Torpedo Thoughts

[aman]

Have been reading "Japanese Destroyer Commander" and really enjoying it. One thing author discusses in depth is torpedo usage, as he was the IJN top shooter.

In his account of the Java Sea, the IJN fleet did two large releases of torps, a 48 and 64 torp spread both at long range (note: 18" in ou game). Both times the Allied fleet, in a long column, took drastic evasive action, turning 180 degrees and abandoning their direction at the time of firing. Both spreads were 100% misses.

A few conclusions this leads me to:
- Spotters must have seen the torpedoes fired,
- Commanders correctly guessed that the torps were "leading" their present course and that doubling back would help evade,
- Torps can be used to "herd" the enemy fleet or deprive them of maneuver room.
Can this be reflected in the game at all?

[shigure]

One of my all time favorite books. Captain Hara's writings document the frustration of the IJN DD commanders during the Guadalcanal campaign. A highly recommended read for anyone interested in the IJN during WWII.

Now in reference to your conclusions on the torpedo spreads that were misses. Using "The Battle of the Java Sea" by F.C. Van Oosten he gives the following info.
Initial contact was at 16.12 hours with the Allied ships not able to steam faster than 27 knots due to boiler difficulties in the Dutch DD Kortenaer. IJN Jintsu and her 8 DDs were able to rapidly gain a favorable position to launch torpedoes plus the fact the IJN ships were gaining a position to cross his 'T' caused Adm. Doorman to change course 20 deg. to port. This allowed the range to decrease further such that the Allied CLs were able to open fire. With their speed advantage the Jintsu's group was able gain an even more favorable position to launch torpedoes. This caused another course alteration to port.

The first recorded torpedo hit was at 17.13 hours on the slow Kortenaer which broke her in two causing her to sink in less than two minutes.
Reports by the Allied ships indicated torpedoes in the water, but while they admitted some were undoubtedly from enemy cruisers and destroyers, there was fear that a submarine was in their midst. The Dutch DD Witte de With dropped DC's on a suspected submarine contact and the USN DD Edwards reported a periscope.

The only reported sighting of the IJN launching of torpedoes was around 19.27 hours when the IJN Jintsul launched four torpedoes. This did cause a turn to starboard by the Allied ships.

The Allied forces next turn came at 21.00 hours when the 20-meter depth contour on the NW corner of Java caused another turn to starboard.

Then two hours later the IJN CAs launched torpedoes from extreme range that eventually sank the Java and DeRuyter.

So at least from this action, the turns were made in response to tactical positioning (threat of a torpedo launch or getting one's 'T' crossed) vs. the actual observation of a torpedo launch (except for Jintsu's observed launch).

I would say that the threat of torpedoes is more of a likely to "herd" the enemy. The problem with any naval game that has torpedoes is the eagerness of many novice gamers who command destroyers to close the range to launch torpedoes. Unfortunately, they run afoul of the enemy screen (CLs and DDs) and the usually formidable capital ship secondaries and are sunk before getting in effective torpedo range. Most gamers will learn from this and be a little more cautious with their DD flotillas. This is probably the only way it can be reflected in the game.

The experienced DD commander can manuveur his DDs to affect the enemy ship movements while minimizing their exposure to return fire. In this manner, they could also help "herd" the enemy fleet. The DD attack can be made at the Flotilla commanders discretion (usually when the capital ships secondary batteries have been reduced or fire control damage has reduced the chances of a hit).

The use of smoke is also effective at hiding DDs and causing enemy capital ships to change course when they get to close.

[aman]

yes, it's a great book. I was writing from Hara's perspective. Is Van Oosten's book good?

I was thinking of the more immediate response of ships to torpedoes in the water. My understanding from Hara is that the IJN torp didn't leave a wake and was hard to spot. I'm wondering if there's a possibility to respond to torpedo attacks. Presently there isn't - they're not a delayed attack at all, just another attack that is deadly at close range.

What if ALL torpedo attacks were written on the log sheet at the beginning of the turn (sort of like Main Battery shooting), then torps attacked during the movement phase as ships moved?

It's very hard to get timing right in a naval game.

[TheDreadnought]

Torpedo rules were written the way they were because of the need to minimize bookkeeping and keep the system simple -- while simultaneously making sure torpedoes were effective, but not too effective.

