53 replies to this topic

[jwsleser]

During our last game, the question of the Japanese actual reload requirements cropped up. In the Basic rules it states (my bold):

 

1.4.8 Reloads

Submarines and a few warships carry spare torpedoes. Warship reloads are indicated on the right side of their Ship Logs. Example: 2x4 = reloads for two quadruple mounts. A vessel cannot reload under fire and must steam a straight course for the required number of Game Turns in Force 4 or milder

weather. Wrestling 3,000 pound+ torpedoes on decks canted from course changes or heaving in the middle of a storm is pure Hollywood. If her reloading cycle is interrupted, note the remaining Game Turns required on her division’s Deck Log. Reloading can be resumed when no longer under attack. Reload time is dependent on a vessel’s reload equipment:

• Tactical Reload Special high speed reloading equipment was developed by the Japanese Navy and installed on itsfleet DDs and cruisers to optimize the effectiveness of its 24” Type 93 torpedo. IJN crews can reload a Type 93 torpedo mount in six Game Turns in the tactical area.

What is the Tactical Reload paragraph actually saying? What is in the tactical area? I read it as an exception to the base 1.4.8 rule above. As both paragraphs state the six turn requirement, the difference is where other navies must move straight for six turns, the Japanese ships can freely maneuver during the six turns [the phrase cannot reload under fire and must steam a straight course for the required number of Game Turns has been replaced by in the tactical area]. If this is not correct, then the Tactical Reload paragraph is redundant as it stating what is already stated in the base rule. 

 

​What is also in conflict is Optional Rule 1.4.14 IJN Variable DD Tactical Reloads. This rule states that Japanese DDs might take longer to reload its torpedoes (a die roll), yet any other nation with reloads remains at six turns. This seems odd as the Japanese had installed specialized handling gear that other navies lacked.

 

I have notice that many ships that carried reloads aren't list as having reloads on their ship's log (e.g. Prinz Eugen and German destroyers). 

 

Thoughts?

 

v/r  Jeff

[Jim O'Neil]

Jeff,

Most every Navy I know of had torpedo war heads in a magazine and spare torpedo bodies stored somewhere. These required a lot more than six turns to put together and reload with a crane involved a lot. More a done in harbor than a done at sea operation.

 

The IJN reloads were directly behind the tubes and they merely had to align the tube with the reload and slide it into the tube. The Type 93 weighed about 6,000 pounds! Even with the reload set up, it required a lot of effort to slide a three ton torpedo  some twenty odd feet into the tube.  Six game turns to reload three or four tubes is a very gracious time allowance. The earlier type 90 torpedo weighed 5,000 pounds and was 27 feet long. Note that the Mutsuki, Fubuki, Akatsuki, and Hatsuharu class destroyers were still loaded with type 90 torpedoes between the start of the war to mid 1943, per Wikipedia.

 

I personally would not allow any other nation to reload their torpedoes in combat or at sea in any sort weather. It would be an hours long affair , regardless of RAW.  If anyone has example to contradict this, I'd be appreciative  of a cite (source document, page number, author etc.).

[jwsleser]

Thank you Jim

 

Agree with what you have stated, I am just trying to understand the RAW. 

 

AFAIK, only the Japanese and Germans destroyers/cruisers had spare torpedoes stored on deck near the launchers. Both had dolly rails to move the torpedoes from the storage to the mounts. Reloading was a central tenet of the Japanese destroyer doctrine, hence a skill that was actually practiced. I can understand that reload rules could be different for Japanese ships and that appears to be the case. However what that difference might be is not at all clear. 

 

I agree that other navies likely shouldn't be allowed to reload during a battle, but something that would be done when not engaged. Hard to write a House Rule if you don't understand the RAW. 

 

A note: according to the U. S. Naval Technical Mission to Japan 1945 – 1946, Report 0-01-3 Japanese Torpedoes and Tubes-Article 3, Above-Water Tubes, a mount can be completely reloaded in 3 minutes under ideal conditions. Of course, ideal conditions don't exist at sea. The report states the common reload time was 20-30 minutes. 

