Ship Class Design

[Curtis Lemay]

ORIGINAL: vahauser

Here is some more hard data.  The cruisers at Surigao Strait fired faster than the battleships.  The Louisville opened fire at 0351 (2 minutes before the battleships) at the short range of 15,600 yards.  Within minutes, the Yamashiro was a burning wreck reduced to 12 knots.  Yamashiro was targeted by 4 battleships and 8 cruisers.  A few minutes later, the Yamashiro was reduced to 10 knots and was burning so brightly that she was a sitting duck target.  The HMAS Shropshire opened fire at 0356 and fired 32 8"-gun salvoes in 13 minutes.  The Phoenix was ordered to fire "rapid and continuous" for a few minutes until being ordered to slow down to conserve ammunition.  While firing "rapid and continuous, the Phoenix was firing 6"-gun salvoes 4 per minute.

Note that the crusier data are more telling than the BB data. The BBs just can't get a shell in the air before the last fired reaches the target. But the crusiers can, as the above data show. 4 rounds per minute is a round every 15 seconds; 32 in 13 minutes is one every 24 seconds. The travel time had to be more than a minute at those ranges. Clearly, multiple shells were in the air from each gun.

Here again, the message seems clear.  Even firing "rapid and continuous" at a sitting-duck target at very short range (the firing range got down to around 13,000 yards before the burning hulk of the Yamashiro drifted away south to sink), the 6" cruiser Phoenix was only capable of 4 rounds per minute.  The 8" cruiser Shropshire was capable of of around 2.5 rounds per minute of rapid fire.  Both 4 rounds per minute for 6" naval guns and 2.5 rounds per minute for 8" naval guns are below the theoretical maximum rates of fire for those guns.  And that is "rapid and continuous" fire.  And also note that only a few minutes of this fire could be managed before orders to slow down to conserve ammunition were given.

Bottom line:  you can basically ignore theoretical rates of fire.  It doesn't matter that the Bismark can theoretically fire 3 rounds per minute and the Yamashiro can only theoretically fire 1.3 rounds per minute because in actual combat both ships will be firing less than 1 round per minute anyway.  And in the rough seas of the North Atlantic in a battle at long range (as opposed to the ideal short-range battle conditions at Surigao Strait), the big guns might only be capable of 0.5 rounds per minute, or even less.

My rough estimate of practical sustained rates of fire in actual combat (at standard combat ranges) based on the above data from Surigao Strait:
Battleships = 0.5 to 1.0 rpm (standard combat range = 25,000 to 30,000 yards)
8" Cruisers = 1.0 to 1.5 rpm (standard combat range = 20,000 to 25,000 yards)
6" cruisers = 1.5 to 2.0 rpm (standard combat range = 15,000 to 20,000 yards)

The WitP rate of fire data were relative values, not theoretical. You're arguing a non-issue.

[Curtis Lemay]

ORIGINAL: ColinWright

It seems to me that one approach would be to look at shell expenditure and length of engagement for some well documented enounters: Bismarck vs Hood and Prince of Wales, Washington vs Kirishima or whatever it was. The ranges and flight times for the shells can be calculated -- and it can be inferred whether the gunners were waiting to see the fall of each salvo before firing another. This will be much more meaningful than claims about the accuracy of Task Force 42 or War in the Pacific.

I'll tip my hat to you, Colin. That was quite clever. There could have been pitfalls, of course, since the firing could have been delayed by all sorts of factors, but it appears those pits were missed.

[vahauser]

Curtis,
 
It's clear from the cruisers at Surigao Strait, that they were firing while previous salvoes were in the air (they were under "rapid and continuous fire" orders [although the fact that there are "rapid and continuous fire" orders in the first place means that this is a special case order and not the standard]).  But that isn't the problem.  The problem is that even under ideal conditions, the cruisers at Surigao Strait were still not capable of achieving their theoretical maximum rates of fire.
 
You say your ratings are "relative".  Relative to what?  My guess is: relative to theoretical maximum rates of fire.  And how, exactly, are they relative? Are they relative in a direct linear correlation?  Non-linear?  Normalized or otherwise scaled to fit?  All I'm saying is what I stated in an earlier post this thread: your firepower ratings seem "off".  They don't pass my reality checks.  That might not matter because, after all, they are your ratings for you alone.  This is why I'm glad that we finally have an equipment editor with TOAW. 
 
