The deployment of 3 Field Troop (3 Fd Tp), Royal Australian Engineers to Vietnam under the command of Alec (Sandy) MacGregor was part of a continuum of growing overseas engagements by the Engineers. In 1965 sappers were on operations in Malaysia and Vietnam and remained engaged in major construction program in Papua New Guinea. The sappers of 3 Fd Tp pioneered the way Engineers would operate throughout that futile war. They took on the Viet Cong (VC) at his most dangerous in tunnels and with booby traps.
Image if you can, how it feels to launch yourself headfirst down a hole in the ground thats scarcely wide enough for your shoulders. After a couple of meters of slipping and wriggling straight down, the narrow tunnel takes a U-turn back towards the surface, then twists again before heading off horizontally further than you can see with the light from the battery powered lamp attached to your cap.
Because the tunnel has recently been full of smoke and tear gas, you are wearing a gas mask. The eyepieces steam up and the sound of your own breathing competes with the thump of your heart to deafen you.
You are in the enemys domain some of your comrades have already died. This tunnel thats almost too small to crawl along was dug for slightly-built Vietnamese, not gangly Aussies or broad-backed Americans. Every inch forward has to be checked for booby traps so you have a bayonet in one hand. Every corner could conceal an enemy soldier who can retreat no further, so you have a pistol in the other.
Theres not enough room to turn around going forward is difficult enough. Backing out is nigh on impossible; the enemy knows youre there. You know your miners light makes a perfect target. You switch off the light. The silence is ominous, though not quite complete as the pounding of your heart throbs through your entire body. The velvet darkness is all engulfing. Then the adrenaline rush subsides as it becomes harder to catch your breath. You become lightheaded, then dizzy and confused as the air runs out. Reason and sense evaporate as the darkness claims you… Thats how it felt to be a Tunnel Rat.
Operation Crimp was a turning point for 3 Fd Tp. It had a tragic outcome that bonded the men together as never before and made them the soldiers they needed to be.
When 3 Fd Tp joined the infantry sweep of the area, we expected there would be some tunnels but we had no idea that there would be virtually an underground city, let alone what it contained. It would turn out to be the headquarters of the Viet Cong of the Cholon/Gia Dinh area of Saigon, the nerve center from which the enemy ran their forward operations in the countrys South East and later masterminded their final assault on Saigon.
The Ho Bo woods are about four kilometres to the west of the Iron Triangle, an area North-East of Saigon that was known to have an unusually high concentration of Viet Cong troops. The Iron Triangle hadnt been entered in any great strength for about three years and there was a strong feeling among the top brass that the Viet Cong had not only re-infiltrated the area after it had been heavily shelled and bombed, but had established their southern command Headquarters there. They were right, but what they didnt know was that finding and destroying the VC base was a lot easier said than done. They never imagined it would be right beneath their feet.
One of the American commanders, Major-general Dupuy, named the operation Crimp to describe how he planned to block off escape routes to the north and south, and then squeeze the VC between them with a sweep through the area. Brigadier General Ellis Butch Williamson was to take his 173rd Brigade through the north of the area while the soldiers of the 1st Royal Australian Regiment (Infantry) were to block any escape to the south. But the day before the assault our 1 RAR Operations officer flew low over the proposed landing zone. He didnt like what he saw, there were no leaves on the ground from the surrounding trees. He suspected, rightly, that earth from recent work on defenses had covered them. He raised his objections with the allied forces senior officers, but there was fierce opposition to changing the plans at such a late stage. It was only when Butch Williamson backed him up that they agreed to switch to another landing zone (LZ) nearby. That decision almost certainly saved hundreds of Australian lives.
It was no picnic. For a start, we were under constant fire soon after the first of the Hueys (Helicopters) started landing men and equipment in the relocated LZ. An artillery bombardment and air strike immediately before the ground troops went in should have had the VC on the run. Unfortunately, they were reading a different script and went underground during the shelling and bombing, then, when the main body of 1RAR arrived, they began popping up on all sides from trenches, tunnels and fox holes.
However, the Viet Cong still had one surprise up their sleeve. When the infantrymen reached their LZ, the clearing, which had originally been earmarked as the landing zone, they set about securing the perimeter so that it could be crossed in safety. The area was a mixture of low scrub and dense bush with a plantation of tress next to the LZ. It was well defended with booby traps, from trip-wired grenades to clusters of vicious metal or bamboo spikes hidden under grass in holes in the ground. When some of the infantrymen reached the LZ, they came under machine gun fire. They picked the worst option they could have seeking cover in a washed out gully beside a track. To their cost, theyd gone to ground right under the noses of the VC a machine gun post hidden is a hollowed-out mound of earth. They only realized their mistake when a couple of them were shot, virtually at point blank range. In all the confusion no one knew where the shots had come from. The area was supposed to be secure and there should not have been any enemy troops within range. Two medics crawled in to treat the wounded. They were both shot and killed before the Aussies, realizing the shots were coming from the narrow slits in the mound of earth, returned fire. That deadly mound, which looked for all the world like an anthill, became the key to one of the greatest secrets of the Vietnam War. But all it represented to the soldiers in the gully was a threat to their lives, so a couple of grenades made it safe until it could be investigated.