 

v/r Jeff

[Mark Hinds]

(text removed)

Note that the Mutsuki, Fubuki, Akatsuki, and Hatsuharu class destroyers were still loaded with type 90 torpedoes between the start of the war to mid 1943, per Wikipedia.

 

(text removed)

 

FWIW, other sources say type 90 was discontinued by the end of 1942 (i.e. "The Imperial Japanese Navy In The Pacific War" by Mark Stille, p.239).  The Wikipedia info is from an old "Profile Publications" pamphlet.  

[Jim O'Neil]

Discontinued is the construction of the torpedoes. That does not preclude those ships still having the type 90 aboard  and type 90's still in supply  channels. Each ship would have received the type 93 torpedo upgrade in port and likely a shipyard.

This upgrade required oxygen generating equipment installed and may have required new torpedo tubes as well. The type 93 was some two feet longer than the Type 90.

[JAHinson]

I'm looking forward to someone providing us with clarity on the rules as written. 

 

I read them as, if you have the capacity to reload torpedoes you must 1) not be under fire and 2) steer a straight course.  The bullet point is a response to "Reload time is dependent on a vessel’s reload equipment:"  In the case of specially equipped Japanese ships the answer to the amount of time required to not be under fire and to steam in a straight line is: six turns.

 

I freely admit I don't understand the "in the tactical area" part and that it may mean what Jeff is has suggested as allowing to be under fire and to freely maneuver, otherwise, why include such a statement?   If one doesn't have the special gear for six turns and still has the capability to reload it takes much longer (as the other bullet points demonstrate in turns per torpedo in the mount rather than a whole mount).  If one doesn't have capability to reload then it has to be done in port, relevant for campaign games.

 

Appreciate the historical responses.  While I was in the Navy, I closely observed the loading of Mk 48 ADCAPS both aboard the boat and into the tubes.  At 3700 pounds they were just over half the size of a Type 93.

 

VR,

Jere

[Jim O'Neil]

I looked into the German reload at sea set up and while better than assembling, fueling and loading that other nations had to do, it was still hardly comparable to the Japanese designs. The Prinz Eugen as an example, and it applies to all the German heavy cruisers it seems, stored complete reloads in an armored box one level below the tubes. To reload, the torpedo had to be rolled out on a small set of wheels under the middle of the torpedo, then lifted by a 10 HP winch and slide into the tube with the little wheels I think... one torpedo at a time. So not something you want to do under fire, not in any kind of a seaway and not in a huge rush. So better than other nations but not a quick reload. 

RAW not withstanding, only the IJN has a "quick reload" capability in a tactical (combat) area. 

 

Do the rules specify which turns? Night turns are 3 minutes while day turns are 6 minutes ... makes a difference. i'd  also like to know what sort of power washed to slide 6,000 pound torpedo thirty or forty feet. Grease alone isn't enough.

[jwsleser]

Mea cupla, I realize that I misread a bit of the reloading section and that colored my understanding. 1.4.8 is clearer now. However the research I did caused me to question some less critical points. 

 

First is that Optional Rule 1.4.14 IJN Variable DD Tactical Reloads is still a valid issue. This rule states that Japanese DDs might take longer to reload its torpedoes (a die roll), yet any other nation with reloads remains at six turns. This seems odd as the Japanese had installed specialized handling gear that other navies lacked. See below.

 

Second. The issue of reloads carried. I have notice that many ships that carried reloads aren't listed as having reloads on their ship's log (e.g. Prinz Eugen and German destroyers along with many other foreign cruisers). This is still a valid issue. Now in mitigation is that these torpedo reloads weren't intended to be reloaded in combat as indicated by Jim and the ship's logs were designed to support only a single combat. Campaign games are another matter and ships that carried reloads would reload their tubes if they didn't immediately return to port to rearm. This is something players can work out on their own. 

