of the conversion of fuel into power.

If the HP efficiency is really as low as has been described here, then it must also apply to the fuel efficiency per unit of work. The dependency on motors has motivated initiatives to use Bio-fuels, but the discussion about conservation and energy efficiency when directed toward animal power is still a non-starter.

I wonder if we can get together some detailed info that shows how much more HP animals have in comparison to machines combined with fuel efficiency per unit of force, to show how viable animal power truly is in comparison to machines using bio-fuels.

I would love to have this presented at 2010 NEAPFD. Tim, Ben, anybody else? Would you, could you present some of this at our event in Tunbridge, VT 10/15-17/10?

Carl

This is something that I have always been interested in, in fact I almost did a research paper on it in high school. By this I mean a real world comparison between draft animals and tractors/skidders as prime movers, one that looks at the big picture of, say, a lifetime. In reality, the comparisons would be different depending on what specific piece of equipment you’re talking about, and I am specifically interested in comparisons involving farm work and logging. I may also be interested in research on earthwork too, because when I was talking with the Forest Service in Utah about some large scale dam work, this issue was central to their decision making process. Specifically, what can realistically be accomplished with horses, and all of the other factors involved besides actual production rates that would affect the project. They had wildly ranging estimates on production rates, and were forced make decisions based on the lowest production rates, which resulted in a decision to go with helicoptering excavators into a pristine 500,000 acre wilderness area. This also brings up the point that horses can accomplish a wide range of tasks that many different pieces of equipment have been made to accomplish. For instance, my horses can skid logs, pull any piece of farm machinery, move dirt, be ridden, and pack loads. I was just at a hunting camp where I packed in camp on my team, rode them during the day while hunting, then pulled my truck out of the ditch when we were trying to get over the pass.

There was a fair amount of research done on this in the ’20s and ’30s, when horses were still a major source of power and engineering had advanced to needing hard data, much like what we’re talking about. I would be interested in pursuing this further, such as getting accurate numbers and compiling a list of all the factors involved in using animals and tractors on the ground level, not just theoretically or in artificial environments like a pulling track. Carl’s point about horsemanship is but one consideration that should be included here. Cultural skills are a very important part of this conversation.

And as far as comparing animals to machines on fuel efficiency per unit of force, that is a very interesting idea. You would have to come up with some unit of energy that you could measure both muscles and fuel/engines with. I’m sure somebody somewhere has worked on this idea at some point. I know of several old books that at least deal partly with this. I think I will start looking into it.

On a different note, to apply Tim’s equation for estimating horsepower to some numbers, let’s use some dyno numbers and 3 mph, this being a common working speed for horses. And many forces exerted at a horse pull are actually done faster than a walk. This would definitely be the upper end of anything any team has ever done, but it’s interesting to talk about anyway.

So,
HP = #4000 x 3(mph) / 375 = 32 HP

Or,
#4000 x 2(mph) / 375 = 21.33 HP

Or, to use the biggest numbers,

#4900 x 3(mph) / 375 = 39.2 HP

Or,

#4900 x 2(mph) / 375= 26.13 HP

As you can see, the speed can have a big influence on horsepower numbers, but it is a real world consideration in how much work can actually be done. Interesting to think about.

I wouldn’t rule out making a presentation on some aspect(s) of this if you were interested Carl. I would have to do more research before I would feel comfortable making a presentation. Is anybody aware of research about this stuff? Anybody have thoughts?

[Traveling Woodsman]

Good thoughts. You’re absolutely right Carl in your comments on the variability of a team’s output. I of course know what you’re talking about, I just hadn’t connected it with this discussion.

Tim, I have heard it said by a number of different people that an athletic team in good shape, and like Carl says, in a good relationship with a teamster, can exert a tractive force equal to their own body weight. From all of the dyno pull results I have seen, this appears to be true, and in fact most records involve a greater tractive force than the animals body weight. Check this out http://www.horsepull.com/Record%20Loads.htm . This shows a #3000 team exerting #3650, and some heavyweights exerting #4900. Then it’s just a matter of determining speed. Dynamometers take all of the guesswork out of determining the actual force exerted, since like you said the amount of force required to move a given load is only very indirectly related to the weight of that load.
I’m sure though that making these records involved horse training methods that I don’t approve of. And the dyno track is an artificial environment that has little in common with a log and a wooded hillside. Just some hard numbers to talk with.

Good discussion.

[Traveling Woodsman]

The numbers I quoted above were just off the top of my head, and I would be interested in knowing if anyone else has more accurate and precise numbers.
(At least some info. is available through a google search).

