SUPPORTING ARMS AND INTELLIGENCE
The amount of air and artillery support that the 26th Marines received
during the defense of Khe Sanh was enormous. Few regiments ever had
such an overwhelming amount of firepower at their disposal. The
reason was that General Westmoreland gave SCOTLAND priority over all
other operations in Vietnam. The well-publicized struggle had long
since become more than just another battle; it was a symbol of Allied
determination to hold the line in Vietnam. The stubborn resistance of
the 26th Marines had generated an emotional impact that was felt not
only in the United States but around the globe. Thanks to a small army
of war correspondents and reporters, millions of people followed the
battle day by day and, in essence, the military prowess of the United
States was exposed to the world.
The agency at the combat base which was responsible for coordinating
the vast array of supporting arms was the 26th Marines FSCC which was
headed by the 1/13 commander, Lieutenant Colonel Hennelly. The FSCC,
with its artillery and air representatives, was an integral part of
the regimental staff and it planned and supervised the execution of
all fire missions within the SCOTLAND area of operations. Subordinate
to the FSCC, was the 1/13 Fire Direction Center (FDC), headed by
Captain Lawrence B. Salmon, and the Khe Sanh Direct Air Support Center
(DASC), under Major Charles D. Goddard. The FDC served as the brain
of the artillery battalion where initial fire requests were received
and transformed into numerical data for the gun crews. To speed up the
process, Captain Salmon relied heavily on the Field Artillery Digital
Automatic Computer or FADAC. The DASC had displaced to the KSCB on
19 January with the sole mission of handling the deluge of incoming
aircraft. Requests for air support from the FSCC were channeled through
the DASC to the Tactical Air Direction Center of the 1st MAW. Whenever
the wing could not completely fill a quota, liaison teams within the
DASC called on the other services for assistance. Once the schedule was
met and the strike aircraft arrived on station, the Marine DASC, aided
by an Airborne Command and Control Center (ABCCC) from Seventh Air
Force, coordinated all air operations within the Khe Sanh TAOR.[48](137)
This mammoth air umbrella, called Operation NIAGARA, lasted from 22
January until 31 March and was truly an Allied effort. At one time or
another, the Khe Sanh DASC utilized the assets of all services: 1st
MAW, Seventh Air Force, Strategic Air Command, U. S. Navy Task Force
77, Vietnamese Air Force, and various U. S. Army aviation companies.
The majority of the sorties, however, were flown by U. S. Marine, Navy,
and Air Force crews. Their mission was to "destroy enemy forces in
the SCOTLAND ... TAOR, interdict enemy supply lines and base areas,
... and provide maximum tactical ... air support to friendly forces."
Generally, the type of strike fell into one of three categories:
close air support, B-52 Arc Light strikes, or radar-controlled
bombing.[49](138)
Close air support missions were utilized against pinpoint targets in
proximity of friendly troops. Along with radar-controlled bombing, this
type of air strike was the most responsive to the needs of the ground
commanders and the most accurate; the attack pilots, however, required
reasonably good weather to be able to hit their targets. There were
usually fighter/bombers overhead at Khe Sanh around the clock; if not,
they could be quickly scrambled from hot pads or diverted from other
missions. When the pilots arrived on station, they checked in with
the DASC and were handed off to a Marine or Air Force Tactical Air
Controller (Airborne) who personally directed the strike. There were
seven TAC(A)s assigned to the 26th Marines; the Air Force personnel
were members of the 20th Tactical Air Support Squadron and the
Marines were from Headquarters and Maintenance Squadron 36 and Marine
Observation Squadron 6. At least five of these pilots, flying O1-E
Birddogs or UH-1E gunships, remained over the battlefield during the
day and maintained direct communications with both the attack aircraft
and the troops on the ground. In this manner, the TAC(A)s could rapidly
employ the jets wherever they were needed the most and the close
supervision reduced the chance of accidentally bombing friendly forces.