 

On Japanese reloads. Six turns (36 minutes) seems excessive and appears to be the longest time. The basic rule can stay at six turns for simplicity's sake, but the optional rule makes little sense. Below is the section from p.17 of the USN report cited above to address Jim's question:

 

9. Torpedo Loading Gear

    Four reload torpedoes are carried in water-tight steel boxes aft of the tube mount. The torpedoes are mounted on rollers as shown in Figure 13. The loading mechanism is illustrated in Figures 14 and 15. Power is supplied by a 10-horsepower, compressed air motor operating at a pressure or 215 Ibs/in2. The RPM of the motor are controlled by a valve (10), shown in Figure 14. The loading speed is about O.65 feet per second and it is possible to load all four torpedoes together or separately. The revolution of the air motor shaft is transmitted to a pulley (4) through 1:45 reduction gears. Special attachments (1) which are connected to the loading cables are provided for rolling the torpedoes forward. An idling pulley (13) is employed to maintain positive transmission between the pulley and the cables. Just before the torpedoes are all the way in or out of the tubes, a small piece of metal on the cables (14) automatically releases the idling pulleys (13) and prevents further movement.

    Torpedoes can also be loaded by hand using a rope wound to a drum (12) instead of the air motor. About ten men are required to pull the rope when this method is used.

    It is possible to completely reload the tubes and be ready to fire in a total time of three minutes. This is under ideal conditions however, and usually the reloading gear does not function properly and the time is extended to 20 or 30 minutes. The fastest time for hand-loading was 5 minutes. [diagrams are in the report]

 

I would recommend a house rule that the Japanese destroyers would need to maintain a steady course (no turns more than 3-points, evasive maneuvers, or rolling to evade torpedoes). At the beginning of the 3rd turn (12 minutes) players can roll to see if the reload process is completed (1-2). Beginning of 4th turn, 1-5. 5th turn, 1-8. 6th turn 1-11, 7th turn automatic. The turn of firing is the first turn of reloading as torpedoes are fired before movement if maintaining a steady course. This is merely some initial thoughts that need to gestate a bit.

 

v/r  Jeff

[Mark Hinds]

(text removed)

 

On Japanese reloads. Six turns (36 minutes) seems excessive and appears to be the longest time. The basic rule can stay at six turns for simplicity's sake, but the optional rule makes little sense. Below is the section from p.17 of the USN report cited above to address Jim's question:

 

(text removed)

 

It could take longer in reality.  Either Morison or Crenshaw quotes a Japanese report from one of the later (post-Tassafaronga) Solomons night battles (I'd have to find it), in which IIRC it took over twice as long.  

[Mark Hinds]

Discontinued is the construction of the torpedoes. (text removed)
 

Even if your assumption (...) is correct, this gives us gamers some wiggle-room in deciding who gets what in 1942.  

[jwsleser]

It could take longer in reality.  Either Morison or Crenshaw quotes a Japanese report from one of the later (post-Tassafaronga) Solomons night battles (I'd have to find it), in which IIRC it took over twice as long.  

 

 

​Which can be explained by the destroyer not steaming a steady course. Morrison doesn't offer any information on why it took so long. 

 

My point is that reloading can be done in a shorter time than 36 minutes (six turns) if the conditions are met. 30 minutes (5 turns) is still about a 66% chance in my proposal above (which I also state isn't finalized in my mind). The report (which is a primary source which Morrison isn't) gives the reloaded time with mechanical problems as 20-30 minutes. This implies the use of hand loading which under ideal conditions is 5 minutes. 

 

v/r  Jeff

[Jim O'Neil]

I like jwsleser's idea,  as it seems to reflect historical accuracy . He also makes a good point about secondary sources. Another thing to keep in mind was classifications, which didn't allow a lot of information out for some time (Varies by country and releasing authorities estimation of the informations current value).  We have learned a great deal more, post 1980 about all these things due to the expiration according to the 35 year rule and the subsequent reevaluation and release of information.

[Mark Hinds]

​Which can be explained by the destroyer not steaming a steady course. Morrison doesn't offer any information on why it took so long. 

 

My point is that reloading can be done in a shorter time than 36 minutes (six turns) if the conditions are met. 30 minutes (5 turns) is still less than a 50% chance in my proposal above (which I also state isn't finalized in my mind). The report (which is a primary source which Morrison isn't) gives the reloaded time with mechanical problems as 20-30 minutes. This implies the use of hand loading which under ideal conditions is 5 minutes. 

