ATST Snippet #6 (I think)

I know that this idea would have its limitations. But I would think that a bigger, heavier ship would be a more stable, thus more accurate gunnery platform. And both the Cities and the Haarahlds are starting to be pretty good sized.

Don

-

[quote="PeterZ"SNIP
Absent a fire control system and there is no point to having balloons on board ship.[/quote]
I'm sure your mind was focussed on the fire control discussion but we shouldn't forget the value of being able to see the other guy before he can see you and knowing where he is and how many of them there are and which way he's going, etc

EdThomas wrote:

PeterZ wrote:SNIP
Absent a fire control system and there is no point to having balloons on board ship.

I'm sure your mind was focussed on the fire control discussion but we shouldn't forget the value of being able to see the other guy before he can see you and knowing where he is and how many of them there are and which way he's going, etc

Point

n7axw wrote:I know that this idea would have its limitations. But I would think that a bigger, heavier ship would be a more stable, thus more accurate gunnery platform. And both the Cities and the Haarahlds are starting to be pretty good sized.

Don

-

They will still rock with the waves, Don. Once those 8" & 10" begin firing, the ship will rock even more. Having a gyro that enables a gun to fire from as level a position as possible is really helpful. Perhaps even necessary for accuracy in truly long range gunnery.

n7axw wrote:I know that this idea would have its limitations. But I would think that a bigger, heavier ship would be a more stable, thus more accurate gunnery platform. And both the Cities and the Haarahlds are starting to be pretty good sized.

Don

-

Two kinds of errors that can cause a miss:
- Azimuth errors - shouldn't be too much of an issue given the relatively short ranges we're talking about here. To correct, just move the breech or muzzle a bit to the left or right. Of course you also need to adjust for the speed of the target and your own speed, but again the effects are relatively minor and easy to correct for.
- Ranging errors - a much more complicated issue, with two major factors:
If you know the ballistics of the projectile (either through a formula or through empirical testing), then you know how it will "fly through the air." This assumes (of course) that the launching platform isn't moving.
CASE 1, the cannon is on a ship that is rolling. A difference in the muzzle angle of as little as a single degree will cause a significant range error. The worse the roll (or the faster the roll) the less "easy" it will be to "time the shot" so that the projectile leaves the muzzle at exactly the right time. Further, with a ship that is rolling (let's assume the shot is fired "on the up roll"), the upward vector is imparted on the shell and will still be in effect AFTER the shell leaves the muzzle so you have to "lead the roll." The simple way to reduce this effect is to reduce the rolling of the shooting ship. Simplest way to do this is to increase its mass (reduce the rolling effect of wave action on the ship). A larger / more massive ship will inherently roll less than a smaller / less massive ship.
CASE 2: The ship is "heaving." In this case, the entire vessel is being displaced vertically. In this case, you have the same angle and projectile path of flight, but the entire path is displaced either up (top of the heave) or down (bottom of the heave). Mass is less of a factor in this case, because heaves are more often caused by larger ocean swells. And (as a former naval aviator who spent time landing on aircraft carriers massing up around 85,000 tons) I can tell you from personal experience that heaving is a non-trivial issue. Landed aboard ship one dark, dreary, stormy night in the Bering Sea where the entire 85,000 ton ship was heaving vertically in excess of 30 feet...

Range errors are far more difficult to correct for than azimuth errors. Improved fire control - to include a basic "automatic firing system" that takes into account roll angle, roll rate, firing system "lock time" (the time from when you pull the trigger to the time when the projectile actually leaves the barrel), and a couple of other factors, would be necessary if you want to improve the "first round" hit rate. And that (of course) also assumes a known, predictable ballistic flight path with known, predictable powder performance to give you that path.

Bismark's early hits on Hood were as much a feat of luck as they were of skill...

PeterZ wrote:These balloons are being deployed onboard ships. One assumes the cities and KH VIIs will have them but not the galleons. Yet, as we saw with Hektor's duel with Serpent, the RCN needs fire control to accurately target anything with any sort of range at all.

I suspect that Nahrmahn's brainchild from the last book is a pneumatic fire control system. I know there are designs for a pneumatic gyroscope. I can envision trigger mechanisms using pressurized air in conjunction with the gyroscope. Put them together and we have a pneumatic fire control system that may refine accuracy for truly long shots with the KH VIIs 8" & 10" guns. Add the balloons and the gunnery officers will have information to refine their aim.

Absent a fire control system and there is no point to having balloons on board ship.

