15 September IP: 184.108.40.206 Posted on September 15, 2016 at 11:42:43 AM by Terry
1945…62nd NCB is deactivated at Yokosuka, Japan
1966… Seabees from the NMCB-1 built a schoolhouse at Boc Ninh hamlet during their off duty hours
… NMCB-1 completed installation of a standard D32A refer complex at FLSG-A Building #28 (L701 6659 III 951-797). Construction of this facility consisted of assembling twelve 4000 cubic foot refers and constructing six sheds with concrete decks to house two reefers each. Eleven of the twelve reefers were assembled and five of six sheds completed. Shortage of parts for the twelfth reefer prevented its completion and construction of the sixth shed, which were transferred to the relieving battalion. The units constructed by NMCB-1 became operational on 15 September 1966.
1967…A task force composed of elements of several MCBs deployed in Vietnam was sent to Site “X” (Quang Tri) to begin construction of an alternate airfield for Dong Ha. The airfield, located about six miles south of Dong Ha, was a priority project that was required as an operational facility before the northeast monsoon season. The runway, which had a useable completion date on 1 November, was to be 3,500 feet long and would have a C-130 capability. It was to be constructed of AM-2 matting laid over an 8 inch-thick soil cement base.
The urgent requirement that the airfield be operational by 1 November necessitated the temporary assignment of 150 men of the alert battalion, MCB-10 from Okinawa to Vietnam.
The completed airbase included a 20,000 square yard parking apron, a 90,000 square yard helicopter facility with bin type revetments, a 500 man cantonment, bulk POL storage, an ammunition supply point, and miscellaneous infantry and aircraft facilities
…NMCB-133 deployed a Detail of 32 men to the Dong Ha alternate airfield, Site X at Quang Tri under the command of EOCS Eberlin. The Detail rejoined the Battalion on 21 September 1967.
…NMCB-4 completed the 378 ft. north access bridge to Liberty Bridge.
…NMCB-4’s CM1 J.A. Kelley and EONCN R.G. Maki were both wounded when their dump truck struck a mine on Liberty Road.
…Daytime mortar attack on Lang Vei. No NMCB-11 casualties.
…NMCB-3’s CDR Foley departed TAD as OIC of “Ghost Battalion” Site X, Quang Tri Province. LTCDR T.L. Lonegan assumed command as Acting COMNMCB3. …Due to increased Viet Cong activity in the immediate area, NMCB-3 personnel manned their sector of the Gia Le Combat Base defensive perimeter each night through 04 Setember. (MCB-3 DCR ’67-’68)
…After the Kim Lien bridge was destroyed, NMCB-1 began planning for a 126 foot wood pile structure and construction of Bridge #1 began on 16 July 1967. Because the 7th Engineers had placed a tactical section on the old abutments the new bridge was necessarily located downstream. The requirement for new abutments was not significant since those existing needed extensive repair. The necessary piling was driven with a drop-hammer borrowed from the 7th Engineer Battalion.The bents were spaced at different intervals to eliminate a difficulty in materials existing at that time. The bridge was completed and opened to traffic on 15 September 1967. Shortly afterwards the ARVN forces guarding the bridge were overrun, but for some unknown reason the bridge was not destroyed. To help protect NMCB-1’s two month investment in the bridge, two timber bunkers were constructed with left-over material.
1968…Mr Carl Marohn, Technical Representative from Air Logistics Corporation, Pasadena, CA, arrived at Camp Haines. Mr. Marohn supervised the installation of Mo-Mat test sections which were designed to function as the water barrier between sections of the Camp Evans runway subgrade and the AM2 aluminum runway matting.
…One of the major projects completed by NMCB-4 for the Army at Camp Evans was the resurfacing and matting of a 2,900 foot, all weather runway capable of handling C-130 aircraft.
An interesting fature of the new runway was the inclusion of an experimental 450 foot section of Mo-Mat, an underlayment material placed directly over the compacted soil to serve as a moisture barrier and to distribute the wheel loads.
At the request of COMCBPAC, and with the concurrence of the Naval Facilities Engineering Command, a quantity of Mo-Mat was obtained to be tested in conjunction with AM-2 aluminum matting on an operational airfield. While the material had been used by the Marines as beach assault matting and for helicopter pads, this was its first use as a runway underlayment.