[Traveling Woodsman]

@jac 15004 wrote:

Does anyone know the real “horsepower” of draft horses. Ive heard figures of around 8hp/per average drafter ?? but if thats true then my team only has about 16 hp!! Now mabey Im looking at this to simplisticaly but your average lawn tractor is 16hp.. and I cant see that moving a 4 ton load on a wagon at 5mph or even pulling my grass harrows !!??!!
John

Ok, so here are some of my thoughts. I’m sure there is science and math involved here that you can learn somewhere, this is just some of my musings on the subject, and is by no means comprehensive. I would be interested in what anyone else has to say.

The energy required to move a given object, be it dragging or rolling, is measured in units of force, such as ft-lbs. 1 horsepower is equal to 550 ft. lbs per second, and is a unit of work, which is a force exerted over a distance. So horsepower measures force over time, and by extension distance. Now engines, let’s take for example a 60 HP tractor, are rated usually by brake horsepower. There are other ways of measuring horsepower, but this one is fairly common. Brake horsepower is the measure of the output of an engine after internal losses such as friction, but before external losses are factored in, such as alternator, water pump, power steering pump, muffled exhaust, gearboxes, differentials and other auxiliary components. (Somebody correct me if I’m wrong). All of these together can be significant subtractions to the actual usable HP, somewhere around 20-40%, depending on the situation. I have heard even higher numbers.

So let’s look at the 60 HP tractor. With a brake HP of 60, we might only have 36 HP usable after all deductions are accounted for. This 36 HP can be used on the PTO or on the drawbar, but the drawbar is what we’re interested in for the purposes of this discussion. The percentage of this 36 HP available on the drawbar is a function of the tractors ability to grip the ground and the amount of HP required to move the actual tractor. There are a number of variables that determine this, such as weight, whether the tractor is 2WD or 4WD, whether there is locking differential(s), tire type, surface type, moisture, surface condition and maybe some others I’m not thinking of. I am not currently aware of specific numbers here, and this is also something that can vary significantly. But I have heard numbers as low as maybe 15-20 HP actually available on the drawbar from a 60 HP tractor. Or one number I’ve heard specifies a 40 HP tractor actually having 7-8 HP on the drawbar.

Now let’s consider the output of a team of 1500 lb. draft horses. It is generally accepted that a team in good flesh and condition can exert 1 HP each continuously for a 6-8 hour day. So 2 HP per team. But, that same team could exert up to 25 HP together for a short period. This is the actual output, after the horses move themselves along. And I have actually heard numbers as high as 40 HP for a bigger team on short pulls. So a big team of horses may be able to out-pull a 2WD 60 HP tractor for short distances. In fact, my first team of horses which were 1500 lb. each wringing wet, could move a log in wet conditions that my neighbor’s 50 HP 2WD John Deere couldn’t move in the same condition (although it could move it in dry conditions). However, this was a short term effort for my horses. This is where it gets hard to compare horses to tractors, because a tractor doesn’t have this tremendous short term overload capacity, but what they can do they do indefinitely.

Both engine manufacturers and equipment manufacturers obviously want to cast their products on the best light possible, which is why numbers such as brake horsepower are used. So the horsepower unit has degenerated from a way to compare horses to machines (it’s original purpose), to a way to compare machines to machines, since there are so many variable factors that determine that actual usable horsepower of a given piece of equipment.

To summarize, the 16 HP lawn tractor mentioned cannot provide an actual 16 HP on the drawbar for several reasons. One, there is loss between the crankshaft and the drawbar. Two, the traction capability of the tractor determines the percentage of HP provided by the engine that can actually be translated into useful force. Third, the lawn tractor has to move itself before it can exert a force.

So,

Usable drawbar HP = Brake HP – auxiliary component deductions – force required to move tractor – tractor’s inability to sustain traction.

Don’t get hung up on the numbers, my purpose here is not to provide scientifically accurate data, but to communicate ideas. I hope it helped, and I am interested to see what other people have to say that I might have missed.

[Traveling Woodsman]

Well guess I’m 26 so I don’t quite fall in there, but seeing that I’ve been using draft horses full time since I was 19 I thought I’d throw my 2 cents in. I got started in draft horses when I was 15, I believe, when our family bought a team to do all the work on our farm in the mountains of Virginia. I originally wanted to get a team because of all the nostalgic pictures you see, as well as the exciting atmosphere that surrounds horse pulling. After I got them and used them every day I soon realized that it was a lot different than I thought. You don’t just turn off the key and walk away when you’re dog tired at the end of a dawn ’till dusk day behind the horses. But after facing that reality I can still say that I really enjoy spending the day behind a team of stout horses skidding some good oak logs. After using horses on the farm for several years doing just about everything you can do with a horse, like mowing, tedding, raking, hay loading, walking and riding plowing, discing, harrowing, cultivating, all kinds of wagon work, and others, I ended up doing an apprenticeship through the Healing Harvest Forest Foundation in horse logging when I was 18. Shortly after that, I started out on my own with a 150 tract of woods several miles from the farm and have been all over since then. In addition to Virginia, my logging has brought me to Pennsylvania, Ohio, Minnesota, Wisconsin, Wyoming and Montana. I’ve had many adventures with horses, log trucks, knuckleboom loaders, sawmills, and chain saws, some good, some bad, always learning something. Soon I am headed back to VA to work in the wonderful hardwood forests in the Appalachian Mountains of Virginia. Still the most diverse and interesting forests I have run into. So there’s the short version. I would be interested to know of anyone else with a similar story, ’cause I find that there aren’t many. 🙂 I’m also open to check out any new places where I might find work….

