According to my enemy
Ok, I know there was no electricity in Captain Bligh’s day when he couldn’t make the westward passage through the Horn, so no steam. But they had sails the same as now; how could sails have improved in technology? I don’t see how a sailing ship is better off now than in 1789.
I understand the concept of sailing against the wind not being that easy, requiring a rigamarole of diagonal sailing, but still, why so easy now?
Because we actually know how design affects performance now, and can model and test better designs – better sails, better rigging, better hulls, better everything. Even without that, we’d have made incremental improvements in efficiency over time, just as a result of trying new ideas from time to time.
We also build ships of different materials these days, resulting in lighter hulls that take less energy to move.
Here - Square rig - Wikipedia. Ships designed with sails that way are very much *less *capable of going upwind than ships designed this way Fore-and-aft rig - Wikipedia
At the time of the age of sail, nobody knew how to make the fore-and-aft rigs big enough to provide enough power to move large craft.
Nowadays we use sails only for recreational-sized boats, and fore-and aft rigs are vastly simpler for that role. As well as more suited to going upwind.
All the other incremental improvements in materials & hull shape are icing on the cake. The real problem was they couldn’t build big enough fore/aft rigs back in the day.
The problem is mostly about hull design rather than just sail design, but the two go hand on hand. Back in 1789 a sailing ship was not designed to provide much lateral resistance. This is crucial in being able to sail close to the wind. Without significant lateral resistance to motion, a sailboat basically sails sideways and backwards with the wind to the fore. When there is resistance to lateral motion the boat is constrained to move forwards. Modern boats have deep keels or centerboards that are specifically designed to provide lateral resistance, and also to do so with high efficiency and in a manner that doesn’t compromise control. However they do need a lot of water to sail in, something that was a specific reason why a flat bottomed boat was chosen by Bligh, and why trade boats were not any deeper than absolutley needed.
The underwater shape of an old sailboat versus a modern one is dramatically different. And here, modern really means anything in the last hundred years. Bligh’s Bounty was a collier, which was specifically designed with a flat bottom. The fastest boats of the real golden age of sail - even the clippers were not designed with significant attention to high efficiency lateral resistance. as seen here. Compare this with a modern high performance racing yacht like a Volvo 70. Even a high performance boat from 80 years ago like a J Class clearly has significant attention paid to upwind performance. Indeed the J’s might be that old, but they still hold their own against modern boats upwind.
Rig design is also critical. And modern materials make a big difference. It is hard to make a rig that is dependant upon short heavy masts and floppy canvas work well upwind.
Kind of a hijack to the OP, but you don’t need electricity to fuel a steam boiler. Coal or wood or oil works just fine.
Plus, we have fancy paints to discourage barnacles and other hitchhikers; wherease a ship in Bligh’s day would have much more resistance through the water the longer it went without hull scraping.
To elaborate on what LSLGuy and Francis said:
Sailing upwind is tricky - you can’t point your boat (or ship) directly at the wind, because then you lose power and start being blown backwards. So you sail at an angle to the wind, and zig-zag your way towards it. The closer you can point to the wind, the less distance you have to travel, because you need fewer zig-zags. Fore-and-aft sails can point much, much further upwind than square rigs.
To compound this, no sailboat actually goes straight forwards. You always get pushed a little bit sideways. How much depends on a bunch of things, but essentially having a large keel helps prevent this - it’s like a brake that only works sideways. So those old ships not only couldn’t point very far upwind, and had to make lots and lots of zig-zags, they also lost a lot of ground while they did (because, as Francis mentioned, they didn’t have the very large keels of modern ships). So they’d make very slow progress - to the point of sometimes just waiting for the wind to turn.
It is a little too simple to think of a keel as a brake that stops sideways motion. That would be like saying an airplane wing has more drag with respect to downward motion than forward motion, which while true is far from a complete picture of how it works.
A keel is a hydrodynamic foil that generates lift that counters the sideways motion while also generating forward thrust. During the age of sail, little was understood about shaping a keel for maximum hydrodynamic efficiency. As much as efficient sails, making a boat sail close to the wind depends on an efficient and effective keel or equivalent daggerboards, etc.
It’s worth noting that shipbuilders in the Age of Sail did understand the idea that a deep keel would help prevent lateral motion, but they rarely or never built such ships because a deep keel requires a deep harbour, and a ship with a deep keel must use only deep harbours and runs a much greater risk of running aground on reefs, shoals, and other hazards that shallower vessels have never discovered or mapped. Modern mapping and guidance, along with dredging technology, have made it much more possible to use deep-keeled ships.
