[QUOTE=Lord Helpus;8624206]
You load on the left because many/most roads are crowned in the center and slope off toward the outside (for water run-off).
If you load the horse on the right then you are putting weight on the side that is already a small amount lower and the trailer is (slightly) more likely to tip to the right around corners, etc.
A horse on the left counterbalances the cant of the road and makes the trailer better balanced.
ETA: I see that others have already answered the “crown of the road” reason. So just add me to that number who were taught that and still believe it. I wince when I see a single horse on the right side.[/QUOTE]
yes, the “crown” reason has been given and has received a lot of fan fair. But is a case of perception trumps reality. Most secondary roads have little to no crown. Most roads in country/rural areas fall below “secondary” roads and are lucky to be level. Crowning is expensive to engineer and build.
Interstate highways are “crowned” but they are multi-laned and the cant is ever so slight on the majority of them. Hardly enough to make any difference to how a horse is balanced in a trailer nor would it have much if any effect on how the trailer tracks.
I’ve driven rigs with a trailer cam in them. On the highway and good secondary roads the horse is standing not much different than if it was standing in a stall. So IMO and observation the " counterbalance" theory doesn’t hold water.
I have helped load tractor-trailers and they are not loaded with the heavier stuff on the left. But I have not done this as a “job” just an observation. There maybe times when the weight and type of things being loaded is taken into account by the load master.
Most turns are banked some more than others. So I don’t see how what side of the trailer a horse is put on has any effect on this. If a horse is loaded on the right side and the turn is to the right the horse will be on the “low side” turn to the left and the horse will be on the “high side”.
People can believe what they want, load a single horse the way they perceive it to be the most “safe”. But it is not unsafe to load a single horse on the right. Considering all of the “safety stickers” that lawyers require companies to put on just about everything it seems to me that every trailer would have a BIG safety sticker on the tailgate or inside saying “Load a Single Horse on the Left ONLY”.
All that being said I am the first to admit it feels awkward/uncomfortable to load a single horse on the right. ONLY because that is the way it was drummed into me.
The same as not allowing a horse after heavy training to drink as much water as it wants because it will tie-up, colic. This was disproven a long time ago. But I can still hear my mother/trainers yelling, "Larry don’t let that horse drinks so much he’ll tie-up/colic and may die. The vet bill will come out of your paycheck.