Motor Torpedo Boats

[Kaiser Kirk]

We did have higher DD/SS costs in N3, as I recall.

I have CLs and DDs in the plan but I also had a capital ship slotted in for 1/13 and now I'm pondering how to approach that.

While I just finished 2 of my prized Tiamat, and 2 more are close...and they are looking more target-like than I appreciate.
Granted, the damage done here would not sink any of them, their TDS should hold against these, so no crits, and they can take 7 torps.
But they would be severely damaged, which would be distressing.
So I'm realling thinking of using up some their misc weight with Torpedo nets to supplement the TDS.

On the other hand,  my cruisers have heavy QF broadsides and fire control, as do my destroyers....but there's no way I could stop 100+ torpedo craft if they  arrived at once.
Some scout cruisers with war tubas and Hulesmeyer detectors for a picket line, and then more protected cruisers with 120-165mm guns as the gunline seem called for.
This might be where I go ahead and build a cruiser with little speed but lots of firepower to add to the gunline...basically an "Atalanta" for TBs.

[Kaiser Kirk]

Actually this goes to a different point as well- back in February I was trying to interest folks in cost differences for different architectures.  DDs/SS/ Aircraft cost more to build and maintain than SS's light tonnage would suggest. They are artificially cheap in our system.

I had that discussion in mind, partially why I suggest doubling costs. What did happen to it?

There were a large number of changes considered.
That one had ...well my support and your support. 
It also had some mild opposition.

So when the rule package got finalized, that was not imposed.

As I expressed at the time, the idea is we'll move forward and get the game going.
I want to get the NPCs set, I want to sit down and customize Seekrieg for our ships and tech trees, I want to catch up on Parthia, and I'd like us to get 4-6 turns completed.

Then we will hopefully have some perspective and energy to "fix" problems identified.
Until then, hopefully we can keep actual rule changes - like the cruiser tech mess - minimal.
I   am trying to get this Sim moving smoothly before we tinker with it again.

[snip]

The change in cost was eliminated when I was reforging the rules as a simplification measure. Since we were all going to be playing powers within spitting distance of each other industrially, it did not feel like a meaningful distinction to keep. I'm not going to die on the hill of keeping upkeep and costs the way they are for light ships, but I will fight vigorously before I consider offering retreat.

[TacCovert4]

I think the relative effectiveness of TBs/MTBs at the moment is more due to lack of fire control than TBs being unusually more effective than the OTL.

Historically we're still in that time period that the Jeune Ecole existed in.  There was a reason why Torpedo Boat Destroyers suddenly became so important all of a sudden.....Torpedo Boats were a deadly threat to larger vessels. 

Now, give it another 3 years, and torpedo boat squadrons will be getting wiped out wholesale by everything from destroyers with decent fire control to light cruisers and even the 6in secondaries of battleships.

If I had to weigh in on any one thing, which isn't even really applicable now, I would say that 18in Torpedoes should be the biggest for MTBs.  Historically MTBs over time weren't able to carry the larger and heavier torpedoes, and typically carried either smaller or shorter ranged torpedoes.  So I'm good with that in a resolution sense.

[maddox]

On the higher cost in N3 for MTB's, it was seen as normal that the kinds of engines and light build of those ships would mean they are as expensive to operate as aircraft.

Part of the higher upkeep was in effect building replacement boats for the ones lost during training/misfortune. (but not in war)

[snip]

It looks like WWII-era ones did get access to 21" fish, so I think that's something the later boats should allow.

I'd be ok with looking at limiting the size of torps carried by MTB type. I agree with Tac that the fish carried here should not be the same as the weapons mounted on larger (read, Springsharped) ships, and should have lower range.

20t MTB and early 40t (A, B, C and E): 16" [This is the smallest we have provisioned for in the rules, and so fit the smallest group of MTBs]
Most 40t MTB (D, F and G): 18"
80t, 120t and advanced 40t (H, I, J, K): 21"

The warheads of said fish would of course improve with the Torpedo tech. This makes MTB force makeup a tradeoff between number of hulls and destructive power of torpedo. A fair tradeoff IMO.

While we are on the subject, this might be a good topic to discuss around Subs as well.

