DD top speed?

[rick614]

Not being real familiar with the era what was the top speed of a DD of the time. How about a torpedo boat and what was their size?

[mbv]

Top speed of the Mikasa, Togo's flagship, was 18 knots. Not sure about the torpedo boats though, probably much faster ie. 20+ knots

[Bullethead]

Not being real familiar with the era what was the top speed of a DD of the time. How about a torpedo boat and what was their size?

It's hard to answer any of these questions exactly, because there were so many variables involved at this point in time. To begin with, the idea of a type of ship called a "destroyer" was still a pretty new idea. In addition, ships then called "destroyers" (as in "torpedoboat destroyers") were mostly still just slightly bigger versions of what had been called a "torpedoboat" for a decade or 2 previously. The Brits had finally broken from this pattern in 1902 (for reasons I'll explain shortly), making in the River class what were the 1st truly effective destroyers (and also much different from what had gone before), but the IJN and IRN still had the older "big TB" type in the RJW. Thus, for everything except the newest Brit ships, the line between a DD and a TB was pretty much arbitrary at this time, and varied by nation. Indeed, the Germans continued to use "torpedoboat" as their name for their "destroyers" in WW1. Finally, at this period, DD speed was a very slippery subject, and subject to more interpretations than most statements by politicians and lawyers :).

I highly recommend The First Destroyers, by David Lyon, for a thorough study of the 1st Brit TBDs (later DDs) as they evolved from TBs up until the truly different River class. Everybody else mostly copied, bought, or was heavily influenced by the Brit work, so understanding the Brit ships will give you a good understanding of all DDs at this time.

Anyway, back to your questions, with the understanding that nothing I say will be exactly true in all cases...

In the RJW, the IJN and IRN DDs were of the "large TB" (as in pre-River) type. The newer DDs were a bit over 300 tons and a bit over 200 feet long. Contemporary 1st class TBs were then about 200 tons and about 160 feet long. DDs a few years older were about the same size as the newer 1st class TBs, and their contemporary 1st class TBs were proportionately smaller. You can therefore see why the line between TB and DD was rather blurred at this point in time (at least until the River class appeared).

All these ships, whether TBs or "large TB"-type DDs, were built pretty much the same way. The hull was long and narrow, with only 3-4 feet of freeboard in most places. As a result, the decks, especially forward, were often quite wet (or submerged) in any anything except a dead calm sea state. To help with this, they had a turtleback forecastle to shed water, with nothing on it but the anchors, which sloped up from the top of the stempost to just below the portholes of the pilothouse. The pilothouse itself looked like a chess rook, with the wheel in the main body of the "tower" part, with the turtleback forecastle rising like a glacis up most of its forward side. The bridge, and also the biggest gun carried, was on top of the pilot house, on the "battlements" of the rook. Then there were the funnels, with smaller guns along the sides and 1 or 2 torp mounts between or abaft the funnels, usually on the centerline, and perhaps another of the bigger guns right aft.

Sometimes there was also a fixed torp tube in the bow, and the midships tubes could be single or double. Often, double mounts had a significant angle between the tubes, or the tubes even pointed in opposite directions. On most early DDs (true TBDs), the smaller guns in the waist and the midships torp tubes were either/or options. If you wanted to kill TBs, you mounted guns instead of (all or some) of the torp tubes. If you wanted to use the TBD as a TB, then you mounted more tubes and fewer guns.

Now for the real issue: top speed.....

While the "large TB" type of DD was in vogue, there was a fixation on achieving the highest possible trials speed. In fact, many early DDs were called "27-Knotters" or "30-Knotters", due to the specified top speed in their contracts. This was NOT, however, their actual speeds in service, and in most cases not even on trials. Very few DDs of this vintage achieved their designed speeds, even on trials, and none came close in actual service, for a variety of reasons.

Trials were allowed to be run with the ship very light, often without much of its armament and with only enough coal aboard to do the speed runs. And, of course, trials were run under the best conditions possible. The builders got a bonus for making or exceeding the contract speed, and knew the ships would be floating higher than normal, so put the ships' best hull lines at the light trials waterline. Even so, few ships actually made their contract speeds, with some remaining many months (up to a year in some cases) under trials, with all sorts of tweaks being done to wring out the most speed possible.

