AT guns vs. Artillery guns vs. Naval guns

Guns, torpedoes, mines, bombs, missiles, ammunition, fire control, radars, and electronic warfare.
Bgile
Senior Member
Posts: 3658
Joined: Wed Mar 09, 2005 7:33 pm
Location: Portland, OR, USA

Re: AT guns vs. Artillery guns vs. Naval guns

Post by Bgile »

alecsandros wrote:Brett's making a very good argument about long range hits.

Indeed, the various pressure, temperature and wind speed coming at each atmospheric layer are not predicatable from a battleship. IF the layers are uniformaly distributed for the given battle-space, THAN a correction to the firing soultion can be made, and repeated hits are probable.

BUT IF the layers are not uniformaly distributed, than every salvo will be a shot in the dark. It can hit, but you can't measure the probability, as there are to many variables which you wouldn't know.
That sounds quite logical until you study the actual shoots and see that they were in fact able to do what you say they couldn't. Clearly these external factors aren't as relevant as you think. You are arguing that something which actually happened wasn't possible. Salvoes were fired, and they landed where predicted, with the spreads predicted, at 35,000 yds or greater. How can you argue this wasn't possible?
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: AT guns vs. Artillery guns vs. Naval guns

Post by lwd »

Brett wrote:... As for ulta long range shooting the record at sea is either held by the German 11" or British 15" at a reasonablely short range, compared to theortical maximum range of guns.
That's somewhat dependent on how you define the record for long range shooting. If you are only talking about shots then the US 16"50 clearly holds the title. If you include splinter damage as hits they may also.
The much vaulted super heavy 16" shells used by USA through lack of opportunity to the best of my knowledge were never tested in battle conditions.
I suspect those on the Kirishima and Jean Bart would disagree with you.
To give some idea of the challenge the USA airforce over Japan when using the B29 bomber at designed height managed to miss just about everything so went in at a much lower height. I could be wrong but would not a shell fired at a target at 44,000 metres with an elevation of 45 degress reach a height of around 33.3% of that, say 14,666 metres? Even at half that height (assuming my trig is out) you would have to be predicting wind speed and pressure at many height levels.
The B-29 analog doesn't work that well for a couple of reasons. One bombs are moving a lot slower and because of that and their fins tend to be more influenced by wind. Two the B-29 didn't have a good way of measuring wind in the layers below it. The Battleship does. That's why they spot fall of shot. How many layers and how different the conditions are are not to critical. The stability of them is more so.
alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: AT guns vs. Artillery guns vs. Naval guns

Post by alecsandros »

Bgile wrote: That sounds quite logical until you study the actual shoots and see that they were in fact able to do what you say they couldn't. Clearly these external factors aren't as relevant as you think. You are arguing that something which actually happened wasn't possible. Salvoes were fired, and they landed where predicted, with the spreads predicted, at 35,000 yds or greater. How can you argue this wasn't possible?
From what I know so far, target shooting was done in favorable weather conditions. And the Nowaki incident also occured in good weather.
It's true that I don't know the distribution of upper-atmospheric conditions during 16"/50 trials. They may have been bad, in which case I would be wrong to say long range hits would be so difficult to achieve.
However, from how I understand wind-deflection, I don't think different wind speed and direction would go un-noticed for the shell's trajecory.
Bgile
Senior Member
Posts: 3658
Joined: Wed Mar 09, 2005 7:33 pm
Location: Portland, OR, USA

Re: AT guns vs. Artillery guns vs. Naval guns

Post by Bgile »

alecsandros wrote:
Bgile wrote: That sounds quite logical until you study the actual shoots and see that they were in fact able to do what you say they couldn't. Clearly these external factors aren't as relevant as you think. You are arguing that something which actually happened wasn't possible. Salvoes were fired, and they landed where predicted, with the spreads predicted, at 35,000 yds or greater. How can you argue this wasn't possible?
From what I know so far, target shooting was done in favorable weather conditions. And the Nowaki incident also occured in good weather.
It's true that I don't know the distribution of upper-atmospheric conditions during 16"/50 trials. They may have been bad, in which case I would be wrong to say long range hits would be so difficult to achieve.
However, from how I understand wind-deflection, I don't think different wind speed and direction would go un-noticed for the shell's trajecory.
Obviously weather effects gunnery. Do you really think there is that much difference between 26,000 yds and 35,000 yds from a weather standpoint? I don't. We know dispersion increases as rang increases, but hits were still achieved. You get fewer hits as range increases, but you get hits. Enough to make a difference. One hit at 35,000 yds is likely to be very damaging if it penetrates the armor deck before exploding.

The Jurens / Fischer study indicated 8% hits were likely at 35,000 yds.
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: AT guns vs. Artillery guns vs. Naval guns

Post by lwd »

alecsandros wrote: ... However, from how I understand wind-deflection, I don't think different wind speed and direction would go un-noticed for the shell's trajecory.
Again that's one of the reasons you spot fall of shot and use it to correct your fire. One of the primary reasons optical engagements are limited to around 30,000 yards is that over that it's hard if not impossible to spot the fall of shot.
alecsandros
Senior Member
Posts: 4349
Joined: Wed Oct 14, 2009 2:33 pm
Location: Bucharest, Romania

Re: AT guns vs. Artillery guns vs. Naval guns

Post by alecsandros »

lwd wrote:
Again that's one of the reasons you spot fall of shot and use it to correct your fire. One of the primary reasons optical engagements are limited to around 30,000 yards is that over that it's hard if not impossible to spot the fall of shot.
I know.
But as ships move on water, and fire on each other, they travel some distances, sometimes tens of kilometers. Because of this, the atmospheric conditions above them may be different. That's why I wrote above about different distributions of wind, pressure, and others: maybe at the initial phase of the battle (km 0), the atmospheric layers would have a certain composition, while at another phase (let's say km 15), the layers that a shell needs to pass through are very different from the ones at km 0. That would mean the corrections made for long range deflection at km 0 would be useless at km 15.