I quit playing TOAW years ago since there was no equipment editor with which to change ratings that I believed were inaccurate.  But now we have an equipment editor.  Now we can all design scenarios based on our vision of historical reality.
 
The only reason I entered the discussion in this thread was because I wanted to give you my reasons why I believe your ratings did not pass my reality checks.

[ColinWright]

ORIGINAL: vahauser

4 rounds per minute is a round every 15 seconds; 32 in 13 minutes is one every 24 seconds. The travel time had to be more than a minute at those ranges.

I don't think it does. At a guess, the 8" shells probably had a time in flight of more like fifteen seconds at 15,600 yards -- and the range may well have closed.

At the scale of detail OPART operates at, I would think rate of fire provides a fine yardstick. For one, ships don't seem to have slowed their fire at longer ranges, when the flight time of shells could conceivably become a factor. For another, the actual rates of fire seem to vary pretty much proportionately to the theoretical rates of fire, which they wouldn't if other factors were dominating the equation.

Finally, rates of fire would seem likely to reflect the general quality and modernity of the ship: look at the rates of fire for the older Japanese and American ships and the Italian battleship for evidence of that. I'd be inclined to see ratings based on rates of fire as well as shell weight, etc, as perfectly valid. The more so as in most scenarios we're talking about shore bombardment rather than ship-to-ship combat.

Obviously, the ratings should be relative rather than absolute: I'm not saying we should have ratings based on the Iowa being able to pitch a full salvo into the target every thirty seconds for the entirety of a day-long turn. However, to decide what rating to assign to the Iowa as opposed to the Fuso, it seems just fine. The more so as those ships with high rates of fire seem to have shredded ships with lower rates of fire: Bismarck versus Hood and Prince of Wales, Washington versus Kirishima. It seems to work pretty good as a yardstick.

[vahauser]

Colin,

Here is a screenshot taken from a naval gunnery webpage showing the time of flight for a late-war (Baltimore Class) 8" shell. Note the time of flight of 26.07 seconds at 15,600 yards. Note also how quickly the velocity drops off, which partially accounts for the time of flight.

[vahauser]

Here is the screenshot.

[Curtis Lemay]

ORIGINAL: vahauser
You say your ratings are "relative".  Relative to what? 

Relative to each other.

[ColinWright]

ORIGINAL: vahauser

Colin,

Here is a screenshot taken from a naval gunnery webpage showing the time of flight for a late-war (Baltimore Class) 8" shell. Note the time of flight of 26.07 seconds at 15,600 yards. Note also how quickly the velocity drops off, which partially accounts for the time of flight.

Mmm. And you said flight time at that range 'had' to be more than a minute. I 'guessed' that it was more like fifteen seconds.

In any case, the cruisers at Surigao Strait obviously weren't waiting to see the fall of shot before sending the next salvo on its way -- didn't you say they were firing every fifteen seconds?

Nu? So it would appear the primary limiting factor is theoretical rate of fire. That the practical rate of fire turns out to be less doesn't alter that. It's like my average of fifty miles per hour on the road -- it's basically a function of my top theoretical speed of 70 mph.

[vahauser]

Colin,
 
I'm not sure where you got that quote.  I've read every post I've made in this thread, and nowhere did I state that the travel time at 15,600 yards had to be more than a minute.
 
But that doesn't matter.  What matters is that you and I are largely on the same page.  Whatever quibblings we might have, I've come around to using theoretical maximum rates of fire as the basis for calculating "realistic" combat rates of fire.  Look at my post above where I use TMx to calculate ACRoF (hereby changed to RCRoF, since the word "actual" is misleading so I've changed that word to "realistic").
 
At this point, my only remaining issue regarding theoretical maximum rates of fire is finding reliable TMx data.  For example, I don't trust that 3.0 TMx for the Bismark's 15" guns i saw in the post above and I trust the Wikipedia TMx of 2.4 more.  But both of those numbers might be incorrect. 
 
Anyway, once I have reliable TMx data, then I can calculate RCRoF values that pass my reality checks.

[Curtis Lemay]

ORIGINAL: vahauser

Colin,

I'm not sure where you got that quote.  I've read every post I've made in this thread, and nowhere did I state that the travel time at 15,600 yards had to be more than a minute.