 

v/r  Jeff

I'm not necessarily disagreeing with your rule proposal; after all we gamers can do whatever we want.  However, whether it was Crenshaw or Morison (one "r"), they were quoting from a Japanese report of some sort, and not merely expressing hearsay; there may even have been a footnote.  

[Mark Hinds]

I like jwsleser's idea,  as it seems to reflect historical accuracy . He also makes a good point about secondary sources. Another thing to keep in mind was classifications, which didn't allow a lot of information out for some time (Varies by country and releasing authorities estimation of the informations current value).  We have learned a great deal more, post 1980 about all these things due to the expiration according to the 35 year rule and the subsequent reevaluation and release of information.

Well, Jim, if we are to favor modern versus older published sources, then your Profile Pubs (Wikipedia) source for Japanese 24" torpedo use is from the 70s, while the Mark Stille source I quoted was published in 2013 (...).  Just pulling your leg a bit here.  

We all sometimes engage in a bit of hand waving when arguing for our favorite historical interpretations.  If we really wanted to know if any of the earlier DDs were upgraded to type 93 by the time of the Solomons campaign, we would need to find info on yard visits or some such.  Kind of like trying to track down which of the 4 variants of gray a Japanese ship was painted in.  

[Mark Hinds]

I like jwsleser's idea,  as it seems to reflect historical accuracy . He also makes a good point about secondary sources. Another thing to keep in mind was classifications, which didn't allow a lot of information out for some time (Varies by country and releasing authorities estimation of the informations current value).  We have learned a great deal more, post 1980 about all these things due to the expiration according to the 35 year rule and the subsequent reevaluation and release of information.

I may have missed something, but why does it seem to reflect historical accuracy?  Remember that stuff often doesn't work as well as it theoretically should in real battles.  For example, the use of spotter aircraft in the River Plate battle, USN torpedoes, etc. etc.  

[jwsleser]

However, whether it was Crenshaw or Morison (one "r"), they were quoting from a Japanese report of some sort, and not merely expressing hearsay; there may even have been a footnote. 

 

​Possibly true. I am not stating (or implying) that Morison was making his comment out of thin air. The point is we don't know. It would be great if someone would check those books to see if there is a cite. We know the provenance of the report I cited and the fact that the researchers were looking specifically for the effectiveness/efficiency of the Japanese systems. They specifically examined the Japanese reloading gear and asked about reload times (among other things). The interviews with Japanese officers (including destroyer captains in other parts of the reports) reflects that the researchers were getting primary accounts immediately after the war.  

 

I may have missed something, but why does it seem to reflect historical accuracy?  Remember that stuff often doesn't work as well as it theoretically should in real battles. 

 

We are discussing a simulation and examining what was used to construct the underlying models. The use of a random factor (the dice) as part of the adjudication of the model interactions is a means to inject the uncertainty of whether the models perform to their designed standard. My reload model above states one will never achieve the ideal of three minutes. There is only a 16.7% chance of completing the reload in 12 minutes, etc. At 30 minutes (the time the Japanese officers state reloading is often completed with mechanical problems) is only 67%. It is not until 42 minutes that reload is automatic. The player rolls three times by the 67% chance which slightly modifies the odds but one never knows what the die will say. If the DD doesn't maintain a steady course, that turn doesn't count which increases the time needed. It is historical because it presents a possibility of both a faster and slower reload time. 

 

For example, the use of spotter aircraft in the River Plate battle, USN torpedoes, etc. etc. 

 

​Compared to the success of the Japanese spotter planes at Java Sea. The US torpedo problems have a model in GQ3. The fact that the US torpedoes do have a model for torpedo failure is historical. Having the possibility of reloading in less than 36 minutes is historical. Whether the odds I presented are the best certainly can be debated (hence the use of the word gestate).

 

The reload model in Optional Rule 1.4.14 is not historical as the Japanese must wait 36 minutes and then roll by mount to see whether the mount has been reloaded with only a 33% chance of success for each mount. If unsuccessful, the odds don't increase with more time but remain 33%. Remember there is a requirement for the DD to maintain a steady course during these six turns, possibility increasing the time needed. The primary source states that the usual time for reload manually was 30 minutes or less, with 5 minutes as a very, very distant possibility. 