[Kaiser Kirk]

If I had to weigh in on any one thing, which isn't even really applicable now, I would say that 18in Torpedoes should be the biggest for MTBs.  Historically MTBs over time weren't able to carry the larger and heavier torpedoes, and typically carried either smaller or shorter ranged torpedoes.  So I'm good with that in a resolution sense.

As player or guest, you're welcome to weigh in.

The Chinese tech in this case was 18" torpedoes.
SS3b puts the # torpedoes a ship can take at 20".

The primary difference is a little larger hole, and more power against the torpedo bulkhead (if present).
If the hole floods the same compartments as a smaller hole would have, there's not a big difference.

For these battles I was rolling "hit location" along the length of the ship to both assess the viability of hits, ensure that crits were appropriate to "end" or "amidship", and to see how much of the ship was flooding and compare that to the # of torpedoes it could "Take".

Fox's ships are small and have no TDS.  The Armored Cruisers and Battlecruisers typically could take 1.5 - 2.0 torpedoes.   Many of them have short citadels to cut weight, but leaves them more vulnerable to flooding and can sink from just bow & stern hits. 
The  largest Japanese battleship is only 15000tons and can take 3.1 torpedo hits. 35% is forecastle and 15% stern - it can sink from sufficient end hits causing flooding.  The next largest can take 2 hits.

2 in the Stern or Bow I did not judge as fatal on a 1.5-1.9 ship.   I required 2 separate compartments

[Darman]

I'm not well read about torpedoes, but I am reviewing United States torpedo technology from 1900-1945 on Wikipedia (I don't have time to pursue the information further than Wikipedia, I am happy to see deeper research that differs from my own shallow search).  There were definitely issues with torpedoes, and I think that allowing for duds may reflect some of the inadequacies of torpedoes.  But we might need a little bit more (a sort of malfunction test at launch, for example) of a handicap for torpedo boats.  Motor Torpedo Boats are going to be very finicky craft at the best of times and unless the sea-state is perfect maybe there ought to be a slight handicap for them.  If we choose to run with this new non-OTL set of circumstances then that's fine too. It will create a challenge for us all.  But I think limiting the combat radius of MTBs and maybe some sort of failure to launch in any sea-state but near-perfect  could provide enough of a handicap.  Otherwise the Mediterranean will quickly be filled with so many MTBs you could walk from the Pillars of Hercules to the Dardanelles without falling into the water. 

[Kaiser Kirk]

As I said earlier, I really would prefer a Naval Sim where the the Big Gun was the best tool for defeating a warship.
Mines, Torpedoes, aerial bombs are all kinda..boring.

So some observations.

A) It is important to remember these are being launched at extremely short range.
Seekrieg's formula relies heavily on distance to target instead of time to target. 
With most of these torpedoes being launched ~3500m, at 35knots, there is not much of either.

Key Step 1 : Keep the enemy torpedo craft away from your big ships.

B) This last battle I reduced the "to hit" to 1/3 of what Seekrieg said. 

I'd like to see the torpedo hit rate come down even more.

I was thinking of making it that ships without fire control (range finder and a plotting table) have a lesser TH rate - which would effect all MTBs.

C) Already upped the "Dud" rate from 20 to 30%.   WWII American is given as 40% and that was notoriously high.

D) In the last battle, I gamed it out on the floor with counters, and the final launch formation had the  Chinese destroyers in a slight "L" with one edge crossing the Japanese T, giving the torpedoes a big of a cross hatch, and making it very hard to angle the ships to escape.

E) Speed is another part of the equation, most of the ships hit have been going about cruise speed.  In this last one, to make the spaced lines of skirmish ships work, the BBs and BCs could not put on much speed, they needed to stay near the Amphibious fleet. This meant when the torpedoes came, they still were not going fast.

F) Part of the problem is the RNG - dice or online- seems to generate more hits than expected. 
Hopefully that will even out, but I'm not sure I should be looking at the numbers afterwards and "artfully" reducing them to fit a predetermined narrative.

G) Sea state : The chart describes "Beaufort Sea State" 4 as
"wind :11-16knots, 'moderate breeze', small waves with breaking crests."
I was using that as the roughest weather the MTBs would try to go attack in.