In the game I'm working on right now. . . SDG's entry into the 'flying battleships' genre. . . torpedoes are actually plotted on the map. This has the effect of making them wonderful tools for herding the enemy and breaking up formations. . . but also makes them pretty easy to avoid, which is something that I wanted to avoid in the historical rules, but I'm ok with in the quasi-sci-fi rules.

That said, your idea isn't a bad one. I'd have to see what happened in actual play trying something like that.

The problem (as I recall when we initially thought about that) was what happens when ships move into or out of range during that time, or other ships intervene, or things of that sort. Not impossible things to overcome, but things that have to be worked out.

[shigure]

yes, it's a great book. I was writing from Hara's perspective. Is Van Oosten's book good?

I would recommend the book.

The IJN torpedoes were oxygen propelled. The oxygen mixes with the water and makes it almost wakeless vs. a conventional torpedo that just uses air and leaves a tell tale wake.

Just from my perspective, any ship commander that sees torpedo carrying vessels closing to launch range will try to open the range if possible. If you try something let us know.

[regiamarina]

Aman,

I have played other rules sytems which do add the spotting manouvering aspet of torpedoes that you are talking about but they usually end up with large amounts of bookkeeping and the torpedoes are usually left on the table and are plotted almost like a ship. It can get very messy and shifts the level of detail up but playability down.

I think the balance of NT is that it has the excellent flavour of naval warfare without the copious charts, bookkeeping and incremental movement that turn other sytems into more of a simulation than a game.

Your suggestion sounds like a good and easy attempt to try and make torpedoes a bit more unique. Let us know how they play.

Martin

[aman]

My friend and I are kicking around some ideas now. I think we'll try them this weekend and let you know how it goes. We're both sensitive to the "not complicating the game" aspect. Maybe:
- All ships plot torpedos with movement
- Torpedo attacks at 6" or less are immediately resolved. Ships that plotted Evade get +1 Target.
- Movement
- Gunnery
- Torpdo attacks at >6" now take place. Targeted ships can make a Command Check to "Spot the Wake", -2 if it's an IJN torpedo. If they succeed, they turn directly towards / away from the attacking vessel and get a bonus +1 Target. However, ships that are adjacent to them may also be attacked (representing the torpedo "spread" spreading out - harder to get a hit, easier to spot, but more potential targets at a ship formation)

This involves no counters, markers, or book keeping. But it enables torpedoes to "break up formations" and change ship angles if they want the additional +1 bonus. I also like the plotting early, it took a few minutes to work out torpedo solutions, I understand.

Any thoughts?

[lincolnlog]

A good example of herding is during Samar, Kurita manuevered the Yamato to avoid a US torpedo spread. He in advertently turned in a direction that took the Yamato out of the battle for an extended period. By the time Kurita rejoined, he decided to pull out fearing he would never catch the American flattops and of course fearing increased airstrikes and surface reinforcements.

Speaking of which, does anyone have a good Samar scenario? One with enough special rules to give the US a fighting chance.

[shigure]

For your Samar scenario you might consider the following:
All the IJN ships were under air attack from the aircraft in all three Taffy's. This meant the IJN ships were probably performing some radical maneuvers to avoid bombs and torpedoes. This would affect their shooting accuracy. I would immediately add a +1 to all IJN gunnery rolls. Not only that, but the IJN gunnery crews had been under constant air attack from the main USN Carrier Task forces earlier. They had to be fatiqued.

The air attacks were pretty much uncoordinated, so to reflect that part of the game you could do something like this. The capital ships are the high priority targets, so they would bear the brunt of the air attacks. On every turn each BB & CA would roll to see if they are attacked. On an 8 sided die a 1-2-3 would be a bomb attack, 4-5-6 would be torpedo attack, and a 7-8 would be no attack that turn. If the ship takes an attack you might look at doing this. If a torpedo attack is to be run, you would get an attack with one torpedo from close range. A hit would give 21 points of damage as the USN used 21" torpedoes. For a bomb attack you would get one shot from short range. If you get a hit you would probably take damage from something like an 8" or 6" shell. This reflects the fact that the bombers were carrying anything from 2,000 lb. AP to 500 lb. GP or smaller. They were arming the planes with anything they could get their hands on. If penetrations occur use the appropriate critical hit table. The IJN CLs and DDs were probably less priority targets and were under bomb attack versus use of torpedoes. As they would be harder to hit they would only get a 25% chance to hit on an 8 sided die.

You may wish to modify those guidelines, but it should provide some nervoius moments for the IJN commander. Let me know what you try.