 

Just my thoughts.

 

v/r  Jeff

[Mark Hinds]

However, whether it was Crenshaw or Morison (one "r"), they were quoting from a Japanese report of some sort, and not merely expressing hearsay; there may even have been a footnote. 

 

​Possibly true. I am not stating (or implying) that Morison was making his comment out of thin air. The point is we don't know. It would be great if someone would check those books to see if there is a cite. We know the provenance of the report I cited and the fact that the researchers were looking specifically for the effectiveness/efficiency of the Japanese systems. They specifically examined the Japanese reloading gear and asked about reload times (among other things). The interviews with Japanese officers (including destroyer captains in other parts of the reports) reflects that the researchers were getting primary accounts immediately after the war.  

 

I may have missed something, but why does it seem to reflect historical accuracy?  Remember that stuff often doesn't work as well as it theoretically should in real battles. 

 

We are discussing a simulation and examining what was used to construct the underlying models. The use of a random factor (the dice) as part of the adjudication of the model interactions is a means to inject the uncertainty of whether the models perform to their designed standard. My reload model above states one will never achieve the ideal of three minutes. There is only a 16.7% chance of completing the reload in 12 minutes, etc. At 30 minutes (the time the Japanese officers state reloading is often completed with mechanical problems) is only 67%. It is not until 42 minutes that reload is automatic. The player rolls three times by the 67% chance which slightly modifies the odds but one never knows what the die will say. If the DD doesn't maintain a steady course, that turn doesn't count which increases the time needed. It is historical because it presents a possibility of both a faster and slower reload time. 

 

For example, the use of spotter aircraft in the River Plate battle, USN torpedoes, etc. etc. 

 

​Compared to the success of the Japanese spotter planes at Java Sea. The US torpedo problems have a model in GQ3. The fact that the US torpedoes do have a model for torpedo failure is historical. Having the possibility of reloading in less than 36 minutes is historical. Whether the odds I presented are the best certainly can be debated (hence the use of the word gestate).

 

The reload model in Optional Rule 1.4.14 is not historical as the Japanese must wait 36 minutes and then roll by mount to see whether the mount has been reloaded with only a 33% chance of success for each mount. If unsuccessful, the odds don't increase with more time but remain 33%. Remember there is a requirement for the DD to maintain a steady course during these six turns, possibility increasing the time needed. The primary source states that the usual time for reload manually was 30 minutes or less, with 5 minutes as a very, very distant possibility. 

 

Just my thoughts.

 

v/r  Jeff
 

I found the quotations in the Morison volume "Breaking the Bismarcks Barrier".  At Kula Gulf, describing the reloading operation taking 1 hour and 15 minutes, he states (p172):  "Ordinarily this operation took only 20 to 25 minutes, but Suzukaze had received a hit in the machine-gun ammunition locker, and torpedomen working directly below that fiery spot lost their 'presence of mind and calmness.'".  I assume the inner quotation is from a post-war Japanese interview or report, which of course Morison had access to, given his job at the time.  Later, during the battle of Kolombangara, he states that the Japanese were able to reload in 18 minutes while in a convenient rail squall (p.187).  

WRT the source you referenced WRT reloading times, I would want to sanity test this against reported field performance, in as many plausible accounts as I can find.  The researchers you mention might have been talking to people who were proud of their torpedo systems, and wanted to emphasize this by quoting ideal conditions.  Imagine a similar interview (prewar) with the BuOrd guys who designed the Mk. 13, 14, and 15 torpedoes and exploders.  (...).  My gaming rules philosophy is to take into account the theoretical performance of stuff, and then sanity test it as above.  The final rule is going to be more influenced by the latter than the former.  

MH

[jwsleser]

Tomorrow is today.

 

Mark

 

Thank you for taking the time to find Morison's statement. It is illuminating. Let's take a look at it.

 

First Morison confirms the USN report that reloading was usually accomplished within 20-30 minutes. 

