Classification: How does it work?

[DownhillDino]

Hi everyone! I'm very confused on something so I need the expert's help, the past week or so I've been trying to figure out how exactly countries (of this era, WWI and WWII) designated ships. By that I mean, what makes a destroyer, a destroyer? Why is that ship a light cruiser? Why is that one a frigate? The only information I can find, with my admittedly sub-par searching skills, was heavy cruisers having main battery of 8 inches and up, and capital ships generally weighing over 10,000 tons. Unless I'm wrong on that too. The ones that really get me are the smaller ships, patrol gunboats, minesweeper/layer, destroyer, frigate, corvette, etc. There appear to be a lot of features that are shared and no real distinction, at least to me. So, a little help here would be nice! Post away experts!

[Macabe]

Generally based on tonnage combined with armament. If I remember I'll post a chart I found when I get home later.

[An_Average_Jho]

Generally based on tonnage combined with armament. If I remember I'll post a chart I found when I get home later.

 

It depends on the nation, too. IIRC, some of the French destroyers were called cruisers and some early French torpedo boats were called destroyers by the USN.

[Moksie]

Different countries and time periods used different terminology.  For example the US Navy calls a battlecruiser a fast battleship, and will claim they did not have battlecruisers.  And will call someone else's destroyer a light cruiser. And the Germans made ships that defy classification by conventional means, and the Washington Naval Convention.

It's rather arbitrary and subjective.  But yes on the cruiser differentiation by gun size. Those little boats are all smaller than destroyers and generally made for specific duties.  One country uses frigates the other uses corvettes, is there a difference? Not really, they are half destroyers meant to protect shipping from predators.  Or to harass fishing boats....

 

A major issue you'll run into, is people that are trained in one system, trying to force it on others.  Xin, Qin, Shin, Chin, it's all the same dynasty, it just depends on who you ask, and when.

[DownhillDino]

Generally based on tonnage combined with armament. If I remember I'll post a chart I found when I get home later.

 

That would be great, thanks!

 

Different countries and time periods used different terminology.  For example the US Navy calls a battlecruiser a fast battleship, and will claim they did not have battlecruisers.  And will call someone else's destroyer a light cruiser. And the Germans made ships that defy classification by conventional means, and the Washington Naval Convention.

It's rather arbitrary and subjective.  But yes on the cruiser differentiation by gun size. Those little boats are all smaller than destroyers and generally made for specific duties.  One country uses frigates the other uses corvettes, is there a difference? Not really, they are half destroyers meant to protect shipping from predators.  Or to harass fishing boats....

 

 

A major issue you'll run into, is people that are trained in one system, trying to force it on others.  Xin, Qin, Shin, Chin, it's all the same dynasty, it just depends on who you ask, and when.

 

 

I did not know battlecruisers and fast battleships were the same thing, strange I never read anything about that. And I've definitely read many of arguments over destroyer/light cruiser naming. Tough stuff, something that's definitely messing me up being the nations doing things differently.

[Moksie]

 

That would be great, thanks!

 

 

 

I did not know battlecruisers and fast battleships were the same thing, strange I never read anything about that. And I've definitely read many of arguments over destroyer/light cruiser naming. Tough stuff, something that's definitely messing me up being the nations doing things differently.

 

You will easily find a whole lot of people that will tell you they aren't the same.  And some will get really upset about it because that's what they were taught.

Fair warning.

[Fog_Heavy_Cruiser_Takao]

 

That would be great, thanks!

 

 

 

I did not know battlecruisers and fast battleships were the same thing, strange I never read anything about that. And I've definitely read many of arguments over destroyer/light cruiser naming. Tough stuff, something that's definitely messing me up being the nations doing things differently.

