On 3 September 1965, the battalion was again alerted for overseas movement, this time to the Republic of Vietnam. When alerted, the battalion was heavily committed with one line company at Fort Drum, New York, on road construction, 90 individuals on special duty and TDY support of Fort Devens and Fort Drum, and the remainder of the Battalion engaged in construction of range facilities at Fort Devens. The Battalion was also short a total of 123 personnel as a result of heavy levy actions taken to fill units previously alerted. On receipt of alert notification, all personnel were recalled from special and TDY duty, and the range projects at Fort Devens were transferred to the 86th Engineer Battalion from Fort Dix, New Jersey.
Immediately after receipt of the alert order, major emphasis was placed on inventory, repair and/or requisition or all supplies and equipment required for deployment. During the period 10 to 30 October 1965, a total of 108 vehicles and major items of equipment were turned in and about 100 were received. A significant shortage of organizational equipment persisted through the seventh week of training and included such major items as 15 2 ½ ton trucks and all radio mounts.
Upon receipt of the movement directive on 12 October 1965, and movement order on 14 October 1965, coordination was made with Headquarters, Fort Devens to expedite the receipt of personnel, vehicles and equipment. Task schedules relating to each staff functional area were established for internal control of all organizational actions required to meet the Equipment Readiness date of November 1965 and the Personnel Readiness date of 1 December 1965. In view of the short time remaining prior to movement, a phased personnel pre-deployment leave schedule was established from 26 October to 29 November 1965, which granted each individual 10 days leave. This schedule permitted all personnel to take leave, while providing at the same time sufficient personnel in garrison to prepare equipment for movement and allow for the orderly closeout of administrative and property accounts at Fort Devens. Port calls for equipment and personnel were received on 21 and 24 November. The majority of equipment and supplies were offloaded at the Boston Army Terminal on the USNS LT James E. Robinson, which sailed on 5 December 1965. The reminder of the shipment was shipped by rail to Oakland Army Terminal, Oakland, California where it was loaded on the MSTS Morgantown Victory for shipment to Vietnam. On 8 and 9 December, the main body of the battalion departed Fort Devens via various commercial and military aircraft for Oakland Army Terminal for loading on the USNS William Wiegel. The ship departed for Vietnam on 9 December and arrived at Cam Ranh Bay, Vietnam on 1 January 1966. The Advance Party had already arrived there on 18 December 1965.
Upon arrival in Cam Ranh Bay, the battalion was attached for all purposes to the 35th Engineer Group (Construction), by General Order #5, Headquarters, 18th Engineer Brigade. For the period 1 January to July 1966 the 20th Engineer Battalion and the attached 584th Engineer Company (Light Equipment) were located at Dong Ba Thin. During this time the battalion was engaged primarily in construction work. However, Company C was involved in operational support missions in the vicinity of Nha Trang during May and June. On 15 January 1966 the 584th Engineer Company was attached for all purposes to the 20th Engineer Battalion. On 15 June 1966 both units were attached to the 45th Engineer Group.
While at Dong Ba Thin the battalion and its attached units either completed or worked toward completing the following projects:
The highest priority projects in the Dong Ba Thin Complex was to bring the entire area to grade. It was estimated that 1,500,000 cubic yards of loose measure sand borrow would be necessary to raise the entire area to 6.51 feet above mean seal level at Cam Ranh Bay. It was determined that with this amount of fill, the complex would not be flooded during the monsoon season. At the time the battalion departed from Dong Ba Thin over one million cubic yards had been placed on the area.
Construction of three miles of interceptor ditch on the inside perimeter around the Dong Ba Thin complex.
Construction of two foot steel bridges with reinforced concrete piers on QL-1 across the interceptor ditch.
Construction of shoulders, overruns, and drainage structures for the 3000 foot runway at Dong Ba Thin.
Construction of 75 concrete helipads to be utilized by UH-1 Iroquois helicopters.
Construction of a 1200 ft parking area providing parking facilities for 18 CV-2 aircraft.
Construction of a 3000 ft parallel taxiway with connecting laterals and warm aprons in conjunction with the runway.
Construction of a CH-47 aircraft helipad.
Construction of two CH-47 hardstands (282' x 400')
Construction of three UH-1B maintenance hardstands (60' x 300').
Construction of Republic of Korea 2nd Marine Brigade Headquarters in the vicinity of Dong Ba Thin to include earthwork.
33,000 square feet of vertical construction to include standard tropical buildings for mess halls, administration/supply buildings, latrines, showers, dispensary, post exchange, chapel and arms room for the 1600 soldier cantonment area at Dong Ba Thin.
Construction of a 900 soldier cantonment area to standard three to include tent frames on concrete floors, mess halls, and administration/supply rooms.
Company B replaced the 1100 ft M4T6 float bridge at My Ca with class 60 bridge decking. This was accomplished in three days and two nights and the bridge was broken only at night to minimize the interruption of traffic.
Numerous small projects to include equipment and carpentry support to the ROK Marine Brigade; providing technical assistance to Company B 51st Special Forces detachment; construction of a crusher headwall and loading ramp; improving the bridge approaches to the My Ca float across Cam Ranh Bay.
During July and August 1966, the 20th Engineer Battalion with its attached Light Equipment Company deployed to various locations. Battalion Headquarters, HHC, Company A, and the 584th Engineer Company moved to the vicinity of Ninh Hoa to construct the Division Headquarters complex for the ROK Army 9th "White Horse" Division. Company C moved to the vicinity of Nha Trang to do construction work on the ROK Army Logistical Complex and Company B deployed to the vicinity of Ban Me Thout to begin construction of a Brigade size bivouac area for the 4th Division.
While at Nha Trang and Ninh Hoa the battalion and its attached units completed the following projects:
Construction of 5 miles of standard two road and culvert work in the ROK Army 9th Division headquarters.
Construction of 4 tropical quonsets in the Commanding General's area.
Construction of 24 tropical quonsets in the Division Administration area.
Construction of 7 miles of standard two road and culvert work in the Nha Trang ROK Army logistical complex.
Construction of tent frames, mess halls latrines, and showers for the ROK Army complex.
In September 1966, Company B (-) departed Ban Me Thout for Phu Tuc to begin construction of a C-130 airfield complex while one platoon deployed to Nhon Co to rehabilitate an existing C-130 airfield. From 3-10 September, the battalion supported two companies of the 101st Airborne Division on search and destroy operations in the vicinity of Ninh Hoa. Demolitions teams were provided in direct support of offensive elements. In addition, security for bridge sites and command posts was provided as well as logistical support consisting of hot meals, water, and ammunition.
On 10 September 1966, the 502nd Infantry was committed to the defense of the hamlet of Long Hoa. Concurrent with movement of that force to Long Hoa, Route QL1 was opened from Ninh Hoa to Tuy Hoa. One platoon of Company A was placed in direct support of the 502nd in defense of the hamlet. One squad of Company A provided mine and demolition reconnaissance for the convoy movement. Convoy command and control was assigned to the Company Commander, Company A. The route was opened from Ninh Hoa to Tuy Hoa on 14 September 1966. Defense of the hamlet terminated on 16 September with Company A returning to Ninh Hoa.
