Corps, Vietnam Artillery from his headquarters at Dong Ha. w
Provisional Corps, Vietnam published its order for Operation Thor on 24 June 1968, barely one week before D-Day. In order for the attack to proceed as planned, much remained to be done. While communications personnel from all participating organizations began establishing a network for command and control of the operation, engineers and surveyors began repair and construction efforts which would allow artillery units to displace forward to new firing positions along the Dyemarker line. Marine logistic units also had to stockpile at forward ammunition supply points the large quantities of artillery and air-delivered ordnance required for the operation. Complicating this task was the 20 June 1968 explosion of the Dong Ha ammunition supply point which closed the Dong Ha Logistic Support Area for six days. In the interim, the Quang Tri ammunition supply point provided ordnance for Operation Thor. The Provisional Corps commander. Army Lieutenant General Richard G. Stilwell, later stated that "the execution of Thor so shortly after the huge loss of ammunition seemed out of place with known facts .... " and therefore created an element of surprise.31*
On D-3, VMCJ-1, along with units of the Seventh Air Force, began photo reconnaissance missions of the Cap Mui Lay sector. Based on the intelligence these missions produced, the staff of Provisional Corps, Vietnam prepared a target list and completed the plan. Operating from their bases at Da Nang and Chu Lai, on 1 July, the fixed-wing squadrons of the 1st Marine Aircraft Wing launched into clear skies for their first strikes of Operation Thor. Using intelligence assembled over the previous three days, Marine F-4s, A-As, and A-6s rolled in on suspected and confirmed NVA positions in the Cap Mui Lay sector. At the same time, Air Force and Navy attack aircraft and Strategic Air Command B-52s pounded other targets while Seventh Fleet naval gunfire ships closed range along the North Vietnamese coast to engage Communist shore batteries. Apparently caught off guard by the large-scale attack, the enemy reacted sluggishly. U.S. aircraft encountered little opposition and the ships sailed to within 10 kilometers of the shoreline without being engaged by the normally active NVA coastal artillery.?2
Meanwhile, the artillery units which were to play their part in the following phases of the operation moved swiftly into position. Five Marine self-propelled batteries, located in positions along Route 9 between Camp Carroll and Dong Ha, rapidly displaced closer to the DMZ. Some batteries moved north as far as 12 kilometers, greatly increasing their ability to reach targets in the Operation Thor area. The 30 howitzers provided by the 3d Marine Division represented about half of the total III MAF artillery effort committed to Operation Thor. An additional 31 heavy caliber weapons, including 20 long-range 175mm guns, came from U.S. Army units.33
Following the carefully planned phasing of the operation, air attacks dominated the first two days, although artillery units conducted a few fire missions. During this phase, 1st Marine Aircraft Wing crews flew 194 sorties in support of Operation Thor, contributing significantly to the total Phase I ordnance delivery of over 4,000 tons.34
On 3 July, with the number of attack sorties slightly reduced and the B-52 sorties cut to one-half of the Phase I level, III MAF artillery and Seventh Fleet naval gunfire ships joined the attack in earnest. Remarkably, the ships closed to within five kilometers of the North Vietnamese shore without a hint of NVA fire. Over 12,000 rounds of various calibers struck Communist positions in a single day.
In an effort to exploit the effects of the powerful combined arms attack, psychological operations personnel conducted an aerial drop of 28,000 leaflets over the Cap Mui Lay sector. The leaflets, intended to take advantage of the anticipated lowered morale of NVA troops subjected to continuous heavy bombardment in what had been considered a "safe" area, advised that "desertion, defection, dereliction offer the only alternative to certain death."35
The success of Operation Thor hinged on fire support coordination and target intelligence. The major challenge in fire support coordination was to engage
*Colonel William H. Dabney, who as a major served on the 3d Marine Division staff, recalled some of the extraordinary efforts taken to restock the artillery ammunition. He recalled that the road from Quang Tri to Dong Ha was not cleared of mines and that it required Marine engineers to sweep the road before it could be reopened. Each morning two Marine engineer minesweepers departed, one from Quang Tri and the other from Dong Ha, and when "they met in the middle about noon the road was open and the convoys could begin." According to Dabney, this meant that six hours of daylight was lost before Marine trucks could move the ammunition. At that point, drivers from the 3d Motor Transport Battalion "volunteered [emphasis in the original} to drive the road each morning at first light wearing 2-3 flak jackets and with the truck cab carpeted with sandbags, and if they made it, then the road was open. If not, push their blown-up truck off the road and roll another through till it hit something." From that point, Dabney claimed that as a result "the road was usually open by 0800, which almost doubled the time ammo could be hauled." Col William H. Dabney, Comments on draft, n.d. (Vietnam Comment File).