 

for myself i consider Fast Battleships and Battlecruisers to be separate classes ie: 

Battlecruiser: a ship the possesses battleship main caliber guns (10 inch and up) but much less armored than a conventional battleship (this vary greatly depending on the time period) also normally capable of speeds over 25 knots

Fast Battleship: any battleship capable of speeds in excess of 30 knots

this is how i define them, for smaller ships like light cruisers and heavy cruisers it is done general by tonnage rather than gun caliber but generally most heavy cruisers have 8 inch guns and light cruisers have 6 inch guns or less, were as destroyers vary so greatly its hard to put a name to them, general i consider them by their role ie: if they are ONLY supposed to escort i consider them a corvette, for general fighting and operating alone etc. - destroyers, and for picketing and also escort frigates. but i consider classification of destroyers more by their armament ( how much and what caliber in comparison of the time period) 

for example late war Germany DD's had 150mm guns were as America stuck with 127mm (or 5 inch guns), both for me are DD's

[Windhover118]

Hi everyone! I'm very confused on something so I need the expert's help, the past week or so I've been trying to figure out how exactly countries (of this era, WWI and WWII) designated ships. By that I mean, what makes a destroyer, a destroyer? Why is that ship a light cruiser? Why is that one a frigate? The only information I can find, with my admittedly sub-par searching skills, was heavy cruisers having main battery of 8 inches and up, and capital ships generally weighing over 10,000 tons. Unless I'm wrong on that too. The ones that really get me are the smaller ships, patrol gunboats, minesweeper/layer, destroyer, frigate, corvette, etc. There appear to be a lot of features that are shared and no real distinction, at least to me. So, a little help here would be nice! Post away experts!

 

A lot of terminology can be traced back to the age of sail. Back then, the standard form of combat was for the biggest most powerful ships in the Navy to form a battle line. Eventually ships were designed specifically to fight as part of the line. These ships were referred to as Ships of the Battle line or Line of Battleships. Which eventually became shortened to just Battleships. From there, the biggest ships, with the largest guns and the thickest armor were battleships. Cruiser's originally was a very broad term. In the age of sail, a cruiser was any ship that wen't on a cruising mission. Basically ships that wen't out to sea by themselves on long range patrol missions to just cruise around. Eventually Navies just started building ships specifically for the purpose of cruising missions and these ships were referred to as cruisers. The word Frigate was used to identify a large number of vessels ranging in side and armament. But the standard definition was a smaller ship that put more emphasis on speed than firepower or protection and were meant to escort larger slower warships like the ships of the line. Frigates were basically the destroyers of the age of sail. Destroyers now are a relatively new design of warship. In the late 19th century, small fast attack boats began carrying torpedoes so a new class of ship was needed to destroy these boats before they could get close to the larger ships. This new class of ship needed to be fast, maneuverable and carry enough firepower to overwhelm any attack boat it came across. These early ships were known as Torpedo Boat Destroyers and the name was eventually shortened to just Destroyer. 

[Moksie]

 

A lot of terminology can be traced back to the age of sail. Back then, the standard form of combat was for the biggest most powerful ships in the Navy to form a battle line. Eventually ships were designed specifically to fight as part of the line. These ships were referred to as Ships of the Battle line or Line of Battleships. Which eventually became shortened to just Battleships. From there, the biggest ships, with the largest guns and the thickest armor were battleships. Cruiser's originally was a very broad term. In the age of sail, a cruiser was any ship that wen't on a cruising mission. Basically ships that wen't out to sea by themselves on long range patrol missions to just cruise around. Eventually Navies just started building ships specifically for the purpose of cruising missions and these ships were referred to as cruisers. The word Frigate was used to identify a large number of vessels ranging in side and armament. But the standard definition was a smaller ship that put more emphasis on speed than firepower or protection and were meant to escort larger slower warships like the ships of the line. Frigates were basically the destroyers of the age of sail. Destroyers now are a relatively new design of warship. In the late 19th century, small fast attack boats began carrying torpedoes so a new class of ship was needed to destroy these boats before they could get close to the larger ships. This new class of ship needed to be fast, maneuverable and carry enough firepower to overwhelm any attack boat it came across. These early ships were known as Torpedo Boat Destroyers and the name was eventually shortened to just Destroyer.

 

Very well written.

[DownhillDino]

Thanks for the response Windhover but I do know at least that much. Doesn't really cover the era I'm looking for though, still a good summary. 

[NGTM_1R]

Different countries and time periods used different terminology.  For example the US Navy calls a battlecruiser a fast battleship, and will claim they did not have battlecruisers.

 

This would work if the USN hadn't, y'know, actually developed a battlecruiser class (CC-1 USS Lexington, look it up), and if the SoDak/NoCar classes had been able to fit into any kind of battlecruiser definition without excessive reaching despite being fast BBs, and if it wasn't the dumbest thing I've heard since the last time it came up.