Meanwhile, a counter attack was anticipated, so that first night we set about consolidating our positions. As darkness fell, we could hear the sounds of the Viet Cong below us. We expected theyre to be tunnels and we knew the VC were in them. But had we known the extent of the tunnel system, or what it contained, none of us would have slept that night.
The next day I was called up to look at the mound of earth from which the two medics had been shot. This was definitely a job for engineers. We gained entry by blowing open a hole and, sure enough, found spent cartridges, presumably from the bullets our four lads had copped. But we also discovered a tunnel leading away from the position, and disappearing far under the ground. Obviously, that was how the snipers had got into their position. But how had they got into the tunnel? The standard practise when any tunnels were discovered was to blow smoke down them then looks for the telltale signs of other entrances. Once the entrances were secured, tear gas was blown down to flush out any enemy troops and then the tunnel entrances were destroyed with explosives.
Two months earlier, in my initial report, I had highlighted how inadequate this was and had suggested a radical new approach to tunnel warfare as it would become known. I suggested then that, after smoking the tunnels out and pumping tear gas down them, rather than seal them up, we should blow fresh air down them, and send men wearing gas masks down to investigate. After the tunnel had been cleared it could then be destroyed. We had developed a tunnel search kit, complete with miners lamp style lights for our hats, just for such an occasion. This would be our first chance to put it to proper use.
We blew smoke into the tunnel and I divided the men into smaller sub units of twos and threes and sent them off to investigate. It was my radio operator who found the first entrance, which was booby-trapped. Wed already had a lot of experience with VC booby traps, and he spotted that there were lines running from the entrance to hand grenades in nearby trees. The idea was that if anyone opened the entrance, the lines would pull the pins of the grenades and ka-boom! Just to make sure the entrance wasnt booby-trapped on the inside too, I sent a team of two men underground from the mound to check it out. It was clear, and thats when the tunnel entrance could be opened and the search could begin in earnest.
Prior to this, the tunnels we had investigated had only been rat runs from underneath houses out to safety of nearby paddy fields. But these entrances in the middle of the Ho Bo Woods were signs of something bigger and more complex, which was confirmed when an infantryman found another part of the tunnel system by accident while he was digging a latrine several hundred yards away. We discovered that the first tunnel ran right around the original landing zone to another mound with its gun overlooking the clearing. It was obvious then that if 1RAR had landed there as planned, wed have been the meat in a hot metal sandwich.
Once wed blown smoke, then tear gas, then fresh air down the tunnels, I sent a couple of men down to investigate. The entrance was so narrow it was hard to imagine it was intended for people at all. There was a straight drop then it doubled back up, like the U-bend under a sink. The tunnel turned again to go along under the surface and became a little wider, but there still wasnt room enough to turn around. It was terrifying down there, armed only with a bayonet to probe for booby traps and a pistol to defend yourself.
Once youd negotiated the tight entrance and the U-bend, you had to crawl along tiny passages, rubbing your shoulders on each side of the tunnel, on all fours, with no way of turning round if you got into trouble. Often youd find larger rooms, sections of tunnel that were big enough to crouch or kneel in, but you werent to know that when you first set out. The further the men went, the more complex the tunnel system was revealed to be. There were drops, twists and turns, corners around which the whole North Vietnamese Army could be waiting, for all they knew. The men burrowed away, ever further, ever deeper, until they discovered a hidden danger in the operation. Some of them began passing out in the tunnels due to lack of air. But, despite the fact that there was no room to turn they were all dragged back to the surface, usually after wed blasted more fresh air down to them.
I had been sending the men down in twos, but even then, on at least one occasion, both of them had to be rescued when they ran out of air. So I organized some teams of three and even four, with the tail-enders paying out telephone wire as their mates negotiated the twists and turns of the tunnel. The man in front would check for booby traps as they went along, the second man would support him and stay in touch with the surface by phone. The guys at the back would sit at the tighter corners, making sure the cable didnt snag. All the time theyd be taking to me or their section commander on the surface, whod be using their reports to try to work out at ground level where they were so that they could be dug out from above if necessary. We also tried to draw maps of the tunnel system as they described it.
During the operation, one Tunnel Rat, Corporal Bob Bowtell lost his life investigating the tunnel systems. Lest We Forget.
The Underground City. What we did and what we learned on Operation Crimp was incredible. 3 Field Troop came close to changing the course of the Vietnam War that week in January 1966. If we had, it might well have changed history.
We had gone to find and destroy the Saigon/Cholon/Gia Dinh political and military headquarters of the Viet Cong. By the time we left we knew wed found it and were pretty sure wed destroyed it. History shows that the former assumption was correct while the latter was well off the mark.
We were in the Ho Bo Woods for six days on Crimp, but every day dawned to startling revelations, each of which was followed by even more amazing discoveries.