Mo-Mat is fabricated from a fiberglass reinforced plastic called Statoglas, developed by the Stratoglas Division of the Air Logistics Corporation. It is molded into a structural shape resembling that of a waffle and is available in two thicknesses.
The Mo-Mat provided at Camp Evans came if 48’-6”x12’-2” panels tied together in 480 foot rolls.
Material thickness was 0.042 inch, and its weight one-half pound per square foot. T thicker mat, 0.085 inch, was available and was being used successfully by the Army at Camp Evans over short sections of deteriorating camp roads.
The 3,000 pound Mo-Mat rolls were handled and staged with forklifts, then rolled out by hand over the compacted and graded soil. The remainder of the runway received a soil cement base before being covered with AM-2 aluminum matting.
A crew of approximately five Seabees worked with a representative from the Air Logistics Corporation who supervised the installation. The Mo-Mat was unrolled parallel to the runway in seven rows. Adjacent rows and end sections were sealed with a bead of plastic sealer, provided in the package, and “pop-riveted” together utilizing prepunched holes in the Mo-Mat.
Except for pop-rivet guns, no special tools were required. (Mo-Mat was also available which could be assembled with bolts and a special nut plate).
Although different methods were tried to cut the material, such as axes, cutting torches, and electric hand saws with special blades, it was found that a good pair of tin cutters did the best job.
The ends of the Mo-Mat were carried into the soil cemented portions and feathered therein using a shallow grader blade cut covered with hot AP-3 and asphaltic cold patch mix. The sides were rolled into a three foot deep ditch and backfilled. Aluminum matting was then layed directly on top of the Mo-Mat.
In moving the aluminum matting over the Mo-Mat, some minor damage was caused by careless forklift operation. Repairs were made quite easily by overlaying a patch of the same material on the damaged portion. Holes were punched through the patch and the original material, (the sealer being applied all the way around near the hole line) and the patch pop-riveted in place.
Aside from equipment damage, the only real problem came from low flying helicopters. On more than one occasion before the ends were secure, sections of Mo-Mat became airborne from helicopter backwash. As was the usual case when this happened, portions of the riveted sections pulled apart and the seals were broken. It then became necessary to punch new holes, apply fresh sealer and pop-rivet the sections together again. A general order fianally grounded all helicopters in the area until the installation was complete.
It was the consensus of those evaluating the installation that Mo-Mat as an underlayment material had good potential. NMCB-4 departed RVN approximately one month after completing the airfield and therefore could not comment on its durability after a period of use and subjection to monsoon weather.
Once the Seabee crew got the swing of it, the Mo-Mat installation went smoothly and rather rapidly. Base preparation, requiring only ordinary grading and compaction, had obvious advantages over the slower soil cement operation with its large requirement for labor. Cost of the .042 inch Mo-Mat was about $1.00 per square foot (1968).
Aside from keeping helicopters out of the area, one additional recommendation was made. In backfilling over the Mo-Mat in the longitudinal ditches, it was almost impossible to obtain a flat, smooth shoulder. Without an almost perfectly straight, uniform ditch, and a positive method of holding the Mo-Mat securely in the ditch, the backfilled soil produced a noticeable rolling contour in the Mo-Mat. This was alleviated by using T-17 membrane in the ditch, and indeed, Air Log showed this method in their literature.
It was also recommended that the exterior sections of Mo-Mat, which cover the shoulders and join to the T-17 membrane, be .085 thick in lieu of the .042 inch material. These exposed sections over the shoulder were not protected by Am-2 matting and were subject to heavy traffic in backfilling operations and equipment operation in the airfiels area. In fact, the .085 inch material should be considered over the entire area to help prevent damage from operating equipment during installation.
The shoulder and ditch sections of Mo-Mat were cut and damaged during backfilling and also during attemps to re-ditch and cover the Mo-Mat, the latter being done in an effort to eliminate the rolloing shoulders mentioned previously.
Another test section was to have been made on the same runway using the Air Logistics Corporation’s “Flat Sheet”. Flat sheet is best described as Mo-Mat without the waffle texture. As the name implies, it is perfectly flat sheet, four feet wide, and comes in rolls 250 feet long. It comes with a strip of contact cement on one edge, protected with a plastic tape which is peeled off on the job site prior to joining adjacent rows together.
