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02.12
Early Digital
Technology and the Navy
By John Vardalas, Ph.D., IEEE History Center
[Correction: Seymour Cray was
incorrectly credited with having worked on the
Atlas (Univac 1101), but Cray worked on the
successor Atlas II (aka ERA 1103).]
Introduction
Steeped in long traditions,
Navies tend to be very conservative
organizations. And yet, there are times when
these organizations will exhibit a remarkable
willingness to blaze new technological trails.
Two examples, one from the history of the Royal
Canadian Navy (RCN) and the other from the U.S.
Navy (USN), offer striking examples of this
boldness. Nearly 65 years ago, both these Navies
had emerged from World War II with a heightened
sense that the long-established analog design
paradigms would be inadequate for naval
effectiveness in the postwar era. Electronic
design, based on digital techniques, seemed to
hold the key to unlocking a whole new generation
of naval command & control systems. In the
context of the late 1940s and early 1950s, the
idea was extremely daring. In today’s world,
where digital techniques support every facet of
our material existence, it is very hard to
appreciate the enormous gamble that these navies
were taking. Few people, if any, on the planet
had ever heard of digital electronics, and even
fewer knew how it worked. The uncertainties of
the gamble were compounded by these two Navies’
desire to introduce digital computation into
ship weapon systems, to link all ship computers
through wireless digital communications system,
and to have it all respond in “real-time” to
enemy threats. The end results were two
groundbreaking technological achievements which
presaged the age of real-time
computer/communication networks: the RCN’s
Digital Automated Tracking and Resolving (DATAR)
system and the USN’s Naval Data System (NTDS).
Both these stories share a common thread: the
sea created a specific set of general needs for
which bold innovation was needed. And yet, these
stories also illustrate how national contexts
also shaped the details of the innovation
process.
The Royal Canadian DATAR
Story
Early in World War II, the Royal
Canadian Navy (RCN) managed to win a role that
was absolutely vital to the success of the
Allies in Europe. After the Nazi’s had swept
through the European continent, Great Britain
stood alone as the last hope of democracy in
Europe. As the “island fortress,” Britain seemed
to stand alone facing constant aerial attacks
and impending invasion. If she fell, all would
be lost in Europe. Her survival depended on the
constant trans-Atlantic flow of much needed
supplies from Canada and the United States. The
Nazis believed that if they could sever the
life-line from North America, it would only be a
matter of time before Britain fell. When the
German surface fleet failed to command the seas
around Britain, Hitler turned to the submarine,
which had long been advocated by one of his
Admirals, Karl Dönitz. It wasn’t long before
Dönitz’s submarine “wolf packs” were taking a
terrible toll on Allied shipping to Britain. By
1943, the struggle to control the shipping
lanes, which came to be called the “Battle of
the North Atlantic,” had become the pivotal
battlefield of World War II.
Oil tanker hit by German U-boat.
Source: IEEE Global History Network (http://www.ieeeghn.org)
The Allies had concluded that
safety lay in numbers, so supplies were moved in
large convoys. These convoys moved slowly and
could spread out over many miles. The notorious
storms of the North Atlantic would further
scatter the convoy and leave the transport
vessels isolated and even more vulnerable to
attack. Keeping track of where everyone was and
protecting the convoy as it moved across the
vast expanse of the Atlantic Ocean was a
formidable task. Using highly maneuverable ships
called “corvettes” and sonar (or ASDIC as the
British and Canadians called it), the RCN moved
through the convoy playing a deadly game of cat
and mouse with the German submarines. The
circumstances of WWII had thrust Canada into a
more prominent role than ever before. What would
Canada’s role be in the postwar era?
With the end of WWII, Canada
hoped to retain an important role in the new
world order, and the RCN wanted to retain its
prominence within the Western military alliance
that was to be called NATO. The RCN presented
plans to build a full battle fleet: aircraft
carriers, destroyers, battleships, etc. When
political and budget realities killed this
grandiose aspiration, a group of mid-level,
technically trained naval officers, in the
Development Section of the Electrical
Engineer-in-Chief’s Directorate (EECD),
suggested that the RCN use its wartime
anti-submarine expertise as a way to carve out
an important defense role with its British and
America allies. At the same time they realized
that rapid advances in submarine technology
would very quickly render current methods of
anti-submarine warfare obsolete. The inability
to capture, extract, display, communicate and
share accurate tactical information in a timely
manner had severely limited the effectiveness of
anti-submarine warfare. In a battle situation,
the long human chain needed to convert sonar,
radar and other tactical data into useful
information for command-and-control was slow and
often unreliable. In a highly fluid and quickly
changing battle situation, where there are many
ships, submarines and aircraft, this slow
human-intensive chain would seriously compromise
the effectiveness of anti-submarine operations.