Of course, once the ships were in service, in the open sea (see description of basic design above), with all armament, fuel, and crew aboard, they couldn't make anything like their contract speeds, nor come close to what they achieved on trials. The "27-Knotters" and "30-Knotters" all usually made 22-23 knots at best under service conditions. Therefore, when you look at DD stats from this period keep all this in mind. Conway's All the World's Fighting Ships 1860-1905 gives the RJW IJN DDs a top speed of 30-31 knots. However, these were copies of Brit designs, and at sea they could at best equal what the same book gives the opposing IRN DDs: 25 knots. And that would be in pretty good weather, IMHO.

After suffering through this for a decade or 2, the Brits finally wised up and changed the rules considerably when specifying the River class. They called for a much bigger DD, over 500 tons, with a full forecastle deck, and a contract top speed of only 25 knots (and under more realistic conditions). The increased hull size and better hull design, especially the increased freeboard forward, enabled these ships to make 25 knots fully loaded in pretty much any sea state, so they were always faster than the "30-Knotters", except when the latter were running trials under their special conditions. This marks the real beginning of the true destroyer, but all this was too late for the RJW.

[rick614]

Bullethead, thanks for the info.

[NormKoger]

First rank Japanese destroyers could to 30 knots. The better Russian destroyers could do about 26-28. A few Japanese torpedo boats were in the 28 knot range, but most torpedo boats on both sides were 24 knots or slower. Size was an issue. 350 tons was big for a destroyer, and torpedo boats were considerably smaller. On many of the torpedo boats, you could sit on the deck and dangle your toes in the water. Life must have become quite exciting when the waves exceeded 1 meter. In the game, these small ships sometimes look more like submarines, half submerged, than surface vessels. Sea state had a substantial effect on these ships' maximum speeds. In heavy seas, you could easily drop 20% off your best case maximum. Togo had good reason for sending most of his smaller ships to shelter at Takeshiki before the battle of Tsushima. "The skies are bright, but the waves are high" - Togo's poetic way of telling the admiralty that he was going to engage with only his heavy units, and that all the clever things they'd spent the last decade dreaming up for small ships in major battles were going to have to go untested.

[Bullethead]

First rank Japanese destroyers could to 30 knots.

I respectfully, but strongly, disagree with this. Based on their stats, which are directly comparable to contemporary Royal Navy TBDs/DDs (because the IJN ships were essentially identical to the RN ships), there is no way the IJN TBDs/DDs could make anywhere near 30 knots in service. Their performance, therefore, would have had to have been the same as the RN versions of the same designs from the same builders. Simply changing the ensign on the flagstaff wouldn't change the performance.

All the IJN "DDs" of the RJW were what the Brits were then calling "30-knotter" TBDs. The Murakumo- and Shirakumo-classes were built by Thornycroft, and were clones of the Royal Navy's "30-knotter" Angler and Stag, respectively, built by the same firm at the same time. Both the IJN and RN ships barely reached 30 knots after prolonged trials at light displacement under ideal conditions (several damaging their machinery in the attempt), and never came close to that speed in service. Regardless of builder, none of the RN's "30-knotters" ever exceeded 25 knots under service conditions, even on a good day.

It was even worse for Thornycroft designs, which were unanimously considered in the Royal Navy to be the worst sea boats of all the "30-knotters". This was because they had a lower freeboard than the designs of other firms, plus some tumblehome, which made them rather wetter. In addition, their "tunnel" stern, which helped them on trials in calm conditions, caused the stern to broach frequently at sea, resulting in loss of speed both from the screws leaving the water and from having to correct the yaw induced when the rudders left the water. Growing dissatisfaction with Thornycroft designs led to that firm getting fewer orders, and put them into the export market for the Japanese.

The newest Japanese "DDs" of the RJW were the Harusame-class, which were built in Japan but to a Thornycroft design. They were the same size and specs as the last "30-knotters" built for the Royal Navy by other firms, but there are no direct RN Thornycroft clones due to the problems noted above. Again, however, even the last RN "30-knotters", with the same stats as Harusame, could barely attain 25 knots in service conditions. Therefore, there is no reason to assume these ships were any better.

The other IJN "DDs" of the RJW were built by Yarrow, the Ikazuchi- and Akatsuki-classes. These ships were also of the Royal Navy's "30-knotter" TBD type, and were nearly identical in all respects to their RN contemporaries (dimensions, displacement, power, armament, etc.). Unlike the Thornycroft ships, however, they were not clones of RN contemporaries because Yarrow had had a falling out with Admiralty over contract terms and prices stemming from previous "27-knotters", and therefore built no "30-knotters" for the RN. Regardless, they were still "30-knotter" TBDs, and it is therefore unreasonable to assume that they would have performed significantly better than their near-sisters in the Royal Navy. Thus, once again, a top sea speed under good conditions of about 25 knots is IMHO quite realistic.

