That is really cool.
I suppose that there are tall ships that don't have modern engines in them but I am not aware of any.
This is, in a way, too bad but I think the 'convenience' is a real good idea really. Power made using ships much safer particularly within sight of land. Anytime you can see land you are in much more danger of running into something or being driven by wind and/or current onto something that will destroy the ship.
Navigating rivers is pretty challenging and propulsion that is consistently directional when seconds count is absolutely a big plus.
But you actually had that option without engine power. All you need is experienced boat commanders and well trained crews for those boats and "simply" deploy all the ships boats and tow the ship, particularly, up river. This is a great way to give the ships crew healthy exercise. Of course this may be a slight problem in a long voyage, before things like refrigeration (dependent on modern engines for electricity) when dietary requirements were met pretty much with bad meat, rotten potatoes resulting in malnutrition and scurvy. Not a good, healthy crew to put to the hard work of rowing small boats to tow ships upstream with.
I think we will be seeing more small commercial shipping using sail again on a common basis. I think this is unavoidable. And we have the tech to do so as costs of operation go up. But they will not be at all like the old tall ships which are such beautiful examples of, particularly, 17th, 18th and 19th century marine architecture.
So far this is not a major area of research but there are a lot of people looking at it. Currently most is aimed at wind as a supplemental power with little or no change in the standard designs of hulls.
Improved battery size and function, different ways of producing the energy to fill them will change this I am pretty sure to serious research for ships within the next 10 years or so though.
Quite a bit is being done on small floating platforms that is fairly exciting if viewed as very basic proof of concept research.
And we have had, for decades, the ability to run fairly conventionally designed multi masted Baltimore clipper type hulls with very minimal crews with reliable power sail management (rotating masts and power sail setting). This just needs a reliable alternative power source. Would be very usable right now for short run (local) passenger/light cargo hauling.
We really haven't seen any major improvement for a long time on diesel/electric (think rail locomotive power) which is what is used in maritime shipping today and I don't think that we will. It is just pretty damned well maxed out right now limited by the potential for diesel power that is economical to actually use and the cost of that is only going to go up.
Wind power for shipping is pretty reliable and constant. Does come with some limiters in that you do need masts of some sort and that takes up cargo space. But this is, as it has always been, an economic issue. Sail replaced human powered ships, *remes and the classic Viking ship designs, because it was more economically efficient.
I think we are actually past that economic tipping point already but you have to factor in inertia of thought and the current capacity for change in the ship building industry and those two things are not at all ready for being ready yet.
But get some really large capacity batteries that don't take up too much space and this will change rapidly. For short haul, light traffic I think we will see this happening pretty soon though.
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