Forward into Battle

by Paddy Griffin

  The case of FSB Crook, however, does not prove a very great deal. Firebases without sensors had on occasion notched up equally amazing kill-rates, while the role of sensors in firebase defence elsewhere was usually much less spectacular than at Crook. In some cases sensors did not even prevent the enemy from overrunning a position. We should not therefore be dazzled by the achievement of this new weapon in Vietnam, but see it as just one more subsidiary aid.

  The vast array of sophisticated American surveillance equipment never provided a complete answer to the problem of visibility in Vietnam. Admittedly it greatly helped the security of firebase perimeters, and eventually turned night into day at will in areas which were relatively clear of vegetation. The jungle nevertheless retained much of its mystery. The land clearing and unmanned sensor programme came too late and on too modest a scale to provide anything but rather local answers to that problem.

  If technology failed to deliver the total solution which it seemed to promise in the field of surveillance, surely we can point to its successes in the field of firepower? The fact that firebases containing no more than one or two companies habitually beat off full NVA regiments is a sobering reminder of what modern weapons can do. An attacker could be engaged from within the base by rifles, machine guns, claymore mines, grenade launchers, recoilless rifles, mortars, and artillery firing high explosive, white phosphorous, flechette or cluster-bomb rounds. After short delays additional artillery could be called from other firebases within range, and helicopter gunships might arrive with their rockets and mini-guns. Finally there might be tactical air strikes and perhaps a visit from a flareship. It was a determined attacker indeed who would press forward in the face of this devastating hail of shot. His only chances of penetrating the perimeter lay in achieving total surprise, a silent sapper infiltration, or perhaps a series of improbably lucky hits on key leaders of the defence. The fact of the matter was that American firebases were rarely penetrated and hardly ever overrun. To that extent their firepower can certainly be called overwhelming.

  A firebase, however, was a fixed point of known location. Its defenders were dug in and its artillery pre-registered. Heavy pieces of equipment could be emplaced, and open fields of fire cleared all around. It was a fortress in the classic sense, and indeed often had a groundplan which would have been familiar to the great masters of nineteenth century military engineering. Viewed in this light, it need scarcely surprise us that the ‘kill ratio’ in firebase battles was usually heavily in favour of the defenders: such has always been the case when fortresses are stormed by infantry who are weak in artillery.

  If we are to evaluate American firepower in Vietnam we must really ask how well it could be applied in mobile warfare, against targets which appeared at unexpected times and places. This is when firepower was most important to the Americans, since in this type of combat the NVA would hold the advantages of surprise, camouflage and entrenchment. Mobile war was also the most important type of action in the strategic sense, since it was only by taking the war to the NVA that free-world forces could win the initiative. If they had done no more than wait in their firebases until the NVA chose to massacre themselves against the defensive firepower, the Americans would never have been able to impose their own tempo on the war. It would always have been the enemy who chose the level of attrition at any particular moment. It was with this consideration in mind that General Westmoreland adopted ‘Search and Destroy’ (or ‘Find, fix and destroy’) tactics in late 1965.14 It was essential to his strategy that the enemy should be deprived of the initiative by a war of movement.

  The problem in mobile warfare was that the enemy was hard to locate before he sprang an ambush. We have already mentioned some of the difficulties of finding him with surveillance equipment. An alternative was to use firepower itself, in a so-called ‘reconnaissance by fire’. Thus a unit moving forward into uncharted terrain might call down artillery concentrations in front of it to flush out any NVA who might be lurking there. Preparatory fire was also often used before helicopters touched down in a landing zone which had not been scouted on foot. These speculative fires were sometimes productive and certainly gave confidence to the troops; but they also served to warn the enemy of what was happening. They saved him the trouble of doing his own reconnaissance, and in effect told him when to camouflage himself and take cover. To this extent they operated in a sense diametrically opposite to the one for which they were designed.15

  It was the fate of the Americans in Vietnam to be ambushed. The enemy usually fired the first shot of an engagement, and in ambushes it is usually the first shot which is the most effective. Only gradually would the ambushed unit be able to patch together its return fire, during which time the ambushers would be able to bring down a prepared barrage from well-sited weapons. The NVA had generally good fire discipline, and were practised in firing volleys at a given signal. At the start of a firefight it was often they, rather than the Americans, who had the upper hand. It was not uncommon to hear of actions in which The North Vietnamese had numerical and fire superiority. Initially, it was they who freely employed supporting arms’16 including mortars and recoil-less rifles.

  Ambushed American units had to ‘build up a base of fire’ piece by piece, if they were to hold their own. They would first reply with their M16 rifles and M79 grenade launchers and a little later these would be joined by M60 machine-guns, which were slightly more difficult to bring into action. In these weapons the Americans enjoyed little superiority over their NVA counterparts, and indeed many Americans who had been shot at with the communist AK47 assault rifle quite naturally imagined it to be more dangerous than their own M16, which had a reputation for jamming. In the case of the M79 there was certainly a clear advantage over the NVA’s hand thrown, unreliable and sometimes home-made grenades, although in practice the NVA seemed to get hold of a fair number of M79’s themselves. The NVA also used B40 rockets in a similar role, although in this case they lacked the M79’s canister round for direct fire at very short range.