During the day, the air around Khe Sanh was filled with the
high-pitched shriek of jet engines: Marine, Navy, and Air Force
F-4 Phantoms; Marine and Navy A-6 Intruders, A-4 Skyhawks, and F-8
Crusaders; Air Force F-105 Thunderchiefs and F-100 Super Sabers. In
addition to the jets, the South Vietnamese prop-driven A-1 Skyraider,
a rugged attack aircraft of Korean War vintage, was in evidence. At
times, the sky overhead resembled a giant beehive. When a flight
arrived on station, the Khe Sanh DASC normally directed it into a
holding pattern until a TAC(A) or a Forward Air Controller on the
ground was free to handle the strike. These patterns sometimes extended
up to 35,000 feet with scores of planes gradually augering their way
downward as each preceding flight unloaded its ordnance and scooted for
home.
When a TAC(A) picked out a lucrative target or was assigned one by
the FSCC, he cleared the strike aircraft into his area. The pilots
then broke up whatever formation they were in, slipped into trail,
and snaked their way through holes in the overcast--all the while
keeping a sharp eye out for helicopters. Below the clouds, the TAC(A)s
and attack pilots often had difficulty finding each other because of
the ever present haze and dust. Even on a clear day, the camouflaged
Birddogs and Hueys were hard to spot because they blended in so nicely
with the surrounding landscape. To expedite the link-up, the jet
pilots frequently used Automatic Direction Finders to get a fix on the
TAC(A)s radio transmissions. All the while, the airborne spotter was
passing on pertinent information such as target description, elevation,
run-in heading, direction of pull-off, number of passes, direction
and distance of nearest friendly troops, and whether ground fire was
expected.
[Illustration: Marine and Air Force TAC(A)s controlled strike aircraft
from light observation aircraft called Birddogs. (USMC Photo A402048)]
[Illustration: UH-1E Gunships of Marine Observation Squadron-6 were
also used to direct close air support missions. (USMC Photo A421451)]
When the controller and his flight made visual contact, the real work
began. The TAC(A) made a marking run during which he either fired a
smoke rocket or pitched out a colored smoke grenade on the position he
wanted hit. Once the attack pilots had the smoke, the TAC(A), and the
nearest friendlies in sight, they rolled in on the assigned heading and
made dummy passes until the controller was satisfied that the jets were
lined up on the right target. He then cleared them in for hot passes.
While the jets streaked in, the controller monitored his VHF tactical
net to the ground troops and gave short corrections to the attack
pilots over his UHF radio. An example of an average commentary follows:
TAC(A): Number One, from my smoke go six o'clock at 100 meters....
PILOT: Roger, One's? in hot.... TAC(A): I have you in sight, you're
cleared to fire.... TAC(A): PILOT: Ones off target.... Switches
Safe.... TAC(A): Number Two, from One's hits come three o'clock at
50 meters.... PILOT: Roger, Two's in hot ... etc., etc.
The aircraft continued their race track pattern until all ordnance was
expended at which time the leader announced that his flight was pulling
off "high and dry."[50]
The TAC(A) would then swoop low over the smoke-shrouded target and
attempt to record the results of the strike. This Battle Damage
Assessment (BDA) was relayed to the departing pilots for their
intelligence debriefing back at homeplate. An example of one such
transmission would be:
Your BDA follows: 5 KBA (killed by air); two bunkers, 1 automatic
weapon, and 50 meters of trenchline destroyed; one secondary
explosion. You have been flying in support of the 26th Marines;
your controller has been SOUTHERN OSCAR. Good shooting and good
afternoon, gentlemen.
While the strike pilots checked out with the Khe Sanh DASC and headed
for home, the TAC(A) looked for another target and waited for another
flight.(139)
One of the most unusual incidents involving the use of strike aircraft
occurred near Hill 881S and the key figure in the episode was a Marine
from American Samoa--Lance Corporal Molimao Niuatoa. The corporal was a
bull of a man, who because of his origin and wedge-shape physique was
nicknamed "Pineapple Chunk." (A second American Samoan in the company
of considerably smaller stature was dubbed "Pineapple Tidbit.") But it
was not the muscles which distinguished Niuatoa, it was his eyes; the
man had absolutely phenomenal vision. During his recruit training, this
gift had enabled him to post a score of 241 out of a possible 250 on
the rifle range. Besides his vision, the corporal had the patience of
Job and a deep power of concentration--qualities which were essential
in his job as an artillery spotter.
