Middle age transportation by river questions [closed]

Question

I am playing in a medieval fantasy type setting and am trying to determine travel speeds when people are traveling on rivers. This is similar to this previous question, but that question really only covered ground-based travel speeds. Assuming normal medieval/early Renaissance type methods of travel, and putting aside the question of magical augmentation,

• How fast can a sailboat travel downriver with a tailwind?
• How fast can a sailboat travel upriver with a tailwind?
• How fast can a sailboat travel downriver with a headwind?
• How fast can a sailboat travel upriver with a headwind?
• Were there other commonly used forms of travel by river?
• Did boats typically dock for the night?

Thanks for any help!

Answer 1

According to this source, the speed of a sailing boat depended on the waterline length.

The exact formula quoted there is hull speed = 1.34 * sqrt(waterline length)

A boat with a waterline length of 50 feet would therefore go about 9.34 knots (~17.3 km/h or ~10.75 mph). This of course only applies on open sea with good wind.

I have not found any sources for the maximum speed on a river, but I guess it's safe to say that it would be half the speed, at best.

Those guys discussed something similar, and came up with an average travelling speed of 5 knots (~9.26 km/h or ~5.75 mph) for a trading ship with a waterline length of 75 feet. That would, of course, change depending on wind conditions, the river (Does it run straight or in a lot of turns?) and your direction on the river (Upriver, downriver). But I have no Idea how the exact modifiers are for this.

As for the rest of your questions, I have no idea and hope that someone else here can help you. Take this as a general direction, not a fully fleshed out answer. ;-)

Answer 2

"Were there other commonly used forms of travel by river?"

Yes, there were: towpaths, (timber) rafting, rowing, and warping (for example on river barges: people with a small boat rowed ahead and farther away from the big ship sank an anchor. Now the team on the big ship adducted themselves and the great boat with the rope (connected to the anchor), pulled the anchor again, and the tedious game began again. Cf. also the German Wikipedia article or its Google translation.)

Answer 3

I have to assume that you're talking about a major river (Rhine or Thames up to London). Anything smaller is just going to be too twisting and shallow to be practicable for trading. That simplifies it, because current is fairly negligible, assuming the captain/pilot has enough local knowledge and is not constrained by draught (I've tried it). Wind direction, on the other hand, was vital. Sailing barges early last century, with considerably more advanced rigging, often waited days for a favourable wind; that was one reason why steamships (expensive, slower in favourable conditions but reliable) took over so fast. The Vikings were among the most advanced sailors of their time, using a tacking pole or beitiass, but even they couldn't go closer than maybe 60 degrees to the wind; a lot of tacking in open sea, a lot of waiting for a wind in a river. Rowing, poling (like punting) or towing by packhorse were useful substitutes. None of them were faster than 3-4 mph. Sailing with the wind would probably be 5-6 mph, but anything faster than that (on average) would be spectacular.

Answer 4

You should definitely check out http://orbis.stanford.edu/

You can figure travel speeds between real roman places, and come up with an analogue in your world, or just use their travel speeds.

And they have a whole section on river travel speeds in the "Building" tab on the introductory popup page.

In the "civilian" mode, the most common downriver speed is 65 kilometers per day ... Daily upriver speeds are set at 15km for all of these rivers ... Conditions on the Nile were of considerable complexity but are rendered here in a highly simplified format to capture merely the main trends: downriver speeds in Lower Egypt are set at 90km from July to October and at 35km in other months, and at 100km from July to October and 50km in other months in Upper Egypt. The upriver values are 90km in Lower Egypt from July to October and 30km in other months, and 65km from July to October and 35km in other months in Upper Egypt. Canals are assigned a daily default rate of 15km in both directions that conservatively presupposes towing. The "military" mode is constant at 120km per day downriver and 50km upriver, which approximates the probable performance of oar-driven vessels.

Answer 5

Here are a few references, although you'd have to read through some journals, etc.

Captain John Smith's Voyages - includes boat description

Sir Francis Drake: Traversed Strait of Magellan in 16 days.

Viking ship speeds - Lists the speeds of Viking ships as 3-6 knots depending on conditions, and links at the bottom to further discussion by the author. It also says that the crossing to Iceland could take as little as 3 days, but that was an extreme rarity.

Edited to add: I have really come up dry searching for this, but did run across something that might work. It referenced the fact that the Thames used to be twice as wide, and ran half as fast. So, maybe if you can find (or make up) the current speed of the river, take that either away from or add to the average speed of the desired craft you would be pretty close.

So if you take the hull speed calculation and then add/subtract the river current, you should have it. I don't think there is going to be a definitive answer, from what I've been able to find.