  The average engagement range in Vietnam was between ten and thirty metres, as a result of the thick vegetation. Even then the two sides would by and large be invisible to each other, and so almost all fire would be unaimed. Since it was fatal to stand up in those conditions, rifles would be fired from ground level and their shots would probably fly high. Only an ambusher who had placed tree snipers overhead, or prepared fire lanes in advance, would be in a position to score many hits after the first volley.

  The next American firepower elements to come into action would be the supporting mortars and then the artillery. These had to be called up by radio from the ambushed unit, and this could not always be done quickly. Radio reception might be upset by the lie of the land or the jungle itself. The person calling for support might not be able to see exactly where it was needed, since his area of visibility would inevitably be restricted by his being in a prone posture in thick jungle. In one battle it took a radio conversation of 20 minutes before a unit’s grid reference could be established, and even then it turned out to be totally incorrect. There were other cases where local commanders remained unaware that artillery support was required at all, since there was no one with a radio near enough to the point of contact to appreciate the seriousness of the battle, and the jungle tended to deaden the noise of firing.17

  Once artillery support had been called there would be further delays for registration and clearance. The latter depended not only upon the location of the unit calling the fire, but also on that of any other unit in the area. If the gunners could not establish the whereabouts of every friendly unit it was obviously very dangerous to fire at all. In some cases there might also be restrictions imposed by the rules of engagement. In or near villages or in the Cambodian border area, for example, fire had to be cleared and cross checked for both safety and political acceptability. All this served to delay the arrival of the first accurate shells, and to give the enemy a respite.

  Perhaps the most important
restriction of all in the use of artillery and mortars was the need to observe safety distances from friendly troops. These might be 100 metres or more, which naturally made the fire somewhat irrelevant to a battle being fought at ranges of 10–30 metres. Enemy formations which were in contact could thus be hit only on their rearward parts or on extended flanks. That could be useful for counter-battery work or for pinning the enemy in place; but his front line fighting portion would often be too close to the Americans to be hit.

  Mortars also posed certain problems of their own, since they would often have to be deployed during an infantry operation itself, very close to the enemy. They could not be positioned in jungle with overhead cover, but would have to find a clearing. In practice it was found that the light 60mm mortars used by the NVA were very much more useful than the less manoeuvrable 81mm weapons of the US army. In this particular arm, indeed, it often almost seemed as though the enemy had a distinct advantage.

  The effectiveness of mortars and artillery against targets in forests was also reduced by shells striking treetops and exploding before they reached their intended targets, or even ricocheting into friendly troops. It was found, in fact, that only 155mm or bigger guns were fully effective against jungle targets. This immediately downgraded the usefulness of the 105mm pieces which composed about half of the artillery park.18

  Similar considerations also applied to rocket firing helicopter gunships. Of one battle in the central highlands in 1966 S. L. A. Marshall wrote:

  Most of the rockets are HE rounds. Against jungle the ARA gets a lot of detonating that is high in the trees. That scares the people below. But it very seldom hurts anybody.19

  In another battle the same year Marshall recounts a different type of disappointment with the weapon: There were only two gunships. They made a couple of passes, dropped half a load and dropped it in the wrong place.’20

  This last quotation illustrates two more difficulties with armed helicopters; reaction times and accuracy. Helicopters needed about ten hours’ maintenance for every hour’s flying, so at any one moment only a fraction of their total numbers would be ready to go into action. Time and again we hear of units with six or eight ships having only one or two ‘hot’.21 Usually more could be readied within an hour or two; but in combat an hour seems to be rather a long time.

  A particular difficulty for helicopters was the problem of finding the target. Especially in jungle it was difficult for ground units to mark their own position clearly for an airborne observer, since smoke bombs fired on the ground would not rise above the canopy. In some other cases when marker smoke was fired, the enemy would immediately follow suit with smoke of the same colours to confuse the pilots.22 It was eventually found that efficient target indication required experienced air liaison officers, either on foot or orbiting overhead, who could keep a proper track of the positions on the ground, and ‘talk in’ helicopter or fixed-wing strikes. In jungle conditions this was very much an acquired art rather than a precise science. It carried no certainty.

  Helicopters could sometimes bring their fire very close indeed to a friendly perimeter, but as with the other supporting arms this practice was risky. The closer the enemy hugged the friendly perimeter, the more reluctant commanders would be to bring down their full firepower. Accidents were all too easy with rockets, bombs and artillery alike. In normal times, at least, it was better to keep these weapons at a healthy distance, and fire well behind the enemy front line. A possible alternative was to back away with your own troops just before the strike went in. In this way you could avoid the risk of being hit by your own supporting arms; but the very act of moving backwards exposed your men to greater risks from the enemy. It was an unenviable choice.