One day, Corporal Niuatoa, using a pair of 20-power naval binoculars,
was scanning in the direction of 305 when he picked up the muzzle flash
of an enemy artillery piece; he then saw the gunners hurriedly cover
the weapon with a screen. As the round sputtered overhead on its way to
Khe Sanh, the corporal noted the position and reported his discovery
to the company commander. Referring to a map, Captain Dabney could not
get anything other than a general idea of the location because the site
was from 12,000 to 13,000 meters away and the terrain in that area was
so mountainous that he could not pinpoint the exact contour line. Not
so Corporal Niuatoa, he could see exactly where the gun was and kept
his eyes glued to the binoculars. Normally, he would have adjusted on
the target with marking rounds but the site was beyond the range of
friendly artillery. The only way the gun could be taken out was with
aircraft.
While Pineapple Chunk maintained his reference point, an O1-E Birddog
aircraft arrived on the scene, and was directed to the general area of
the artillery position. On the heels of the spotter craft came several
flights of Marine A-4 Skyhawks armed with 500-pound bombs. Although
the TAC(A) didn't know exactly where the target was, he rolled in
and cranked off a smoke rocket. The puff from the 2.75-inch rocket
wasn't visible to the Marines on 881S but the billowing clouds left by
the 500-pound bombs of the first A-4 were. Using standard artillery
terminology, Corporal Niuatoa adjusted: "Left 2,000, add 1,000."
The corrections were passed to the TAC(A) who fired another rocket,
on which an A-4 pilot placed another string of bombs. Gradually,
the bracket was closed until a Skyhawk in the fourth flight scored
a direct hit and the gun position erupted in a series of secondary
explosions.(140)
[Illustration: Marine F-4B Phantom delivers Snakeye bombs on enemy
trenches. Large tail fins retard the descent of the bombs. (Photo
courtesy David D. Duncan)]
[Illustration: Corporal Robert J. Arrotta (center), controlled over 200
airstrikes from Hill 881S. (Photo courtesy Major William H. Dabney)]
The NVA troops, however, were not always on the receiving end; they
frequently dished it out. In addition to numerous helicopters shot
down around the combat base, several of the speedier jets were also
knocked out of the sky. During one close air support mission, an A-4
flown by Major William E. Loftus of Marine Attack Squadron 311 received
heavy battle damage and the pilot realized that he could not make it
to the coast. Not wanting to end up in "Indian Country," he nursed his
crippled Skyhawk toward Khe Sanh and ejected right over the base. As
the smoking A-4 knifed into the lush jungle growth and erupted in a
brilliant orange fireball, Major Loftus floated down and landed in an
outer ring of barbed wire just outside the Company B, 1/26 perimeter.
Lieutenant Dillon, the 2d Platoon commander, took several men out and
helped extricate the major who had become hopelessly entangled in his
parachute shroud lines and the barbed wire. After being freed, Major
Loftus grinned and told the lieutenant: "If you weren't so damn ugly,
I'd kiss you." After a quick medical check-up, the major climbed aboard
a helicopter and returned to his squadron at Chu Lai for another plane
and another day.(141)
One of the closest escapes, however, occurred to the southwest of
the base. In late January, Lieutenant Colonel Harry T. Hagaman,
Commanding Officer of Marine Fighter Attack Squadron 323, and his Radar
Intercept Officer, Captain Dennis F. Brandon, were leading a flight
of F-4B Phantoms against what the TAC(A) described as a "suspected"
antiaircraft position. The enemy gunners confirmed their presence
during the first pass. As Lieutenant Colonel Hagaman's F-4B, armed with
napalm and 250-pound Snakeyes, skimmed low over the treetops, the North
Vietnamese cut loose and laced the belly of his plane with a stitch of
50 caliber shells. The aircraft shuddered under the impact and burst
into flames. Captain Brandon, a backseat veteran with over 300 combat
missions, knew instantly when he heard the series of ominous "thuds"
that the Phantom had been mortally wounded; he quickly pulled his
face curtain and ejected. Lieutenant Colonel Hagaman stayed with the
bucking Phantom momentarily in a vain effort to stabilize the aircraft
by using his rudders. The delay almost cost the pilot his life because
the F-4B began to tumble end-over-end barely 100 feet above the ground.
