Consideration that come into play are size of equine, size of drag, age of animal.
Your animal needs to be VERY responsive on the long lines, both to voice command and rein signals. This takes a while to develop. Most baby horses under 4, have VERY little patience or any length of attention span to learn in! If you force the issue, you will develop other bad habits or evasions, because they are not having fun, can’t pay attention at this age. Then you get to FIX bad things later.
You want LONG long-lines, so animal is making big circles out there, not little short 20ft lines. As with a Dressage horse, he is moving out freely, lines down along his sides, not thru rein rings up high on his spine. Horse is BETWEEN the lines so you control both ends, whole body when working him. So a surcingle is usually needed, but doing it cheap, a saddle with tied down stirrups will work. You want stirrups for lines to run thru easily, give and take, no hanging up in rein pull or release way out there. Tied down under belly, stirrups keep the lines steady, no extra motion flopping when line is pulled.
You will need a breastcollar and long traces, a singletree, for basic pulling equipment. We start with small tires, they drag well, don’t hurt if they swing out and hit something. Logs or posts dragging are dangerous, snag easily, jump after catching on things. Punch a hole in the tread of tire, put a heavy stick or metal rod across the hole, with chain links hanging out to attach singletree to. We have someone drag the tire ahead of horse on long lines, let him follow it, watch it. Horse may be worked inside circle of dragging tire, gets used to seeing and hearing it. Horse is in an open bridle so he has excellent vision of what is happening. You should probably have someone walk WAY behind horse with breastcollar on, holding traces, with some occassional resistance. Person can lean back to pull traces, move them around so horse feels traces on rump, sides. Maybe work horse with traces between legs for a couple circles. Horse is NOT reactive to strange feel of harness in odd locations. If he is goosey, he needs more practice with traces there.
This work above, is going to cover a few weeks, of 3-5 works a week. Horse is responsive to voice, whip, reins, not just a robot to what you ask. Then you can attach the singletree, let it drag along on the ground. Couple sessions with singtree dragging thru the lesson, then attach the small tire to singletree after he is warmed up. We use a light string for tire the first few times. NOT binder twine, that stuff will hold an elephant when you NEED it to break! If and when string breaks, you stay calm, say Whoa, get your helper to tie tire back on. Everyone is calm, quiet. Horse stays quiet, because “This is training, WEIRD things happen, but people are not excited. Guess it is OK.” He gets to practice his STAND STILL. Horse needs to learn that pull and release of pull when string breaks, just happen.
After a few session of string attached tire, then you can link the singletree to tire with the chain length of about 12-16 inches so tire doesn’t come loose any more. Horse learns to deal with consistant drag, feel of tire swinging out on circle, may get a leg over trace, but doesn’t bother him because you have ALREADY practiced that. I would make some circles with leg over, before fixing trace. Do go in both directions, get the feel and pull on both sides of horse.
At this point, you may want a real harness or to add a crupper to the surcingle. We will put trace carriers on to hold traces up now, so we can do other things with horse in his Driving training.
Arena drags can be VERY heavy, they create constant friction with dirt contact. Different types of drags pull differently on the horse. With a young animal, they will quit when work scares them. Pulling heavy things that don’t come, is scary! Even older horses not used to pulling, have to LEARN that load will move if they try. Teaching them all to be brave, PULL, takes a bit of time. You have to build them up over a while, develop the muscles.
You MUST decide what kind of movement you want from horse, before loading him down with a possibly heavy dragging implement. If his future is as a Dressage horse, you will lose airy, light, lifted front end, when he drags heavy things. Heavy loads require horse to lower head and pull with the front AND hind legs to get things moved. Not a problem if horse is already a flat mover, low headed Western breed, his movement is not going to change dramatically. Pulling a bit of weight can change muscling too, you might like it or not.
We do use car and truck tires for any dragging, dragging pull is consistant, yet not real heavy. We want light and airy movement on our Driving animals that do Dressage. We have several tire sizes, depending on what we need. I have large horses, 16-17h. Smaller tires would be suitable for very young animals or small animals. Have only used the large implement tire on one horse who did NOT develop into a driving animal. Did show how athletic he was though, hopping back and forth across the traces at a canter! Certainly NOT afraid of a load behind either!! He just did not like Driving, wanted to stay a riding only, horse. Most folks use the big implement tires to develop strength in trained horses, way too heavy for beginning horses.
Have to say my barnyard always looks great when long lining colts dragging tires!!
I would be careful using young animals. Very easy to work them harder than you think, with driving. Bones and muscles are soft, unfit, still growing. I would be careful with arena dragging, probably do it all walking. Covering a lot of ground, slow and deliberate is best with weight behind. Farmers don’t work fields at the trot!! Long lining is different work, so different gaits would be fine there as long as horse stays obedient.