 

Hi everyone! I'm very confused on something so I need the expert's help, the past week or so I've been trying to figure out how exactly countries (of this era, WWI and WWII) designated ships.

 

Internal doctrine, comparative construction size and technique, and a little general "why not" for the most part. The French contre-torpilleur classes existed in a doctrinal paradigm unknown to the other Western navies, as an example. They were destroyers by how they were designed compared to other ships, but they were exceptionally large and powerful destroyers because of their design role for small-group actions where they would roam the Med in groups of three attacking enemy shipping and reinforcing threatened convoys. Because they were so incredibly powerful by comparison to its own destroyers and their operational profile shared more with a light cruiser in RN service, the Royal Navy opted to treat them as "light cruisers" when they were under its operational command. From a design standpoint this was clearly nonsense; they had no armor, too few guns, and were clearly designed for torpedo warfare rather than the polyvalent capabilities of a cruiser. But the Brits didn't have anything comparable to them because they existed for roles the RN didn't make ships for.

 

The definitions of a "heavy cruiser" were laid out in the Washington Naval Treaty; a ship armed with guns of greater than 155mm caliber and weighing not more than 10000 tons. A "light cruiser" was defined as any ship with guns up to 155 caliber and weighing not more than 10000 tons by the same token. Destroyers and battleships/battlecruisers are not defined; carriers aren't either. The last three are just lumped into "capital ships" in fact.

 

Japanese light cruisers show a clear line of descent from WW1 light cruisers, with spaced out open mounts as they had, but fill a doctrinal role as squadron leaders for destroyers and submarines that other navies would have just built a slightly larger destroyer for; it's their design features, particularly the addition of relatively extensive armor belts, and their clear ancestry in WW1 cruiser design, that make them cruisers rather than destroyer leaders for the most part.

 

One of the primary reason's Moksie's argument for "fast battleships are battlecruisers" doesn't work is that battlecruisers, by definition, are trading either armor or armament for speed. (Or put another way, they're making the ship bigger to go faster, or making it weigh less to go faster.) This was a choice the USN deliberately did not make with South Dakota '39 and to a lesser extent the other fast BBs. With SoDak they were demanding they get a ship that had small tactical diameter (so no long battlecruiser-like hull and no armor tradeoff) and high speed and heavy armament. The state of USN turbine design was sufficiently advanced to actually build that fast ship without any of the traditional battlecruiser concessions. As there was very deliberately no battlecruiser in the ship's design, only a fool would call it one.

[Zinegata]

One of the primary reason's Moksie's argument for "fast battleships are battlecruisers" doesn't work is that battlecruisers, by definition, are trading either armor or armament for speed.

 

Actually, if we look at the original definition of the battlecruiser from the conceptual standpoint it differs from a fast battleship primarily in terms of role. The battlecruiser was not meant to take a spot on the battle line and to trade blows with enemy battleships. It was instead meant to be a cruiser-hunter: it should be fast enough to hunt down cruisers and avoid battleships, it should have guns big enough to kill cruisers, and its armor should be proof against cruiser guns.

 

The fast battleship by contrast was armored with the intention of going up against a peer-equivalent and surviving from the get-go.

 

Problem is the British forgot the original concept behind the battlecruiser and tried to use them as heavy scout units to combat enemy battlecruisers; and they got lucky in several of the opening engagements where the battlecruisers managed to escape destruction despite some hits potentially causing catastrophic explosions and destruction. Their luck finally ran out at Jutland, when three battlecruisers blew up outright and a fourth nearly did so. 

 

There is also the obsolescence issue. Hood was in all respects a fast battleship in 1916 - with her armor pretty much equivalent to the Queen Elizabeth class fast battleships. Problem is  gunnery ranges increased and the chances of a plunging hit increases - while her armor was not updated to the new battleship standard. Indeed, it's worth noting quite a lot of "battlecruisers" in fact significantly outweighed older battleships (and even dreadnoughts).

[DownhillDino]

Generally based on tonnage combined with armament. If I remember I'll post a chart I found when I get home later.

 

You totally forgot man!  

[Macabe]

 

You totally forgot man!  

The link doesn't work anymore.

[DownhillDino]

Nuuuu!! 

 

I appreciate what everyone has told me thus far, but it looks like I may still have to search around some more. 

[Windhover118]

Nuuuu!! 

 

I appreciate what everyone has told me thus far, but it looks like I may still have to search around some more. 