The problem gets more complicated as the atmospheric conditions themselves change with time. Imagine the battle starts, and at 4km in the air, the air-currents are traveling at 40km/h, blowing N-E. But, 15 minutes later, the air-currents get 70km/h, and change direction to the North.

The point: the firing solution needs to be corrected for every siginificant change in the atmospheric layers needed to be passed through by the shell. The higher the trajectory, the bigger the probability of severe deflection, because higher in the atmosphere conditions are more unpredictable and more violent than lower.

That's why my guess is that repeated and numerous long-range hits are only possible in certain internal and external conditions (excellent gun and shell quality, excellent radar, excellent training for the crew, good weather, good sea, no significant variations between the atmospherical layers present between the attacking ship and the target ship).

I'm pretty sure most of the above conditions were met at certain places and moments of World War 2. But I don't think they were the rule... (the aero-dynamic qualities of the shells for instance, were extremely important for this kind of hits to be realised. For what I know, only US and German shells had a reasonable quality in this respect.)

Cheers,
ALex
lwd
Senior Member
Posts: 3822
Joined: Sat Jun 17, 2006 2:15 am
Location: Southfield, USA

Re: AT guns vs. Artillery guns vs. Naval guns

Post by lwd »

alecsandros wrote:
lwd wrote:
Again that's one of the reasons you spot fall of shot and use it to correct your fire. One of the primary reasons optical engagements are limited to around 30,000 yards is that over that it's hard if not impossible to spot the fall of shot.
I know.
But as ships move on water, and fire on each other, they travel some distances, sometimes tens of kilometers. Because of this, the atmospheric conditions above them may be different. That's why I wrote above about different distributions of wind, pressure, and others: maybe at the initial phase of the battle (km 0), the atmospheric layers would have a certain composition, while at another phase (let's say km 15), the layers that a shell needs to pass through are very different from the ones at km 0. That would mean the corrections made for long range deflection at km 0 would be useless at km 15.
But they are updating based on the most recent salvo. A ship moving at 60 km/hour (which is over 30 knots) would take 15 minutes to cover 15 km. If it hasn't shot in 15 minutes then it's like starting the engagement all over in many ways.
The point: the firing solution needs to be corrected for every siginificant change in the atmospheric layers needed to be passed through by the shell.
Indeed that's why I mentioned stability of the atmospheric conditions but if you are firing once a minute or so unless things are really unstable you should be able to keep a reasonably good firing solution.
User avatar
tommy303
Senior Member
Posts: 1528
Joined: Mon Oct 18, 2004 4:19 pm
Location: Arizona
Contact:

Re: AT guns vs. Artillery guns vs. Naval guns

Post by tommy303 »

But as ships move on water, and fire on each other, they travel some distances, sometimes tens of kilometers. Because of this, the atmospheric conditions above them may be different. That's why I wrote above about different distributions of wind, pressure, and others: maybe at the initial phase of the battle (km 0), the atmospheric layers would have a certain composition, while at another phase (let's say km 15), the layers that a shell needs to pass through are very different from the ones at km 0. That would mean the corrections made for long range deflection at km 0 would be useless at km 15.
Your initial salvo, assuming the fire control team has done its work properly, should be close for line but will probably be somewhat off for range due to cold barrel effects. Corrections will be made based on fall of shot and subsequent salvos will be walked onto the target until straddles occur. This will tend to cancel out any atmospheric variables. From this point on, your ship will be firing as rapidly as feasible, probably using turret salvos or turret groups. Fewer shells will arrive at a time, but the delay between salvos, and subsequently the distance the target can travel will be shorter. Observers will be spotting fall of shot for each salvo as it arrives and will be transmitting corrections to keep the salvo on target or to make sure the MPI corresponds to the target. As range drops during the course of the engagement, there may be some exterior ballistic variables which will change, but this will be corrected for by spotting.

The fire control computer is providing a constant flow of data to the guns based on rate of change predictions. As the range drops and the salvos do not have to climb so high into the atmosphere, one may experience a change in the external forces acting on the shells--i.e., if at 30,000m your shells are encountering winds at x velocity from the right, but at 20,000 they are encounter wind at y velocity from ahead, then the salvos will start to arrive to the left and short of the target. A correction right and up will walk the next back onto the target.

The above is of course assuming the target is maintaining a steady course; if the target is altering course frequently, as in salvo chasing, everything becomes much more difficult and spotters will have to be alert to note the changes and send them to the transmitting station so corrections can be applied.

Their shoulders held the sky suspended;
They stood and Earth's foundations stay;
What God abandoned these defended;
And saved the sum of things for pay.
Post Reply