– Walter MacWilliams
The project involved the
construction of a data handling system for simplifying the assignment of
track-while-scan circuits to the search-radar blips, the assignment of gun
directors to the tracks on the most-threatening incoming aircraft, and a
data presentation display for dynamically displaying the tactical
situation. How effective could the ATEWA be, with its automatic evaluation
of rapidly-changing attack and
defense data, compared to the manual operation of the sophisticated attack
and defense display? A
much-debated question was how effective an air defense could be provided by
gunnery personnel, simply by making use of the sophisticated calculation of
critical data on the attack and the capabilities and limitations of the
defense data display. To answer this question, I proposed the construction
of a Gunnery System Simulator, which would represent incoming air attacks,
represent the defense assignments of gun directors to incoming aircraft and
groups of defensive gun mounts, and compute the effects of the defensive
gunfire, in real time, so that the defense personnel would be working under
the same time constraints that would exist in an actual air attack.
Before discussing the
Gunnery System Simulator, it’s appropriate to say a word about the course
of the Mark 65 project following construction and use of the Simulator.
– Walter MacWilliams
Following the tests using the Gunnery System Simulator, the Mark 65 system
was successfully designed and installed in the USS NORTHAMPTON for the
control of its six 5”/38 gun
mounts. The tests of the system
included defense at sea, both manually-aided and fully automatic, against
simulated air attacks by actual aircraft.
The means for handling the data and making defense decisions worked well.
With the passage of time, surface-to-air Terrier missiles began to
supercede the 5”/38 gun mounts, and the antiaircraft defensive armament
became a mixture of gun mounts and surface-to-air missiles. However, the track-while-scan and
assignment-switching features continued to be used, with appropriate data
displays. These arrangements became
known as Weapon Designation Equipments, and were used in around 100
combatant ships in the U.S. and about 20 Allied navies.
One component of the
Simulator was the Gun-to-p-computer switch, which represented the individual
shots fired against the incoming aircraft, and allowed the computation of
“p”, the probability that a particular projectile would destroy the
aircraft against which it was directed.
To MacWilliams Oral History, Pg 5