With a new generation of faster and more deadly
submarines on the horizon, the inability to
process and communicate tactical data in a
timely manner undermined all postwar
anti-submarine operations. These young naval
officers reasoned that if the RCN could
revolutionize anti-submarine operations by
automating the production, processing and
communication of tactical data, Canada would be
assured of a prominent military role in the
postwar North Atlantic alliance.
As early as 1947, the engineers
in the Development Section had zeroed in on
electronic digital computation and
communications as the foundation for
their automated tactical data system. The entire
basis for their gamble was ENIAC, which had been
worked on during the war and only became fully
operational in 1946. Throughout ENIAC’s
development, these Canadian officers had access
to the secret and non-secret U.S. government
reports related to ENIAC. They were attracted to
the high-speed and high precision of ENIAC’s
computation. Since no other fully operational,
program controlled, electronic, digital computer
was known to exist in the world at this time,
the EECD’s strategy to modernize anti-submarine
warfare by introducing a computer on every ship
was a remarkably bold leap for the otherwise
traditional culture of the RCN. But before they
could proceed, the idea that data could be
digitally communicated between ships had to be
demonstrated. In 1949, the EECD’s ambitions came
to the attention of Sebastian Ziani de Ferranti,
the president of the British firm Ferranti Ltd.
He was very much intrigued by the idea, since
his company had just decided to commercialize
the Mark I computer pioneered by Alan Turing and
others at the University of Manchester. After
meeting with EECD representatives, Ferranti
agreed to set up a separate all-Canadian R&D
team in his Canadian subsidiary, Ferranti
Electric, in Toronto. The DATAR project was
launched. In 1949, the DATAR team demonstrated
the feasibility of digital techniques for
communicating tactical data. They had used an
exotic idea proposed by British engineer Alec
Reeves in 1937, while he was working for IT&T in
Paris, as way to transmit voice digitally. The
technique was called pulse-code modulation (PCM).
Nothing had come of it then, but in 1949, the
DATAR team transmitted analog radar data from
Toronto and displayed it as data on a screen in
Ottawa, using PCM. The only other previous
implementation of PCM was the top secret SIGSALY
encryption equipment developed by Bell Labs in
1943.
In1953, the prototype of the
entire DATAR system underwent successful sea
trials. The highest echelon of the RCN was
there, as were senior officials from the U.S.
Navy and the Director of the U.S. Office of
Naval Research. The test consisted of two
Canadian Bangor class minesweepers. The presence
of submarines was simulated from an installation
on shore. Each ship was equipped with an
electronic digital computer. On each ship, a
sophisticated display depicted aircraft, surface
ships and submarines as distinctly different
icons. Taking the motion of all the ships into
account, the computer presented data relative to
the ship’s reference frame. PCM communications
ensured that all data was shared in real-time.
DATAR was a distributed system in that all the
ship’s computers were equal nodes in the
network. By means of a new device called a
trackball, invented by the DATAR team, a cursor
could be moved over any target on the monitor
and speed, direction, range and bearing data for
the target would be displayed and refreshed in
real-time.
Prototype (circa 1951) of trackball used in the 1953
sea trials of DATAR. The ball floated on air-suspension. This is probably the
earliest known Trackball. Source: IEEE Global History Network (http://www.ieeeghn.org)
Operator console for DATAR (1953). Screens that
displayed the movement of friendly and enemy ships are on the surface of the
console. Source: IEEE Global History Network (http://www.ieeeghn.org)
Although the test was an
unqualified success, it failed to win U.S.
buy-in. From the very beginning, the RCN
understood that Canadian requirements alone
could not justify the high development costs
needed to move from a prototype to full-scale
naval system. For example, the DATAR prototype
worked on vacuum tubes, as did all the computers
in the early 1950s. Cramming thousands upon
thousands of vacuum tubes, with all the
ancillary power and cooling equipment, into the
tight confines of a warship did not bode well in
the inhospitable marine environment. The
thousands upon thousands of vacuum tubes
consumed a lot of energy and produced a lot of
component failures. During the sea trials,
sweating engineers, stripped down to the waist
and armed with cartridge belts filled with
vacuum tubes, ran around below deck replacing
failed tubes. Everyone knew that the system
would have to be miniaturized, and there were
plans to use the still new idea of transistors.
Canada alone could not underwrite a full-scale
transistorization of DATAR. Sales to the United
States were essential. But in the context of the
Cold War, the U.S. Navy was not about to
outsource its command & control technology to
another country. Another factor in the U.S.
Navy’s decision may have been its preoccupation
with defending against massive air assaults, in
part a result of the disaster at Pearl Harbor,
which DATAR did not deal with directly. Though
DATAR never came to full-scale fruition, the
effort nevertheless spawned a whole series of
breakthroughs in Canada’s civilian computer
industry. Though the United States did not adopt
the Canadian system, the U.S. Navy (USN) saw the
overall design concepts of DATAR as the way to
go in its own planning.