The better Russian destroyers could do about 26-28.

Almost all the Russian DDs of the RJW were of Yarrow extraction (the 1st built by Yarrow itself, most others designed by Yarrow). The Puilki-class were essentially clones of Yarrow's "27-knotter" Charger-class of the RN, except for smaller guns and torps. The RN versions again rarely reached 25 knots in service, so it's unlikely the Russian versions were any better. The later Boiki-class were Russian versions of a "30-knotter" design never built for the RN due to disagreement over price, and were in all important respects the same as their contemporary RN and IJN near-sisters. Therefore, they would have had the same performance, with a top sea speed no more than 25 knots.

The Russians also had a few German and French DDs during the RJW. They were clones of their contemporaries in those navies, and likewise had similar performance.

Size was an issue. 350 tons was big for a destroyer

Actually, the average size of TBDs/DDs had reached 350 tons in the mid-1890s and remained there, or very slightly more, until right about the start of the RJW. Thus, almost all TBDs/DDs in service in all navies at the time of the RJW were of this size, with a few older, smaller ships still in service, and a few new, bigger ships of much different design just appearing.

The important thing to note is that all the "DDs" of this era, regardless of who designed, built, or used them, were very, very similar. They were still called TBDs in most navies, and were just larger (mostly in length) versions of the older TB-type of ship. They therefore shared the general TB-type hull design and superstructure/armament layout, and thus also their seakeeping qualities (or, rather, the lack thereof).

The first TBDs/DDs were called "27-knotters", as that was their designed trial speed. The very first few were about 250 tons in 1892, but the bulk of them were about 300 tons by 1894. After that, they started building "30-knotters", which were just the same designs scaled up to 350 tons (which equated to about 10% longer hulls). The idea was to pack more power into the same ship as before. This didn't work out in practice, however. Despite most "30-knotters" being able to achieve that speed on trials (often after great difficulty, and only just barely), none of them could do anything like that in service. In fact, the "30-knotters" were no faster at sea than the "27-knotters", despite being about 50 tons heavier and about 20 feet longer.

Size really didn't matter for these ships. Their sea speeds were a function of their hull design, not their power. No matter how much power they had, it was just impossible to drive a scaled-up TB hull any faster than 25 knots in the open sea with all combat stores aboard. DD sea speed only started to increase about the time of the RJW, with the introduction of much bigger DDs of very different design. But none of these served in the RJW.

Life must have become quite exciting when the waves exceeded 1 meter. In the game, these small ships sometimes look more like submarines, half submerged, than surface vessels.

Out in the ocean, a 1m swell is practically a dead calm, and an unusual occurance. 3m swells are more to be expected on a "pleasant" day at sea. These would reach the bridges of RJW-era TBDs/DDs, so even such light weather conditions gave these ships very serious problems. Trying to operate guns and torps on the open deck of these ships in any kind of "rough" seas was nearly impossible, but it was even worse than that. These ships were very difficult to conn at the best of times, let alone fight effectively.

The OD had the best view on the spray- and wave-covered bridge, where he was in the way of the main gun crew. In addition, the helmsman himself, inside the conning tower, was usually totally blinded by spray and green water coming over the forecastle at his eye level, even in "calm" weather. There were other conning and steering positions available, but these offered even less visibility and even more exposure to the elements. The result was that pursuits by TBDs/DDs of this era were not conducted as continuous high-speed runs. They would charge along as fast as they could for a few minutes, being both blind and unable to work their weapons. Then they'd slow way down and usually change their direction to the wind and waves, to allow the OD and gunners to see and engage the target for a few minutes. When the target moved out of range again, it would be another leg of high-speed, blind, and non-firing pursuit.