Suddenly the world outside became a spinning blur of blue and green.
The second time that he saw green--indicating that the aircraft was
inverted--Lieutenant Colonel Hagaman started to pull his alternate
ejection handle which was located between his knees. In the second that
it took the escape mechanism to function, the Phantom flipped upright
and the ejection cartridges blasted the pilot from the flaming cockpit.
Seconds later, the plane cartwheeled into the ground and exploded. The
pilot was so low when he "punched out" that the chute had scarcely
deployed when his feet touched the ground. Both crewmen hid in the
tall elephant grass within earshot of the North Vietnamese who were
searching for them. Within minutes, rescue helicopters lumbered on
the scene and, while the downed crew's wingman made dummy passes to
discourage the enemy soldiers, the choppers darted in and plucked the
shaken, but otherwise uninjured, Marines to safety.[51](142)
If there was anything that could top that performance, it was the
spectacular air shows provided daily by B-52 Stratofortresses of the
4133d Provisional Heavy Bombardment Wing, based at Andersen Air Force
Base, Guam, and the 4258th Strategic Bombardment Wing in Thailand. The
B-52 pilots did not count on finesse as much as they did on sheer power
because each Stratofortress carried a 27-ton payload of 108 mixed 500-
and 750-pound bombs. Since these giants had the means to virtually
move mountains, the Arc Light strikes were used on area targets such
as troop concentrations, marshalling points, supply depots, and bunker
sites. The result of the enemy build-up around the base was an enormous
number of targets located in dispersed but common areas and such
complexes were ideal for heavy bombers. These targets were programmed
into computers aboard the aircraft and the strikes were conducted from
altitudes above 30,000 feet. To the bomber crews, it was an impersonal
type of warfare because, from above the overcast, they rarely even saw
their bombs explode. The bombs did not have to be seen to be felt.(143)
When several flights of B-52s worked over a target, the results
were awesome. The exploding bombs churned up strips of the terrain
several thousand meters long and the ground for miles around literally
shook from the blasts. Many enemy casualties were sustained from the
concussion alone. One entry from a captured North Vietnamese diary
read: "18 February: The heavy bombing of the jets and B-52 explosions
are so strong that our lungs hurt." In some instances, NVA soldiers
were found after an Arc Light strike wandering around in a daze with
blood streaming from their noses and mouths.[52] Often the internal
hemorrhaging induced by the concussion was so severe that it resulted
in death. Quite understandably, such missions could not be unleashed
too close to the Marines.(144)
In the early stages of the conflict, Arc Light strikes were not
authorized within a prescribed distance of friendly lines. The same
rule had applied during the heavy fighting at Con Thien the year before
and the NVA had taken advantage of the buffer zone by moving troops and
supplies in as close to the Marine base as possible to avoid the bomber
raids. They tried the same thing at Khe Sanh. When American airborne
observers noted enemy bunker complexes cropping up near the KSCB, the
no-bomb line was moved in to about half of the original distance. At
first the regimental commander was afraid that the resulting concussion
would collapse his own bunkers and trenches; as it turned out, the
enemy fortifications were the only ones which suffered. The first
few B-52 raids inside the old line touched off scores of secondary
explosions and undoubtedly snapped the North Vietnamese out of their
sense of security. The closer strikes also served as a morale booster
for the defenders who flocked from their bunkers to watch, what the
Marines called, "Number One on the hit parade."(145)
According to the regimental Target Intelligence Officer (TIO), Captain
Mirza M. Baig, the B-52 was an accurate weapons system which the FSCC
employed around Khe Sanh much the same as the other supporting arms.
About 95 percent of the Arc Light missions were targeted at the 26th
Marines headquarters.[53] Requests were submitted to the 3d Marine
Division Air Officer 15 hours prior to the drop at a rate of 8 strikes
every 24 hours. Up to three hours before the strike, the TIO, upon
direction, could divert the bombers to new unscheduled targets, but
after that the Stratofortresses were restricted to their original
target. The response time was later trimmed even more by using cells
of three B-52s which left Guam and Thailand every three hours; this
put the bombers over Khe Sanh every hour and a half. In spite of
this streamlining, the B-52s were never as responsive or flexible
as the droves of fighter/bombers which were overhead constantly.
