Swingle tree height?

[TreeDog]

I'm looking at upgrading my two wheel cart to a four wheeler There's a second hand cart available locally to me, the seller said they think it'd suit around 14.2hh, my horse is 15.2 but compact so shaft length (which is adjustable) should be fine, but the swingle tree looks quite low. I read an article about the line of draft for driven horses, essentially it said breast collar harnesses should have an almost horizontal trace line from swingle tree to point of collar so the horse is pulling from their centre of gravity, whereas a neck collar can have a lower swingle tree attachment. Does it really make much difference? We don't do any competitive or long distance driving, so far we've just been going for a gentle walk/trot around a 4-5 mile road loop on the weekend (when the weather is nice!)

 

[tda]

I don't know all the technical terms, but think whatbyouve said is correct.
I would also be concerned , when cornering that the traces may catch on the horses hocks

 

[scruffyponies]

You're correct as far as it goes, but line of draft runs to the axle (unless you're pulling a harrow or plough), so truly horizontal line of draft is more correct for a two wheel vehicle, where the wheels are larger. On a modern 4-wheeler the wheels are lower, so a lower swingletree give a better (unbroken) line of draft. An empathy collar is a great compromise, but truthfully most modern vehicles aren't heavy enough to cause that much of a problem with draft. A bigger issue is that the damn things will clip the horse's legs if you harness too close, or your britchin has much slack in it. I like hitching two wheelers so close that they shit on the pivot, but you can't do that when the swingletree is below the hock.

 

[rabatsa]

As scruffyponies said however I do not like the empathy collars as they fit very few animals and do not touch them all the way round and so give a very thin draught line.

 

[TreeDog]

I don't think the height is so low that he would catch himself on the traces, though I've asked the seller if they can measure it for me so I can compare against our two wheeler. He's probably as big a horse as I'd want in the two wheeler but it has loads of room behind and I've found he prefers less slack in britching so never comes close to his hocks.

As scruffyponies said however I do not like the empathy collars as they fit very few animals and do not touch them all the way round and so give a very thin draught line.

Can you elaborate what you mean? I've seen some pictures of these and they look quite good and I've only heard good things about them before. They are expensive, but thought if I upgrade the cart maybe I'll upgrade the harness too ?

 

[scruffyponies]

Empathy collars need to be carefully adjusted. Much more so than normal breast collars. No doubt they would 'tilt' and present a narrow bearing surface if fitted incorrectly. However, if OP is worried about line of draft, then your choices are empathy / French or round collars which bear in line with the shoulder, not the front of the chest.

 

[rabatsa]

I have found that many empathy collars touch at the bottom just in front of the point of shoulder but gape at the top and some also do the reverse at the front of the chest. The draught line of them is just the same as with a straight breast collar but over a narrower line. I have had to tell a fair few people that the harness is not a good fit when assessing it on the ponies. This is even more noticeable with synthetic harness.