Karen -
That is a Fore Cart made by Pioneer Manufacturing out of Dalton, OH. Fore carts are also built by a company called White Horse out of PA and think there are a couple of others as well now. I believe that all the companies that build the Forecarts are Amish, but not positive about that. The fore cart is a very heavy duty cart meant to be pulled for farm work. It has a drawbar behind the axle that is reinforced to attach farming equipment to. You can also attach a reese hitch to it - with a ball for some equipment. For the larger sizes, you can get different types of wheels - including one that is round but the "tire" part is a flat piece of metal with ... uhh - metal "threads" or "bumps" - great for traction in mud. For the smaller shetlands - we can attach ATV and garden tractor sized implements for them to work. There are also at least two companies that I know of now that make a forecart for minis - tho it's sized much smaller - it isn't necesarrily less expensive nor does it have the same features. I also have the implement seat - so that I can attach equipment that might need me to work with a handle - the implement seat can be turned in different ways to accomodate that. It can also take on two implement seats - sometimes done w/ the plows and given the name of a "honeymoon" plow...
The one drawback right now is that Pioneer doesn't make a plow small enough to attach to this size forecart that the shetlands can handle. Here is a side view of my forecart taken this spring.
Other than for basic training, it's not really meant to be pulled alone as it's not considered to be weighted right for them to pull. Mine can be even more of a problem - as I purchased a larger cart so that I can use it to train my Shetland xbreds that go up to 13.2 hh. I did, however, have a pony tongue put on it. Mine is the Hafflinger size with 13" wheels. I have Hafflinger shafts in storage right now - personally this cart is too heavy for a single Shetland pony, especially my smaller or lighter ones, to pull alone - so I didn't get the shafts in that size. I can actually "lock it down" - with the brake that is on it. I really like it - rides pretty darn nice for an "ole farm cart". You ca also order a shade for it (i might eventually do that).
My girlfriend bought a pony sized one and it has 12" wheels, the seat is narrower and doesn't sit as high. The area in front of the seat is also smaller than mine. I have attached a pic of her this summer with her pair of 40" shetlands pulling a double disk.
I have now got two pairs working - but ordered the wrong size lines for this size of pony. I have to special order another set to do a 4-abreast team. Then we will school them with the motorized pull behind mower and my ponies will bushhog the fields we have. Evenutally, I will have the bracing struts/platform attached directly to the mower - so that I can attach an implement seat to it - then the ponies can pull the mower directly. Also, I now have a Cyclone Rake - and it can be attached to the forecart and can be used to vacuum manure up from the paddocks and pastures. Still putting it together - right now it's attached to the riding lawnmower to do the leaf work in front of our property where there isn't enough room to manueaver a forecart and pair of ponies with it between the trees.
Draft horse sized forecarts can carry motors - that then run a PTO to large farming equipment. Or not... Many options. You can get farm equipment now that is either PTO or ground driven to pull with the horses.
Here is a 6 abreast of riding mules pulling a two implement seat forecart made by White Horse. It was being hooked to a very LARGE harrow which I will show next.
and here is one with a 3-abreast of spotted draft horses w/ the 2 implement seat pulling a disk (I think they didn't have the horses directly hitched to the disk becase one man is green and this allows his mentor or boss to ride along with to show him the ropes, so to speak). This is the same plowday that I was able to hitch my pair to a riding disk and we proved that Shetlands can also pull in the fields. However, it was very deep and the disk sank and it was hard work for the single pair. Next spring I should have the 4-abreast team ready to do this type of work and it won't be a problem...