U.S Navy NTDS Story
While the RCN arrived at the
idea of an automated naval tactical data system
from its anti-submarine experience in the North
Atlantic, the USN came to it from its own WWII
experience in the Pacific, and the role of radar
in defending a fleet from heavy Japanese air
attacks. Despite the Navy’s slow-changing
traditional culture, radar won instant
acceptance. Radar’s great utility for ships was
evident even to the most conservative members of
the USN’s senior officers and they supported any
R&D that would increase the effectiveness of
shipboard radar. Naval radar was capable of
showing 300 aircraft stacked up from the horizon
to 30,000 ft., but World War II had demonstrated
the inability of humans to process the large
amounts of radar data that flooded in during the
heat of battle. “Every element of the
information,” writes naval historian David
Boslaugh, “was handled manually on radar scopes,
plotting sheets, status boards, notes pads,
maneuvering boards, and in men’s minds.” All
calculations were done manually. Under enormous
stress, the people processing the radar data
were overwhelmed. They could only process a
small fraction of the information presented to
them. In 1945, the Chief of Naval Operations,
Admiral Ernest J. King, put the situation
bluntly: “The display of information was slow,
complicated and incomplete, rendering it
difficult for the human mind to grasp the entire
situation either rapidly or correctly…Weak
communications prevented information from being
properly collected or disseminated either
internally aboard ships or externally between
ships.” The USN needed new ways to automate the
processing of radar information. The appearance
of fast moving jet aircraft and missiles into
the naval combat scene further underscored this
urgency.
In 1951, the Navy Electronics
Laboratory (NEL) turned to electronic digital
computers. Like their counterparts in Canada,
they saw great potential in this embryonic
technology. In 1951, the NEL started a research
project to see if a special purpose computer
system could be developed to simultaneously
record, store, and display the range and bearing
of a large number of aircraft in the form of
electronically generated symbols. From the radar
data, the system would also have to display a
velocity vector for each target. Working with
the Teleregister Company, the NEL concluded that
the state of electronic digital technology was
still too immature to handle these complex tasks
reliably. The NEL then started to look at analog
techniques as a way of speeding up the handling
of radar data. But in the end, the analog
paradigm also proved an inherently
unsatisfactory solution. Ironically, little did
the team working on digital radar processing
know that, elsewhere in their own organization
were some of the world’s best experts in digital
computers. Working in great secrecy, navy code
breakers had been building some of the world’s
most powerful digital computers.
In 1954, Project Lamplight
rekindled the USN’s hope of introducing
electronic digital computers into the processing
and display of radar data. Earlier that year,
the Secretary of Defense had requested that the
tri-service Joint Research and Development Board
established a study group to review and improve
the combined capabilities of the services to
provide a continental air defense system for the
United States. A specific item in this study
group’s mandate was to see if elements of the
SAGE (Semi-Automatic Ground Environment) system,
an integrated aircraft tracking system still
under development, could be extended to ships at
sea. This study became known as Project
Lamplight. The study was to be directed by the
SAGE managers at MIT’s Lincoln Laboratory.
However, six months into the study, members of
NEL became disenchanted with the way it was
going. From the Navy’s perspective, the study
had not addressed radar data automation, and,
even more importantly, there had been no
discussion on how one could apply SAGE concepts
to ships at sea. SAGE was land-based system that
depended on very large centralized data
processing. A centralized computer/
communications architecture was inherently
dangerous in the fluid context of a battle
fleet. The fleet would be blind if the ship
carrying the computer was sunk.
By 1954, computer technology had
advanced enough that the NEL felt that it was
time again to revisit the design of computerized
command & control system suited specifically to
naval needs. The success of the DATAR sea trials
in Canada further solidified the USN’s belief in
the feasibility of an automated tactical data
system based on digital computation and digital
radio communication. Even though the USN did not
want to buy a Canadian solution, DATAR’s overall
digital computation and communications design
philosophy did inspire and inform the American
approach.
In 1954, Lieutenant Commander
Irvin McNally, who had been the key champion
within the NEL for a digital approach, put
together a concept paper called the Naval
Tactical Data System (NTDS). Remembering the
WWII Japanese saturation air attacks, the NTDS
concept paper called for a system in which each
ship could simultaneously process 1,000 target
tracks (later reduced to 250), show whether they
were air, surface or submarine tracks, and also
could show whether they were friendly, hostile
or unidentified. The NTDS concept also called
for the computer to assess the relative threat
of each hostile target, and then assign the most
appropriate response: the guns or missiles on
specific ships, or airborne interceptor.
Finally, there had to be real-time sharing of
data between all the ships via digital radio
links. Jamming all this equipment in the narrow
confines of a frigate meant that it had to be
designed around transistors.