On 5 October 1966, Company A was temporarily reorganized as infantry, attached to the 1st Brigade 101st Airborne Division, and moved to the vicinity of Long Hoa for defensive operations. During the attachment Company A manned outposts and conducted combat patrols and ambush site operations. This operation ended on 13 October 1966.
In October, the Battalion minus deployed to the vicinity of Pleiku where it immediately began construction effort in the 4th Infantry Division base camp and provided combat operational support to Operation Paul Revere III, IV, and V (renamed Operation Sam Houston). After arriving in Pleiku, Company C moved out in support of 3rd Brigade, 25th Infantry Division in "Tropic Lightning" and the 4th Infantry Division in Operation Paul Revere IV. The mission involved the construction of bridges and bypass on Route 509 ( the main land logistics operations center of the division) and of the installation of culverts and a bridge on Route 14B (a lateral highway connecting Routes QL19 and 509). In 17 days of direct combat support, Company C installed 210' of culvert, erected 88' of dry span bridging, completed 140' of tank bypasses, prepared 5 AVLB abutments and stabilized bridge approaches with 415 cubic yards of crushed gravel. During Operation Paul Revere IV the division passed an average of 160 vehicles (wheeled and tracked) a day over the road. This marked the first time in six months that any heavy traffic had used Route 509 as a main supply route. The opening of this road markedly contributed to the success of Operation Paul Revere III and IV.
On 10 November 1966 the 20th Engineer Battalion and the 584th Engineer Company was attached to the 937th Engineer Group.
On 13 November 1966, Company A (-) with one platoon of the 4th Engineer Battalion attached, was airlifted to a small landing zone vicinity ZA 6055 where it immediately began to enlarge the area. By 1800 an LZ large enough to accommodate an infantry battalion was completed. Concurring with clearing operations, the 1/12 Infantry Battalion with supporting artillery, moved into the landing zone. Clearing, enlarging and improving the defensive positions continued throughout the next day and Company A was extracted on 15 November 1966.
On 16 November 1966, Company C (-) moved to the Se San River vicinity YA 7450 to continue a pioneer road (designated 509B) previously initiated by the 4th Engineers. The battalion's responsibility for the road began on the north shore of the Se San River. Almost immediately the scope of the work changed from the construction of a well-shaped, adequately drained, and correctly oriented one-way road. Two Rome plows (with KG cleared blade) were attached to Company C. The Rome plows were assigned to expedite cutting a 30-foot-wide path through the dense jungle. When enemy contact began to drop off in this area, the work on 509B was discontinued on 6 December 1966 after 5500 meters of roadway and one fire support base had been constructed.
On 2 January 1967, 3/C/20E moved back across the Se San River to resume construction of Route 509B. Two Rome plows, in addition to two bulldozers, were attached to the platoon. Work continued on building the road to the northwest and constructing fire support bases so the artillery could move to a forward position.
On 3 December 1966, Company D, 35th Engineer Battalion, now Company D, 20th Engineer Battalion, moved to the vicinity YA 8646 to construct the New Polei Djereng CIDG Camp and C-130 airfield. In addition to the CIDG Camp, a camp was constructed for a U.S. Artillery battery. Effort on the CIDG Camp consisted of clearing and leveling specified areas, emplacing the outer defense wire, and building a bypass road around the camp. Work on the artillery position was more extensive. Four gun pads with their associated ammunition and personnel bunkers were constructed. In addition a latrine, shower, mess hall, fire direction center, and maintenance slab were constructed and slots for future self-help construction were dozed. The C-130 airfield was constructed. The runway was initially an earth strip capped with a 62 layer of laterite. 3/B/20E, attached to Company D, then covered the runway with MX-19 aluminum mat, the first use of the MX-19 matting in Vietnam. No accessory kits were available, and an expedient anchorage system was successfully installed. On 24 January 1967, a C-130 standardization flight was made and the runway was found to be in excellent condition.
On 24 December 1966, Company C (-) moved to Ban Blech to rehabilitate the existing airfield, which had fallen into serious disrepair. The western 1000 feet of the runway was badly rutted, the under the T-17 membrane was extremely saturated, and the drainage of the area was found to be inadequate. After removing all the T-17 membrane, the runway and parking apron were sacrificed. Both the runway and parking apron were allowed to dry, were refilled and recompacted, and the centerline was raised one foot and capped with a 6 inch layer of decomposed rock. The runway was again graded and compacted.
On 1 February 1967, Company C (-) began a long distance move from Ban Blech to Duc Lap to construct a new C-130 airfield. Due to the fact that Duc Lap was so far removed from Battalion Headquarters, approximately 150 miles through unsecured territory, and because there was no existing airfield facility to effect receipt of supplies, all construction materials, POL, and rations for the project were assembled and loaded on a convoy originating at Battalion Headquarters in Pleiku and delivered to Company C at Ban Blech in the early afternoon of 1 February. After the supply convoy married up with the Company C convoy, the journey to Duc Lap proceeded with a stopover in Ban Me Thout that same evening.
Work on the project began on 4 February with clearing operations and the moving of a village which was located on the east end of the airfield centerline. Scope of work for this project consisted of building a C-130, T-17 membrane covered airstrip and packing apron to accommodate five C-130 aircraft. On 15 February 1967, six C7As landed on the newly completed 1000 foot runway. In addition a two-way all-weather access road, approximately three miles from Route QL-14 to the Special Forces camp, which provided bivouac and job site security, was required.
On 2 February 1967, Company D, 35th Engineer Battalion (now a One Station Unit Training battalion at Fort Leonard Wood, Missouri) relocated to Oasis to rehabilitate the existing 3000 foot runway to C-130 criteria, provide parking facilities for 5 C-130 aircraft, and construct a staging area for 40 helicopters. The existing airfield had been covered with T-17 membrane which was severely damaged by constant use and the airfield drainage had failed, causing deep ruts in the runway. The new 3500 foot runway was to be covered with MX-19 and the C-130 parking area with M8A1.
On 7 February 1967, 3rd Platoon, Company C closed in the Battalion Base camp after extending Route 509B approximately 11,000 meters to the northwest and constructing two fire support bases.
On 17 February, 3rd Platoon departed base camp for Phu Nhon to engage in an airfield repair project. This C-130 airfield had fallen into a serious state of disrepair with many ruts, soft spots, drainage problems, and sever damage to the T-17 membrane.
On 12 March 1967, Company B (-) completed its missions at Phu Tuc. The scope of the work as outline in the project directive was to construct a C-130 airfield in the vicinity of Phu Tuc Special Forces camp by extending an existing 2200 foot earth runway to 3500 and surfacing it with T-17 membrane. In addition, parking facilities for five C-130 aircraft, a forward assault heliport for three Airmobile companies, two turn-around and a 5300 foot access road from Route 7B to the staging area were constructed.
In March 1967, Company B (-) returned to Dragon Mountain base camp. On 16 March, 1st Platoon, Company A relocated to the Danner (Oasis) Quarry and began commuting to construct an 80 foot pile bent bridge on Route 14 B.
On 16 March 1967, Company D, 299th Engineer Battalion (now stationed at Fort Hood, Texas) was attached to the 20th Engineer Battalion to support base camp development of the 4th Infanty Division headquarters at Dragon Mountain Base Camp, Pleiku.