 

Secondly Morison indicates that the events on Suzukaze were such an outlier that it was significant enough to include in his account. We know it was an outlier because he compares her performance against the standard, the fact he doesn’t discuss any of the other destroyer’s reloading time, and that Suzukaze’s failure to reload to standard had no bearing on the outcome of the battle. It is an observation of something unusual.

 

Thirdly he gives us the reason for the failure to reload to standard: fire.

 

Finally it likely Morison’s source is not the USN report. The latter stated 20-30 minutes, Morison gave 20-25 minutes. Two different time sets. If Morison had been using the USN report, he wouldn’t have changed the times. When I cite a source, I use exactly what the source provides or the information is no longer supported by the source. 

 

WRT the source you referenced WRT reloading times, I would want to sanity test this against reported field performance, in as many plausible accounts as I can find. 

 

Agree. We have one primary account and one likely primary account (Morison’s info is likely from interviews) for a time to complete reloading under all but exceptional circumstances as 20-30 minutes. We have one outlier that is explained by a unique situation. 

 

So we have nothing that challenges the 20-30 minutes reload time under all but unique circumstances. The outlier can be handled in the rules that a fire onboard prevents that turn from being used for reloading. Bad weather is already in the rules. Being under shell fire doesn’t affect reloading as ships do everything under fire and I have already included radical maneuvers as preventing reloading. 

 

After working through this discussion, here are my recommended changes:

 

'I would recommend a house rule that the Japanese destroyers would need to maintain a steady course (no turns more than 3-points, evasive maneuvers, or rolling to evade torpedoes), take no hits, have no fires onboard, or have weather greater than Force 4 for a turn to count towards reloading. At the beginning of the 3rd turn (12 minutes) players can roll to see if the reload process is completed (1-2). Beginning of 4th turn, 1-6. 5th turn, 1-10. 6th turn automatic. The turn of firing is the first turn of reloading as torpedoes are fired before movement if maintaining a steady course.' 

 

I will need to think about the Force 4 weather. 

 

The final rule is going to be more influenced by the latter than the former. 

 

Which my House Rule does. It uses information we have, not information that we assume to exist. It incorporates outliers using our available information using models that already within the simulation. Find more data and the model can be adjusted. To assume there is more data that contradicts what we have is hope, not a method. We can also assume that new data will only confirm what we already have. Find the data that breaks the model. That is what I am doing here, challenging the current reloading model with data. 

 

v/r  Jeff

[JAHinson]

'I would recommend a house rule that the Japanese destroyers would need to maintain a steady course (no turns more than 3-points, evasive maneuvers, or rolling to evade torpedoes), take no hits, have no fires onboard, or have weather greater than Force 4 for a turn to count towards reloading. At the beginning of the 3rd turn (12 minutes) players can roll to see if the reload process is completed (1-2). Beginning of 4th turn, 1-6. 5th turn, 1-10. 6th turn automatic. The turn of firing is the first turn of reloading as torpedoes are fired before movement if maintaining a steady course.' 

 

I like this rule.  I think the 3rd turn would be nine minutes (at night) vice 12 minutes?  Or am I missing something?   Also, same rule for Japanese CAs which can reload?  We can try it out in our next battle.

VR,

Jere

 

 

 

 

[Jim O'Neil]

Mark, Please don't pull my leg! At 6' 6" buying clothes is hard enough  

 

Jeff,  I like the model better too.  Do allow me to make one comment, this is NOT a simulation. Lonnie and I have talked about this at some length, and it is a game that reflects some of the decisions a naval commander was presented with.  Gunnery hit rates are at least double reality. Armor and Shell performance is standardized, when in real life each of these gun calibers would have a variety of different performances, even in the same nation's Navy! I.E> theUS 6"/53 which had a good bit less penetration than the later 6"/47. Even the various shell designs for one gun change penetration and salvo distribution. It is Pandora's box! Just the charts for one nation could be pages long.  KISS is very much in effect here.

 

It has been a most interesting discussion and I think it would be a good optional rule. I think some clarification about other nations reloading torpedoes at sea is in order as well.

 

OH, I looked at the weather chart and Force 4 is probably correct as the upper limit.