3 ms·

> Clearly, this was no cargo vessel; ships built to haul cargo or passengers tend to be wider, built for capacity rather than speed and agility. Wouldn't a wid

> Clearly, this was no cargo vessel; ships built to haul cargo or passengers tend to be wider, built for capacity rather than speed and agility. Wouldn't a wider ship be more agile? Maybe my intuition fails me, but to me it would seem like like a longer ship is far harder to turn (think of rotating one of those large chef knives in water vs a bowl).

npsomaratna 5y ago
I think that longer = more rowers; less wide = less mass. Wouldn't that mean a more powerful and agile ship?
- eftychis 5y ago
  Wide relates in the end to drag. And yes the number of rowers matters -- a bigger ship requires more rowers, thus more mass etc. Generally, there is the "optimization problem" with each such system that a bigger vehicle requires bigger engine and more fuel which means more mass. But here they mainly refer to the ratio of length versus width and from my and above posters guess they refer to the profile of the boat in the water. Edit: to amend and clarify: mass in a fluid affects displacement (assuming you stay above surface) and thus drag and maximum speed. Here is a crude reference about boat speeds https://www.boats.com/reviews/crunching-numbers-hull-speed-boat-length/ https://www.boats.com/reviews/crunching-numbers-hull-speed-b... -- if I get time I will do more Google fu but I am pretty sure anyone can find the complete derivation online.
  - julosflb 5y ago
    The wave making resistance is generally much larger than pure viscous drag/friction on the hull for conventional boat.
- deleted 5y ago
  [deleted]
coryrc 5y ago
On the water, speed is agility, and speed is limited to the square root of length for displacement hulls (which these are). Wider means heavier for a given length, taking longer to speed up, and more friction to overcome.
- pge 5y ago
  wider also means more frontal surface area. Just like a car going through air, less frontal surface area means more aerodynamic (or hydrodynamic), ie lower coefficient of drag. Olympic rowing shells and flatwater kayaks provide good visuals of what a fast displacement hull boat looks like - long and as narrow as possible.
  - coryrc 5y ago
    I think GP is thinking about a row boat, how it can turn on a dime quickly, which is true, but not useful in a sea battle.

npsomaratna 5y ago

I think that longer = more rowers; less wide = less mass. Wouldn't that mean a more powerful and agile ship?

eftychis 5y ago
Wide relates in the end to drag. And yes the number of rowers matters -- a bigger ship requires more rowers, thus more mass etc. Generally, there is the "optimization problem" with each such system that a bigger vehicle requires bigger engine and more fuel which means more mass. But here they mainly refer to the ratio of length versus width and from my and above posters guess they refer to the profile of the boat in the water. Edit: to amend and clarify: mass in a fluid affects displacement (assuming you stay above surface) and thus drag and maximum speed. Here is a crude reference about boat speeds https://www.boats.com/reviews/crunching-numbers-hull-speed-boat-length/ https://www.boats.com/reviews/crunching-numbers-hull-speed-b... -- if I get time I will do more Google fu but I am pretty sure anyone can find the complete derivation online.
- julosflb 5y ago
  The wave making resistance is generally much larger than pure viscous drag/friction on the hull for conventional boat.
deleted 5y ago
[deleted]

coryrc 5y ago

On the water, speed is agility, and speed is limited to the square root of length for displacement hulls (which these are). Wider means heavier for a given length, taking longer to speed up, and more friction to overcome.

pge 5y ago
wider also means more frontal surface area. Just like a car going through air, less frontal surface area means more aerodynamic (or hydrodynamic), ie lower coefficient of drag. Olympic rowing shells and flatwater kayaks provide good visuals of what a fast displacement hull boat looks like - long and as narrow as possible.
- coryrc 5y ago
  I think GP is thinking about a row boat, how it can turn on a dime quickly, which is true, but not useful in a sea battle.