January-February - Air Defense Artillery

1943 IDENTIFICATION OF MERCHANT SHIPS 33
a vessel as it appears over the horizon. Then haze and
distance will cause problems that V\.ill complicate the
identification procedure. For example there is the difficulty
frequently encountered in the identification of
ships such as the Liberty ships that have a topmast
erected on the athwartship section of kingposts stepped
in pairs. At first the observer will see the kingposts
only and not the masts, although ships with topmasts
erected upon athwartship joined kingposts have those
structures classified as masts because of their profile
appearance. When the ship comes closer the observer
will then see the mast, and any typing already done
will have to be rearranged. Other problems that confront
the observer are those caused by refraction which
makes a vessel appear to ride high on the water or
creates other distortion; those due to foreshortening,
caused by the angle at which the observer sees the ship;
and those caused by the height of freeboard, which
depends upon the weight of the vessel. Naturally
enough, a ship loaded rides much lower in the water
than an empty one.
The observer must be trained in the practical application
of the system, learn to anticipate problems, and
make proper discounts for various conditions that call
for the modification of decisions. He should study the
Coast Artillery film strip, Identification of Merchant
Ships, this article, and appropriate naval manuals, and
actually memorize the profiles, characteristics, and type
of ships frequently encountered. The use of the system
at close range provides good practice in the mechanics.
of the system, but the observer must be further trained
under the actual conditions that he will encounter. The
goal of training should be to effect correct identification
by deciding upon type and characteristics of a vessel at
the earliest possible moment even under difficult conditions.
Glossary of Terms
Coast Artillerymen who are required to become proficient
in the art of ship identification should first
master the simple glossary following:
Aft.- The rear portion of a ship. Also used to denote
location in rear of some part of a vessel.
Amidships.-In or toward the middle of a ship.
Atlnrartship.-Direction crossways of a ship.
Bow.- The front portion of a ship.
Bridge.- The structure usually in forward portion of a
ship from which the navigating of the vessel is directed.
Characteristics (ships).- The kind of construction of
bow, stern, funnels, superstructure, deck, ventilators,
and cranes.
Deck.- The Hoor-like covering of the hull of a vessel.
Electric crane.-A device utilizing pulleys and chains in
the handling of cargo.
Flush-deck.-A deck constructed so that when viewed
from profile it appears as a single straight or curved
line from bow to stem.
Fore.-Front section of a ship. Also used to denote location
in front of some part of a vessel.
Forecastle.- The part of the upper deck or superstructure
forward of the foremast.
Foremast.- The forward mast of a ship.
Funnel.- The tubular pipe erected on the deck or superstructure
for carrying away the smoke. Commonly
called the smokestack.
Gangway.-A railed footpath from one part of a vessel
to another, usually found in vessels such as tankers
or ore boats, where walking on the deck would be
treacherous.
Island.-A structure on the deck of a ship isolated from
other parts of the other deck construction.
Kingposts.- The posts used for attaching the booms of
cranes used in the handling of cargo.
.Mainmast.- The principal mast of a vessel, usually the
second mast from the bow, whether a vessel has two,
three, or more masts.
Motor ship.-A ship driven by Diesel-electric, Diesel, or
gasoline motors.
Stern.- The rear portion of a ship.
Superstructure.- The portion of the ship that extends
above the line of the deck. In a passenger ship it is
quite large and contains cabins and living quarters.
T anker.-A ship with the hull divided into compartments
for the carrying of oil, molasses, or other products.
T opmast.- The second mast from the deck. In steam
vessels a mast erected from another mast or other
suppor~ as the athwartship connection sometimes used
between kingposts.
Type (ships).-A term used to denote the masts, funnels,
and kingposts whose sequence and number are
the basis of the system of ship identification.
Ventilators.-A device for carrying air to various interior
parts of a ship.
W wher deck.-A deck exposed to the weather.
Well-deck.-A deck constructed on several lines. The
line from bow to stem appears to be broken by several
steps or indentations, when viewed in profile.
Whaleback.-A vessel having the sides curving in to-
1-vardsthe center.