 

Maybe you need to clarify your question. What defines one ship from another is the ships intended role. 

 

Corvette: Smaller than a frigate, Corvettes generally operate closer to shore and can aft as small fast attack craft. 

 

Frigate: Smaller then a destroyer, Frigates are designed to provide close escort for larger warships. 

 

Destroyer: Can be defined as any ship designed to hunt down enemy torpedo boats and provide escort to larger combat vessels. Destroyers also operate independently or as part of small squadrons of destroyers often patrolling far away from the main fleet. Destroyers and Frigates share many commonalities. The main difference is in their lineage. Destroyers trace their history to the Torpedo Boat destroyers of the late 19th century while Frigates go all the way back to the age of sail. 

 

Light Cruiser: Can be defined as any ship larger than a destroyer, but smaller than a Heavy Cruiser meant to act as fast scouting ships for the main battle fleet. Some Light Cruisers also act as flotilla leaders for destroyer units. 

 

Heavy Cruiser: Can be defined as any large warship smaller than a Battleship intended for use as long range patrol vessels, convoy hunters, or operate in the line of battle as escort for battleships. 

 

Battlecruiser: Any battleship sized vessel designed specifically to hunt down Heavy Cruisers. 

 

Battleship: A ship designed to fight in the line of battle, forming the center piece of a traditional battle fleet. They have the heaviest armor and largest armament of any other ship in the fleet. 

 

Aircraft Carrier: This one should be obvious. 

 

Disclaimer: These definitions are very brief and very broad meant to give a person an idea of what makes different classes of ship different from the rest. Some ships like to blur the ones from one class to another. For example, the Alaska Class is considered a large Cruiser by the United States but many people refer to it as a Battlecruiser. The Deutschland Class is bug gunned Heavy Cruiser but some like to refer to them "Pocket Battleships". 

[DownhillDino]

I had a feeling I might have had to clarify. I know the roles of each class, I was looking for how/if tonnage/armament and the like set them apart. 

[Windhover118]

I had a feeling I might have had to clarify. I know the roles of each class, I was looking for how/if tonnage/armament and the like set them apart. 

 

A ships armor and armament are dependent on its role. A ships tonnage is dependent on those things as well. 

[DownhillDino]

And that's what I'm looking for. Like what are the parameters and such, or average. For example, when I look at a type of ship and see they're usually around 4000 tons, but then there are outliers that are 2000 tons or 5000. So I question is there some kind of range or whatever for a type of ship to fall in. It sounded like the chart Macabe was offering would have answered my questions but unfortunately that didn't work out (not his fault!). 

[Windhover118]

And that's what I'm looking for. Like what are the parameters and such, or average. For example, when I look at a type of ship and see they're usually around 4000 tons, but then there are outliers that are 2000 tons or 5000. So I question is there some kind of range or whatever for a type of ship to fall in. It sounded like the chart Macabe was offering would have answered my questions but unfortunately that didn't work out (not his fault!). 

 

There really are not any size parameters. The Washington Naval treaty limited Heavy Cruisers to 10,000 tons but once the treaty got thrown out, countries like the USA began building heavy cruisers displacing almost 20,000 tons, more than the first dreadnoughts. So more important than size is the ships role. I think the best parameter to judge a ship by is its armor. 

 

Destroyer: Has virtually no armor. They are called Tin-Cans for a reason

 

Light Cruiser: Actually has some armor 

 

Heavy Cruiser: Has enough armor to defend against the guns of a light cruiser. 

 

Battlecruiser: Has enough armor to defend against Heavy cruisers

 

Battleship: Has enough armor to defend against everything. 

 

[NGTM_1R]

And that's what I'm looking for. Like what are the parameters and such, or average. For example, when I look at a type of ship and see they're usually around 4000 tons, but then there are outliers that are 2000 tons or 5000. So I question is there some kind of range or whatever for a type of ship to fall in. It sounded like the chart Macabe was offering would have answered my questions but unfortunately that didn't work out (not his fault!). 

 

Size and weight are dependent on what people think the ship needs to be able to do, so they're variable. Some combination of speed (via hydrodynamics and hull shape), armament, armor, range, and the like produces a ship. Different people think different things are needed to full the role, based on differences in doctrine or differences in what the role actually entails, so you get different sizes and weights.