I didn't send the Naha TB squadron across several hundred miles of ocean to join in the big attack even though it was "In range"
Currently those aren't in our rules, but I felt there should be a restriction on their performance.

The thing is, the Japanese fleet parked itself under a known enemy observation post, 60nm off the enemy coast, and stayed there.
So...the MTB could wait for decent weather, plan a joint attack, and execute it.
The Chinese did not manage to time their attacks properly, but they did send 121 vessels with 320 (?) torpedoes. 32 were kept unfired so one DD squadron had a reserve.
The big damage of this last strike was done by full destroyers, with fire control, taking the Japanese in the flank.
They did not launch them all, many boats did not survive long enough, some didn't launch, but about 8% of the torpedoes sent to the battle got to a target.
Actual hit rate of those launched wound up being around 18-20% I think- the RNG liked the last attack. 

[TacCovert4]

If I had to weigh in on any one thing, which isn't even really applicable now, I would say that 18in Torpedoes should be the biggest for MTBs.  Historically MTBs over time weren't able to carry the larger and heavier torpedoes, and typically carried either smaller or shorter ranged torpedoes.  So I'm good with that in a resolution sense.

As player or guest, you're welcome to weigh in.

The Chinese tech in this case was 18" torpedoes.
SS3b puts the # torpedoes a ship can take at 20".

The primary difference is a little larger hole, and more power against the torpedo bulkhead (if present).
If the hole floods the same compartments as a smaller hole would have, there's not a big difference.

For these battles I was rolling "hit location" along the length of the ship to both assess the viability of hits, ensure that crits were appropriate to "end" or "amidship", and to see how much of the ship was flooding and compare that to the # of torpedoes it could "Take".

Fox's ships are small and have no TDS.  The Armored Cruisers and Battlecruisers typically could take 1.5 - 2.0 torpedoes.   Many of them have short citadels to cut weight, but leaves them more vulnerable to flooding and can sink from just bow & stern hits. 
The  largest Japanese battleship is only 15000tons and can take 3.1 torpedo hits. 35% is forecastle and 15% stern - it can sink from sufficient end hits causing flooding.  The next largest can take 2 hits.

2 in the Stern or Bow I did not judge as fatal on a 1.5-1.9 ship.   I required 2 separate compartments

Just to briefly note, I agree with how the fights went with the TBs.  In this very early period, TBs were a deadly threat.  That's why the major navies started building Torpedo Boat Destroyers.....they were originally built just to keep the TBs from wrecking entire battlefleets.

There was a reason that the Russian 2nd Pacific squadron shot up ghost 'torpedo boats' and shot at the British fishing fleet because the mistook them for TBs.

I think that by the time we get to 1916 or so, TBs will not be as effective for their tonnage as they are now.  And bigger ships will be more effective at long range....and medium caliber fire control will be shredding them.  And when aircraft get going well, daytime TB attacks will be impossible.

I was only noting that if there was one thing I'd keep in mind, it's that TBs can't typically carry the full-up large torpedoes that Destroyers and larger subs can......and typically wound up with torpedoes a generation behind.

[snip]

As I said earlier, I really would prefer a Naval Sim where the the Big Gun was the best tool for defeating a warship.
Mines, Torpedoes, aerial bombs are all kinda..boring.

I agree the Big Gun is the "most fun" tool to have as the final word in Naval combat, but I disagree that this scenario invalidates that. As you noted, this was a fleet in a reasonably fixed position under constant observation that lacked a lot of modern fire control and got wrecked for it. Take the same fleet and give it orders that allow for more freedom of movement and I would be willing to bet the outcome would be less in favor of the torpedo spam. This was a prefect storm for a statistically-abnormal torpedo attack and I think that shows. This is nothing more than a practical example of the scenario that a lot of early 20th century navies feared and worked to avoid, and that is really the only way (IMO) that it significantly diverges from OTL.

To avoid this, a couple thing are really clear from a tactical and design perspective. Keep big capital ships out of littoral zones as best you can. Try and destroy as much of the hostiles ability to project power as you can before forcing amphibious landings. Make sure everything has Fire Control and modern QF guns. Do everything you can to keep the range beyond where torpedoes become deadly with minimal Time-To-Target and the big guns will do the rest.

