Motorized yachts seem to be quite a bit larger with much more Sq footage built above the water level than their masted brethren, why is this?
I’m assuming the masts have something to do with it. Is it because they would torque the boat too hard if they were higher up? They already seem pretty high up as is and older vessels like Galleons in pirate movies seem just peachy with a ton of room above the water level. Why is it that most luxury yachts now are so low?
Edit: to clarify I mean shorter as a function of verticality not the length of the boat.
In: 21
Galleons had really big crews. It’s relatively simple to operate a modern motorized yacht. One person can basically do it. But the whole reason to have a sailing boat is because you want to do all the stuff manually. Do it the old fashioned way. But you probably don’t have a crew of like a hundred guys to help you do that. So modern sailing ships are going to be limited, size-wise, to what a small group can handle.
The dynamics of these boats have some serious differences though.
A motorized boat is driven by some sort of thrust out the back. The hull is designed to behave certain ways in the water to maximize cruising efficiency/speed.
Sailing vessels are powered by the wind. The big concern there is how the hull reacts to the forces the wind puts on the sails. Think of your standard recreational sailboat. It has a mast, and then right below the mast, a keel. Often a very deep one. An upside down sailboat hull sometimes looks a lot like a shark or an orca. A big fin on the bottom. That is there to counteract the force of the wind on the sail. The wind will want to lever a boat over using the sail, but the keel provides a counter force to it. If the wind is to push it over, it has to overcome the weight of the water on the keel.
So, right there the hills are dramatically different simply due to propulsion.
Now, galleons came up and they have a different keel than most recreational sailboats. The bottom is flatter, but the keel is also heavily ballasted to move the center of gravity down and help counteract any forces on sails. There are actually several different approaches to a sailing hull, but they all have some sort of counter to the forces that the wind will put on the sails.
Looks like I’ll have to cancel my plans for a solo galleon adventure with just me, myself, and I.
limits of the material is one thing. Steel structures allows for bigger structures than wood.
There are explanations here about the dynamics of ships, but one thing to consider is that bigger boats are heavier, and therefore need more power to move them. With sails this means that you need to pile on more and more sails to move bigger and bigger boats, and the extra weight of the sails themselves means that a lot of the power goes to move the sails, not the ship. Engines have a lot more “power density” for want of a better word, and you get a lot more extra energy from a larger engine.
One thing to note though, in recent years, months even, there have been plans announced to add sails to modern container ships as the price of fuel, and the carbon they spew into the atmosphere are becoming a concern, so we are beginning to see a return to sails, but not as they were before – [this is one concept image](https://assets.newatlas.com/dims4/default/bdcc4de/2147483647/strip/true/crop/1440×960+0+60/resize/1200×800!/quality/90/?url=http:%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Farchive%2Fsail.jpg) and [here’s another](https://images.hgmsites.net/hug/wisamo-wind-sail-project–michelin_100793878_h.jpg)
So I’d say generally they are not shorter for the same displacement (weight) but they are thinner and generally not as tall.
Imagine the force of the wind pushing on the sail. It tips the boat over so you need some force to counteract that. This comes from having weight really low down that gets ‘lifted up’ and pushes back down via gravity.
They are generally thinner as this will reduce drag and sails aren’t as powerful as engines so you have to be more efficient.
There’s a lot more going on but that’s the basics.
Sails are not powerful like modern engines. A horse can carry one person, 2 people need two horses, cars have hundreds of horsepower to move 5 people. Modern engines allowed boats to have bigger superstructures, and move towards the wind.
One part of this is to do with design speed. The maximum efficient speed of a vessel is related to its length at the waterline. So if you want it to go faster without applying disproportionate amounts of extra power, you need to make it longer. The relatively compact nature and easy controllability of engine power, even with a small crew, makes this more desirable.
With sailing vessels, adding length also adds weight requiring additional sail area. This in turn requires additional complexity and manpower. Instead, vessels are typically designed to be easier for smaller crews, in turn only requiring a length suited to a more manageable sail area.
Are you mixing up length and height? You question seems a bit confusing, you ask why shorter then discuss height above waterline.
Length is a question of economy and legality plus the need for way more crew if you’re going to operate a large sailing vessel compared to a motor yacht. There’s a length limit of 50 feet or so, in most countries, for what an ordinary person without special licenses can operate. So virtually all privately owned yachts, sail or motor, that are operated by the owners without paid crews will be 50 feet long or less.
Height is a different matter, and stability is one big part of that. Minimising wind forces acting on the hull is another consideration, as is making as much room for sails as possible.
Motor yachts generally dgaf about some wind pushing on the hull and superstructure, as long as they don’t roll over too much.
Sail yachts need to ensure as much of the available wind force as possible acts in the desired direction to help propulsion, rather than blowing the boat off course or slow it down. So you want a low, sleek hull and superstructure with a huge sail on top. Stability and leverage also matters, for a given sail area you get less stability the higher up the center of sail effort is. It’s safer to have most of your sail area low close to the waterline than high up. And you want to maximize the available sail area, especially down low, so you can’t have a large deck house like you would on a motor yacht as it would get in the way of sail and boom.
Looks like I’ll have to stick to my paddle boat then. No crew needed, just some strong arms and a lot of patience!
Latest Answers