How Maintainable is Flank Speed?

[Keith]

This is just a brief historical example. The quote from Wicipedia is

"Alberico da Barbiano was an Italian Condottieri class light cruiser, that served in the Regia Marina during World War II. She was named after Alberico da Barbiano, an Italian condottiere of the 14th century.

Da Barbiano was launched on 23 August 1930. During her trails she managed to reach a speed of 42,05 knots but to do that the propulsion was pushed to 123,479 hp, far beyond the safety limits. She could only maintain this speed for about 30 minutes."

I have it from another source that despite the 30 minute limit on 42.05 knots it did, during the same trials, maintain 40 knots for 8 hours.

By my calculations 1.5" of move equates to 5 knots. This assumes that the normal move is a cruising speed so that the 50% increase for flank speed can be justified (e.g a typical warship of the period cruises at 20 knots and flank speeds at 30 knots) making these extra 2.5 knots insignificant in game terms.

Is this example typical or the exception that proves the rule.

 

[DM]

"Normal" movement is actually based on maximum speed, so "flank speed" represents the engineers coaxing that last few horsepower out of the engines. So the shorter duration is more relevant to the special action. Of course then one could argue that the speed increase should actually be smaller than it is now.

 

[juggler69uk]

"Normal" movement is actually based on maximum speed, so "flank speed" represents the engineers coaxing that last few horsepower out of the engines. So the shorter duration is more relevant to the special action. Of course then one could argue that the speed increase should actually be smaller than it is now.

But since Flank Speed is an automatic special action, then it is not restricted to shorter durations, Maybe there is a case to have it rolled for, thus producing the shorter duration

 

[Keith]

"Normal" movement is actually based on maximum speed, ...

So a 1" move equates to a speed of 5 knots? I am guessing from the stats that this is rounded to the nearest 5 knot increment, e.g. in the case of the Navagatori 38 knots is rounded to 40 to give a move of 8".

Of course then one could argue that the speed increase should actually be smaller than it is now.

The Alberico da Barbiano was rated by Wikipedia as having a speed of 37 knots (7" if my above assumptios are correct) so assuming engineering could get the 5 knot increase to 42 knots from the trials the special action would equate to an extra inch.

The fact that, taking the worst case, the rules currently allow a Navagatori to "coax" an extra 20 knots (giving it a 60 knot Hydrofoil like speed) makes this a bit of an understatement.

Surely this approach makes the flank speed special action just a hang over from ACTA, adding flavour to the game at the expense of historical accuracy.

It also explains another point I was thinking of raising. That being, according to my understanding, ships making smoke almost always did this at flank speed to maximize the screen. According to the current rules this iilegal as it would combine 2 special actions.

Similarly come about and going evasive do not seem to be contradictory commands, in fact you might consider the former a prerequiste for the latter.

 

[High Sierra]

but would a formation of different ship types all be cruising at their respective max speed? Or would they be cruising at the speed of the slowest in order to maintain formation?

perhaps the best solution is to give the 50% in the first turn of flank speed and then having to roll for it if you want to maintain flank speed in the subsequent turn. (i.e. scotty calls the bridge and screams 'Its nae guid cap'n I cannea hold her')

 

[Keith]

Cruise speed is another thing all together. Fuel consuption a sea is influenced hugely by the cruising speed. The range of ships was a major element in naval warfare. It was rare, and probably still is, for a battle group to cruise at more than 20 knots even if the slowest vessel has a top speed of 30 knots because of this consideration.

I can't remember the details off the top of my head but I know this was of particular relevance for some elements hunting the Bismark.

I am not sure what the standard battle speed of ships was but I suspect that it was not flank speed, even for the slowest ship. However, when planes are making a bombing run at you your priorities change.

 

[DM]

The power required to maintain a specified speed does not vary linearly. Doubling the power output will not double the speed (more likely it will increase speed by 3-4 knots). However, fuel consumption variation is generlaly linear, so charging about at "flank speed" will have an enormous effect on your mission endurance (for an eextreme example see the current LCS - an endurance expressed in weeks at cruising speed, reducing to an expression in HOURS at maximum speed). For that reason warships will spend the vast majority of their time at cruising speed (in WW2 typically 15-20 knots), increasing to full speed in action. Extreme measured (having the engineer "screw down the safety valves" was, if it happened at all, extremely rare and was probably as much an effort to increase morale as much as to improve the performance of the ship

 

[juggler69uk]

The Alberico da Barbiano was rated by Wikipedia as having a speed of 37 knots........

How accurate are all these sites for warship information as Warships of WW2 only has it at 35 knots

while

http://www.comandosupremo.com/Sea.html <<< Italy at war site has it at 36.5 Knots

Im sure there are other variations out there, but which do you go by, if they differ in that small detail what else do they differ on, Is the only answer to buy Janes or Conways ????

 

[Lord David the Denied]

but would a formation of different ship types all be cruising at their respective max speed? Or would they be cruising at the speed of the slowest in order to maintain formation?

perhaps the best solution is to give the 50% in the first turn of flank speed and then having to roll for it if you want to maintain flank speed in the subsequent turn. (i.e. scotty calls the bridge and screams 'Its nae guid cap'n I cannea hold her')

That's the best post in the VaS board yet, just for that Scotty line. I love it.

 

[Keith]

Given DM's input on the speeds of ships it seems there are three options open to the game designers regarding the flank speed special action.

1. Leave it as it is. The game is more important than historical accuracy, it probably won't make much difference to the outcome anyway.

2. Update the flank speed special action to reflect reality

3. Change the scaling to 1.5" move equating to 5 knots of speed. This will just shorten the time for a turn by a few minutes and perhaps have ships unrealistically fighting a cruising speeds.

 

[Chernobyl]

"Normal" movement is actually based on maximum speed, so "flank speed" represents the engineers coaxing that last few horsepower out of the engines. So the shorter duration is more relevant to the special action. Of course then one could argue that the speed increase should actually be smaller than it is now.

Having served in the guts of an aircraft carrier propulsion plant for several years, I would really challenge that there's any more to be coaxed out most engine plants. And even if there is, There's No Way that "little bit more" is going to add up to a 50% increase in speed.

I would find it very likely that the 42knots speed quoted above was really pushing the limits (indeed, even exceeding them) but the "rated maximum" speed was actually in the 35-40 knot range.

It makes far more sense to assume the "speed" rating of a ship is a "crusing" (what I would call an "ahead standard") speed. Otherwise, a 50% increase in speed doesn't make sense.

Chernobyl

 

[E Nicely]

When I read the title "How Maintainable is Flank Speed" I wanted to reply "It lasts until the VaS supplement comes out." :wink: Changes will be made that better reflect reality. In the mean time I'm sure there's house rules somewhere out in internet-land that have changes to Flank Speed.

As far as the core rules go (by-the-book) there is no limit to how many turns in a row Flank Speed can be used.