74                                 U.S. MARINES IN THE PERSIAN GULF, 1990-1991


Colonel Fulford had deployed these elements on 23 February to check and mark
the  route, secure the attack position,      and make   last-minute adjustments
preparatory  to ensure the assault went       smoothly. Unit movements  were
controlled through the use of phase lines. The lack of identifiable terrain features
meant that for the ground offensive the division's phase lines were arbitrary lines
on the map acting as reference pointS. Commanders used a combination of
position location recording system (PLRS) and global positioning system (GPS)
to provide them the unit's exact location.'22  Phase lines were generally named
after colors, going from Black at the Kuwait border to Red just south of the
Kuwait International Airport.
    Ripper's advance, well rehearsed before the ground offensive, proceeded so
well that it arrived at its attack position at 0200, an hour ahead of schedule.'23
Engines idled in the darkness then were shut down as the task force settled in
to await orders from division headquarters to start the attack.
    At 0359 General Boomer informed General Myatt that G-Day and H-Hour
had been confirmed. The division attack was     preceded by a B-52 strike and at
0410 Myatt told task force commanders to execute the attack plan. An hour later
General Myatt directed Colonel Fulford to send Task Force Ripper across the
line of departure near the first obstacle belt and begin the main attack. While
Task Force Ripper moved to the first obstacle belt, a flight of A-6s struck the
four Iraqi tanks identified earlier. The tanks then withdrew north. However, in
doing so they inadvertently drew the fire of 3d Tank Battalion to Task Force
Grizzly, still in Task Force Ripper's zone of action.
    After continuing in wedge formation to Phase Line Saber, the forward edge
of the minefield, Task Force Ripper began breaching operations. At 0617 and
continuing for the next five minutes, the horizon in front of the task force
became lit by a series of red star clusters as the 1st Battalion, 7th Marines, and
the 1st Battalion, 5th Marines, i~dicated their arrival at the minefield and the
beginning of breaching operations. The 1st Battalion, 7th Marines, experienced
a slight delay because the forward edge of the minefield in its sector proved to
be further north than originally believed.'24 Both battalions immediately put their
obstacle clearing detachments (OCDs) to work clearing lanes.
    The obstacle clearing detachments used procedures rehearsed many times in
the previous months and quickly opened four lanes. A light drizzle had turned
to rain, making visibility difficult when Colonel Fulford directed 1st Battalion,
5th Marines, to clear the two left flank lanes while 1st Battalion, 7th Marines,
cleared the right two lanes. He gave the 1st Combat Engineer Battalion the task
of creating two additional lanes when the two mechanized infantry battalions
finished.'~
    Each obstacle clearing detachment used similar equipment and techniques. On
order from the officer commanding the detachment, an M60A1 tank equipped
with a track-width mine plow (TWMP) moved to the edge of the minefield and
fired a MK58 single-shot line charge (MCLC) from a trailer towed behind the
tank. Attempts to remotely detonate this type of line charge invariably failed and
a combat engineer then left the comparative safety of an accompanying AAV and
manually primed the charge. When subsequently detonated, the resulting blast