  The most awesome weapon in the array of supporting arms was the fixed wing bomber. The weight of concentrated ordnance it could deliver was prodigious, and the suddenness of its intervention was numbing. For a bigger effect, however, a bigger price had to be paid. The reaction time was longer, the safety range greater, and the target indication problem more acute. Even more than artillery and helicopters, the bomber was best used against targets at a distance from one’s own front line. It was for interdiction or counter-battery work rather than for the point of contact itself. Its effective use required a good fix on a relatively concentrated target, and we have seen that this was harder to achieve than one might imagine.

  In considering the effectiveness of American firepower we must remember that in many cases the target would be dug in. NVA soldiers were expert diggers, and would try to make trenches and bunkers wherever they stopped. When they lay in ambush they would often have only their heads showing above ground, preferably with overhead cover as well. This made them a very difficult proposition to kill. Even if they could be accurately located it took a more or less direct hit from something heavy to knock them out.

  The sort of firepower really required by the Americans in their mobile battles was direct fire artillery, or in other words a gun which was much heavier than an infantry weapon, but with sufficient protection to be deployed in the very front line of the fighting. It had to fire accurately outwards from the ground rather than inaccurately downwards from the sky. There was such a weapon in Vietnam, in the shape of the tank; but for a variety of reasons tanks were not available in sufficient numbers in the right places.

  The initial appreciation in 1965 had been that tanks were inappropriate for counter-guerilla operations, and that they would in any case be unable to manoeuvre through much of the Vietnamese countryside. They required what was considered at the time to be disproportionately extensive back-up facilities, and their deployment was deemed to be less urgent than that of infantry and helicopter resources. They were slow to appear in numbers, and it was only in 1967 that the armour lobby was able to demonstrate their value conclusively in the detailed MACOV report.23 By this time it had become apparent both that there was more to the Vietnam conflict than simply the village war against local guerillas, and also that far more of the terrain was practicable for tanks than had at first been supposed.

  It was found that a great deal of the jungle could in fact be negotiated by tanks, and that even more of it was passable by armoured personnel carriers. Especially in the warzones north of Saigon this allowed mounted action where previously the war had been conducted mainly by relatively light airmobile forces. In the steep highland regions of the centre and north, however, there were greater problems. In these areas airmobile operations continued to be the most convenient, and tanks were confined to roads and tracks to a greater extent. The tank was thus restricted in its usefulness in many of the most hotly contested battles of the war.

  Another problem with the use of armour in Vietnam was one of doctrine. Many commanders preferred to use it for static or road security tasks rather than to send it out in mobile sweeps. This led to excessive dispersion and a failure to realise its true potential. The lesson was gradually learned that armour could be extremely useful in encounter battles; but as with so many other lessons this realisation dawned just at the moment when American forces were starting to withdraw. The solution to the problem came too late in the day.

  All the above considerations meant that American firepower was often inadequate to destroy an enemy in contact. Firefights could not be quickly resolved, and they dragged on for hours and sometimes days. It is perfectly true that heavy casualties could be inflicted by artillery or airpower upon an enemy discovered out of contact or in the open; but this did not directly solve the problem of the firefight itself.

  For their part the NVA was also capable of inflicting casualties upon Americans out of contact, by the use of stand-off weapons such as mortars, rockets and especially mines. The extent of the mine threat varied greatly from one part of Vietnam to another; but it was always present. A wide range of booby traps, claymores and jumping mines could hit men on foot, while grenades strung in trees could hit men riding on vehicles. For the vehicles themselves there were anti-tank mines and converted bo
mbs or artillery rounds. Against helicopters there were sometimes windmill mines placed in likely landing zones. No complete answer to mines was ever found, and they took a heavy toll throughout the war.24 This toll was certainly not as great as that inflicted upon the NVA by American stand-off weapons; but it was a constant reminder that technology could not find an answer to every threat.

  If American surveillance technology and firepower technology were ultimately inadequate to meet all the challenges of the mainforce battle, what of that other much-vaunted advantage: mobility? The Americans prided themselves on their capacity to multiply numbers by mobility, as in the celebrated case of the marine platoon which made combat assaults in three separate provinces during the course of a single day. Surely this at least was a potent advantage against an infantry enemy who had no option but to walk into battle through thick jungle terrain?

  The Americans were able to choose between movement on foot, in ground vehicles, helicopters and (at least by the end of 1966) in a specially designed riverine flotilla. They could parachute in and get out on rope ladders dangling from the sky. On one occasion in the Mekong delta they even experimented with hovercraft. They can certainly be forgiven for imagining that technology gave them an almost limitless range of options.

  By far the major part of this technological vision was provided by the new generation of turbine helicopters, which represented an important advance over previous models in range, payload and serviceability. Vietnam was their first major test, and great hopes were placed upon them by their enthusiasts. They were deployed in many varieties and great numbers, and they seemed to open the way to an altogether new style of combat. As one commentator remarked: ‘Every infantry unit in Vietnam was, in fact if not in name, airmobile infantry; and its direct support artillery was airmobile artillery.’25