The Flat Sheet proved to be anything but successful. It was subject to the same airborne characteristics as the Mo-Mat, but much worse, the adhesive would not stick when wet and the joined rolls would not lay flat. When it became evident that the material would not provide a watertight barrier between sheets, this test section was abandoned and was soil cemented.
Flat sheet was also tried for revetments, but again proved unsuccessful when the material deformed and split.
One other successful use was found for Mo-Mat. The NMCB-4 bridge crew was putting the finishing touches on Bridge 20 when the monsoon rains hit. The Bridge 20 bypass road was covered by so much water that it was impassable. The new timber bridge, Bridge 10, was complete except for compacting the approaches. Compaction at this point was out of the question for the super-saturated soil.
In order to keep the vital National Route 1 open to traffic, the approaches were covered with ľ” asphalt aggregate to fill in the ruts. Then 100 feet of Mo-Mat was placed on each side of the bridge and covered with M8A1 steel matting. This combination did indeed keep Route 1 open to heavy convoy traffic for 19 days until the weather permitted permanent repairs to be made. The Mo-Mat and steel matting were envisioned to be used for only a week or so. The fact that it stood up for 19 days is a real tribute to the potential of this material.
AS was mentioned earlier, the Army Corps of Engineers at camp Evans was using the .085 inch Mo-Mat with success within the camp on certain sections of bad road.
This limited experience with Mo-Mat convinced most who worked with at that Mo-mat has a tremendous potential and a definite future in military operations.
…Five B-40 rockets impacted in the Vinh Binh Provincial Public Works Maintenance Compound, seriously wounding two RF guards and causing minor damage to Team 0102 equipment parked in the compound.
CBPAC, visited NMCB-133 at Camp Campbell to inspect Plans, Training, and Ordnance and Communications.
…93 men from NMCB-3 arrived onboard Camp Haskins South to assist the the NMCB-62 BEEP.
…Two 50’ sentry towers were erected from August to September 1968 by NMCB-7. Construction of these TSFC units was a simple task; however, setting them in place on the Dong Ha perimeter posed a small problem. An unsuccessful attempt was made utilizing a flying crane helicopter. The towers were later hauled to the site and erected with a crane.
…At times, it seems that everything is just a little different in Vietnam. Now the Seabees are building bridges that are intended to work underwater.
The bridge builders of NMCB-3 erected a submersible bridge 11 miles south of Da Nang for convoys through the An Hoa valley. After peace returne to Vietnam, the Seabees expect their bridge will continue to play an important role as a civilian.
Precast concrete beams were used in the bridge’s roadway. The beams were made in the Seabee yards at Da Nang and had weep holes to equalize water pressure on the bridge floor during the flood season.
Without the holes, water pressure produced by the flood would lift the beams off the pilings.
The normal level of the Thu Bon River was from six to eight feet below the bridge floor but floods were expected to submerge the span from eight to 10 feet below water. The floods usually occurred twice a year and lasted from seven to 10 days.
An asphalt coating on the roadway was expected to prevent deterioration while it was underwater
1969…NMCB-58 began construction of a 7500 sq. ft. area of asphalt-surfaced parking around the MAG-12 GSE Maintenance Building. Non-availability of mineral products and inclement weather slowed the project. It was ultimately turned over to NMCB-7 on 10 Octber 1969 at 8% complete.
…Ten men from NMCB-133 Detail Zulu rejoined the Battalion at Camp Wilkinson.
…NMCB-74 Detail Foxtrot, consisting of 1 CPO and 50 other enlisted men from Charlie Company, deployed to Da Nang to assist NMCB-53 on improvements to Ammunition Supply Point Two
1970…RADM R.E. Adamson, Commander NSA Saigon visited NMCB-5’s Detail Charlie at Cho Moi.
…CBMU-302 ECHO Company took over operations from CBMU-301 in Military Region One (I Corps) and commenced construction at Tien Sha and Thuan An with NAVCAT One and Nineteen respectively
1971... Seabee teams working in Vietnam in support of USAID projects as of 15 September:
04-17 Xuan Loc Ens Murray OIC
05-18 Soc Trang WO2 Lucey
10-19 My Tho Ltjg Hong
10-20 Go Cong Ltjg Howe
40-06 Tan An Ltjg Roussos
62-06 Ham Tan Ltjg Burrus
133-08 Ben Tre Ltjg Healy
MO-MAT - By JOHN WILBORN September 15, 2016 at 04:15:43 PM