The DF rating for ships

[cathar1244]

Looking through documentation, I see ship values like durability can be based upon the DF factor of the ship.

Some questions.

How does one determine the DF factor for a given ship? For example, why does the Iowa class BB in the Pacific War scenario rate at 1066?

Is the DF used in game combat at all? Naval combat appears to use armor and durability ratings from what I'm reading. If the DF rating is used, what is it used for as far as ships go?

Cheers

[Curtis Lemay]

ORIGINAL: cathar1244

Looking through documentation, I see ship values like durability can be based upon the DF factor of the ship.

Some questions.

How does one determine the DF factor for a given ship? For example, why does the Iowa class BB in the Pacific War scenario rate at 1066?

Is the DF used in game combat at all? Naval combat appears to use armor and durability ratings from what I'm reading. If the DF rating is used, what is it used for as far as ships go?

Cheers

https://www.matrixgames.com/forums/tm.asp?m=1403648

[cathar1244]

Thank you for the thread pointer mentioning how DF is calculated.

Still wondering about,

If the DF rating is used, what is it used for as far as ships go?

Is the DF rating a measure of resistance to anti-personnel fire, or ... what? I am trying to understand what DF represents in terms of ships in TOAW.

Cheers

[Lobster]

Words might help instead of letters. Exactly what does DF stand for?

[Curtis Lemay]

ORIGINAL: cathar1244

Thank you for the thread pointer mentioning how DF is calculated.

Still wondering about,

If the DF rating is used, what is it used for as far as ships go?

Is the DF rating a measure of resistance to anti-personnel fire, or ... what? I am trying to understand what DF represents in terms of ships in TOAW.

Cheers

See 19.4 in the manual.

[Curtis Lemay]

ORIGINAL: Lobster

Words might help instead of letters. Exactly what does DF stand for?

Defense Factor.

[Lobster]

Thank you. Lots of noobs coming in so I just wanted to clarify that. [;)]

[cathar1244]

See 19.4 in the manual.

Thank you for the reference. So what I see there is,

For Carrier Naval:
Durability = 0.2251 x DF
Armor = 0.203395 x DF
Agility = 93 x (1-damage%)

.
.
.

But that doesn't clarify what "DF" represents. This is not a theoretical question: if I want to rate a ship that is modern, how do I know what its DF should be? From the examples in 19.4, it seems that durability and armor can only be calculated once one has determined a DF for the ship.

Since modern ships tend to be practically without armor (heavy offense / thin defense), from what may one calculate the DF for a ship? Displacement or something else? Thus my question as to what DF represents in terms of ships in TOAW.

Okay, I see this in the thread mentioned:

DF = 1.53*(2XDurability + (0.25XDeck Armor + 0.5XBelt Armor + 0.1XTower Armor + 0.15XTurret Armor))

Note that the 1.53 scale factor was again selected to make the Warspite DF match the genereic battleship.

But the definition seems circular (to know durability, I have to know the DF to begin with, yet this implies I have to know the durability to calculate the DF).

Plus, if I am reading this correctly, with a practical lack of armor on modern ships, we are looking at, what -- a DF of 1 or so, perhaps multiplied a bit by an agility factor? Sounds like those ships would vaporize in the game quickly. Which may represent, to some extent, reality, except real ships are now better equipped to stop incoming missiles etc. than the British ships that got hit in the Falklands War.

Cheers

[Curtis Lemay]

ORIGINAL: cathar1244

See 19.4 in the manual.

Thank you for the reference. So what I see there is,

For Carrier Naval:
Durability = 0.2251 x DF
Armor = 0.203395 x DF
Agility = 93 x (1-damage%)

.
.
.

But that doesn't clarify what "DF" represents. This is not a theoretical question: if I want to rate a ship that is modern, how do I know what its DF should be? From the examples in 19.4, it seems that durability and armor can only be calculated once one has determined a DF for the ship.

Since modern ships tend to be practically without armor (heavy offense / thin defense), from what may one calculate the DF for a ship? Displacement or something else? Thus my question as to what DF represents in terms of ships in TOAW.

Okay, I see this in the thread mentioned:

DF = 1.53*(2XDurability + (0.25XDeck Armor + 0.5XBelt Armor + 0.1XTower Armor + 0.15XTurret Armor))

Note that the 1.53 scale factor was again selected to make the Warspite DF match the genereic battleship.

But the definition seems circular (to know durability, I have to know the DF to begin with, yet this implies I have to know the durability to calculate the DF).

Plus, if I am reading this correctly, with a practical lack of armor on modern ships, we are looking at, what -- a DF of 1 or so, perhaps multiplied a bit by an agility factor? Sounds like those ships would vaporize in the game quickly. Which may represent, to some extent, reality, except real ships are now better equipped to stop incoming missiles etc. than the British ships that got hit in the Falklands War.