On 22 March 1967, Company A moved to the Oasis rock quarry. Due to the remote location of Companies B and C, it was necessary to resupply by aircraft. A rear detachment was established at Cam Rahn Bay to provide support for Company B at Phu Tuc and Company C at Duc Lap. Cam Rahn Bay was chosen as a base of support due to its extensive logistical facilities and the availability of C-7A aircraft for transporting supplies. Supplies including repair parts, POL and rations were flown to these companies from Pleiku Air Force Base and the Battalion Base Camp. In addition, aircraft from the 937th Engineer Group were utilized.
On 17 April 1967, a new OPLAN on base camp defense was initiated by the 4th Infantry Division. Though this OPLAN relieved the 20th of sole responsibility for a perimeter sub sector, the Battalion was still required to augment Infantry personnel in manning the perimeter bunkers within the 1st Brigade sector. The OPLAN further integrated the battalion into the 4th Infantry Division's Village Visitation Program. Company B was assigned the responsibility of visiting the villages of Plei Breng and Plei Monu Dooch and submit periodic reports to the 4th ID G-5.
On 6 May 1967, Company D closed at Duc Co Special Forces Camp to upgrade, construct shoulders, staging area, and drainage system for a C-130 airfield. They also upgraded QL-19W eastward from Duc Co to class 35 two-way, class 50 one-way capability with a parallel class 55 tank trail. The Duc Co airfield was to be used extensively by aircraft in support of tactical operations during the 1967 monsoon season.
Since November 1966, the responsibility of the construction of the Division cantonment, both vertical and horizontal, was assigned to Company A. ON 20 March 1967, Company B relieved Company A of the responsibility for the construction of the Division special staff area complex. Company D, 299th EN BN, joined Company B to support base camp development.
The 4th Infantry Division now had an active self-help program. Full-scale production of prefabricated buildings did not start until early February. The Battalion prefab yard was opened on a 24-hour basis starting early in March and production increased to approximately 10 buildings per day. The yard was run during the day by 8 enlisted men and 75 civilian workers. Approximately 12 enlisted men operated the yard at night. Total construction through 1967 was:
62,600 square feet of mess hall
13,872 square feet of maintenance facilities
46,720 square feet of medical facilities
8,800 square feet of administrative facilities
62,400 square feet of troop housing
252 20x80-foot buildings.
8 20x480-foot Quonset huts
3 40x100-foot warehouses
2 40x100-foot track maintenance facilities
3 26x90-foot automotive maintenance facilities
1 26-x104-foot automotive maintenance facility
1 20x200-foot mess hall
1 20x120-foot mess hall
11 20x100-foot tropical buildings.
Prior to being attached to the 4th ID Village Visitation Program, the battalion and attached units found time to participate in many civic action projects. All of these projects were undertaken and carried out during off-duty time. Some of the noteworthy programs completed were:
Clearing of a 400 x 500 meter refugee area located about two miles north of Dong Ba Thin military complex.
Construction of a 60 pupil school house with associated furniture and adjacent playground in the village of Than Thanh.
Construction of a 36 x 76 foot dormitory at the Loving Cross Orphanage in Lap Dinh.
Installation of a generator which was used as a power source for the village of Nihn Hoa.
Construction of a series of earth dams with wooden flood gates to control the flow of water to the Nihn Hoa area.
Assistance in digging wells in Montagnard villages near Ban Me Thuot.
An aggressive MEDCAP program was established in all battalion areas.
In mid-1967, the Battalion civic affairs section was active in welfare support of 2 villages of Montagnards that border the Dragon Mountain base camp.
By mid 1967, soldiers of the 20th Engineer Battalion had been awarded 22 Purple Hearts, 5 Bronze Stars with V device, and a total of 103 Bronze Stars and Army Commendation Medals for meritorious service.
In the second week of May 1967, Company A closed at Jackson's Hole, forward command post of the 1st Brigade 4th ID, and was engaged in upgrading and recapping three MSRs. In order to accomplish this project, one earth moving platoon, one dump truck platoon, one engineer line platoon, and various smaller elements were attached to the company.
Simultaneously, Company D, after completing the upgrade requirements of QL-19W from Duc Co east to road junction 14B-QL19W, began consolidating equipment and personnel to begin M8A1 surfacing project on Duc Co airfield. A survey of the airfield revealed that the existing strip was 100 feet wide by 3000 feet long. Rains continued for 20 days, during which time the effective work accomplished amounted to cutting and shaping all airfield drainage ditches, removing about 75% of the laterite cap which had become saturated, and maintenance of Route QL-19W.
On 22 May, Company C moved from its base camp at Combined Arms Hill to Danner Quarry. Company C was assigned construction of a two way class 55 tank trail from Dragon Mountain base camp to Duc Co. The company was given the secondary mission of keeping QL-19W open to traffic during the monsoon season. Company A was given a similar task. A tank trail from the intersection of QL-19W and 14B to the vicinity of the SF camp at Polei Djereng. It was emphasized that this project would not be allowed to interfere with the road maintenance mission. Due to a lack of equipment, progress on the trail was somewhat hampered. On 29 May, the tank trail projects were deferred until the end of the monsoon season since heavy equipment and compaction equipment could not be used effectively. Both companies cleared 60% of the tank trail right of way.
On 29 May 1967, the 173rd Airborne Brigade (now stationed in Italy), at their bivouac site at Catecka became bogged down in mud and was unable to get their supply areas or maneuver in their base camp. Company C was committed to provide drainage and build drainage and build all weather road capabilities throughout the 173rd area.
Road maintenance, airfield construction, helicopter hanger erection was well under way in June 1967. Revetments and land clearing continued to be prominent in the daily work schedule. Company D commenced work on a forward support helipad. In the designated area of the helipad, a minefield was uncovered. Before work could progress, the minefield was cleared. The minefield contained 88 M14 and M16 mines.
On 24 June 1967, Company D, 299th Engineer Battalion returned to the control of their parent unit. Company C (-) worked on the 173rd Airborne Brigade cantonment area. On 3 July 1967, the 173rd Airborne Brigade moved headquarters from Catecka to Kontum to engage in Operation Greely. Company C began to devote full effort in maintaining QL-19W from intersection of QL-19W and QL-14 to Danner Quarry.
On 10 July 1967, Company A received a priority directive to cover the airstrip at Duc Co with MC-30 and to emplace M8A1 mat on 3500 feet of runway. 3rd Platoon was deployed and began laying M8A1 at an average of 18 to 20 thousand square feet a day. Later in the month Company A received an additional directive to construct 150 ft square turnarounds at the end of the runway. This project was complete on 31 July.
Company A continued the maintenance of highways QL-19W and 14B throughout the monsoon season. On 15 August, Company A assumed the repair and maintenance responsibility for 600 meters impassable section of the interior road net through Jackson's Hole. The project involved ditching, draining, and shaping the 600 meters of road before placing the necessary quantity of crushed rock. The road work was done mostly by hand during the heavy rain. On about 20 August, the impassable section of the road was opened for traffic, allowing desperately needed 4th ID supply vehicles into Jackson's Hole.
