Taken from :
http://www.gruntonline.com/NVAandVC/nva_bunkers4.htm
A series of articles on NVA bunkers is based upon an analysis of enemy positions at Khe Sanh that was carried out by the 3rd Marine Division.
I thought it could be usefull of sort. I guess we will be constructing individual strongholds for historic missions.
CONCLUSIONS
NVA Fortifications
From the compiled data of the various bunker complexes and trench systems at Khe Sanh, certain facts could be summarized:
Construction consisted of locally available materials.
Entrances to bunkers were kept as small as possible and were at right angles to the main axis of the bunker.
The most common bunker measured 4x6x4 feet and was rectangular shaped with 18-24 inches of overhead cover.
Overhead cover consisted of logs covered with a grass matting and earth.
Camouflage was deliberate and detailed.
Bunkers had a low silhouette, and blended with the terrain and foliage.
Extensive booby traps were not encountered.
Bunker complexes were located on reverse slopes adjacent to trails and water sources.
Positions were mutually supporting and interconnected by trench systems or communications wire.
Supporting Arms Effects:
The supporting arms effort directed against the NVA fortifications in the Khe Sanh area was successful in driving the enemy from his entrenched positions. General comments concerning the effects of these supporting arms can be summarized as follows:
The NVA bunker withstood anything but a direct hit by bombs or artillery.
Delay fuzing produced the best effects against bunker complexes; however, much of the ordnance penetrated too deeply before detonating in the soft soil.
Quick fusing was effective as a means of stripping away camouflage and exposing the position. It was not effective against bunker systems.
Napalm was not effective as a defoliant over large areas.
Artillery of 105 and 155mm was not effective in a bunker destruction role.
Lessons Learned
Avoid piecemeal expenditure of ordnance against scattered targets.
When areas of high activity were located, isolate and expose them with stand-off fuzing, napalm and incendiary ordnance, then attack the position with the type and quantity of ordnance best suited for destruction.
Reduce delivery CEP by employing more observation aircraft, and using area type munitions such as the CBU and BLU series against personnel targets.
Deny the enemy the use of his bunkers and living areas through intensive observation exposure and CS contamination.
Utilize lapse or neutral atmospheric conditions for CS employment against personnel targets.
Emphasize surprise through random selection of high intensity areas of activity.
Increase delay fuzing sensitivity for soft soils.
Employ surprise fire during periods of reduced visibility.
Utilize incendiary munitions in lieu of napalm for exposing fortified areas in high grass.
Use observed fires whenever possible.
Thoroughly search NVA trench systems for living bunkers prior to expending large quantities of ordnance on the trenches alone.
Consider selection of a delivery system which will place persistent CS in selected portions of the trenchline to deny its use as an attack position, or force a new system to be constructed.
The aerial observer (AO) must be permitted to conduct a methodical reconnaissance of every suspected position to insure positive location and identification of living areas. Once they have been identified they must be further exposed and reduced. Pilot accuracy increases greatly when he is able to visually identify and follow his target, and aerial observers should encourage the pilots of supporting aircraft to make several dummy runs from different headings until the pilot sees the target.
When hostile fire prevents low level observation or dummy runs, the AO and the supporting aircraft pilot should pick a prominent reference point close to the target to be used in conjunction with the marking smoke.
Initial runs should be made with hard ordnance employing 'daisy cutter' fuze, or napalm.
Artillery white phosphorus can be used to burn away the grass or mark the entire area. The important point is to first expose the target by destroying the surrounding vegetation, then conduct systematic attacks against the bunkers employing heavy artillery and air ordnance with delay fusing.
Map Prototype: NVA stronghold
Linear Mode
