- #1

AK Husky

- 1

- 0

## Homework Statement

This is a real world problem, which I have been thinking about for some time now.

The problem is this: I have a weighted sled which requires a pulling force to move it, and I have a team of dogs generating that pulling force. I am trying to figure out the differences between two different ways of configuring the team.

Terms being used are

"gangline" -central rope, all the dogs and the sled are attached to this

"tugline" -two to three foot line coming off of the gangline in pairs, and attached to the harness of each dog

__Configuration 1__: Each pair of dogs is pulling on either side of the gangline, with the pulling force being applied via the tugline at an angle of about 30 degrees off of the gangline. Essentially, each dog is running forward, but also pulling outward at a bit of an angle to the direction of travel, in order to run alongside the gangline.

__Configuration 2__: Each pair of dogs is pulling on either side of the gangline, with the pulling force being applied via the tugline, with a spacer bar perpendicular to the gangline which allows the tugline to be parallel to the gangline. Each dog is basically running straight forward all the time.

## Homework Equations

Components of force. Fx = F sin(30), Fy = F cos(30)

## The Attempt at a Solution

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My intuition says that configuration 2 is the more efficient setup, if all the force being applied by the dogs can be applied in the direction of travel, the Y axis (think, traveling up the trail), there are no X components of force on either side of the line cancelling each other out.

I am trying to figure out if the X component of force each dog applies in configuration 1 is entirely wasted effort and does in fact cancel itself out. I do not think it does, thinking: if you hold up both ends of string with a weight in the middle, and move your hands apart along the X axis, the weight still progresses along the Y axis.

I have used configuration 1 for many years and it definitely works, but I would like to know if I am limiting my efficiency by a significant amount.

I haven't used many specific values in this question because in a real world setting the entire system is pretty dynamic; sled weight, pulling force required, and amount that each dog is pulling can vary quite a bit, but if you guys need more info or any clarification let me know.

TL;DR

Is having sled dogs pull at an angle significantly less efficient than having them pull in a straight line?

Thanks

Hopefully I posted this in the right section.