[NormKoger]

I concede the point on reported speeds. It's pretty well known that the max speeds listed for ships in standard references tend to be best case figures, trials when new, etc. The real question is whether the ratios of published maximum speeds to actual maximum speeds is fairly consistent across the large range of ship classes we're trying to model. I have made the assumption that the ratio is fairly constant, and that the simulation works pretty well as long as there is no systematic bias. If all real world speeds are, say, 10 percent lower than reported speeds across the board, the relative capabilities of the ships are preserved and we don't lose much as a simulation if everyone is moving around a hair faster than they really could. I did go ahead and use the published figures for the ship database. If a good argument can be made for a constant bias, or some kind of simple scaling function, it would be easy to add that to the code the returns a ship's maximum speed. Things become a bit murkier if someone makes the argument for some bias in the reporting of capabilities in a large group of ships. The Russians, for example, are reported as fairly consistently slower on average for any particular type of ship than the Japanese. If this were the result of some kind of bias in the reporting that unfairly penalized the Russians, it would have a noticeable impact on the quality of the simulation. Since the code can still easily be modified at this point, do you know of any particular bias in the reported figures? I would be happy to consider adding the effect.

[Bullethead]

The real question is whether the ratios of published maximum speeds to actual maximum speeds is fairly consistent across the large range of ship classes we're trying to model.

In the case of the IJN TBDs/DDs, I'm pretty sure the published figures are inflated, at least if you go by Conway's or anybody using that same data. These ships were virtually or exactly identical to their counterparts in the Royal Navy, and there is plenty of data out there showing that none of the Brit ones could do better than 25 knots at sea. In fact, Conway's even says so itself. The only reason I can think of for Conway's reporting the actual in-service speed for the Brit ships OT1H, and the best trials figures for their IJN clones OTOH, is that the RN and IJN chapters of Conway's were written by different people who didn't talk to each other. I just can't see how an IJN ship, rivet for rivet the same as a Brit ship, could be 5 knots faster under the same conditions.

I also think the Russian TBDs/DDs had essentially the same sea speed as the IJN ships. The Russians were mostly a mix of "27-knotters" and "30-knotters", and Brit reports indicate all of these had about the same sea speed, regardless of size or name. However, the discrepancy isn't as great for the Russian ships in Conway's, so maybe the Russian ships were a bit faster. It's somewhat hard to tell, because Yarrow built so few TBDs/DDs for the RN to compare them to, but Yarrow's ships were generally very well received in the RN, as opposed to Thornycroft's.

But either way, there's a difference in how far off the published speeds are for different DDs. The IJN ships are shown as way too fast, while the Russians are closer to their real sea performance (although possibly over-stated slightly). I don't mind one side or the other being a bit faster, and you justify doing it either way, but IMHO the available data doesn't support any significant sea speed difference between IJN and IRN DDs, and IMHO all of them should top out around 25 knots.

As for other ships, I'm not aware of any significant departures between their published speeds and actual speeds. But the odds favor these ships being more accurately reported, as they were fewer in number and drew more contemporary attention. There was a lot more room for deception and misunderstanding for the TBD/DD types.

[Rhetor]

Well, maybe it's obvious, but let me say that the real advantage of TBs and DDs was the acceleration time, not the top speed.

A question to Mr Koger - would the occasional breakdowns of machinery be simulated (of course, as a on/off realism option :-D?). As I have written in some other post, keeping up top speed was risky, and not possible over longer periods of time. Would this be simulated?

[agentorange]

One of the interesting things I read about the development of torpedo craft ( in Conways maybe ? ) was the whole issue of Torpedo Gunboats. As folks know they were developed in the 1890's to protect the battle fleet from swarms of TB's although they did have a torpedo armament the main focus was a relatively heavy gun armament, they looked almost like miniature cruisers.

Anyway, at the time they took heavy criticism as most lacked the speed for their designed role and so were regarded as failures. However since most of the trials were conducted in perfect conditions they didn't reflect the advantages that their larger size would of conferred in terms of seakeeping and stability. In real conditions ( as it were ) I suspect they would have performed pretty much to their designed role. Of course the advantage of having a good naval sim is that we may get the chance to test that hypotheses.......

[NormKoger]

would the occasional breakdowns of machinery be simulated (of course, as a on/off realism option :-D?). As I have written in some other post, keeping up top speed was risky, and not possible over longer periods of time. Would this be simulated?

Tactically:
Right now, no. I do realize the appeal. But I made a serious effort to look for any evidence that breakdowns from overdriving the machinery either actually happened in the war (during combat - not talking about the well known Russian mechanical problems during the long voyage to the far east) or were seriously taken into consideration by either side when deciding on speeds in combat. I wanted to add this. It's easy to do in a computer game. But I couldn't find any evidence that it would be justified. I don't want to introduce an element that wasn't actually a consideration during the war. It could always be that I missed something. Does anyone know of any incidents of breakdowns during combat during the RJW that are not related to combat damage, or of any decisions to restrict speeds during combat because of concerns about breakdowns?