I'm gonna disagree with your statement and I'm gonna disagree with your idea. First as regards that their is no point to having a balloon observer aboard ship absent a fire control system. I disagree. Knowing the disposition of the enemy fleet and or fortifications before you get within their visual range is the key to assuring that your ships dispositions are correct. Knowing the layout of a fortification or enemy deployment before you sail into range of it is also advantageous. Being able to use Owls remotes to spy for trouble ahead has saved Caleb many times. Now allowing those without access to Owl is going to give a similar strategic advantage to other admirals and captains. Also Generals and such in the field of battle upon land.
As for a pneumatic fire control system. Sorry but I am giggling just a little at just how clunky and difficult such a thing would be. Consider this little video on the mechanical computer that the US Navy used for this purpose.
https://www.youtube.com/watch?v=lr1uK24SND8

Consider the statement that some "25 factors, many of which are constantly changing" must be factored into the design and consider that this was only possible with the precision engineering of the 20th century, and electrical inputs, electrical motors to drive the mechanism at constant speed, and electrical transmission of the shoot function so that guns are fired at the precise time tick to hit. And even then they missed with a rogue wave. And you think that this is accomplish-able with Safeholdian manufacturing standards, using pneumatics to power, drive, and time the firing. Sorry not going to happen. The state of the art in manufacturing, mathematical modeling (of the gun and powder charges trajectories/relationships),understanding of gunnery ballistics, mathematical factoring, time keeping and... well heck the list just goes on and on. Without electricity there are just simple reality limits to what you can build. Plus the damn ships aren't big enough even yet, to hold the monster this thing would be, along with the steam engine that would have to power the air compressor to provide the central air supply that would fire the guns and drive the beast. And the safety factor of all those high pressure steam and air lines in a ship if someone did get a lucky shot in????
https://www.youtube.com/watch?v=XcIrbpCgah4
Nasty.
Nope. The whole thing is not a good idea and ain't happening anytime soon.

Larry
P.S. Unless of course David wants it to happen. Authors have access to unlimited supplies of handwavium to make all kinds of stuff.

Larry,

I am just suggesting a pneumatic gyroscope and a mechanism to fire when the gun is level as indicated by the gyro. When did I argue for a fire control computer?

Larry wrote:

PeterZ wrote:These balloons are being deployed onboard ships. One assumes the cities and KH VIIs will have them but not the galleons. Yet, as we saw with Hektor's duel with Serpent, the RCN needs fire control to accurately target anything with any sort of range at all.

I suspect that Nahrmahn's brainchild from the last book is a pneumatic fire control system. I know there are designs for a pneumatic gyroscope. I can envision trigger mechanisms using pressurized air in conjunction with the gyroscope. Put them together and we have a pneumatic fire control system that may refine accuracy for truly long shots with the KH VIIs 8" & 10" guns. Add the balloons and the gunnery officers will have information to refine their aim.

Absent a fire control system and there is no point to having balloons on board ship.

I'm gonna disagree with your statement and I'm gonna disagree with your idea. First as regards that their is no point to having a balloon observer aboard ship absent a fire control system. I disagree. Knowing the disposition of the enemy fleet and or fortifications before you get within their visual range is the key to assuring that your ships dispositions are correct. Knowing the layout of a fortification or enemy deployment before you sail into range of it is also advantageous. Being able to use Owls remotes to spy for trouble ahead has saved Caleb many times. Now allowing those without access to Owl is going to give a similar strategic advantage to other admirals and captains. Also Generals and such in the field of battle upon land.
As for a pneumatic fire control system. Sorry but I am giggling just a little at just how clunky and difficult such a thing would be. Consider this little video on the mechanical computer that the US Navy used for this purpose.
https://www.youtube.com/watch?v=lr1uK24SND8

Consider the statement that some "25 factors, many of which are constantly changing" must be factored into the design and consider that this was only possible with the precision engineering of the 20th century, and electrical inputs, electrical motors to drive the mechanism at constant speed, and electrical transmission of the shoot function so that guns are fired at the precise time tick to hit. And even then they missed with a rogue wave. And you think that this is accomplish-able with Safeholdian manufacturing standards, using pneumatics to power, drive, and time the firing. Sorry not going to happen. The state of the art in manufacturing, mathematical modeling (of the gun and powder charges trajectories/relationships),understanding of gunnery ballistics, mathematical factoring, time keeping and... well heck the list just goes on and on. Without electricity there are just simple reality limits to what you can build. Plus the damn ships aren't big enough even yet, to hold the monster this thing would be, along with the steam engine that would have to power the air compressor to provide the central air supply that would fire the guns and drive the beast. And the safety factor of all those high pressure steam and air lines in a ship if someone did get a lucky shot in????
https://www.youtube.com/watch?v=XcIrbpCgah4
Nasty.
Nope. The whole thing is not a good idea and ain't happening anytime soon.

