Torpedo Boat and Light Combatant Rules

[Carthaginian]

OK...

Delta - 'Adjusted Speed' isn't what the ship can make all the time; it is what the ship can make in flat water with almost no wind. You're seldom going to see these guys making the adjusted speed.
Also you do not have enough machinery weight.

If you build to 0.5 Cross Sectional/0.5 Composite and have >60% Machinery Weight, you get a fairly accurate torpedo boat...
You just have to ignore the >24 knot 'Light, Fast Combatant' warning when you do it.

None of your designs have >60% machinery weights, so none of these ships are valid.

Sorry; they cannot be built.
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Jef - depending on your placement on the map, torpedo boats could be a great asset or completely useless. It's all about the needs of a particular nation.

[Walter]

First of all, it does not read as being mandatory. It just says that if you do that, you get a fairly accurate torpedoboat.
Secondly, mayby I am blind but I cannot find it in the "Design Rules for Gentlemen... and Scoundrels".

[Carthaginian]

First of all, it does not read as being mandatory. It just says that if you do that, you get a fairly accurate torpedoboat.
Secondly, mayby I am blind but I cannot find it in the "Design Rules for Gentlemen... and Scoundrels".

It never received any feedback- positive or negative- so I never added it.
I wanted to present the option, hear some input from the community and then make the final decision... much like the discussion K and had about liners. No discussion was forthcoming, so I just kind of let this slip to the back burner for 'lack of interest.'
Thus, in a way, you're right that it isn't mandatory to build to >60% machinery weight... technically, these carft can't be built at all under any conditions as things stand ATM. But should everyone like the idea of torpedo boats, we will have them added to the design rules and they will have to have >60% that much weight devoted to machinery.

[KWorld]

First of all, it does not read as being mandatory. It just says that if you do that, you get a fairly accurate torpedoboat.
Secondly, mayby I am blind but I cannot find it in the "Design Rules for Gentlemen... and Scoundrels".

It never received any feedback- positive or negative- so I never added it.
I wanted to present the option, hear some input from the community and then make the final decision... much like the discussion K and had about liners. No discussion was forthcoming, so I just kind of let this slip to the back burner for 'lack of interest.'
Thus, in a way, you're right that it isn't mandatory to build to >60% machinery weight... technically, these carft can't be built at all under any conditions as things stand ATM. But should everyone like the idea of torpedo boats, we will have them added to the design rules and they will have to have >60% that much weight devoted to machinery.

What rule are these, and my second class TBs, breaking?  They seem to be legal by the current rules as written.


I'm NOT in favor of a requirement for +60% machinery, because it will fail miserably in later years as boilers and turbines become more efficient.

[Walter]

technically, these carft can't be built at all under any conditions as things stand ATM.

I don't know about that. As I see it, the "Design Rules for Gentlemen... and Scoundrels" says we can... and so does "the Agreement upon Limitations for Naval Vessels"... so I am kind of confused by your words. :-\

it will fail miserably in later years as boilers and turbines become more efficient.

That is easily solved. Warp Speed, Mr. Sulu. ;D

[Delta Force]

I managed to find the quote, but it is indeed not in the rules: http://www.navalism.org/index.php/topic,5790.msg75736.html#msg75736

I think that a 60% machinery limit may be too strict because even the example given by Carthaginian is barely within the limits. It will be even more difficult to achieve 60% with the larger torpedo boats as ships up to 500 tons are included, and those larger ships are going to devote more tonnage to armor and armament than smaller ships because at that point speed and size are not going to provide enough protection.

[snip]

Ok so I split this off so we dont clog Delta's ship thread.

I also feel that 60% is a bit steep, but feel that we do need a cap. In the previous restart attempts a limit of 50% was adopted. I think that 50% serves as a bit better baseline as it allows for slighly more variation. The cap is needed so we dont get people building ubber gunboats that are effectively ultralight under DD rules.

[KWorld]

it will fail miserably in later years as boilers and turbines become more efficient.

That is easily solved. Warp Speed, Mr. Sulu. ;D

Heh.  I've tried to get to +60% machinery on my 1908 TBS design, and to do that you have to try to drive it at 27 knots, which drives the cross-sectional strength down to 0.49 with a 0 nm range at 20 knots.  Ie, it's not possible, and that's not even considering the horrendous seakeeping at 27 knots (0.21).  Even switching to pure oil firing (not allowed, but worth testing) doesn't help, you still have a range of 0 nm (though the cross-sectional strength is now up to 0.50).

[Carthaginian]

What rule are these, and my second class TBs, breaking?  They seem to be legal by the current rules as written.

I'm NOT in favor of a requirement for +60% machinery, because it will fail miserably in later years as boilers and turbines become more efficient.