Nevertheless, the devastating power and psychological effect produced
by the Stratofortresses, coupled with the surprise factor, made them an
extremely valuable adjunct.[54](146)
The type of strike which most impressed the regimental commander,
however, was the ground-controlled radar bombing. Although these raids
lacked the punch of an Arc Light strike, they were as accurate and
flexible as dive-bombing attacks and could be conducted in the worst
weather. In fact, the technique was designed especially to cope with
the inherent bad weather which accompanied the monsoons in Southeast
Asia when attack aircraft could not get below an overcast to hit the
target.
The controlling agency at Khe Sanh for these strikes was Air Support
Radar Team-Bravo (ASRT-B), Marine Air Support Squadron 3 which had
moved from Chu Lai on 16 January. The ground controllers operated
from a heavily reinforced van which housed their sensitive computer
equipment and used the TPQ-10 radar to guide aircraft to their target;
thus, the missions were called TPQs.[55](147) The radar emitted a
pencil-shaped beam which detected and locked on to the aircraft. Using
target coordinates provided by the FSCC, the controller programmed
the enemy position, ballistic characteristics of the bombs, current
winds, and other pertinent data into a computer which was connected to
the radar. The computer also received inputs from the radar and, in
turn, provided corrections in airspeed, altitude, and heading which
the operator passed on to the pilot. The controller closely monitored
his set and, at a predetermined release point, called a "Mark" to the
pilot who "pickled" his bombs.[56] In specially-equipped aircraft, such
as the A-4 Skyhawk and the A-6 Intruder, the bombs could be released
automatically from the ground. One ground controller could handle a
single plane, a section (two planes), or a division (four planes) on
the same pass as long as the pilots flew in a tight formation and the
radar did not break lock. One of the controllers' favorite aircraft
was the A-6 because it packed such a heavy wallop; a single Intruder
usually carried 28 500-pounders. Any fighter/bomber, however, could be
used as long as it carried low-drag ordnance and the pilot could make a
smooth run.(148)
Even though most TPQs were conducted from around 14,000 feet, the
accuracy of ASRT-B was phenomenal. When new personnel arrived at
Khe Sanh, they were given several check drops on a nearby hill to
test their proficiency before the newcomers were allowed to conduct
strikes near friendly troops. The first drop was always within 40
meters of the target and, after they adjusted there was virtually no
error. Calibration drops were also conducted twice weekly to ensure
the accuracy of the equipment. One member of the FSCC stated that, if
he were in a foxhole and under attack, he would have no qualms about
calling an ASRT-B controlled TPQ within 35 meters of his position.
The rule of thumb which the FSCC generally applied when determining a
safe distance for normal operations, however, was one meter from the
friendlies for every pound of conventional ordnance being delivered.
Thus, for TPQs, a 250-pound bomb would not normally be dropped within
250 meters of Allied troops, a 500-pounder within 500 meters, and so
on. This criteria was not established because the men on the ground
lacked confidence in the system but because of the large fragmentation
pattern produced by the bombs. Besides, anything inside the prescribed
radius could be handled just as effectively by artillery, mortars, and
direct fire weapons. In an emergency, the regimental commander would
have undoubtedly lifted the restriction. Concerning the quality of
support he received from ASRT-B, Colonel Lownds said, "Anything but the
highest praise would not be enough."(149)
[Illustration: A-6 Intruder, under TPQ control, provides precision
bombing around Khe Sanh despite poor weather. (USMC Photo A422000)]
[Illustration: B-52 Stratofortresses flew strikes daily in support of
the 26th Marines. (Photo courtesy USAF)]
In addition to its accuracy, the TPQ system was extremely flexible.
A strike could be programmed and executed within 10 or 12 minutes
utilizing any available aircraft. Most of the missions were at night
when it was inefficient and dangerous to conduct dive-bombing strikes.