Company C continued maintenance of QL-19W. On 3 August and again on 15 September, the Bailey Bridge collapsed under a combination load of a VTR and M48A1 tank and a UTR. Company C diverted its effort to repairing an existing bypass at the bridge site supporting the 509th Panel Bridge Company in replacing the destroyed bridge. On 3 August the 584th Engineer Company (LE) was committed to maintaining the portion of QL-19W (MSR) from the bridge site, east to Camp Enari. This MSR mission was assigned the Light Equipment Company, while Company C was engaged in repairing the bridge. The 584th LE Company retained maintenance responsibility until 26 September 1967.
On 15 August, word was received that prop wash from a CH-47 helicopter had displaced 480 linear feet of MX-19 runway at Polei Djering Airfield. On 16 August the second and third platoon of Company B were airlifted to Polei Djering. By 17 August 30,000 square feet of matting had been realigned and reconnected when another CH-47 disconnected an additional 435 linear feet of runway. On 18 August, a field expedient anchorage system, consisting of 36 inch V shaped pickets and #9 tie wire, was flown in and realignment and anchorage wire completed on 19 August. Both platoons had returned to Camp Enari by 20 August.
On 19 August, Company C and the 584th Engineer Company moved form Danner Quarry to the Wooly Bully Quarry - 2.3 kilometers from Danner Quarry. The new bivouac site was prepared by 1st Platoon, Company C.
The 35th Engineer Platoon (Land Clearing) was attached to the 20th Engineer Battalion and closed at Camp Enari base camp on 19 August 1967. During the next week the first and second squads were supporting the 70th and 299th Engineer Battalions respectively. The third squad remained attached for land clearing operations to the 20th Engineer Battalion for work in the area of operation. The third squad began a clearing operation on QL-19W in the vicinity of the Wooly Bully Quarry on 25 August. From 25 August through 22 October the 35th Land Clearing Platoon cleared over 3648 acres on Routes QL-19W, QL-19E, QL-14S, and TC-6C. On 24 October the 2nd squad of the 35th was reassigned from the 70th Engineer Battalion to the 20th for work at the Edap Enang settlement village.
With the shift of the 1st Brigade, 4th ID from Jackson's Hole to the Oasis, Company A moved one platoon to the Wooly Bully quarry on 17 September to prepare a company sized bivouac area. Company A (-) relocated to base camp on 21 September and assumed several small proects. On 21 October 1967, Company A opened its CP at the Wooly Bully Quarry, assumed the mission of MSR maintenance and upgrading of QL-19W from the west to Duc Co.
On 22 September, Company C and Company D exchanged tasks and locations. Company C took over Company D's base camp projects and Company D assumed responsibility for a portion of QL-19W. Among Company C's projects was the construction of 88 helicopter revetments for the 7/17th Air Cavalry Squadron scheduled to arrive in the Republic of Vietnam on 23 October.
On 11 October 1967, Company B's CP and its second platoon, reinforced with earth moving equipment from the Battalion Equipment platoon, moved to Plei Do Lim to begin upgrading of Route LTC-7B from Plei Do Lim village. The scope of the work involved upgrading the roadway from a fair-weather to limited all-weather capability and repair of a bridge. This was an operations support mission in general support of 4th ID's OPLAN Middleton. The first platoon of Company B moved to Phu Tuc airfield to repair the T-17 runway that was ripped open by C-130 prop wash. On 20 October, Company B's CP and second platoon returned from LTC-7B MRS upgrading and bridge repairs were reported as 100% complete. On 28 October, the first platoon of Company B returned to base camp having completed repairs of the T-17 membrane at Phu Tuc Airfield.
On 25 October 1967, the first platoon deployed to Ban Blech to begin work on upgrading the existing airfield and to provide general engineer support to CP 2nd BDE, 4th ID. On 2 November, one squad of first platoon Company C convoyed from Ban Blech to Phu Nhon to undertake repair of the T-17 airstrip. This project was completed on 7 November and the squad returned to Ban Blech.
Land clearing and upgrading on QL-14B was completed on 4 November 1967. At this time, the second platoon of Company A and its attached Land Clearing Section were committed in general support of the 6/14th Artillery and the Special Forces detachment at Polei Djerang. Work at this location involved draining and leveling of abandoned positions. The Polei Djereng project was completed on 10 November 1967. Company A was assigned to the mission of LOC upgrading of QL-19W from the Wooly Bully Quarry west to the intersection of QL-19W and 14-B; Company D retained responsibility of QL-19W from the quarry east to Dragon Mountain.
On 11 November 1967, the 35th Engineer Platoon (LC) was committed in general support of the Battle of Dak To. The mission of the detached platoon was to conduct land operations along the 4th ID's Pleiku to Dak To MSR. With the Battle of Dak To termination on 31 December 1967 with total US victory, two sections of the platoon were returned to the 20th Engineer Battalion operational control and were recommitted to agricultural draining at Edap Enang.
On 10 November, the battalion received the mission to upgrade Ban Blech airfield to MACV Class II, C-130 criteria; a survey team was dispatched to obtain data on the center line profile and conduct a topographic survey of the existing facility. On 22 November 1967, the survey was completed and preliminary planning and work estimates began. Due to the fact that the airstrip was situated in a cut across the tip of a hill with extensive filling at one end, it would be necessary to do massive cut and fill operations to satisfy MACV specifications of line and site of lateral drainage criteria. For this reason waivers of line of sight, lateral drainage, and overruns were submitted to the 937th Engineer Group. A waiver was approved for runway length, but all others were refused. Preliminary work estimates indicate that the cut and fill operation would require the moving of approximately one-half million cubic yards of earth to have the strip conform with unwavering criteria. When these figures and accompanying equipment requests were submitted to the 937th Engineer Group, a conference was arranged with IFFV's Army Logistics Officer. As a result of this preconstruction conference, the existing airfield was accepted with modified lateral clearance and line of sight criteria.
In late November, enemy activity with the battalion's area of operations increased. On 24 November a minesweep team from the third platoon, Company A was ambushed by an estimated NVA Company north of Jackson's Hole. Prompt reaction by 3rd platoon and the attached security force caused the enemy to be driven off and minimized friendly casualties.
On 7 December, the 584th Engineer Company (LE) began a project to pave QL-19W through Tanh village. It was decided to accelerate the paving effort in this area because of the extreme dust problem caused by US traffic. On 16 December 1967, the project was completed and the road was officially opened with a ceremony attended by the battalion commander, 20th Engineer Battalion; commanding officer, 937th Engineer Group, Commanding General, 4th Infantry Division; the Pleiku Province Chief and several local Vietnamese officials. The efforts of the Engineers were well received and the commanding officer of the 584th Engineer Company was presented a plaque as a token of appreciation of the Tanh Anh villages.
On 20 December 1967, Company B was committed in direct support of the 5th Special Forces Group's Operation Florida. The mission: construct a Civic Irregular Defense Group (CIDG) camp and a C-7A capable airfield at Tier Atar. Due to the fact that Tier Atar is completely inaccessible by road, all equipment, personnel, and supplies were moved to the job site by CH-47 Chinook and Ch-54 Skycrane helicopter. An advance party consisting of a platoon (-) was air lifted to the site on 20 December. The remainder of the company closed on 21 December 1967 utilizing 12 CH-47 helicopter sorties. Airmobile engineer equipment necessary to accomplish the mission was obtained from the 8th Engineer Battalion, 1st Air Cavalry Division, the 937th Engineer Group, and the 5th Special Forces Group.