Continuing in the vein of technical development, America the boat that gave its name to the America’s Cup was a technical leader of its era. This picture clearly shows the keel design of the time - and the lateral resistance is clear. Note however how the keel essentially runs from stem to stern, and how the boat will have quite poor response to the helm - the boat will be difficult to turn with so much resistance along its length. The time span from the America, to the mighty J’s is about the span from the days of the J’s to now. The J Class benefited greatly from modern technology. Aeronautical engineering was applied to the rig design, and to construction techniques. The leap in performance was huge. And as I wrote, the J’s still hold their own in upwind sailing against more modern designs that are commonly optimised for downwind or reaching speed. A very interesting counterpoint is Firefly. A very modern take on the ideal of the J, Firefly is 115 feet long, and a design derived from the ideals of the J Class, but with modern underwater design. Clearly visible here is the very aggressive and modern design. Much of this design is both a product of modern understanding of hydrodynamics, and modern materials. It simply wasn’t possible to build a boat like this out of wood using traditional techniques. The keel is also a very highly stressed member, and is milled from a solid blank of high tensile steel. (Shamrock V, one of the remaining original J Class is wood, but techniques for wood construction were very much advanced since the time of America - and even now wood remains a viable material - although the techniques are much closer to composites. For instance Spirit Yachts.)
I’ve heard that a boat with a fore-and-aft sail can sail about 45 degrees from straight into the wind. A square rigger I know of could only do about 60 degrees off the wind. I always figured part of the reason is the fore-and-aft has a rigid mast acting as the leading edge, and a square-rig has an edge that’s only as taut as the lines and wind can stretch it. Also, there’s a lot of rigging in the way that limits how far you can turn the yards and sails, although if the hull and sails worked well enough into the wind, maybe they’d have redesigned the rigging to allow a greater range of motion.
And it’s a lot trickier to tack in a square-rig ship, especially with multiple masts. For each yard (the horizontal parts that the sails hang from), there’s a line going to each end, called braces. When you brace the yards, you do the whole mast at once; at least one person on each brace, hauling or easing. And there’s a sequence to how you do it; you’re running between the different masts, bracing from full port to full starboard, and all before you lose momentum coming into the wind.
I imagine it’s quite a sight.
Well, if we’re talking age-of-sail keels, those weren’t foils - actually, they weren’t much of anything, since keel was a structural term. But, yes, you’re absolutely right, that’s a huge part of what keels (in the modern sense) do.
Modern yachts can do even better than that - 35 for sure, and I’ve heard claims of sailing well at 25-30 degrees (but of course, you know sailors and stories…)
Apparently, the best a square rigger could achieve in normal conditions was seven points off the wind, or 7/8 of the way to 90 degrees. In optimal conditions, with forgiving rigging and skilled sailors, and with a talented helmsman, a ship could make way at six points off the wind.
The skill of the helmsman became paramount here because compasses weren’t very accurate and were barely able to provide a rough guide in stormy seas. The helmsman needed to use fixed points of reference and the feel of the wheel to keep the ship on course.
Read all about it in this detailed doc (11 page PDF)
Consider economics as well. How much of an ordinary sailing ship’s life would be spent rounding the Horn? Very little. So why spend gobs of money and compromise the ship’s ability to avoid running aground in dicey unbuoyed Oriental harbors just so the boat can take a few days less to round the Horn?
25 degrees is pretty much the limit for any boat. The usual data is presented as a polar plot, which displays speed versus true wind angle, usually for a range of wind speeds.
This plot which is for a generic Volvo 70 (as produced for part of an on-line game) is for a very high performance ocean racer. You can see that 25 degrees really is it. You can also see how these boats are highly optimised for reaching. At 140-145 degrees true wind they are jaw dropingly fast. - YouTube
For more conventional or lesser performing boats 30 degrees is a pretty solid cut off. For high performance catamarans the angle is even worse, the shift in apparent wind that occurs with the boat speed possible pulls the wind around to the fore too quickly.
A freight ship is by definition heavy and requires a lot of power. That’s why the sailing freight ships were not optimised for head winds. The modern sailing boats are ultra-light person carriers that could not satisfy Europe’s need for silk, china or even cinnamon. A freighter would need full frame forms to facilitate cargo space, unless you make it very long. So the people at that time did not have the technology to make it work but I seriously doubt we have it either.
How about the Junk Rig? Junk rig - Wikipedia Junk (ship) - Wikipedia
That seems to be an old idea, and wiki states that it can sail more closely into the wind. Also, some of the historic ships listed seem to be biggies… so size doesn’t appear to be an issue.
Why didn’t the idea of the junk rig not find much purchase in Europe?
Surely by Bligh’s time frame, regular contact with China would make the Junk Rig a known tech…
methinks we probably have the tech to cobble something together of sufficient size to haul cargo with a modern keel and fore-aft rig capable of sailing close-hauled…
It’s a little too “green” of an idea to take off just yet though… give it a few decades until oil starts getting a little scarce 
This.
A modern sail is basically a wing which allows a ship to tack at a much greater angle than a square rig but without a keel with some kind of center board design built into it it’s next to useless. They go together.
