My big on-again-off-again project is getting a little closer to being finished, at least in terms of writing, but layout will take a while and is out of my hands. In the meantime I have been filling in some gaps, and pulling at some threads where I thought I was finished.
One area I was bothered about is nailing down some numbers for how much a pack animal (sumpter) can carry and how much a riding animal can carry (the live weight of a rider being somewhat less burdensome than the dead weight of a pack load) and how much a draft animal can pull in a wheeled cart or sled.
I figured there must be a formula, so I enlisted my brother, who is both an engineer and more knowledgeable about the size and strength of animals than probably anyone, for some help with this. He had already looked into horses, and found some great sources, but I thought I’d like to include more exotic animals that people have used for sumpters, draft animals, or mounts.
Well, maybe not EVERY animal…but certainly more than just the usual horses and mules. He found a study on agricultural uses of animals and the article included a table of the recommended pack-loads for various animals from (water) buffalo to yaks! Apart from wanting to have some details on the usual animals you find in medieval settings, I thought it might be useful to extrapolate the ratio of an animal’s mass to the load it can reasonably carry or pull.
The draft numbers are incredibly complicated because you really ought to figure in the type of conveyance and its weight, the wheels, the road, and so on — apparently teams of animals lose significant efficiency too. I will probably just have to give round numbers for “a wheeled cart, on a packed dirt road,” “a wheeled cart off road,” and a “a sled on snow,” and just fudge something where I assume the conveyance is around ½ of the weight of the load for carts and ¼ for sleds — so to convey 1000 pounds of stuff, you need a cart of 500 pounds or a sled of 250 pounds. Instead of putting that in the charts, I’ll just give estimates of how many animals of a given type is needed to pull a given load, and how many carts, wagons, or sled you need to have to do it, because my aim is just to have some information useful for planning long journeys in a medieval world. “I want to take three tons of goods from Paris to Rome. How many pack mules would I need, or how many oxen and carts?” The relative speed of each mode would also be a factor. But because one player in our group has repeatedly economized on mounts by riding an ox, and other PCs have been unusually large and unlikely to be able to ride a horse, it seemed worthwhile to figure out how heavy a rider each type of animal can bear.
Once I had a bunch of numbers, I started plugging them into a spreadsheet to see what patterns emerge. My brother had warned me that the ratio for horses would not apply across the board — generally speaking, the larger the animal, the lower the ratio of load:mass. But the animal’s build is also a factor, and camels, though bigger than horses in mass, carry a greater load both absolutely and proportionally.
Now my brother might be able to use calculus or some other dark art to come up with an accurate formula to cover how increasing mass lowers the ratio, but that is a convenient place for me to throw up my hands and say, well we have dragons in the game, let’s ignore that reality of physics too.
So, without further ado, I have a very crude ratio that works for various animal types. Bear in mind these are not the absolute maximums the animal can carry; they are the maximum safe loads for travel. For a short time you can certainly overload an animal with no long-term harm, but exceeding these loads on a journey will lame or even kill a sumpter or mount. Much more complete data, including rates of travel for various species and guidelines on average mass for them will be in the book. All loads are expressed as multiples of the animal’s mass. For example a rider load of .25 means the animal can carry a rider & gear of up to .25 x its mass (or ¼ or its mass)
|Type of animal||working load||max load||rider load|
|Yaks, Yak hybrids||.25||.3||.3|
|Camel, llama, reindeer||.3||.4||.5|
The reader will notice that horses don’t seem to be very strong, relatively speaking. They aren’t. But they combine the critical advantages of being obedient, large, and fast, making them very good choices for general use as well as mounts for warfare. (Camels are much less tractable; oxen and yaks are slow; canines and ostriches are too small to carry humans any significant distance; etc.) Some animals like oxen and yaks have shorter work-days than horses as well, needing more time to graze and/or ruminate.
Anyway these numbers should get you started. How much can a 1000 kg giant ram carry? I’d compare it to a buffalo, and say a rider of 200 kg, or a load of 160 kg. (In fact I do have some stats for goats and sheep — which are used in some mountainous areas like Nepal — but they are close to horse/buffalo range. My book will have the exact numbers too.)
The rider weight for the canines seems improbable to me, but pack dogs do carry a heck of a lot, relative to their weight. It might be more reasonable use .4 for riders on oversized dogs, wargs, etc., if you like.
*I couldn’t find any data for pigs, but a 250 kg hog is routinely ridden by an elderly man in China, so I’m guessing a pig type animal can carry a rider of at least .2 its mass.