These specifically don't meet the >24 knotrequirement for 'Light, Fast Combatant' base speed in Springsharp; your light TB does not meet this requirement, either.
Thus, the designs cannot be built.

Having a 60% machinery requirement is there to ensure that a proper amount of ship displacement is devoted to engine weight... to prevent people from building slow mini-ships to destroyer rules and overloading them with weaponry. There has to be some kind of limiting agent to ensure that the designs stay reasonable, and since the engine is the heaviest part of a small torpedo boat, that is why I chose it. I simmed multiple Japanese torpedo boats (among the earliest) and a couple of British and French ones (possibly the earliest) as well. The results consistently gave me a >60% engine weight.

Pull out a copy of Conway's and give it a go for yourself. It's pretty reliable.
I could see possibly see lowering the weights required to 55% if a good case could be made... but nothing will really get me to go lower than that. Springsharp occasionally requires artificial 'corrections' because of it's flaws- we know this. Ensuring that engines take up an appropriate weight is just one of those.

technically, these carft can't be built at all under any conditions as things stand ATM.

I don't know about that. As I see it, the "Design Rules for Gentlemen... and Scoundrels" says we can... and so does "the Agreement upon Limitations for Naval Vessels"... so I am kind of confused by your words. :-\

it will fail miserably in later years as boilers and turbines become more efficient.

That is easily solved. Warp Speed, Mr. Sulu. ;D

Springsharp says you can't.
The rules say you can build the ships... if you can get them to work in Springsharp. As I realize this is well nigh impossible, I wanted to add some looser requirements specifically for these ships. Remember, Rule #1 says that we use Springsharp 3.0b3 to build ships; if you can't build it in Springsharp, then you can't build it. ;)

And yes, this will HOPEFULLY also allow us to build the extremely fast light TBs of later time periods... and can be adjusted later if need be.

[KWorld]

This one's legal by SS3.3, but not by the +60% rule.

TBS-08, Columbiad Republic Torpedo Boat, Second Class laid down 1908

Displacement:
   99 t light; 102 t standard; 111 t normal; 118 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (123.75 ft / 123.03 ft) x 11.48 ft x (7.22 / 7.50 ft)
   (37.72 m / 37.50 m) x 3.50 m  x (2.20 / 2.29 m)

Armament:
      2 - 1.97" / 50.0 mm 45.0 cal guns - 3.85lbs / 1.74kg shells, 150 per gun
     Quick firing guns in deck mounts, 1908 Model
     2 x Single mounts on centreline ends, evenly spread
      4 - 0.43" / 11.0 mm 90.0 cal guns - 0.04lbs / 0.02kg shells, 1,200 per gun
     Machine guns in deck mounts, 1905 Model
     4 x Single mounts on side ends, evenly spread
      4 raised mounts
      Weight of broadside 8 lbs / 4 kg
      Main Torpedoes
      2 - 17.7" / 450 mm, 19.69 ft / 6.00 m torpedoes - 0.901 t each, 1.801 t total
   In 1 sets of deck mounted centre rotating tubes

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 3,179 shp / 2,371 Kw = 24.00 kts  Trial speed = 29.66 kts
   Range 130nm at 20.00 kts
   Bunker at max displacement = 15 tons (90% coal)
     Caution: Delicate, lightweight machinery

Complement:
   16 - 22

Cost:
   £0.013 million / $0.051 million

Distribution of weights at normal displacement:
   Armament: 6 tons, 5.1 %
      - Guns: 2 tons, 1.8 %
      - Weapons: 4 tons, 3.3 %
   Machinery: 63 tons, 56.6 %
   Hull, fittings & equipment: 31 tons, 27.9 %
   Fuel, ammunition & stores: 12 tons, 10.4 %
   Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     24 lbs / 11 Kg = 6.2 x 2.0 " / 50 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.11
   Metacentric height 0.2 ft / 0.1 m
   Roll period: 9.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 42 %
         - Recoil effect (Restricted arc if above 1.00): 0.21
   Seaboat quality  (Average = 1.00): 0.68

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.380 / 0.388
   Length to Beam Ratio: 10.71 : 1
   'Natural speed' for length: 11.09 kts
   Power going to wave formation at top speed: 72 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   Bow angle (Positive = bow angles forward): 5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  8.20 ft / 2.50 m,  6.56 ft / 2.00 m
      - Forward deck:   30.00 %,  6.56 ft / 2.00 m,  5.74 ft / 1.75 m
      - Aft deck:   35.00 %,  5.74 ft / 1.75 m,  5.74 ft / 1.75 m
      - Quarter deck:   15.00 %,  5.74 ft / 1.75 m,  5.74 ft / 1.75 m
      - Average freeboard:      6.16 ft / 1.88 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 187.8 %
      - Above water (accommodation/working, high = better): 43.2 %
   Waterplane Area: 858 Square feet or 80 Square metres
   Displacement factor (Displacement / loading): 31 %
   Structure weight / hull surface area: 14 lbs/sq ft or 66 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 4.77
      - Overall: 0.62
   Cramped machinery, storage, compartmentation space
   Extremely poor accommodation and workspace room
   Caution: Lacks seaworthiness - very limited seakeeping ability