[Traveling Woodsman]

I’m not sure that I communicated clearly what I was thinking. I was not saying that I think the log is elm, or that it’s not locust. I would agree that it is locust, as Carl said the grain type is clear. My purpose in mentioning elm is to contribute to the discussion on tree and wood ID, and the different factors that are involved, like locality that is being discussed.

As far as a picture, I do not make it a habit to photograph bark of various tree species, so I do not have a picture. And since I am currently living in Wyoming, I can’t go take a picture. I am however moving back to Virginia in a little while and I may be able to get a picture. I have to say that it won’t be very high on my priority list, so I can’t guarantee that it will happen. If I happen to think of it when I run into one, I may try to do it. Sorry.

I found this discussion very interesting…..

[Traveling Woodsman]

@lancek 12474 wrote:

as far as it being elm give me a break the bark is totaly different ! Lancek

If there’s one thing I’m picking up from this thread, it’s that there can be great variation in a tree’s identifying factors, depending on it’s locality. I might suggest that elm is included.

[Traveling Woodsman]

If both of the pictures are of the same log, and there was compound leaves and thorns on the branches, then I would have to call it locust, even though I’ve never seen black locust with bark like that. Although, honey locust could possibly have bark like that. But if I couldn’t see the leaves and branches, I might suggest that the log is some kind of elm. I’ve seen certain elm logs mistaken for cherry, and elm lumber can closely resemble locust. Not seeing everything, I can’t say for sure, just throwing it out.

[Traveling Woodsman]

@Carl Russell 12426 wrote:

Looks a lot like black cherry on the left, and white ash on the right, to me.

Ditto…..

[Traveling Woodsman]

Black Cherry. Sorry to say probably not worth much because of the heart rot. If it were in a pile of cherry logs there would be some buyers out there who might reject it. There are some who would buy it, though, and it would have a board foot reduction or price reduction, depending on your buyer. However if you wanted some cherry lumber for your own use, you would probably get some nice character boards from it. There’s approximately 120 bd. ft. in this log, and a depending on local markets you might get it sawed for $0.25/bd.ft. Although some sawyers might have a minimum order or hourly charge.

[Traveling Woodsman]

@Carl Russell 12209 wrote:

, but the active power that animals use to move a weight forward is lift,

Carl

I would reiterate what Tim said, there is both a vertical and horizontal component to a draft animal’s forward motion. They are not mutually exclusive, they are both part of what an animal is doing when it’s working. The active power that animals use to move forward cannot be just lift, because lift is vertical, not the horizontal direction of an animal’s motion. You can calculate the vertical and horizontal component of an animal’s draft easily by using trigonometry. There is more pull than lift on an average angle of draft. I would agree that lift is a commonly overlooked or misunderstood aspect of an animals draft.

And yes, the horse (or any animal) is actually pushing when it is working, but the collar, hames, and tugs transfer that push into a pull, which is what we experience when using animals for work.

[Traveling Woodsman]

That’s a skidding plate, designed by Glenn French if I’m not mistaken. I’ve used several like that, and I’ve made my own variation. It has two grab hooks on each side, for either pulling multiple logs, or if you do a cradle type hitch. There is a slip hook in the center for holding the plate, or for hooking tongs to. My impression of it is that it was longer than it needed to be, thinking about keeping the horses as close to the load as possible. So I made my own version, which isn’t actually a plate, but a a piece of 1″ round stock bent into a big hook (for holding and to attach tongs to) with 2 grab hooks welded on the outside of the big hook. Everything is on a swivel. It is several inches shorter than any skidding plate I’ve seen, and there are times when a few inches can mean the difference between moving a log or not, although they are admittedly few. My personal take is that I want to give the horses every chance that I can give them, and if I can make them a little less tired at the end of each day because they had better lift, I will do it. But I don’t imagine it is the kind of thing that will make or break you. Would be interested to know if there are reasons to have a big wide plate that I haven’t thought of.

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