WesWorld

I've been asked to critique the use of Springsharp v3 with respect to Springsharp v2.1 as is the "standard" currently.

A brief history of versions

Springstyle; Rick Robinson's original programme running in Dos

Springsharp v1; Written in C# by Ian Ross-Gowan. This version essentially served to replicate Springstyle with a much better GUI.

Springsharp v1.1; A number of improvements to the basic v1, the most major being an introduction of metric/imperial inputs.

Springsharp v2.0; A major rework with lots more functionality. Major change this time was in the resistance/propulsion model, moving to Holtrop-Menen method (I seem to remember) which is a more standard method in use for this sort of task. GUI was updated again and allowed for more flexibility in armament configuration and armouring.

Springsharp v2.1; Some reworking of v2.0 to iron out some bugs and some incremental improvements.

Springsharp v3b2; Start of a big restructuring which I'll get to in a moment

Springsharp v3b3; Should be generally similar to b2 but different GUI and not thoroughly debugged. Lots of functionality which currently doesn't do anything in the current release.

A general point before moving on; Springsharp is far from being a perfect design tool. It has significant limitations in what it can be used for. It is best used for 1910-1940 capital ships that are weight dominated, but has been tuned for US ships specifically. There is significant inter-navy variation which again increases uncertainty. In WW we've developed some rules of thumb which serve in part to work around the limitations. However, I would strong urge that results coming out of SS are compared against similar historical ships for sensibleness checks. This seems to be a particular issue for smallish escort vessels (which will likely be dominated by stability and volume concerns rather than mass like capital ships).

Anyway, onto the main issue; Is SS3b2 suitable for use? I'll exmaine the differences to SS2.1 and the impact.

1. The armour deck input is now split into forecastle, citadel and quarterdeck areas instead of averaging over the entire waterplane. This gives greater accuracy in trying to get armour thickness to match armour mass. Most capital ships did not feature heavy deck armour outside the citadel. SS3b2 gives the capability for us to specify this easily. You may notice on some of my older ships notation as to deck armour thickness. This was because I essentially did the calculations myself and came up with an average thickness over the entire waterplane area that gave the same armour mass. SS3b2 gives a more flexible approach that better reflects reality.

2. Sections to put in multiple torpedo tube sections. This doesn't really change anything, and the torpedo calculations in SS are still nonsense. SS still doesn't take into account the mass of torpedoes or launchers and I'm very skeptical of the deckspace calculation as well. I'd strongly urge people to sim torpedoes as misc. weight on deck. I think from looking at some historical data for Italian cruisers a while back, I came up with a rule of thumb for launcher mass being 0.5x torpedo mass. If you're looking at reloads, look to the IJN destroyers and sheer amount of space taken up by these.

3. Small and large transom sterns included. The large transom stern gives the same results as the transom stern tag in v2.1. It's not clear what the "small" transom stern is so I'd stay away from that option.

4. Resistance prediction from large transom stern is increased at low speeds. It's an equally wrong approach as that in v2.1, but will likely give more realistic results for most ships.

5. Increase in capability to add different amounts of ammunition to gun types. E.g. so your 40mm Bofors can now be specified to have 2,000rounds instead of the 150 default in v2.1

6. Increased capability for mounting armament in ship. Most use is in the double stacked arrangement which increases barbette armour mass and effect on stability. Improvement over v2.1 which couldn't do this.

7. Ability to add misc. weight in various vertical heights around the ship. It's still all a bit rough with the impact on stability, but better than v2.1. Will probably be issues when large radars and missile systems start to be mounted high up in ships.

So, I think that in summary, SS3b2 is still giving us a "wrong" answer to our inputs, but the answer that comes out is better than SS2.1. This is mostly due to the increased flexibility detailed above because there have been no major changes to the underlying programme.

Thanks for putting this together, RA. I'm looking forward to seeing the comments and discussion.

Has anyone ever tried the hull depth locking option? Does it work?

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Originally posted by Hood
Has anyone ever tried the hull depth locking option? Does it work?

Yes and sort of.

Major issue is that it isn't linked to the propulsion section. Currently you specify speed rather than power. In order to use the hull depth lock option to need to note the power, change the draft, and then re-enter the speed in order to get the same power level. This then means you've got the same engine mass.