As a matter of routine, two Marine and three Air Force flights were
scheduled every hour unless an emergency developed. On 18 February,
ASRT-B set a new squadron record for a single 24-hour period by
controlling aircraft which delivered 486 tons of ordnance on 105
separate targets. After that, the record was approached frequently but
never broken. During the siege, ASRT-B controlled 4,989 TPQs in support
of the 26th Marines.(150)
Beginning on 20 February, ASRT-B also assisted with supply drops
whenever the Khe Sanh MATCU was inoperable. Normally, the controllers
could have guided the transport pilots to an exact release point but,
at Khe Sanh, the C-130s had to fly directly over the station and the
TPQ-10 would break lock.[57](151) Therefore, the ASRT personnel used the
same technique as the MATCU controllers and called a "Mark" when the
Hercules was over the eastern threshold and the pilots completed the
runs with Doppler navigation and stop watches. The only problem was
that, when the ASRT conducted supply drops, it was drawn away from the
primary mission of handling TPQs.(152)
While air support was vital to the defense of the base, Colonel Lownds
felt that his artillery played an equally important role. When the
fighting first broke out, the colonel surmised that the side which
managed to keep its artillery intact would win the battle. The Marine
artillery emerged almost unscathed. Many incoming rounds landed within
the battery positions, however, very few actually hit the gun pits and
throughout the operation only three artillery pieces at the base were
destroyed; one was a 155mm howitzer parked alongside the loading ramp
awaiting airlift to Dong Ha.[58] Generally the pieces, were tucked away
inside heavily sandbagged revetments and, while the crews were often
showered with fragments, it would have taken a direct hit, squarely on
top of the weapon, to knock out a howitzer. Fortunately for the Marine
gunners, the North Vietnamese scored only one such a hit which led the
regimental commander to the conclusion: "Either they were amazingly
inaccurate or we were amazingly lucky."(153)
The enemy's failure to silence Lieutenant Colonel Hennelly's batteries
was a big point in favor of the Marines. While American news reporters
gave wide coverage to the number of shells falling on the base, they
frequently neglected to mention that 1/13 answered each enemy round
with 10 of its own. Throughout the battle, 1/13 cranked out 158,891
mixed rounds in direct support of the 26th Marines. The methods
employed by the FSCC were reminiscent of those used in World War I.
Time On Target (TOT) by massed batteries, Harassment and Interdiction
(H&I) by battery volley instead of a single piece, artillery boxes,
rolling barrages, and battery zones were a few techniques adopted by
the FSCC which more than lived up to its motto: "Be Generous."[59](154)
Since the enemy did most of his maneuvering under the cover of
darkness, that was when the Marine and Army batteries were the most
active. Captain Baig, who wore one hat--Target Intelligence Officer--in
the S-2 section and another--Target Information Officer--in the FSCC
later described a good night's work:
An average night's pattern of pre-planned fires was as follows:
Combined TOTs from 9 batteries (4-6); separate battalion TOTs
(Army 4-6, Marine 10-15), battery multiple volley individual
missions (40-50); battery H&Is (20-30). Normal 1 gun, 1 round
H&Is were not used; this type of fire was of little value. Marine
and Army artillery were employed in target areas and at ranges to
reduce to a minimum check fires caused by the arrival of TPQ and
reconnaissance aircraft. Later, as we learned finesse, air was
given the targets south of the base and west of the maximum range
of the 175mm guns; 1/13 was given any targets whose range required
a maximum ordinate of less than 14,000 feet (altitude of TPQ run);
and the 175mm guns were assigned targets to the north, northwest,
and east of the base. Such were the pre-planned fires.(155)
[Illustration: A 105mm howitzer of 1/13 lashes out at NVA troops
surrounding Khe Sanh. The artillery battalion was in direct support of
the 26th Marines. (USMC Photo A190832)]
[Illustration: The 175mm guns of the 2d Battalion, 94th Artillery, USA
were in general support of the Khe Sanh garrison. This gun was located
at Camp J. J. Carroll. (USMC Photo A190709)]
In addition to volume, reaction time was a key factor. Unless friendly
aircraft in the target area necessitated a check fire, artillery
response was immediate--no matter what the weather. To test the
proficiency of the Fire Direction Center and the gun crews, Colonel
Lownds periodically walked into the FSCC bunker, pointed to a spot on
the huge map which adorned the wall and directed Lieutenant Colonel
Hennelly to hit it. The coordinates were quickly sent to the FDC where
they were either fed into the FADAC computer or worked out manually and
the firing data was then passed on to the gun crew. After adjusting
the tube, the gunners slammed a round home and sent it on its way.
