Evening star., 1946-01-20
BY w. H. shippen, Jr.

BY W. Il. Shippen, Jr.
Auintion Editor OF The Star.
A secret, war-tested system OF radio
navigation which may add inmeaNlr-
ably to the safety of air and sea COM
rherce was demonstrated to the public
for the first time yesterday.
Airmen and mariners on combat duty
in both oceans had been guided through
fog and storm from long range for years
before the general public ever heard Of
the cryptic military term Of 'Loran."
In fact, the new system was al oper-
ational whole, with scores OF shore sta
tions trimming the Atlantic and Pacific
months before the Navy and Coast
Guard showed how it worked yesterday
to airmen. mariners and writer's at the
Naval Air Station, Brooklyn.
System 80 Per Cent Accurate
Loran is said to eliminate errors of
older methods because It is based on
speed of radio waves rather than their
direction, which vary at times. Fixes
can be obtained in minute or two, al
most independent of weather conditions,
and can be relied upon to b about 90
per cent aaccurate, 1t was said.
Throughout latter years Of the war
aircraft and ships were guided BY Loran
from distances OF from 75O miles in the
daytime to double that at night over
vast ocean areas completely covered by
radio impulses from shore stations
spotted at strategic points. The only
equipment needed by planes or ships
was a small receiver, or electronic stop
watch, and set of Loran charts or
tables.
The stop watch" calculates distances
to shore stations in millionths Of a sec
ond on the basis Of the known speed Of
radio waves, enabling navigators to OBJ
tain cross fixes rarely more than mile
of for every hundred miles separating
favorably with the accuracy Of celestial
fixes obtained under the best weather
conditions, experts said.
In All Weather
While operators can be trained to use
Loran in few days, celestial navigators
require long schooling backed by expert
ence, and they must work out most cal
culations with elaborate mathematical
formulas. Too. the system often fails
when most needed because the very
storms which bring emergencies at sea
are apt to prevent navigators from OBJ
tanning fixes on celestial bodies or even
the horizon.
Has Saved Countless Lives
Loran was credited with saving many
lives at sea during the war. Planes or
ships in distress were able to fash back
quick and accurate positions, and rescue
vessels as we'll as craft crippled on the
surface knew their location as long as
Loran receivers remained in operation.
These emergencies occurred most fire.
quently in foul weather where ships
otherwise would have had to rely on
dead reckoning or on radio direction
finders subject to unpredictable varia-
tions, it was said.
with q small Loran receiver some
what resembling television set, fixes
can be obtained entirely independent of
compass, chronometer and various radio
devices.
A further advantage is the fact that
no transmission by the aircraft or ship
is necessary.
Postwar Possibilities
The Coast Guard, while not attempt
ing to sell Loran as long-range naW-
cation aid, or various types Of radar for
short-range work, Is anxious to simplify
and standardize equipment. Thus far
Loran and various radar aides have been
confined to military use for security
reasons. But as to its postwar use the
Coast Guard believes that 'Loran will
make possible to commercial air and
surface craft the same unfailing and
exact navigation that carried military
planes safely and directly to and from
their targets in fair and foul weather.
Helped Naval Victories
Postwar engineering may we'll extend
daylight range Of transmission up to
Il