Tedder Advice

Great question George. I wish I knew the answer. It would be extremely helpful to have basic data on draft requirements for various pieces of equipment (plows, tedders, mowers, etc).

Has anyone seen this sort of data (pounds required to pull various implements)? This ties into the work that Tim Harrigan and Andy have been doing.

With draft animals we’re working with limited power, delivered over a fairly limited speed range. A tractor has extra power to waste and multiple gear ratios to optimize shaft speed relative to ground speed. I think it’s reasonable to assume that we aren’t going to exceed 1hp per animal for extended time durations. I’m talking about real work, not a 6 foot exhibition pull. 1hp = 550 foot*pounds/second. Given that a draft animals gait is basically fixed at something on the order of 5 feet per second that equates to about 110 pounds (in the horizontal direction) per animal.

It’s definitely a challenge to design an implement around those limitations, not impossible but challenging. I suspect that efficiency was not a primary design criteria for tractor implements. When you’ve got 40 plus horse power to work with it really isn’t that critical if you waste a few. Next time you jack your car up, turn a wheel by hand. The amount of bearing and brake drag is significant. Now imagine that same amount of drag on a bicycle. It would kill you.

In general what we need for animal drawn implements are VERY efficient mechanisms, narrow “swaths” (width of plow bottom, tedder width, mower bar length, etc), and light weight construction. This last one (weight) is also critical. A ground driven implement should weigh just enough to get the job done. I’m convinced that my MD9 mower is far heavier than it needs to be to provide enough traction to work. This is an artifact of the cost effective manufacturing methods of the day. Think “light wall tube bicycle construction” versus heavy iron casting.

Regards,

Matt

hey george, i haven’t tried all the tedders made but have used quite a few. still, i haven’t tried them all, and the one i have isn’t the best one i ever tried, but it works pretty good.

don’t know how three horses would do over on some of them vermont hills. that might be a good challenge. let me know how it turns out. i’d be interested in finding out how they’d do on a good hill in good hay. mitch

@mstacy 22043 wrote:

I think it’s reasonable to assume that we aren’t going to exceed 1hp per animal for extended time durations. I’m talking about real work, not a 6 foot exhibition pull. 1hp = 550 foot*pounds/second. Given that a draft animals gait is basically fixed at something on the order of 5 feet per second that equates to about 110 pounds (in the horizontal direction) per animal.

Matt

I agree that it is unlikely to exceed 1 hp for an extended time such as in field work. In the interest of historical accuracy, Watt measured the output of an average horse at 22,000 ft-lb/min, 366 ft-lb/sec. Because Watt wanted to rate his steam engines in terms of hp but did not want to overstate the ability of steam engines, he increased his estimate of 1 hp by 50% to 33,000 ft-lb/min, 550 ft-lb/sec. In some of the measurements that I have made I have noticed that a single horse is unlikely to sustain a pulling effort of 1 hp for very long. 2 mph is about 2.9 ft/sec so 1 hp would require a sustained pull of about 190 lbf at that speed. 190 lbf is equivalent to a stoneboat load of about 475 lbs on firm ground. Most conditioned horses or oxen can generate 1 hp or more for short periods, but sustaining that level of pull is another matter.

Hi George, I just bought a NH 162 tedder (1600$ from a dealer). It is said to be a 17′ tedder, but I don’t see how they measure that as that is like from end to end. It should easily handle two 7′ mower swaths. the one I pulled last summer was a similar size and three pulled it easily. Folks at Essex farm have been pulling one all summer with two horses (7000 bales, about six hours a day some times), but they have a very flat farm(they have an I & J cart). I think the extra horse will give us the power we need for the hills. Can you work across the hill as much as possible? It is much easier for the animals if they can do the up hill in 100′ sections and then do a longer traverse. I know it is a hassle to break a small field up into even smaller pieces, but if it was steep enough it might be worth it.

The grim tedder is a good tedder and I have been happy with it. I am hoping to achieve three things by adding this tedder. First, when I want to do six to ten acres at one time, this tedder will still get it done in a shorter amount of time (like before one pm.) Second, a rotary tedder is the only tedder that will really touch a rained on windrow. I work hard to avoid those but it will still happen and I want to be able to ted them out. Finally, I think it will do a better job with some of the heavy cutting, right after mowing. If the last was the only benefit, I don’t think I would have done it, but the speed is a big factor for me as I am mowing and raking with two teams.

Donn

George, someone here had a great design for a roll over tongue that easily flopped from two horses to three. I would be perfect for what you want to do. I hope they see this. Donn