Cheers

TOAW uses those Durability, Agility, and Armor ratings. It no longer uses the DF value (except, as shown, to derive those, more basic, parameters if the designer doesn't provide them himself). It also gives the player some idea of how survivable the ship is via its counter display.

And you didn't look at the DF formula carefully enough if you think that no armor = DF of 1.

Ideally, the designer will research the ship's parameters himself, and provide them. But he will still want to figure a DF value just for counter display purposes.

[cathar1244]

And you didn't look at the DF formula carefully enough if you think that no armor = DF of 1.

Ideally, the designer will research the ship's parameters himself, and provide them. But he will still want to figure a DF value just for counter display purposes.

Except that durability, as defined above, depends on knowing a DF factor.

Research is no problem, but what defines durability (I mean, a real world characteristic(s) that can be checked in Janes or on the internet) in the absence of a predetermined DF factor?

Then one could calculate 1.53 * (2 * durability) to generate a DF value (assuming the ship has essentially no armor).

I appreciate your replies, but it seems like a way to calculate at least a rough durability factor without using DF is necessary to avoid the circular dependencies in the DF and durability calculations given above.

Cheers

[cathar1244]

@Curtis

Okay, I found this in the old discussion. So another question I have is, has a better definition for durability emerged since 2007 or is the ( displacement / 280 ) considered a valid way to generate a rough durability factor?

Cheers

ORIGINAL: Erik Nygaard

Here's a zipped Excel-5 sheet with a bunch of additional ship classes.
I've used Bob's original with a few slight changes.
There are a lot of ship classes not classified in WITP
so I've used the various 'All the World's Fighting Ships' books published by Conway as my main source.
The WITP 'duration' classification is a subjective one, I've taken the normal displacement/280 for other ships,
this to make Warspite the default as Bob did.

Great job, Erik!

By the way, it's "Durability", not "Duration". It certainly does seem subjective. And wherever I didn't have a WitP value (any German, Italian, or Soviet vessel), I just took a blind guess. If there is a systematic way to calculate it, the WitP board would be the place to find out. I may post a question there about it.

[Curtis Lemay]

ORIGINAL: cathar1244

And you didn't look at the DF formula carefully enough if you think that no armor = DF of 1.

Ideally, the designer will research the ship's parameters himself, and provide them. But he will still want to figure a DF value just for counter display purposes.

Except that durability, as defined above, depends on knowing a DF factor.

Research is no problem, but what defines durability (I mean, a real world characteristic(s) that can be checked in Janes or on the internet) in the absence of a predetermined DF factor?

Then one could calculate 1.53 * (2 * durability) to generate a DF value (assuming the ship has essentially no armor).

I appreciate your replies, but it seems like a way to calculate at least a rough durability factor without using DF is necessary to avoid the circular dependencies in the DF and durability calculations given above.

Cheers

I used the Durability values in WitP (original one, but later versions are similar, I think).

If you don't have WitP, or your ship isn't in WitP, you can use the values I've posted for various ships as points to extrapolate from. Or, displacement probably is a good starting point, provided the comparison is to the same ship types (BB to BB; Merchant Ship to Merchant Ship, etc.).

Clearly, the folks at WitP managed. If they can, so can we.

[Lobster]

ORIGINAL: cathar1244

See 19.4 in the manual.

Thank you for the reference. So what I see there is,

For Carrier Naval:
Durability = 0.2251 x DF
Armor = 0.203395 x DF
Agility = 93 x (1-damage%)

.
.
.

But that doesn't clarify what "DF" represents. This is not a theoretical question: if I want to rate a ship that is modern, how do I know what its DF should be? From the examples in 19.4, it seems that durability and armor can only be calculated once one has determined a DF for the ship.

Since modern ships tend to be practically without armor (heavy offense / thin defense), from what may one calculate the DF for a ship? Displacement or something else? Thus my question as to what DF represents in terms of ships in TOAW.

Okay, I see this in the thread mentioned:

DF = 1.53*(2XDurability + (0.25XDeck Armor + 0.5XBelt Armor + 0.1XTower Armor + 0.15XTurret Armor))

Note that the 1.53 scale factor was again selected to make the Warspite DF match the genereic battleship.

But the definition seems circular (to know durability, I have to know the DF to begin with, yet this implies I have to know the durability to calculate the DF).

Plus, if I am reading this correctly, with a practical lack of armor on modern ships, we are looking at, what -- a DF of 1 or so, perhaps multiplied a bit by an agility factor? Sounds like those ships would vaporize in the game quickly. Which may represent, to some extent, reality, except real ships are now better equipped to stop incoming missiles etc. than the British ships that got hit in the Falklands War.