He's more or less quoting me, not you. But I was basing it on the "standard ranges" you listed of 20,000-25,000 yards. Only one of the crusiers had a range given for it. I assumed the rest opened up at max range. At 25,000 yards it probably would have taken more than a minute, or close to it.

[vahauser]

Okay, after rooting around in the attic I finally found that dusty old box of naval and air ratings I did back in the 1990s when I worked for Pacifica Games.  Heh.  I just discovered that I was using modified theoretical rates of fire as one of the core values needed to determine firepower.  That made me chuckle.
 
Anyway, Colin is correct.  TOAW almost never involves naval ship vs ship combat, so rating naval units for their primary TOAW role of ground support is probably the wisest course.

[ColinWright]

.

[Erik2]

Some of us already use 2-3 aircraft carrier equipment to represent one CV unit depending on wether we want the CV to carry 2-3 squadrons. I've been toying with the idea to us this method on other warships (larger than destroyers).
This would allow ie the main guns to be destroyed while the secondary guns kept firing (at their own range and with their own shell weight).

In the example below I've split the battleship Warspite into 3 pieces of equipment representing the main, secondary and tertiary guns. The total AA factor of the pure AA guns is divided evenly on all 3 pieces, any AA rating of the 1st/2nd/3rd gun is added to the specific equipment.
Def for the 1st equipment = 'Def tot*5/8'
Def for the 2nd equipment = 'Def tot*2/8'
Def for the 3rd equipment = 'Def tot*1/8'
(These simple formulas are more or less qualified guesses, with a 2-equipment ship I'd use 5/8 and 3/8)

Comments?


Edit: The ranges are max ranges and should probably be reduced to get 'combat ranges'.

[ColinWright]

ORIGINAL: Erik Nygaard

Comments?

The first problem I see is that one gets the phenomenon of a Warspite that has lost all her 'main guns' (that unit has been sunk) but is still bobbing around. In fact, 'she' is just fine. Now she's some sort of useful little escort and scout vessel. Of course, if you've got the events, you can make allowing the whole ship to be destroyed to be prohibitively expensive.

Second, I just ha' my doots when it comes to battleships and heavy cruisers being able to exert the same impact on combat thirty km inland that they had on combat near the coast. The German attacks on Sicily and at Anzio didn't collapse in the face of naval gunfire landing thirty km inland -- at least, that's not my impression. They collapsed as they were nearing the beach. That's when naval gunfire was able to exert a decisive effect.

Your solution addresses this issue to some extent -- but not completely. After all, the Warspite can still exert 75% of her full effect at a target that's well away from the coast. I suspect that while WW2 warships could lay down indirect fire, to get really effective they needed to see what they were shooting at, or at least have it pop up on their radar screens. It might even turn out that the best solution is simply to allow naval vessels to participate only in combat in which at least one of the contestants is in a coastal hex.

[vahauser]

Erik and Colin,
 
Wow, this is a cool concept.  Talk about thinking outside the box.  I think Erik is really onto something here.  In other words, scenario designers would be able to "compose" their naval units in much the same way as they do with ground units (i.e., by building their ground units equipment type by equipment type).
 
I'm gonna spend some time with this to see if I can make something useful out of it.  My first impression is that it is an idea worth exploring.

[Erik2]

ORIGINAL: ColinWright

ORIGINAL: Erik Nygaard

Comments?

The first problem I see is that one gets the phenomenon of a Warspite that has lost all her 'main guns' (that unit has been sunk) but is still bobbing around. In fact, 'she' is just fine. Now she's some sort of useful little escort and scout vessel. Of course, if you've got the events, you can make allowing the whole ship to be destroyed to be prohibitively expensive.

Second, I just ha' my doots when it comes to battleships and heavy cruisers being able to exert the same impact on combat thirty km inland that they had on combat near the coast. The German attacks on Sicily and at Anzio didn't collapse in the face of naval gunfire landing thirty km inland -- at least, that's not my impression. They collapsed as they were nearing the beach. That's when naval gunfire was able to exert a decisive effect.

