Three-Abreast hitch Tongue Length?

Thanks everyone for great feedback and suggestions.
Donn, I took a team out on the cart today and as best I could estimate we have 20″ from hock to singletree when they are in motion (about 24″ when standing). The other factor I just thought about, is that when the hitch on the Pioneer cart is put into off-set position, it draws the hitch back about 2″-3″, thus gaining a little bit of tongue length.
Stephen

Three-abreast hitch update: On Friday afternoon we finally got around to trying three. Since I could not find any Pioneer cart tongues locally, and cost of shipping one from Ohio was exorbitant—went ahead and spliced six inches of wood back into the tongue (at base end–ship-lapped, lag bolts, and wood pegs), to make up for the extra length of the three-abreast evener. In earlier posts I was confused about how this would all set up. We got an off-set three abreast evener from E-Z Trail, so we did not have to use the off-set hitch capacity that is standard equipment on the Pioneer draft cart. We put our most forward horse in the middle, her regular teammate to her left, and a younger mare to her right. We used the team lines plus two 36″ snub lines from middle horse hames to inside bits of two outside horses. We hitched up to a disc–because we had a bunch of discing to do and figured the best way to get them to settle into the new circumstance was to have some good work in front of them. everything went Okay–but my old mare is still such a hothead—that even after 45 minutes of discing, she never really settled down to an acceptable work pace and I had to hold them back pretty hard the whole time (this is not typical of how we go in teams these days—reminded me of what it used to be like when I was working young green-broke animals). I think the two outside horses would have settled down to a nice walk if the old gal in the middle had been willing. On a plus side, everybody stopped and stood well on request. Steering-wise, I had a sense they were responding more to voice command then line pressure—it felt kind of like steering an outboard motor boat–slow and not as precise as I want. Younger mare on right was visibly nervous and tended to wing her butt out—compounding her nervousness by having an uncomfortable relationship to outside tug. Thinking about maybe putting my gelding in the middle, this younger mare to his rightt, and her daughter to his left—in this configuration I don’t have as clear a leader, but the gelding has plenty of experience, and all three are much more naturally mellow than Old Hickory Cassima—who is a hell of a horse but hard-headed. Also, think maybe we should shorten snub lines a couple of inches for Fjords to gain a little more contact? Any thoughts appreciated!

I think I follow you and that it’s making sense—next question: on the Pioneer cart I can’t move the tongue—but you’ll see in the picture that the hitch point can pivot to either side by just pulling a pin, shifting the hitch, and re-setting the pin. So it seems like I should follow your directions about swapping out the double and single trees, except shift my hitch point rather than move the tongue? Thanks a whole lot!

Following mlelgr’s excellent advice we took out three on the Grimm tedder today. We switched out our hothead old mare and put a 6 year old in the left slot. Everything went very well, we worked for an hour and forty-five minutes and got the field tedded and the horses found a comfort level with the new hitch. Only problem is the young mare still tends to hang back a bit–but she is slowly getting better about this—a late bloomer, I think. Thanks to all for help with this thread—a great example of the practical utility and community spirit of this forum!