The equipment was flown to Ban Dan Special Forces camp by C-130 aircraft and lifted 33 kilometers to the work site by CH-54 Skycrane. All construction materials were supplied by the 5th Special Forces Group and were air dropped into the work site by C-7A aircraft. Initially all work efforts were directed toward sitting up a defense perimeter and clearing fields of fire for the engineer work force and the security unit. Since the entire area of the camp and airfield was heavily forested with large hardwood trees, clearing was a major task. All possible work was done with the attached engineer equipment. A demolition squad followed approximately two days behind the equipment to remove large trees. Native timber was extensively used in bunker construction. By 30 December 1967, preparation of the defense perimeter was sufficiently advanced that the work effort could be diverted to clearing of the airfield.
On 20 December 1967, arrangements were made for the 35th Engineer Group (Construction) to use its organic tractor/trailer capability to have M8A1 matting and asphalt for the upgrading of Ban Blech airfield. The haul was to be through shipped from the Logistical Depot at Qui Nhon to Ban Blech. With the procurement and delivery of these items assured, Company C (-) moved by convoy from Camp Enari to Ban Blech on 21 December to undertake the project. The move into the bivouac site was accomplished quickly and work began immediately. The scope of the work involved the construction of a 3000 foot M8A1 runway with a 150 x 150 foot turnaround and a 750 x 160 foot parking apron severed by two 170 foot taxiways. All surfaces to be covered with M8A1 matting were first treated with penaprime and RC-3.
The close of 1967 found Company A, Company D (-), and the 584th Engineer Company (LE) engaged in upgrading of QL-19W and quarry support at Tier Atar; Company B continued the upgrading of Ban Blech airfield, and the first platoon of Company D remained at Camp Enari with responsibility for the Battalion Batch Plant and Prefab Yard. Headquarters and Headquarters Company remained in Camp Enari.
During the period of February 1968 to October 1969, the 20th Engineer Battalion and its attached units, namely the 584th Engineer Company (LE) and the 35th Land Clearing Platoon (reorganized as the 538th Land Clearing Company under MTOE 5-500C on 20 January 1969), completed or worked toward completing the following missions in their Area of Responsibility.
(1) Land clearing
From 1 May 1968 to 31 July 1968, the 35th Land Clearing Platoon with support from Companies C and D, cleared QL-19E from Many Yang pass to Pleiku and QL-14N north of Kontum through an often used ambush site. At the end of this period the 35th Platoon was detached from the 20th and attached to the 35th Engineer Group (Construction) for missions in Bong Son. Total acreage cleared during the period was 10,800.
During the period 1 May 1968 through 31 October 1968, 2/C/20 was engaged in clearing 300 meters (line of sight) along QL-14N. The mission totaled 330 acres of regrowth being cleared.
From 1 November 1968 through 31 January 1969, 1/A/20 was engaged in clearing QL-14N totaling 1100 acres of virgin jungle. ON 7 December, the 35th Platoon was again attached to the 20th, and with Company D began clearing QL-14S north of Ban Belch to Ban Me Thout, then continuing 76 kilometers to the south. Utilizing 17 Rome plows and 10 Bull Blade 07E Dozers, a total of 4800 acres had been cleared at the end of the period.
From 1 February 1969 through 30 April 1969, heavy emphasis was given to land clearing operations throughout the 20th Engineer Battalion Area of Responsibility. The major routes cleared were QL-19E west from An Khe; QL-2E, from Ban Blech to Muan Man to include the construction of 18 kilometers of one lane road 8 to 10 feet wide with V ditches, and spanning a 23 x 9 foot gap on the roadway; organization of Task Force Stinger, comprising a 4 phase Joint Vietnamese-American clearing operation which included an M4T6 rafting operation across the Ea Krong River; clearing QL-19E, from An Khe to Qui Nhon; and the completion of Task Force Bush Hog along QL-14S, to include a total of 6895 acres cleared. The primary emphasis on all clearing operations during this period was clearing densely covered areas along main supply routes in an attempt to diminish the possibility of ambushes.
During the period 1 May 1969 through July 1969 the completion of Task Force Stringer was consummated with extensive civil affairs projects being incorporated. Along with this additional clearing operations around a proposed firebase for the 2/8 Infantry (Mech) and the organization of Task Force Rapid Cut along LTL-6B which was begun on 14 June 1969. From 1 August to 31 October 1969, the 538th Land Clearing Company prepared to undertake Task Force Land Sweep consisting of clearing QL-19E through An Khe and Mang Yang passes. This project was completed on 31 October at which time the Land Clearing Company extracted for a 14 day stand-down.
From 1 May 1968 through 31 July 1968 airfield missions including an emergency repair mission on Plei Djering Airfield caused by a helicopter crash on 18 June 1968 which damaged 24 MX-19 panels; the mission was completed in one day and the expeditious performance permitted air traffic missions to continue without delay.
During the period 1 August 1968 through 31 October 1968 the 20th Engineer Battalion was committed to only one airfield repair project at Ban Blech airfield. The work required the repair and upgrade of the shoulder slopes along the runway which had begun to erode due to monsoon season. The repair work consisted of building three retaining walls secured by V pickets, driven at 4 inch intervals. The eroded ditches were filled and reshaped to original contour to include a 120 square meter area laid with sod.
From 1 November 1968 through 31 January 1969, two major airfield repair missions were undertaken. The first consisted of extensive upgrade of failed subgrade underneath the taxiways at the An Khe airfield. The scope of work accomplished included the use of soil cement and M8A1 matting in repairing 145,000 square feet of eroded taxiways. The second mission again concerned with erosion on the existing airstrip at Cheo Reo incurred during the monsoon season along with damaged turning points caused by pivot action of C-130 and C-123 aircraft.
Airfield repair was also accomplished on Ban Blech airfield and Polei Kling between 1 February and 30 April 1969. The mission at Ban Blech included placing timber and sandbags along both sides of the airstrip to control erosion subsequent to the upcoming monsoon season. At Polei Kling repair work was required due to enemy artillery fire which caused extensive damage to existing parking aprons and the substrip. Work consisted of upgrading and replacing the damaged areas on the airstrip and rebuilding the parking aprons.
From the period 1 May 1969 through 31 July 1969, increased emphasis was again placed on airfield repair missions. A total of four projects were undertaken to include airfields at Cheo Reo initially required placing 4 large concrete patches on the airstrip at touchdown and turning points. The failure was caused due to problems with the penetration macadam. During the mission, additional failures occurred from twelve sorties of C-13s landing on the airstrip. The damage was extensive on the surface of the runway. The increased scope, due to this failure, included excavation of failed areas, upgrade of subgrade, and an application of a 4" cold mix asphalt covering the entire runway area. At An Khe airfield the repair project included repair of subgrade and replacing 105,000 square feet of M8A1 matting over the airstrip caused by repeated turning of C-130 and C-123 aircraft. Dak Seang airfield required airlifting 130 barrels of RC-800, an asphalut kettle, and 1 squad of engineers. The entire airfield was sanded, shot with RC-800 in tow coats, and sanded again. The 52nd Artillery airstrip required a complete upgrade of the airstrip to include scarifying, shaping, and resealing utilizing RC-800.
From 1 August through 31 October 1969, two airfield repair missions were undertaken. At Dak To the airstrip, damaged by enemy incoming artillery rounds, received extensive repair. The Ben Het airfield failed under constant use, and repair began by removing the SSP from the entire airfield.