Your solution addresses this issue to some extent -- but not completely. After all, the Warspite can still exert 75% of her full effect at a target that's well away from the coast. I suspect that while WW2 warships could lay down indirect fire, to get really effective they needed to see what they were shooting at, or at least have it pop up on their radar screens. It might even turn out that the best solution is simply to allow naval vessels to participate only in combat in which at least one of the contestants is in a coastal hex.

All my scenarios with naval vessels have events with VP penalties when ships above destroyers are sunk.
The range is a problem as you want a short range for bombardments and a longer one for ship combat.
But this is a general problem with the standard TOAW naval values.
Another thing, I wonder if its possible to add some anti-armor rating to the main guns (only). It would be nice to see tanks being disrupted/disabled by heavy naval bombardment.

[vahauser]

Erik,
 
As somebody pointed out in another thread, approximately 10% of AP strength delivered to a hex is converted somehow into AT strength and applied against armored targets.  I interpret this to mean that since the big naval guns have a lot of AP strength, then armored targets will suffer some damage when fired on by large naval guns.  Medium and small naval guns not so much.

[Curtis Lemay]

ORIGINAL: Erik Nygaard

Some of us already use 2-3 aircraft carrier equipment to represent one CV unit depending on wether we want the CV to carry 2-3 squadrons. I've been toying with the idea to us this method on other warships (larger than destroyers).
This would allow ie the main guns to be destroyed while the secondary guns kept firing (at their own range and with their own shell weight).

In the example below I've split the battleship Warspite into 3 pieces of equipment representing the main, secondary and tertiary guns. The total AA factor of the pure AA guns is divided evenly on all 3 pieces, any AA rating of the 1st/2nd/3rd gun is added to the specific equipment.
Def for the 1st equipment = 'Def tot*5/8'
Def for the 2nd equipment = 'Def tot*2/8'
Def for the 3rd equipment = 'Def tot*1/8'
(These simple formulas are more or less qualified guesses, with a 2-equipment ship I'd use 5/8 and 3/8)

Comments?


Edit: The ranges are max ranges and should probably be reduced to get 'combat ranges'.

I do the same thing with Carriers in my Okinawa scenario. I just haven't done any human testing with it yet.

The thing I wonder about is whether the sum is truely equal to the whole? In other words, is it just as difficult to sink the three smaller pieces as it is to sink the one big piece? If that is the case, it's a good idea that solves some issues with secondary armament.

[Curtis Lemay]

ORIGINAL: ColinWright
Second, I just ha' my doots when it comes to battleships and heavy cruisers being able to exert the same impact on combat thirty km inland that they had on combat near the coast. The German attacks on Sicily and at Anzio didn't collapse in the face of naval gunfire landing thirty km inland -- at least, that's not my impression. They collapsed as they were nearing the beach. That's when naval gunfire was able to exert a decisive effect.

Your solution addresses this issue to some extent -- but not completely. After all, the Warspite can still exert 75% of her full effect at a target that's well away from the coast. I suspect that while WW2 warships could lay down indirect fire, to get really effective they needed to see what they were shooting at, or at least have it pop up on their radar screens. It might even turn out that the best solution is simply to allow naval vessels to participate only in combat in which at least one of the contestants is in a coastal hex.

I don't see why naval guns are any different than any other artillery in that regard. Spotters can direct their fire.

[vahauser]

Okay.  I've spent some time thinking about Erik's concept.  I'm still liking it.  For example, the database has most of the guns already in it.  Just take 9x 18" guns, add 6x 6.1" guns, add 125x 28mm AA guns, etc., to your "hull" (haven't figured this part out yet), then figure out a way to model late-war fire control and damage control (perhaps through artificially altered proficiency ratings? something else?), and voila, you have the Yamato in 1945.  [For instance, old primitive ships might have a proficiency range of 20%-40% representing poor compartmentalization and fire control, whereas warships launched late in the war (like the Iowa class) might have a proficiency range of 80%-100% representing advanced radar fire control and advanced damage control and compartmentalization.  Not sure about all this yet, though.]

I'm liking it even more since, by using Erik's concept, things like torpedoes can be added to a ship's armament (as anti-shipping only) without throwing everything out of whack.

I'm certain there's a downside to all this, but the upside looks pretty sweet to me as of today.

EDIT: Indeed, even submarines might be possible to model: figure out a way to give them a high "recon" value and ability to avoid detection and it might be possible to do.