VOLUME I Multinational Maritime Tactical Instructions and Procedures

MTP 1(D), Vol. I
SECTION I — EMPLOYMENT OF ASW UNITS
9100 ASW SHIPS
9101 SURFACE SCREENS
The design and selection of ASW surface screens will depend on:
a. Number of screening units available and their individual and collective weapons and sensor fits.
b. Size and disposition of the force being Screened.
c. Availability of ASW aircraft.
d. Anticipated threat.
e. Environmental conditions.
f. Tactical sonar ranges.
g. PIM, including any navigational constraints.
h. Requirement for command, control, and communication, including Emission Policy.
i. Requirement for supporting operations; for example, replenishment.
j. Requirement for other forms of defense; for example, AAW.
k. Requirement for nuclear spacing.
l. Deception policy.
NOT RELEASABLE
9102 — 9104 SPARE
9105 SURFACE SHIP TOWED ARRAYS
9106 GENERAL CONSIDERATIONS
NOT RELEASABLE
a. Generally, the method of employing a towed array ship will depend on the type of array fitted.
Surveillance Towed Array Systems (SURTAS) tend to have an extremely long length and are optimized
for very slow towing speeds. For this reason, they are best suited to stationary operations which allow them
to patrol their stations at slow speed and to avoid frequent maneuvers which cause array destabilization and
degrade its performance. Tactical Towed Array Systems (TACTAS) are specifically designed for higher
speeds and are the best option for moving-PIM operations such as convoy escort. The actual performance
of an array depends as well on its design. Critical Angle Towed Array Systems (CATAS) tend to be less affected
by tow ship noise due to the greater length of tow cable than do arrays towed from a depressor
(DTAS). Hence a CATAS will tend to provide better all round ranges of initial detection and tracking than
can be expected of a DTAS.
b. To enhance effectiveness as an ASW sensor system, it is necessary for a towed array ship to reduce
the range at which it may be counterdetected by the submarine. For this reason, the towed array ship
9-4 CHANGE 1