(3) Lines of Communication Maintenance
During the period, work on Highway QL-14N encompassed the entire road stretching from Ben Het to Camp Enari access road. Throughout the period the 20th Engineer Battalion was tasked with upgrade, repair, and construction of various sections of this road to insure constant trafficability. The battalion was tasked with many other maintenance projects along QL-14N, QL-19W, and QL-14S. The projects included preparations for paving, paving, improving drainage, installing lateral ditches and culverts, improving road surfaces, and maintenance of the above roadways.
(4) Prefab Yard and Batch Plant
The Battalion's Prefab Yard and Batch Plant were operated by Company D and Company B from 1 February to 30 April 1968. The work accomplished in these months included stockpiling and issuing prefab materials for various missions throughout the AOR to include cement for LOC upgrading and self-help projects.
From 1 May to 31 July 1968 the yard and plant were operated by 2nd platoon, Company B. Work accomplished during this period consisted of prefabricating 46 20 x 100 foot two story tropical buildings, 2 40 x 100 warehouses, 13 latrines, and 24 tent frames. The Batch Plant produced over 676 cubic yards of concrete during the same period. By August, Company B had the additional responsibility of operating a rock quarry operation at the base of Drago Mountain. On 5 September, Batch Plant operations were discontinued at Camp Enari.
From 1 November 1968 to 31 July 1969, the Battalion's Prefab Yard was operated at full capacity by Company B. On 1 February 1969 the Prefab Yard operations were augmented by the addition of 40 local nationals to aid the company in the upcoming construction season. Work during this period included the prefabrication of SEA huts for firebases at Oasis, Blackhawk, and Mary Lou; construction of latrines for Mary Lou and Ben Het firebases; and forms for Bridge 14-22-1.
On 26 August 1969, with the Battalion relocated at Engineer Hill, the prefab yard moved from Camp Enari to Engineer Hill. Upon relocation, work was begun on prefabrication of bunker complexes for perimeter upgrade on Engineer Hill. In addition an enormous prefabrication mission was undertaken to construct Living/Fighting bunkers at Ben Het firebase. The scope of the work was large enough to warrant another prefab operation. Company D relocated from Engineer Hill to Kontum and began operating an additional prefabrication yard. With this new yard being in operation, the yard at Engineer Hill was given an additional mission of constructing Living/Fighting bunkers for the perimeter upgrade at Tan Kanh.
(5) Minesweep responsibilities
Since one of the major requirements of any unit in a combat environment is mobility, the responsibility of insuring that all major routes throughout the AOR are kept open and free of mines is of vital concern. The 20th Engineer Battalion was tasked with numerous minesweep responsibilities to include the following road networks: daily minesweeps on QL-19W, QL-14, and QL-14N.
To insure the constant trafficability of the road networks throughout the 20th Engineer Battalion's AOR, emphasis was placed on bridge construction and repair throughout 1969. Bridges were repaired along QL-19W, bypass construction for bridges QL-19W-47 and QL-19W-38, repair of bridge QL-14B-1, repair of Bridge QL-19-30, construction of a pile bent bridge north of Bridge 19-33, and a bypass at Bridge 19-38. Construction of an AVLB abutment at Bridge QL-19-37 was also completed. A double bailey and treadway were replaced on the bridge. Other bridge construction projects included a class 120 bridge, a MACV type L bridge over the IA Meneye, and the construction of Bridge 19-37. Bridge 19-37 was a 60 foot single span bridge with steel stringers and augmented with timber decking.
(7) Vertical construction
(a) Oasis Airfield - Much construction was accomplished at the Oasis Airfield. 3rd Platoon of Company B was tasked with repairing the 7th Squadron, 17th Air Cavalry's helicopter revetments. The scope of work included widening the existing revetments, changing the height of various revetments, and bringing to final grade areas around the revetments. On 2 May 1968, Company C began construction of gun pads and berms for heavy artillery pieces. The work consisted of constructing the following: 1 8 inch gun pad, 3 175mm gun pads, 8 ammunition storage bunkers, 1 Tactical Operations Center, 1 Executive Bunker, and 1 mess hall.
(b) Tieu Airstrip - The scope of work at Plei Djerang included the construction and erection of 2 ammo storage bunkers, the redecking of the existing 175mm gun pads, 3 personnel bunkers, 1 gun pad, and 4 additional ammo storage bunkers which were required due to the existing bunker complex having been destroyed or severely damaged by an enemy rocket attack. The scope was extended to include 2 underground powder and shell magazines. Work also was done for the 6/14th Artillery to include redecking of 4 40 foot gun pads.
(c) Camp Enari - Base camp construction for the 4th Infantry Division at Camp Enari consisted of many varied projects to include 1 two story administration building; 1 40 x 100 warehouse; 2 40 x 100 repair and utility shops; 4 prefabricated steel PASCOE buildings for the General Education Development Center; 1 90 x 160 theater-gymnasium type tropical building; 3 175mm gun pads; 6 ammo storage bunkers; 1 aircraft maintenance hanger for the 7/17th Cavalry including one 800 x 140 standard wood modular building with a 12 inch reinforced concrete pad; 3 20 x 50 concrete pads; 1 40 x 100 concrete pad for the 704th Electrical/Communications Maintenance Building; reconstruction of a 40 x 130 snack bar for the 4th ID PX concessionaire which was destroyed by fire; an 80 x 144 maintenance hanger for 7/17th Cavalry which included the pouring of 440 cubic yards of reinforced concrete; a controlled environment engine maintenance shop; and 4 72 foot valley drains; 2 40 x 100 warehouses, wood frame with installation of 5000 square feet of shelf space; a 60 x 100 concrete pad, footers for columns, and side walls for a raised stage including the use of 240 cubic yards of concrete for the Ivy Theater; prefabrication of generator revetments for the central power facility; 7 50 x 50 concrete helipad wash pads.
(d) 283rd Dust Off - Pleiku - Work included the erection of 2 19 foot high guard towers, 1 50 man protection bunker, 10 3 man fighting bunkers, 5 30 x 50 aircraft revetments for protection of UH-1H helicopters.
(e) Camp Holloway - Work included completing an aircraft control tower which has transferred to the 20th from the 70th Engineer Battalion which was preparing to move to a new AO. Work consisted of erecting guard rails on the roof of the cabin, plexiglass windows, 3 air conditioners, 6 inch reinforced concrete pads to accommodate a 14 x 17 foot generator shed and a FAA Communications Van.
(f) Wooly Bully Quarry - Work included pouring two each 20 x 100 x 8 foot reinforced concrete pads, a 90 x 26 foot maintenance shop, a quarry chinaman, and one each grease trap; two each 22 x 27 foot concrete pads for mess halls; replacing the damaged chinaman to include the posts, footers, decking, and siding.
(g) 815th Engineer Quarry Site - The scope of the work included placing 6000 meters of triple concertina fencing; 2500 meters of cyclone fence; and the construction and replacement of 10 guard towers around the perimeter.
(h) Blackhawk Firebase - Construction consisted of one mess hall, five living and ammunition bunkers, and truck revetments. Construction began on a helicopter rearming point to include cut, fill, and drainage; 16 helicopter rearming points; 8 each 32 x 9 foot revetment; and a complete application of pencprime over the entire area.