Larry
P.S. Unless of course David wants it to happen. Authors have access to unlimited supplies of handwavium to make all kinds of stuff.

For completely predictable ballistics, you need to know a great deal about the properties and behaviour of the air mass the round is moving through, too. Which is why an artillery regiment has a complete met office in tow. The flatter trajectories of naval rifles do mean that there's rather less variation to deal with, but they will still have problems knowing exactly where each round is going until it gets there.

WeberFan wrote:Two kinds of errors that can cause a miss:
- Azimuth errors - shouldn't be too much of an issue given the relatively short ranges we're talking about here. To correct, just move the breech or muzzle a bit to the left or right. Of course you also need to adjust for the speed of the target and your own speed, but again the effects are relatively minor and easy to correct for.
- Ranging errors - a much more complicated issue, with two major factors:
If you know the ballistics of the projectile (either through a formula or through empirical testing), then you know how it will "fly through the air." This assumes (of course) that the launching platform isn't moving.
CASE 1, the cannon is on a ship that is rolling. A difference in the muzzle angle of as little as a single degree will cause a significant range error. The worse the roll (or the faster the roll) the less "easy" it will be to "time the shot" so that the projectile leaves the muzzle at exactly the right time. Further, with a ship that is rolling (let's assume the shot is fired "on the up roll"), the upward vector is imparted on the shell and will still be in effect AFTER the shell leaves the muzzle so you have to "lead the roll." The simple way to reduce this effect is to reduce the rolling of the shooting ship. Simplest way to do this is to increase its mass (reduce the rolling effect of wave action on the ship). A larger / more massive ship will inherently roll less than a smaller / less massive ship.
CASE 2: The ship is "heaving." In this case, the entire vessel is being displaced vertically. In this case, you have the same angle and projectile path of flight, but the entire path is displaced either up (top of the heave) or down (bottom of the heave). Mass is less of a factor in this case, because heaves are more often caused by larger ocean swells. And (as a former naval aviator who spent time landing on aircraft carriers massing up around 85,000 tons) I can tell you from personal experience that heaving is a non-trivial issue. Landed aboard ship one dark, dreary, stormy night in the Bering Sea where the entire 85,000 ton ship was heaving vertically in excess of 30 feet...

Range errors are far more difficult to correct for than azimuth errors. Improved fire control - to include a basic "automatic firing system" that takes into account roll angle, roll rate, firing system "lock time" (the time from when you pull the trigger to the time when the projectile actually leaves the barrel), and a couple of other factors, would be necessary if you want to improve the "first round" hit rate. And that (of course) also assumes a known, predictable ballistic flight path with known, predictable powder performance to give you that path.

Bismark's early hits on Hood were as much a feat of luck as they were of skill...

Essentially, you did it when you started talking about fire control. There's a _lot_ more involved than 'fire when the gun is level'. In fact, you probably don't even want to fire when it's level, and even if that is optimal, you certainly don't want to pull the trigger then - you need to do it sooner, so the gun will be level when it goes off. And as was said upthread, how much sooner depends on several factors, including how fast the ship is rolling.

PeterZ wrote:Larry,

I am just suggesting a pneumatic gyroscope and a mechanism to fire when the gun is level as indicated by the gyro. When did I argue for a fire control computer?

Thanks for clarifying. I was focusing on connecting a gyro to the gun.

I still believe having a gyro is necessary to fully utilize the range those 8" & 10" riles can achieve. Have a adjustable timer connected both the gun and the gyro would be even better. The idea is to make as many of the variables measurable and repeatable rather than rely on pure intuition. Being able to set the time to appropriately trigger the gun prior to being level will make it possible to take advantage of the range. A balloon will really add to the gub's accuracy.

I wouldn't be surprised if a mechanical fire control computer does eventually get developed.

Louis R wrote:Essentially, you did it when you started talking about fire control. There's a _lot_ more involved than 'fire when the gun is level'. In fact, you probably don't even want to fire when it's level, and even if that is optimal, you certainly don't want to pull the trigger then - you need to do it sooner, so the gun will be level when it goes off. And as was said upthread, how much sooner depends on several factors, including how fast the ship is rolling.

PeterZ wrote:Larry,

I am just suggesting a pneumatic gyroscope and a mechanism to fire when the gun is level as indicated by the gyro. When did I argue for a fire control computer?