Cheers

It appears that the DF values you see in TOAW IV was derived from TOAW I manual, page 125, where they have the basic ship stats and multiplied Def. by 10 except for the aircraft carrier. And TOAW I didn't have all of the various sub classes of ships like AA cruiser which was just a cruiser outfitted for AA duty. So those values were probably just fudged in there according to WW2 ship types. If you need more than the game offers you would make your own DF for the type. For instance Destroyer Escorts are not there. Modern Frigates and Corvettes are totally unlike any WW2 ship.

What was Norm thinking when he came up with the various DF values? Don't know, I don't see any formula and not able to read his mind.

[cathar1244]

Clearly, the folks at WitP managed. If they can, so can we.

Yes, no doubt there are smart people here. The only thing about WitP is that in that era, many warships had some or substantial armor, which makes rating modern ships somewhat different.

I'll ask on the WITP forum to see if they have guidelines on rating durability based on displacement.

Thank you for the discussion.

Cheers

[cathar1244]

I don't see any formula

Well, the formulae I see unfortunately depend on each other. The WITP people may be able to provide some insight.

Cheers

[cathar1244]

This is from 2009 in the WITP forum.

Maneuver and durability are data file values that are used by the code engine to calculate certain things. It all depends on what code you use. I will only speak to AE, because I had much to do with development of these values in the context of the AE algorithm, and only the AE algorithm.

In so far as durability is concerned, it is a function of an AE value called “tonnage”. “Tonnage” is a functional parameter that has nothing to do with GRT; it is a function of a geometric coefficient x cubic size x displacement.

We chose warship “standard” tonnage as the calculation basis, because it is a physical displacement parameter, and we could get good results off of that for non-Navalized ship vectors. There’s a lot of internal code that tweaks things, and there’s lots of traps for the unwary, so the suggestions are for nominal ships, only.

In AE, figure on 1 point of durability for each 250 tons of standard displacement for a warship. Figure on 1 point of durability for each 500 tons of “tonnage” for a merchie. And figure on 1 point of durability for each 350 tons of “tonnage” of an auxiliary or Navalized merchie.

Not sure if we'll get much closer to a way of generically calculating durability than this.

So, a practical example: A Type 42 destroyer from the Falklands War. (Sheffield was a Type 42, batch 1). At 3,600 standard tons, that works out to 14.4 durability points. Doesn't seem like the Type 42's had any armor from what I'm seeing on the 'net, so one could generate the DF as (1.53 * 2 * 14.4), or a DF of 44. But the durability rating beats the durability rating for World War II destroyers (according to a ships spreadsheet generated at one point for TOAW), including destroyers that at least some armor ... so I'm not sure what to think here.

If the "auxiliary" definition is used, it works out to 10.3 durability points, or a DF of 31. The DF doesn't look bad in this case, but durability seems high compared, again, to the WWII destroyers.

Cheers

[Curtis Lemay]

If ship-to-ship combat is going to be by missile, and ships now have missile defense systems...isn't that about the same as armor was to gunnery? So, one way to model that might be as armor. [:D]

[Curtis Lemay]

Durability would be primarily displacement, but a BB with a lot of compartmentalization and lots of crew to fight fires, etc. would be more survivable than a Merchant Ship with no compartmentalization and relatively little crew.

[cathar1244]

ORIGINAL: Curtis Lemay

If ship-to-ship combat is going to be by missile, and ships now have missile defense systems...isn't that about the same as armor was to gunnery? So, one way to model that might be as armor. [:D]

I thought about that yesterday. Two things come to mind.

One is a limitation of the software (TOAW). It is not really meant to model in detail naval combat. I understand a lot of progress has been made on that front as far as World War II naval combat is concerned (disregarding subs, mines, etc.)

The rub is that any armor added to a modern ship by a scenario designer or equipment file modder will function as armor against non-missile fire as well, for example, a 5-inch shore battery. I've no idea how that works out in reality; could a Phalanx close-in defense system drop an incoming 5-inch projectile out of the sky? Maybe?

The other thing is the abstracted nature of electronic warfare in TOAW. EW plays a strong role in defeating missiles, so an ideal representation would have an EW rating for each equipment item, or perhaps even two ratings -- EW and ECM. (I know this won't be added to the game for valid reasons, just pointing out how abstracted some of these considerations get.) The blanket EW ratings for a force cover some of the issue, but by its nature is a very general approach.

Cheers

[Lobster]

The Titanic displaced 52k tons and had a crew of about 1000. The Warspite displace 32k tons and had a crew of about 1000. The Titanic would not have been more durable than the Warspite, it had no armor. Except in TOAW. Could be displacement does not equal durability? Just a thought.

BTW, is it possible to have critical hits? As in the Hood.