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On Tue, 23 Nov 2004, Charles Seitz wrote:

> There appears to be some interest about the Fire Control
> problem here.  If
> we stretch the point, its also a navigation problem!

I think we are "streching the point" here indeed:-)
Same with torpedo "navigation". By the way, I see no difference
in principle between aiming an artillery shell and aiming
a torpedo. Mathematically, this is the same problem.

When I earlier said that an interesting navigation problem
was involved in the coast bombardment, I meant a real
navigational problem: determining the position of the
bombarding ship on the map. Apparently this is of no use
in ship-to-ship shooting. The method of determining ship's
position by mine explosions heard on the shore seems very unusual,
indeed:-)

But I agree that there is some similarity between fire
control and navigation: both involve angle measurement and
triangle solving:-)

> Analog computers represent a computational variable

I am very well familiar with one of these devices,
an electro-mechanical analog computer for directing anti-aircraft
fire. This was the most sophisticated piece of equipment
in our anti-aircraft battery of 57mm guns.
If I remember correctly, it was
replaced by a digital computer in the late 1970-s.

The divice looked like a hudge box with a 2.5 meter-base optical
range-finder attached. It was operated by 3 soldiers,
two of them continuously "followed" an airplane in altitude and
azymuth (by rotating the whole divice),
and one continuously measured the distance.
The output of the device was continuously transmitted by wires
to the aiming motors of the guns.
All sorts of parameters which could affect the projectile trajectory
were taken into accound, like the velocity of the wind
on all altitudes,
temperature and pressure of the air, temperature of powder in
cartridges,
and even the number of shots already made from each gun.
The gun positions with respect to the device were carefully
determined with a sort of theodolite in advance.

As I understand from the brief description in a history book,
similar devices were used in the battleships from the beginning
of XX century. In  particular, they mention a calculator invented
by Leutenant Dumaresq in 1901.

As I understand from the same book, the Germans had much superior
optical range finders, in both World wars, produced by Zeiss.
They had 27 feet base, while the British ones only 9 feet and
later 15 feet
(I am talking of WWI here).
They permitted the German ships to "stradle" a British ship
from the first or second salvo, which happened in almost all
German-British
battleship encounters mentioned in the book.

Alex.

   

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