(i) An Khe - Construction of 60 8 foot revetments which were prefabricated at Engineer Hill and then transported to An Khe for erection; helicopter revetments at the golf course; installation of a 24 foot high B-40 standoff around the POL tanks in the An Khe Tank Farm to include elevating the existing berms an additional 5 feet; construction of U-21 aircraft revetments; assembling burying five miles of pipe west from An Khe. Work included laying 26,000 feet of coupled tubing using five entrenchers and an MCA Gradall; it included a 24 hour operation with a two platoon effort.
(j) Kontum - Construction of FOB II helipad for CH-34 helicopters to include repairing and surfacing a 30 x 200 foot area firebase at Kontum to include site preparation with the construction of 4 each 175mm/8 inch gun pads, revetments, and berms; eight ready storage ammo bunkers and two each powder bunkers; constructing a tower to support 3000 gallons of water; eight ammo storage bunkers and replacement of decking on gun pads at Mary Lou; B-40 standoff for asphalt plant including driving 38 12 inch piles on 16 foot centers and hanging a 20 foot high cyclone fence curtain; in addition 2 16 x 16 foot gates were constructed of 3 inch pipe and cyclone fence; and work on a MACV Get Well project.
(k) Ben Het - Construction included 2 each 20 x 20 projectile bunkers, two 20 x 20 powder bunkers, connected by a 15 foot side by 14 high by 60 long covered passageway; replaced decking on 4 175mm gun pads; refurbishing berms around ammo and powder storage bunkers; 15 20 x 40 living/fighting bunkers; 5 mortar pits; 5 priority roads, 1 helipad, and an airstrip apron.
From 1 January 1970 to 28 August 1971, the 20th Engineer Battalion with its attached units, the 584th Engineer (LE), 15th Engineer Company (LE), and the 509th Engineer Company (PB) provided virtually all engineer support in the Central Highlands of MRII. Primarily situated near Pleiku, the Battalion pursued its engineer mission from Dak To in the north to Ban Me Thout in the south and from the Cambodian operations in the west to An Khe in the east. During the initial months of this period, the battalion was involved in a change over process from the primary mission of providing combat support to the 4th Infantry Division to a mission with emphasis on Lines of Communication construction. Consequently the unit was in a highly fluid situation.
Support of the 4th Infantry Division called for Company A to be located at Camp Enari near Pleiku disassembling maintenance hangers and preparing them for movement to the 4th Infantry's new base camp at Camp Radcliff near An Khe. Company B was at Camp Radcliff constructing living/fighting bunkers and building an Artillery firebase. In March 1970, Company A relocated to Camp Radcliff to reconstruct the maintenance hangers they had disassembled at Enari. Headquarters Company was located at Engineer Hill near Pleiku along with a portion of Company D and A. Company D had elements at both Engineer Hill and Camp Enari. A platoon from the 584th Engineer Company and one platoon of the 15th Engineer Company were preparing the earthwork of QL-14S. The 538th Engineer Company (LC)( was based at Engineer Hill but spent most of its time in road camps on QL-14S and QL-14N due to their land clearing mission. The remainder of the Battalion was stationed at the Weigt-Davis Industrial Site, 40 kilometers south of Pleiku. There Company C and the 584th Engineer Company were involved in base cam construction, preparation of a soil stabilization plant to produce black base for QL-14S, and quarry and crusher operations.
As the construction season of 1970 progressed and the Battalion became highly committed to Operation Last Chance, a tremendous push to complete as many kilometers of pavement as possible was initiated and in February the Battalion formed a provisional Dump Truck Company to provide the haul support for the extensive paving operations. Trucks were pulled form each line company and from the 509th engineer Company (PB) which was only OPCON to the battalion at that time. A complete Company Headquarters was established and the new unit rapidly assumed an important role in hauling asphalt from the CTA yard near Pleiku, base course from Webb quarry near Pleiku and black base from Weigt-Davis. Company D relocated to Camp Enari to be closer to the paving site as the Battalion responded fully to the operation.
Near the last of February, Company B competed its operational support of the 4th ID, moved to Engineer Hill and began its contribution to LOC projects by repairing bridges 19-33 and 19-34. As the dry season of 1970 reached its second half, the Battalion continued to readjust to efficiently perform its road construction requirements. In late March 1970, Company D, having completed the soils stabilization plant moved one platoon to Cheo Reo to perform an upgrade of 24 miles of Route TL-7B between Cheo Reo and 14-S. To add to the Battalion's haul capabilities, the 585th Engineer Company (DT) was attached to the battalion near the first of April and located at Weigt-Davis. The Battalion's provisional Dump Truck Company remained at Engineer Hill, Pleiku in order to be closer to the asphalt plant at the CIA yard. On 1 April 1970, the 509th Engineer Company (PB) was officially attached to the 20th Engineer Battalion.
Although the major efforts of the Battalion were in the field of Line of Communication maintenance, the 20th Engineer Battalion did not abandon the high priority mission of operational support. Mine sweeps for 1/92 Artillery, airfield and revetment construction as well as repair for 52nd Aviation Battalion at Camp Holloway, rehabilitation of several fire support bases, and upgrade of outlying airfields were all accomplished during the spring and summer of 1970. The LOC construction season came to a close with the Battalion having completed QL-14S between Enari and LTL-7B and having continued earthwork and black base lay down on QL-14S, south of LTL-7B and on LTL-7B itself. The bridge repairs on 19-33 and 19-34 had also been completed.
During the months of May and June the Battalion prepared to vacate Engineer Hill and move to Camp Wilson near Pleiku. This move was completed in July with HHC, Company A, Company B and the 509th occupying the post. Engineer Hill was turned over to elements of the ARVN Engineers. The end of the road building season brought about the detachment of the 585th Engineer Company in late June to the 589th. The 538th Engineer Company (LC) transferred to the 299th in mid July and the 1st Platoon of the 15th Engineer Company (LE) returned to its parent unit.
As the monsoon season of 1970 covered the Central Highlands, the 20th Engineer Battalion began to prepare for the next construction season and also shifted some of its emphasis to vertical construction. The highlights of August, September, and November was the relocation of the asphalt plant from the CIA yard to Weigt-Davis. Company A was called on to disassemble, transport and reassemble the plant while Company D was given the task of site preparations at Weigt-Davis. Company B was involved in the repair of the runway at Camp Holloway for the 52nd Aviation Battalion and the building of a headwall for a 75 TPH crusher at Weigt-Davis. The 509th Engineer Company relocated to Weigt-Davis and was given the sole responsibility of transporting the black base material and asphalt. The 20th Engineer Battalion was constantly involved in improvement of its defensive posture and living conditions as the monsoon season afforded a good opportunity to increase these efforts. Company C built nine new guard towers at Camp Wilson while also improving the perimeter wire and Company B was tasked with the construction of four SEA huts on the compound. In late October a reinforced platoon from Company A relocated at Ban Me Thout to assume responsibility for projects of the 19th Engineer Battalion following their deactivation. Involved was Project 1000 requiring the construction of twenty PASCOE buildings and Project 25 which called for construction of four 96 x 20 foot buildings at MACV Team 25. Both projects had barely been initiated by the 19th Engineer Battalion left the 20th Engineer Battalion as the only major US Engineer Unit in the entire Central Highlands.