I think as we see fire control ranges go up as tech improves and proliferates as older ships get scrapped or refit and modern designs replace them, the ability of a hostile torpedoboat force to pull off what the Chinese Navy did here is going to decrease a lot. This is also the conflict fought in the proverbial backyard of both combatants. IMO, any colonial-theater conflict is going to be decided by gunpower; torpedo will be in shorter supply overseas and will need to be used more cautiously than being able to basically back the ship up to the factory and reload.

In short, I think there are some valid IC lessons to draw from the use of MTBs and TBs in this conflict [eg heavy FCed secondaries good], but it far from replaces the big gun.

[Desertfox]

I am seeing two different problems.

1) 1905 MTB tech is anachronistically early, we don't see equivalent designs in OTL until the Italian MAS boats in 1915. The Italian and British MTBs where powered by aircraft engines, which shouldn't exist here in a 1905 tech.

2) The two main examples I can find of massed TB attacks against fleet units not int harbor are the Japanese at Tsushima and the US at Suriago. At Tsushima, 58 mixed destroyers and torpedo boats spent 3 hours attacking Russian ships, they managed to torpedo three (6 torpedoes), one of them a stopped battleship (mine). At Suriago, the US had 39 PT boats with radar, they managed no hits.

As far as torpedoes go, PT boats tended to use special light weight torpedoes. Where this can have an effect is not so much the warhead but the effective range, say if MTBs have to launch at 1000m instead of 4000m, that changes things a lot.

Because of how MTBs are structured in the rules, I feel we can restrict them fairly easily and painlessly. Limiting torpedoes is straightforward, medium/fast range can become combat radius, and cruise range becomes ferry range. And an extra column can be added for cost say 0.05BP and $0.1 per MTB. 

[snip]

Im against any cost increase for MTBs at this time. Effectiveness adjustments coupled with increased countermeasures will resolve the issue nicely. Cost increases of the nature you propose will make MTBs a complete waste of materials that may as well not exist in the game. They are meant to be cheep, quasi-disposable platforms.

[Desertfox]

A) It is important to remember these are being launched at extremely short range.
Seekrieg's formula relies heavily on distance to target instead of time to target.
With most of these torpedoes being launched ~3500m, at 35knots, there is not much of either.

So I decided to look at torpedo performance pre-WWI, and I think that is part of the problem. Looking at US WWI torpedoes, the first with a range of 3,500m and 35 knots was the Mark 7 in 1912, earlier 18" torpedoes were under to 2,000m and 30 knots, and some under 1,000m:
http://www.navweaps.com/Weapons/WTUS_PreWWII.php

The Tsushima torpedo attacks are mentioned to have occurred at distances under 600m.

[Kaiser Kirk]

At the beginning I did notice there was no index weapons indicating what the various did.

I did indeed browse Navweaps looking for an idea of what the torpedoes should do.

I believe the one I used was the British Whitehead Mk VI
I only used the "short" 5000m setting as allowing the 7000m with an algorithm that does not penalize slower torpedoes seemed ill considered.

Using the Gun Research Rules as the only guidance as weapon development : It's a 1907 design. The 1905 tech can be completed by 1907. So that would be what that tech level can produce.

So... this was my try.

: http://www.navweaps.com/Weapons/WTBR_PreWWII.php
18" (45 cm) Mark VII and Mark VII*
Ship Class Used On   Pre-World War I torpedo boats, destroyers and Flying Boats in the 1920s
Date Of Design   1907
Date In Service   1910
Weight   N/A
Overall Length   N/A
Explosive Charge   320 lbs. (145 kg) TNT
Range / Speed   Mark VI:
   6,000 - 7,000 yards (4,570 - 7,650 m) / 30 knots
   3,000 yards (3,280 m) / 41 knots
Mark VI*:
   5,000 yards (4,570 m) / 35 knots
   7,000 yards (6,400 m) / 29 knots

Power   Wet-heater
Introduced on the 1908 members of the 'Tribal' class. First Torpedo to be designed with wet-heater propulsion. Some Mark VI torpedoes were modified for aircraft use.