The entire process usually took less than 40 seconds. This "instant
artillery" constantly hampered enemy movement within the TAOR and
helped break up numerous attacks.(156)
The defensive fire plan adopted by the FSCC was separate from and
not to be confused with the final protective fires employed by the
defenders who manned the perimeter. The artillery batteries were used
to prevent the enemy assault forces from reaching the wire and to cut
off the lead elements from reinforcements. The fact that the North
Vietnamese usually attacked with their battalions in column made it
somewhat easier for the FSCC to isolate the assault elements from
the reserves. When the enemy launched his attack, the FSCC placed a
three-sided artillery box around the lead battalion; three batteries
of 1/13 executed this mission. The fourth battery then closed the
remaining side, which faced the friendly positions, with a barrage that
rolled from one end of the box to the other--much like a piston within
its cylinder. The NVA force in the box could not escape and could not
avoid the rolling barrage. Those North Vietnamese who spilled out of
the open end of the box were subjected to the final protective fires of
the Marines along the perimeter.
At the same time 1/13 worked over the assault force, the FSCC put a
secondary box into effect for the benefit of the back-up units. The
Army 175mm batteries were responsible for two sides which were about
500 meters outside the primary box. On order, the gunners rolled their
barrages in toward the sides of the primary box and back out again.
The third side was sealed by continuous flights of aircraft under the
control of the TPQ-10 radar. Whenever B-52s could be diverted in time,
Arc Light strikes were used to saturate the approach routes to the
battle area.(157)
Another key factor in the defense of Khe Sanh was the manner in which
Lieutenant Colonel Hennelly's FSCC coordinated their air effort with
the artillery so that the two components were complimentary. One prime
example was the Mini-Arc Light which was devised by the Assistant Fire
Support Coordinator, Captain Kenneth O. W. Steen and the TIO, Captain
Baig. As the name implies, this technique was used against an area
target the same as a B-52 strike, only the former could be organized
and employed much quicker. When intelligence reports indicated that NVA
units were in a certain region, the FSCC plotted a 500 by 1,000-meter
block in the center of the suspected area or across a likely route
of march. Two A-6 Intruders, each armed with 28 500-pound bombs,
were called on station for a TPQ and the batteries at Khe Sanh, Camp
Carroll, and the Rockpile were alerted for a fire mission. Thirty
seconds before the two A-6s dropped, the 175mm batteries, concentrating
their fire on one half of the block, salvoed the first of approximately
60 rounds. At the same time the A-6s rippled their load down the
middle of the block, the 1/13 batteries opened up on the second half
with around 200 155mm, 105mm, and 4.2-inch rounds. The trajectory and
flight time of all ordnance were computed so that the bombs and initial
artillery shells hit at the same instant. The saturation of the target
area was such that any enemy soldiers caught in the zone during the
bombardment simply ceased to exist.(158)
During the second week in February, a special Mini-Arc Light was
directed against a major NVA headquarters. Two members of the 26th
Marines S-2, Majors Robert B. Coolidge and Jerry E. Hudson, learned
from their various sources that a force-wide meeting of NVA commanders
and their staffs would occur in an abandoned schoolhouse near the
Laotian border. A beefed-up Mini was prepared to welcome the delegates.
For this strike, the target block was reduced to 500 by 300 meters
around the schoolhouse which would take in, as one of the planners
stated, "the hangers-on and other idlers who usually congregate around
large staffs." Twenty minutes after the meeting was scheduled to start,
the trap was sprung. Two Marine A-6 Intruders and four F-4B Phantoms
unloaded 152 500-pound bombs into the block in concert with the
opening volleys of eight artillery batteries (total of 350 artillery
rounds).(159) The target was obliterated, but whether or not this
unusual ambush netted any NVA brass-hats was never ascertained.