With the end of the monsoons the Battalion once again directed its efforts toward LOC construction. due to a destructive fire at the newly constructed asphalt plant at Weigt-Davis construction of QL-14S was delayed a little more than 30 days. Company B rebuilt the damaged sections and the plant became operational again in early December. Company D once again received the missions of placing the base course and the asphalt in the push to complete QL-14S to Ban Blech by the end of the construction season. The 584th Engineer Company continued its outstanding support of the operations by preparing the earthwork and handling the Quarry Crusher Operation at Weigt-Davis. The 509th Engineer Company (PB) was once again transformed into a Provisional Dump Truck Company utilizing the five ton dump trucks from Companies A, B, and D. They provided the haul capability necessary for work on Routes QL-14S and QL-14N.
In mid-November the 15th Engineer Company moved from Qui Nhon into Camp Wilson with a mission of correcting earthwork and drainage on Route QL-14N. They began work immediately and completed their project in late March. The then prepared to move south to assist the 584th in the earthwork requirements and the construction of QL-14S. After upgrading the Pleiku bypass in November, Company C was tasked to upgrade Route QL-14N by placing 5 feet of black base on the shoulders recently constructed by the 15th Engineers and repairing those areas which exhibited evidence of subsurface or pavement failure. This project continued throughout the construction season and was completed after many inspections in August 1971.
Company A initially began work on repairing the failure area at Deadman's Curve on QL-19E, but in early February they were called to relocate to Ban Me Thout in support of Task Force Sierra. During the period Company A was attached to the Task Force. The constructed the Ban Me Thout Industrial Site. They also opened the quarry, handled the necessary earthwork, prepared the crusher sites, built the asphalt plant, a seven bay maintenance facility, a mess hall, headquarters building and various other buildings. They completed their mission on 1 July 1971.
Meanwhile on QL-14S, Company D had progressed far enough south with paving operations to call for a relocation. Within a few days a new LZ was built by Company D, one platoon from the 584th, and one platoon from Company C. The new LZ was named LZ Lonely and road surfacing operations after mid-February originated form there. Just south of LZ lonely, Bridge 14-17 presented a serious obstacle to the southward push of earthmoving equipment. A Triple-Single Bailey Bridge 150 feet long, was constructed over the partially destroyed bridge by Company C in mid-February to enable 290s and D-9 dozers to continue their work.
As the paving train and earthwork operations progressed southward in February and March enemy activity increased greatly. Mine incidents became an everyday occurrence, ambushes and sniper fire caused many delays, yet paving continued. Finally on 16 March a major NVA offensive was launched in the area and primarily directed against the city of Phu Nhon, which lay astride 14S roadway between Weigt-Davis and LZ Lonely. The 95th NVA Regiment (Reinforced) established control over the 5 to 6 kilometers of 14S north of Phu Nhon and consequently cut off supplies to LZ Lonely. An immediate airlift of supplies to LZ Lonely enabled the units to prepare themselves defensively. The siege of Phu Nhon was finally lifted by the NVA on 22 March 1971 and vehicles were again able to travel to LZ Lonely. However, on 1 April 1971 the road was once again severed by NVA units. Despite the fact that LZ Lonely received mortar and rocket attacks daily, no US KIAs were sustained during this action and 5 Engineers were wounded.
The 20th had been planning to redeploy a line company and a light equipment company to a newly constructed LZ (LZ Marlar) near Ben Blech the terminal point of the assigned road work. These units were to begin earthwork and drainage work northward from Ban Blech to link up with the units moving south. The intense enemy activity however caused a postponement of this move and a reevaluation of the importance of QL-14S.
The importance of the completion of 14S to Ben Blech was weighed against the massive security which would be required by ARVN units in the area, the possible casualties in ARVN and engineer units, and the obviously slow progress that would be made. It was decided to cease operations on 14S, move out of LZ Lonely, and begin as soon as possible paving operations eastward from Pleiku on QL-19E. The plan was to upgrade 19E to CECOM E modified standards. Weigt-Davis industrial site was to provide the base course and asphalt for the paving trains.
QL-19E became of major importance to the 20th Engineer Battalion. After paving operations were withdrawn from 14S in mid-April. Initially, plans were to pave eastward from Pleiku and to add 1.5 meters as shoulder rock as far as possible. Unexpected bad weather, equipment difficulties and altered plans caused various delays. It was finally decided that the Battalion could upgrade the shoulders form Pleiku to a point 12 kilometers eastward and that a 4 kilometer section between bridges 34 and 33 be overpaved. This was accomplished by 8 August 1971.
Certain critical repair jobs on 19E were assigned to the Battalion coinciding with paving operations on the road. Bridges 19-33 and 19-23 were repaired and the entire section of road at Deadman's curve replaced.
Perhaps the major project on 19E was the repair of a slope failure at Deadman's Curve. Due to a culvert and slope failure at that location, the full upon which the road had been built was totally saturated and the road in danger of slipping into a ravine. It was decided to build a bypass, remove the damaged culvert, emplace four 72 inch culverts, and then realign the road as new fill was added. Initially it was necessary to pump many thousands of gallons of water from the uphill side of the fill in order to locate the old culvert and remove the damaged fill. In mid-June close to 100,000 cubic yards of earth was removed in order to reach a stable base. Fill was then added and then compacted up to the desired elevation of the four large culverts. The culverts were emplaced, and extensive reinforced concrete headwalls were constructed to insure that the culvert would not fail as they had in the past. Upon completion of the headwalls in mid-July the filling resumed. Final grade was reached on 9 August, after utilizing 84,000 cubic yards of fill. A six inch lift of base course was placed and the area overpaved by civilian contractors. The bypass was removed and the swamp on the uphill side of the fill drained with the use of 2144 pounds of explosives. A previously failing, very dangerous section of 19E that had often been an ambush site had been replaced with a high speed, well drained section of road.
The stand down of the 20th Engineer Battalion began on 28 July 1971 and was completed on 28 August 1971. During this period every item of equipment from seven companies was either turned in to the Keystone Facility at Cha Rang Valley or laterally transferred to other units. Only through extensive planning, extremely hard work, and aggressive problem solving was the unit able to meet its 28 August deadline. One of the major problems was the transport of more than 120 heavy lifts over 100 miles to the Keystone Facility. Every heavy lift, in the form of dozers, bucket loaders, rollers, deadlined trucks, etc., were carried by organic tractors and trailers. Although the transportation unit near Pleiku provided five ton cargo trucks for miscellaneous items, the were not able to carry any heavy lifts. Only through great efforts of the Battalion Maintenance Section was the Battalion able to continue its heavy life haul. Many 10 tons and lowboys which had previously been deadlined were converted to an operational status by hard work and outstanding preventive maintenance on the part of the operators. The 13 ten tons were the key to the Battalion's successful stand down operations.
The fact that the Battalion did meet its established stand down date and complete its vital construction missions is a tribute to the attitudes and energies of the men and officers of the 20th Engineer Battalion. The colors were proudly encased on 20 August 1971 and transported back to Fort Campbell, Kentucky where the 51st Engineer Battalion assumed the long lineage and heritage of the Wavy Arrow Battalion.
--End of Chapter 5, Vietnam