[Walter]

Well, SS told me I can build them... but then I realized that it is about the really small TBs that are simmed with a speed <24 knots while mine are somewhat bigger and >24 knots. Silly me. :-[

[Delta Force]

The problem with the 24+ knot speed limit is that it would mean torpedo boats under 210 tons in 1895 would have a top speed of around 30 knots. That is quite speedy, and from what I have seen from US torpedo boats of the era (they were 180 tons and of course from only one nation, so this might not always hold true) nothing went that fast.

I think that a machinery tonnage of 55% or possibly 50% is best. Most of the torpedo boat designs that have been put up thus far are within the 55-60% ballpark range. That said, I am not sure if we need strict limits on machinery weight as we do not have specific tonnage categories at start, so "cheating" to get into one category or another is not that large a concern. I guess it would allow you to get "bonus" speed and have to devote less to the engines, but that "bonus" speed helps out the most at very high speeds where ever more power is going into kicking up a big wave and trying to overcome drag as opposed to propelling the ship forward. The biggest boost comes for those ships under 250 tons, and I don't think that we have to worry too much about someone piling up a massive amount of armament on such a small hull, so 50% machinery does not seem too extreme.

[Carthaginian]

The problem with the 24+ knot speed limit is that it would mean torpedo boats under 210 tons in 1895 would have a top speed of around 30 knots. That is quite speedy, and from what I have seen from US torpedo boats of the era (they were 180 tons and of course from only one nation, so this might not always hold true) nothing went that fast.

I think that a machinery tonnage of 55% or possibly 50% is best. Most of the torpedo boat designs that have been put up thus far are within the 55-60% ballpark range. That said, I am not sure if we need strict limits on machinery weight as we do not have specific tonnage categories at start, so "cheating" to get into one category or another is not that large a concern. I guess it would allow you to get "bonus" speed and have to devote less to the engines, but that "bonus" speed helps out the most at very high speeds where ever more power is going into kicking up a big wave and trying to overcome drag as opposed to propelling the ship forward. The biggest boost comes for those ships under 250 tons, and I don't think that we have to worry too much about someone piling up a massive amount of armament on such a small hull, so 50% machinery does not seem too extreme.

Ok... first off the limit isn't about 'categories', it's about 'overloading.'
I don't want to see 'torpedo boats' with 16 torpedoes flying around our oceans.
I'm trying to get a good balance of 'historic small TB' and 'SS crazy NEDS' in our designs. The heavy engine weight limits are to ensure that ships don't get to capable for their size. There was even a discussion on the previous incarnation about limiting DD's to ">X% Machinery" because of a similar problem.

Delta, Trial Speed is not Top Speed. :)
The Trial Speed is what the ship can make in calm seas with a clean bottom and generally just a light load of fuel. It's not what the ship will make loaded under normal operational conditions. You can generally bet that you're going to loose a knot or so off your service speed under most conditions. Ships like this will seldom do more than their SS speed... though I'm planning on this being the way I score them in the battle sims:

Trial Speed = only in perfect conditions
SS Speed = Speed in Service
Poor Weather = TS - 50%
Bad Weather = tied alongside a pier with the crew in barracks

Poor weather is going to be anything between 5-10' seas.
Anything beyond that, and the little buggers simply can't sail.

[Delta Force]

I know that trial speeds are wildly optimistic, but I don't think that torpedo boats of 1895 managed to go anywhere near 30 knots even during their trials. 24+ knots to get into the light and fast category is very hard to get seeing as many torpedo boats of the 1890s were within a few knots of that base speed even in the best of conditions. Making all ships have to reach 24+ knots in effect means the 1895 torpedo boats are reaching speeds of nearly 30 knots for their trials.

[Carthaginian]

I know that trial speeds are wildly optimistic, but I don't think that torpedo boats of 1895 managed to go anywhere near 30 knots even during their trials. 24+ knots to get into the light and fast category is very hard to get seeing as many torpedo boats of the 1890s were within a few knots of that base speed even in the best of conditions. Making all ships have to reach 24+ knots in effect means the 1895 torpedo boats are reaching speeds of nearly 30 knots for their trials.

So, should the Trial Speed item be dropped entirely?
http://www.warshipsww2.eu/lode.php?language=E&period=&idtrida=2066

This would be considered if people think it appropriate.