The Micro-Arc Light was executed in the same manner as the Mini except
smaller amounts of ordnance were used and the block was cut down to
500 by 500 meters. Any aircraft on station would suffice, preferably
ones armed with 12 to 16 500-pounders. Artillery fire was reduced to
30 rounds from the 175mm guns and 100 mixed rounds from Lieutenant
Colonel Hennelly's battalion. The advantage of the Micro was that it
could be put into effect within 10 minutes while it took roughly 45
minutes to plan and execute the Mini. On an average night, three to
four Minis and six to eight Micros were executed, usually to the south
and southeast of the base; both were extremely effective.(160)
The massive firepower supporting the Marines would have been almost
useless had they not known where and when to employ it. The 26th
Marines intelligence section was responsible for this facet of the
operation and these people had more than a passing knowledge of the
enemy's past strategy. At Dien Bien Phu and Con Thien, the Communists
had followed a fairly predictable pattern--not unlike the classic
siege of the 18th Century. There were three distinct phases involved
in this type of campaign: arrival on the scene and encirclement of the
garrison, construction of siege works and support facilities, T-ing
the sapheads and final assault. After investing the base, the North
Vietnamese first established numerous forward logistic bases within
a few thousand meters of the base. Under the cover of darkness, the
enemy soldiers dug a series of shallow trenches, interlaced with supply
bunkers, leading from these points toward the American positions. The
first trenches began to appear at Khe Sanh around 23 February and the
heaviest concentration was to the south and southeast. Once in close,
the main trenches branched off into ones which paralleled the Marines
lines; these secondary trenches, which from the air looked like long
fingers reaching greedily toward the base, were the ones from which the
NVA assault troops intended to attack.(161)
At first, the defenders tried to prevent the enemy from moving in too
close to the base. The routes into the valley were saturated; artillery
H&I fire and frequent air strikes were employed but such tactics
only tended to slow down the enemy and force him to bypass certain
routes--they did not stop him. Constant, massed artillery would have
effectively blocked infiltration but that alternative was, from a
logistics standpoint, impossible. The S-2 personnel recommended that
the best way to counter the enemy was to allow the North Vietnamese to
close and pursue their siege tactics and then, to borrow a phrase used
by General "Chesty" Puller (then a colonel) on 28 November 1950 when
his regiment was surrounded near the Chosin Reservoir in Korea, "that
simplifies our problem of finding these people and killing them."(162)
The S-2 section utilized a multitude of sources to develop an accurate
picture of the enemy's activity around the base. While much of this
information was self-generated, the 26th Marines received substantial
intelligence support from the MACV, III MAF, and 3d Marine Division
Headquarters. Ground and aerial observers, photo reconnaissance,
infrared imagery, target lists of higher headquarters, crater
analysis, shell/flash reports, and agent reports were all tools of the
intelligence community at Khe Sanh. By comparing this information with
the knowledge of enemy doctrine as applied in past situations, the S-2
staff was able to accurately estimate the intentions of the NVA on a
day-to-day basis.
One good example of how this intelligence produced hard results
occurred in late February. From their various inputs, the two men who
were responsible for the earlier attack on the NVA staff conference,
Majors Coolidge and Hudson, pinpointed the exact location of 12
artillery positions and 2 major ammunition depots. These targets were
concentrated in two main areas to the south of the base. Air strikes
were called in on the enemy positions and, after the planes departed,
the whole area erupted in secondary explosions which lasted for the
next 40 minutes. Two weeks later, these officers repeated a similar
performance in another area.(163)
The activities of the intelligence community at Khe Sanh and higher
headquarters were vital to the conduct of the battle. Almost every
major attack against the 26th Marines was picked up well in advance by
the S-2 section. Whenever enemy activity was detected, the information
was passed to the FSCC and this was the signal for Colonel Lownds
to put his defensive fire plan into effect. The base was placed on
Red Alert, the primary and secondary boxes fired, and saturation air
strikes were employed. This method of cutting off the attack force by
massed fires, once the S-2 section had provided a warning, proved to be
a decisive factor in thwarting the major enemy thrusts which came late
in February.(164)