Campaign:
Task forces generally move at a speed roughly halfway between an arbitrary 10 knot "efficient" speed and the maximum speed of the slowest ship in the force.

There are two versions of the long campaign. The standard version is very historical, with very little variability outside of whatever might be introduced by the players. In that version there are no breakdowns. The variable version of the campaign (which we may hold back until after release) does include breakdowns and infrequent but random occurrences such as magazine explosions in port (as happened to Mikasa after the war), variable initial deployments, storm damage, running aground going into or out of port (Bogatyr), etc. This version also includes invisible randomization of technical variables such as gunnery and torpedo accuracy (separate), likelihood of breakdowns, mine effectiveness, spotting distances, ship susceptibility to fire, shore battery effectiveness, etc. The idea here is that by introducing a bit of uncertainty into these things we actually place a gamer more in the situation of the historical commanders - who spent the entire war learning things gamers are likely to know at the beginning.

[Rhetor]

Does anyone know of any incidents of breakdowns during combat during the RJW that are not related to combat damage, or of any decisions to restrict speeds during combat because of concerns about breakdowns?

Indirectly, from Massie's "Dreadnought" :
"The engines resolved at 120 revolutions a minute (...) As a result, the brass bearings were subjected to heavy stress and wear. Afer a few hours' steaming at high speed, a number of bearings had to be adjusted and if the engines were not stopped, a breakdown would occur. After a battleship had run a four-hour full-speed steam trial, she often had to spend ten days in port to adjust her main bearings." (p. 474, Random House, NY edition).
Later there follows an excerpt from Bacon's memoirs (the 1st captain of the "Dreadnought", previously commanding the "Irresistible"), who compared the engine rooms of both battleships, of course in favour of the turbines, as requiring less attention.

There is also the problem of fouling of the furnace grates, which required cleaning after a few hours' of burning coal. However, I don't remember where I have read about it. Possibly it was in J. W. Dyskant's and A. Michalek's "Port Artur - Cuszima 1904-1905", Warsaw 2006.
J. W. Dyskant is a retired Captain of the Polish Navy, professor emeritus of the Polish Naval Academy, and devoted much of his life to study the RJW.

[Bullethead]

Does anyone know of any incidents of breakdowns during combat during the RJW that are not related to combat damage, or of any decisions to restrict speeds during combat because of concerns about breakdowns?

The problems with using prolonged max power in RJW-era ships were well-known to all officers of the time. While there might not be any record of breakdowns occurring in actual action, there are beaucoup instances of breakdowns and damage occurring on full-power trials. It was very common for ships to have some sort of engineering casualty on the "full-power for X hours" runs, which quite often resulted in ships being delayed getting into service by repairs, or being lame for the rest of their lives. And few ships that never faced war ever again reached their trials speeds, due to the risks.

It seems to me, therefore, that if you read enough trials reports, you can get a good idea of the limits for different types of machinery used by the various RJW ships. If the ships were run as hard in combat as they were on trials, it seems to me they'd have the same sort of breakdown rate (or even a bit higher, due to lack of maintenance). The fact that you can't find any instances of breakdowns in combat must mean, therefore, that most officers of the day considered the risk to the machinery outweighed the tactical benefit of that extra knot or 2 of speed they could conceivable wring out of their systems. Thus, they kept their ships below their theoretical maximum speeds.

Maybe this is something you could add in the "variable campaign" version. Have a "normal" max by default (which is 1-2 knots lower than the published max speed), which is pretty much immune to machinery damage. But give the player the option to push things up to the ship's trials horsepower, with an ever-increasing chance of a major engineering casualty as time goes on.

[NormKoger]

Actually, there is one serious game constraint on speeds that has nothing to do with mechanical breakdown dangers. You will find that your formations stay together better if you keep the speed at least a knot below the best speed of the slowest ship. This gives a little bit of wiggle room for the ships to accelerate and decelerate as necessary to maintain position line. (Ships in formation in Distant Guns aren't pulled along like pearls on a string - each one actively navigates to maintain formation position. If you take a look down a line in the game screen shots, you will notice that the ships are not perfectly lined up and spaced.) Staying a bit back from top speeds also means your formation doesn't immediately fall apart with your first propulsion casualty. The programmed opponent code takes this seriously, and almost never orders formations above 90 percent (80 percent in some cases) of max slowest speeds - all in an effort to minimize the amount of active damage control it has to do to formations when the hits start rolling in.