The above is a fairly large limitation of the SS modelling approach that's been carried over from Springstyle. In reality you design an entire hull rather than above and below water bits of it. However, it's easier to do the calcs for this sort of parametric design the way SS treats it.

Well, aside from the things RA pointed out, there is also the ability to select your gun caliber, which does effect the weight of the mount.

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A twin 16"/45 w/o armor in Turret & Barbette weighs 670t while a twin 16"/50 w/o armor in Turret & Barbette weights 781t.

Also the type of gun (BL, QF, AA, DP, RF) effects the weigh as well.

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A twin 5"/50cal in Mount & Hoist weighs 32t as a BL/QF/AA, but weighs 34t as a DP and 42t as a RF

RA - are there any particular tricks to simming light ships (such as destroyers) in SS3? I've tried to replicate some of my destroyers in SS3, and I inevitably end up with a majorly skewed design in some facet or another. Even when I start from scratch, I usually get some pretty loopy results. I think this is because of the machinery weight slider not working (tho I didn't realize that until Sam put me onto that); is there a way to sim realistic destroyers using SS3?

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Well, aside from the things RA pointed out, there is also the ability to select your gun caliber, which does effect the weight of the mount.

There are a few changes like that which are pretty negligible. I'm not a fan of the gun calibre issue or the gun type. There's far too much inter-company and inter-navy variation to get any sensible relationship. The actual answer that comes out in the end is wrong anyway. The main effort needs to be on getting realistic weight estimates for light guns. A quadruple Bofors weighs rather more than the 1-2t that SS estimates at the moment.

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is there a way to sim realistic destroyers using SS3?

Firstly note that SSb2 I was referring to isn't the one with the machinery weight/type slider. That's b3 and I haven't found it that great.

In general, the answer is no. The resistance formulas for SS aren't really applicable to destroyer like vessels. They're a bit too long l:b and some get into semi-planing behaviour at high speeds. You find that things like propeller design make large impacts as well. There's also the secondary issue of SS using capital ship type mass estimates for ship structure and equipment which isn't suitable for things like destroyers.

I seem to remember that I actually got the Capitani Romani to sim quite well in SS as they weren't too far off with regards to the resistance/power estimates for that hull form. However, in order to get the design to come out as working in SS I think I had to add in around minus 1000t of misc weight. There are massive issues which can't really be worked around.

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add in around minus 1000t of misc weight

Ah yes, the infamous Negative Misc weight. The only way known to man to rectify SS's (all SS programs) inherent need to make DD machinery weight way to much.

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Originally posted by Sachmle
Ah yes, the infamous Negative Misc weight. The only way known to man to rectify SS's (all SS programs) inherent need to make DD machinery weight way to much.

It's simply being used for something it wasn't designed to do.

Don't get into submarines. The results SS gives out are simply wrong at the end of the day.

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Increase in capability to add different amounts of ammunition to gun types. E.g. so your 40mm Bofors can now be specified to have 2,000rounds instead of the 150 default in v2.1

Not quite 150 default. That is only true for the main gun.

Using one of my designs and messing around with the 5" guns, I get the next...

SS2 magazine weight
Guns: Eight 5"
Round: 25 kg

Main gun rounds: 250 rounds
Position 1: 61t
Position 2: 73t
Position 3: 73t
Position 4: 73t
Position 5: 73t
73t ~ 300 rounds

main gun rounds: 10000 rounds
Position 1: 2450t
Position 2: 2939t
Position 3: 2939t
Position 4: 2939t
Position 5: 2939t
2939t ~ 12000 rounds

IIRC with the default 150 rounds, SS assumes that the other guns have 180 rounds.

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Ah yes, the infamous Negative Misc weight. The only way known to man to rectify SS's (all SS programs) inherent need to make DD machinery weight way to much.

Well, you could always use the weight of the machinery and then use a speed modifier to get a proper DD speed... Who knows? You might actually get a DD which has a hull strength of 1 or greater.

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Originally posted by Red Admiral
Firstly note that SSb2 I was referring to isn't the one with the machinery weight/type slider. That's b3 and I haven't found it that great.

Hm. I apparently don't have b2 then - just b3. Is it still available off the Springsharp site? *Goes to look*

Found it, playing with it now.

So, would anyone like to vote on whether to use SS3b2 for designing ships?

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Originally posted by Red Admiral
So, would anyone like to vote on whether to use SS3b2 for designing ships?