Diagram prepared by David Boslaugh.
Source:
http://www.ieeeghn.org/wiki/index.php/File:Data_Flow_.jpeg
In the context of 1954, the NTDS
concept paper was calling for the most ambitious
application of transistors to computers that had
ever been attempted. From the outset, it was
also decided that NTDS could sacrifice the
increased performance of a special purpose
computer in exchange for the flexibility that
could be gained from a general purpose,
programmable computer. The NTDS project was
approved in late 1955 and work started in 1956.
Univac won the contract to design and build the
NTDS computers that would be put in each ship.
The NTDS computer became known as AN/USQ-17.
Computer area of the NEL NTDS test site. U. S. Navy photo. Two of the
AN/USQ-17 computers can be seen. Source: IEEE Global History Network (http://www.ieeeghn.org)
Seymour Cray was placed in
charge of the AN/USQ-17’s design. He had worked
on the Navy’s code breaking computer called
Atlas II. While at Remington-Rand, he was put in
charge of the Athena project, the ground
guidance computer for the Air Force’s Titan
ICBM. Athena was Remington-Rand’s first venture
into transistorized computers. Later, he and
other computer engineers left Remington-Rand to
join the new company called the Control Data
Corporation (CDC). There, Cray would become
legendary for his design of supercomputers.
After Control Data, Cray left to form his own
company called Cray Inc., which quickly became
the premier supercomputer manufacturer. The
total cost of developing and testing NTDS on
five ships added up to $136 million, spread over
many contractors, including UNIVAC, Hughes
Aircraft, Collins Radio, Hazeltine, Western
Electric, and the University of Illinois.
UNIVAC’s development and testing of the NTDS
computer system cost $60 million. The USQ-17
computer never actually went to sea. From its
testing at NEL, it was concluded that it could
be improved with a new breed of transistors, and
it was reworked. The resultant shipboard
computers were designated CP-642 unit computers,
although they embodied the architecture and
instruction set of the USQ-17. NTDS went into
operation in 1962.
Naval Tactical Data System (NTDS)
training in full scale mock-up of a shipboard
Combat Information Center.
Source: IEEE Global
History Network (http://www.ieeeghn.org)
In DATAR, the Royal Canadian
Navy came to automated tactical data systems
because of its wartime experiences in
anti-submarine warfare. The U.S. Navy came to
NDTS from its wartime experience of facing
massive air attacks in the Pacific. The USN had
always felt anti-submarine operations and sonar
data would have to be an important part of an
automated tactical data system. But faced with
the complexity of the air defense problem, the
USN thought it wiser to wait until that was
working properly before tackling anti-submarine
operations. It wasn't until 1964 that the U.S.
Navy decided to expand NTDS’s capabilities to
anti-submarine warfare. Considerable new design
work was needed to build new computational
capabilities and interfaces for the expanded
version of NTDS. There was considerable debate
over design philosophy. By 1964, DATAR had
disappeared from most people’s memories. But the
Royal Canadian Navy, which still maintained a
deep interest in anti-submarine warfare, was
asked for its input during the design
specification stage.
NTDS left a very important
technological and organizational legacy in the
United States. It was the first militarized,
solid-state computer, and the first system to
used distributed computers with high-speed
interconnects. The NTDS project led to the
development of the Navy’s first project
management office to handle complex, large-scale
electronics system development. This office
pioneered management techniques by which a very
small group could effectively lead large
engineering projects. In the end, all of USN’s
future automated fire control and command &
control capabilities were heirs to the early
work done to design and first deploy NTDS.
These two stories are taken from
the extensive work done by historians John
Vardalas and David Boslaugh. Vardalas’s work on
DATAR was first published in The Computer
Revolution in Canada (Cambridge, MA: The MIT
Press, 2001). Boslaugh’s work on NTDS was first
published in When Computers Went to Sea
(Los Alamitos, CA: The IEEE Computer Society,
1999). Both authors have also added their
research on these two topics to the IEEE’s
Global History Network (GHN,
http://www.ieeeghn.org). Although most of
the material, including photos, for this article
came from the GHN, it only represents a small
fraction of the information contained on these
topics there. Go to the GHN, log on with your
IEEE web account user name and password, and
then type in DATAR and NTDS into the search box
for more on these stories. If you have served
in, or had any association with, these aspects
of the U.S. or Canadian navies, you are
encouraged to go to the GHN, search for DATAR or
NTDS, and contribute. David Boslaugh has
single-handedly contributed a wealth of
information on NTDS, and you are invited to
participate as well.
John Vardalas,
Ph.D., is outreach historian at the IEEE History
Center at Rutgers University in New Brunswick,
N.J. Visit the IEEE History Center's Web page
at:
www.ieee.org/organizations/history_center.
Visit the IEEE History
Center's Web page at:
www.ieee.org/organizations/history_center.
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