We had three tasks. The first was to investigate the tunnels as fully as possible to discover what they were being used for. The second was to try and map the tunnel system so that we could work out its extent, and if need be, dig down to a soldier who might be trapped. The third, once we discovered what a treasure trove the tunnels were, was to recover everything we could weapons, equipment and paper all of which was invaluable for the intelligence boys.
But with the constant danger of men either collapsing in sections with foul air or coming face to face with the enemy, mapping the tunnels was a priority.
We were down in a tunnel and wed gone as far as we could have gone. But there were branches off everywhere and we were told to just keep talking, tell us every move you make. Every time you come to a corner go to the right, just go to the right and we had to bring back compass bearings. I came to one turn and I just couldnt go on but I thought Ill just go a bit further, and I kept on going.
Then I came across a lot of gear stacked in the tunnel. I was scrambling over the top of it. We got all this gear out, and from there on we got more and more gear.
On the first day, the Demolition Team allotted to A Company 1RAR searched and destroyed a tunnel that was 80 feet long and had a sleeping bay for approximately five people. There was nothing particularly unusual in that. About twenty domestic trench, bunker and tunnel systems were searched and destroyed. We also came across some homemade bombs and grenades set as booby traps.
On day 2 the B Company Demolition Team searched a bunker system under a house and found a room about 15 feet long by 7 feet wide by 5 feet high, full of weapons, ammunition, mortar shells, grenades, clothing and documents. The trapdoor entrance was only 16 inches square and was hidden under a layer of dirt. We also had to deal with more booby traps, including vicious barbed steel spikes in the ground, one of which went through the foot of a soldier. The D Company Team searched bunkers and tunnels starting from houses and finishing in open exits in the field, one was 45 yards long.
On day 3 we investigated a lot more tunnel systems, but only one of the initial searches turned up anything of interest. We werent complaining, it was quite a find. Again, the tunnel began under a house, but this time instead of weapons, we found a typewriter, medical supplies and documents.
The C Company Demolition Team blew smoke and tear gas through after that then, when no one came out, blew up the tunnel entrances to seal it.
The A Company Team found a homemade rifle, a sewing machine and a radio in a tunnel under a house. One Viet Cong was hit by gunfire and disappeared down a hole in the group. The hole was tear-gassed then a grenade was dropped down it. The assumption then was that the enemy would have died. Now Im not so sure. He could have been miles away for all we knew. We found sewing machines and the rolls of material, weapons and a makeshift hospital, living quarters and a cooking area. You cant put the magnitude of it into words. You just think of a tunnel as a tunnel, no rooms or anything like that running off it.
The D Company Team found a wireless and an ID card in another tunnel and a whole squad of Viet Cong was seen disappearing in the same area. When the tunnel system was found this cache of 12.7mm Chicom Anti-aircraft guns, webbing, grenades, magazines, rice, weapons, and heaps of paper work were retrieved. This was our first really big weapons cache.
Day 4, saw us find several trapdoors and tunnels and once again we could hear Vietnamese voices down there. It was on this day that Bob Bowtell died. He was the leader of the B Company Demolition Team. I was astonished to find in my records that the tunnel entrance he squeezed himself into was only 16 inches by 11 inches. On the same day, the C Company Team used the dog team to confirm Viet Cong activity in the tunnel that was later blown up. At night we could hear the sound of VC trying to dig themselves out. We tried to dig down to them and the entrances were opened and teargas was blown through, but nobody came out.
On Days 5 and 6 all the Company Demolition Teams were still finding amazing amounts of arms, equipment and documents, especially from the larger rooms they had found. And despite Bobs death, the men were still keen to go down the tunnels, especially if there was a prize at the end of it.
By the time we got ourselves properly organized, there were four teams of six, each attached to an infantry company, and we had men underground in shifts from dawn until dusk.
Besides all the tunnel work going on within the companies tactical area of responsibility, the major tunnel system was being searched all week. We had investigated tunnels for 700 metres in one direction and 500 metres across that line and we still had no idea how far the tunnels extended. We had taken out truckloads of equipment and documents, including photographs of the Viet Congs foreign advisers and a hit list of political and military figures in Saigon whom the VC wanted to assassinate.
The next day whilst searching the tunnels within the battalion perimeter, we found another trapdoor leading to a third level, before it could be investigated, the Americans decided to wrap the operation up and pull out. We only went back down the tunnels long enough to line them with explosives and bags of tear gas crystals. Our intention was solely to destroy the tunnels as best we could and leave those parts that we couldnt destroy as uninhabitable as possible. We never found out what was beneath that trapdoor, at least, not until many years later.
What we knew was that we had stumbled upon hospitals and classrooms containing so much equipment that the Americans assumed we had found the Viet Cong headquarters. Even if that had been true, it was still an astonishing feat for the Viet Cong to have constructed the parts of the tunnel system we had found. But it was just a tiny part of a larger system, which ran for 200 miles.
We would only discover a couple of decades later that beyond that final trapdoor was the military headquarters of the Southern command of the Viet Cong. At the other end of our search, we were just as close to discovering the VCs political HQ.