Among others, I was specifically requested by the Administrator to resim a design from SS3 to SS2 - a request that I complied with; other have done likewise where appropriate. I for one do not wish to see SS3b2, or any other SS3 variant, adopted.

As to why?

There are several reasons – the greatest being that the vast majority of the designs extant in WW are to SS 2.1 standards, and having resimmed a SS3 design back to SS2.1, I have no desire to resim it back.

Second – peer review requires that we have a single standard to which we all can refer, rather than one set of parameters for some players and a different set of parameters for others; it is the only fair manner in which the Gents Rules (for better or worse) can operate.

No problems with grandfathering in existing ships as has happened previously.

Report output is pretty much the same so no problem when comparing SS2.1 output with SS3b2.

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Originally posted by Red Admiral
No problems with grandfathering in existing ships as has happened previously.

Report output is pretty much the same so no problem when comparing SS2.1 output with SS3b2.

By your own admission, SS3b2 does not sim smaller vessels well at all;

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In general, the answer is no. The resistance formulas for SS aren't really applicable to destroyer like vessels. They're a bit too long l:b and some get into semi-planing behaviour at high speeds. You find that things like propeller design make large impacts as well. There's also the secondary issue of SS using capital ship type mass estimates for ship structure and equipment which isn't suitable for things like destroyers.

I seem to remember that I actually got the Capitani Romani to sim quite well in SS as they weren't too far off with regards to the resistance/power estimates for that hull form. However, in order to get the design to come out as working in SS I think I had to add in around minus 1000t of misc weight. There are massive issues which can't really be worked around.

If it is requires the use of such fiction as "negative misc weight", it seems far worse in simming anything smaller than a battleship. In that case, why adopt a program that is flawed? I have no desire to learn an entirely new manner to sim ships in the future - my interests in the game extend far beyond mere naval design. Hence my desire that we have a single standard, which our rules presently provide, which is SS 2.1.

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Originally posted by BruceDuncan
In that case, why adopt a program that is flawed? I have no desire to learn an entirely new manner to sim ships in the future - my interests in the game extend far beyond mere naval design.

All models are flawed, but SS3b2 is less flawed for designing ships than SS2.

Learning a new manner to sim ships? It's an almost identical user interface!

I have no objection if we wish to make SS3b2 legit, but in my poking around with SS3b2, I'm not highly satisfied with its results in simming either OTL or existing Wesworld ships. As a result, I see no compelling reason for me to switch. SS3b2 admittedly has some nice features that I want, but its inability to sim small ships like destroyers is going to be the deal-breaker for me. It still looks like a beta job to me.

Therefore, I abstain with reservations. I intend to keep using SS2 regardless of whether or not SS3b2 is accepted, but I will not vote to prevent people from using SS3b2 as an option. However, if the proposed vote is to replace SS2 with SS3b2, then I vote no, I do not want to replace SS2 with SS3b2.

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Originally posted by Red Admiral

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Originally posted by BruceDuncan
In that case, why adopt a program that is flawed? I have no desire to learn an entirely new manner to sim ships in the future - my interests in the game extend far beyond mere naval design.

All models are flawed, but SS3b2 is less flawed for designing ships than SS2.

So you would say; however, I do not believe that SS2.1 requires the addition of any "minus miscellaneous weight" to get a design to conform to the Gents' rules. If SS3b2 requires such to even approach an acceptable sim for a smaller ship, it is far more flawed that SS2.1 might be.

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Originally posted by BruceDuncan
So you would say; however, I do not believe that SS2.1 requires the addition of any "minus miscellaneous weight" to get a design to conform to the Gents' rules. If SS3b2 requires such to even approach an acceptable sim for a smaller ship, it is far more flawed that SS2.1 might be.

Ah, you didn't understood my critique. That part was with regards to simming the Capitani Romani in SS and having the output match the historical stats. My point was that whilst the hydrodynamic calculations aren't too bad, the calculation of engine mass for non-battleship combatants is way off. It's not surprising given what SS was designed to simulate. Having more appropriate values of shp/ton for the Capitani Romani actually leads to a hull strength of about 1.0 rather than the 0.5/0.75 for lighter combatants enshrined in the gentleman's rules. That sim of Capitani Romani was made using SS2 not SS3b2.

My general point is that it's an improvement on SS2 so why not adopt it for the future?