3:30 in the morning, 13th of May, 1968, and the dirt around Fire Support Base Coral was shaking under rocket and mortar fire. Regulars of the 141st Regiment of the 7th PAVN Division had punched through the half-finished sandbag walls of the 102 Field Battery. Australian gunners had fallen at their pits as the North Vietnamese seized a 105-mm howitzer in its open emplacement.

The mortar platoon of 1 RAR was already gone. Sapper teams had overrun it inside the first 10 minutes of the assault. The Australians on Coral had been on the ground less than a day. Their fighting pits weren’t dug to depth, and the wire was strung in patches with no overhead cover on the gun positions.

 They’d flown into a coordinate on a map called the Surfers Area of Operations, 40 km northeast of Saigon, with orders to block the corridor the North Vietnamese were using to push regular divisions toward the capital. The Tet Offensive had ended in February, and Hanoi was sending its main force south for a second swing at the city.

Coral sat directly across that path on a stretch of cleared rubber and scrub the maps marked as flat enough for guns and helicopters, but offering no high ground anywhere on the perimeter. Their base belonged to the 1st Australian Task Force, deployed under American command at Field Force 2, and it was supposed to be a forward fire base covering infantry patrols out into the rubber.

By dusk on the 12th of May, the guns of 102 Battery were laid in, but the perimeter was loose, and the wire was still being run. Sentries reported movement in the rubber tree line at last light, while flares went up over the gun positions to keep the engineers working through the dark. Patrol reports back from 1 RAR companies in the bush had been picking up Vietnamese voices and fresh tracks belonging to regular formations moving in close to the base.

Nobody on Coral was expecting an attack at regimental strength before the sandbags went up. When the first salvo came in at 2:30 in the morning, it walked across the base in long lines. Rockets fired from launchers set up in the rubber tore through the gun pits and the radio tents, catching men in their hooches and stripping the radio nets out within minutes.

 An hour later, with the rocket and mortar fire still walking across the gun line, the infantry hit the wire in two waves from the southeastern arc. Sapper teams led with Bangalore torpedoes and satchel charges, and behind them came the assault companies of the 141. They’d picked the seam between the gun line and the mortar platoon, and they went straight through.

 The forward gun pit of 102 battery was the first to go. Its detachment fought hand-to-hand with sapper teams in the dark, and when the North Vietnamese took the pit, they took the howitzer with it, sights and breech intact. Three Australian had fallen defending the position, and several more lay wounded behind the parados. The gun was now a North Vietnamese trophy sitting inside an Australian perimeter with the rest of the 102 battery still in action 200 m away.

What the gunners of the remaining howitzers did next would settle Coral in the dark. After the Tet Offensive of 1968, the war in South Vietnam had changed shape. The North Vietnamese army had taken heavy losses in the cities during January and February, but its main force divisions were still moving south through the corridors east and northeast of Saigon, preparing for what Hanoi expected to be a second wave.

American intelligence read the signs and asked the Australians to plug one of those corridors. The first Australian Task Force, headquartered at Nui Dat down in Phuoc Tuy province, was pulled out of its usual area of operations for the first time and flown northwest into a stretch of rubber and scrub 40 km above Saigon.

Australian maps marked the new ground as the Surfers area of operations and American intelligence had it tagged as a regular avenue of approach for North Vietnamese formations pushing toward the capital. Two infantry battalions came north with the task force, 1 RAR and 3 RAR.

 Their supporting arms included the 102 field battery with six American pattern 105 mm howitzers, a mortar platoon attached to 1 RAR, the 161st independent reconnaissance flight with its light spotting aircraft plus signals and engineer detachments. A squadron of Centurion tanks from C Squadron, 1st Armored Regiment, was on its way up by road to join the task force from Phuoc Tuy.

American support came on call from above and around with artillery batteries from neighboring American firebases ranged in across the corps’ area and AC-47 Spooky gunships overhead that could rake whole hectares with mini guns. Two sites were picked for fire support bases inside the Surfers area and they were named Coral and Balmoral.

It was the first time in the war that Australian troops had been pulled out of Phuoc Tuy as a complete task force and pushed onto ground chosen for them by American command. They were going into a corps area run by an American general alongside American formations against an enemy who just spent 3 months trying to bring down Saigon from the inside.

The Australians had fought North Vietnamese forces before in skirmishes and ambushes around Phuoc Tuy. They had never gone head-to-head with regular regiments of the People’s Army on ground the enemy had chosen and prepared. Coral and Balmoral would settle that question before the end of May. Coral was occupied on the 12th of May.

Helicopters ran in throughout the morning bringing the lead elements of 1 RAR, the gunners of 102 battery, ammunition crates, and sandbags, and rolls of barbed wire stripped out of the back of the gun line. The site was a stretch of cleared scrub among rubber trees flat enough for the guns and the helipad, but close to thick bush on three sides where the rubber gave way to secondary jungle.

The men dug as fast as they could scraping shallow weapon pits out of the red soil while the gunners laid in their pieces and the engineers ran wire. They knew the corridor they were sitting on was a North Vietnamese highway, but the schedule was tight and the perimeter ran out of daylight before it was finished.

 Watching the landings all afternoon, the North Vietnamese had been moving observation teams through the rubber since the first lifts came in. The 141 regiment of the 7th PAVN division was bivouacked within a few kilometers of the new base and had its own forward observers working the tree line in close. From those positions, they tracked the patrol pattern and the gaps in the wire around the gun positions.

By 2:30 in the morning of the 13th, the assault force was forming up southeast of Coral ready to move on a base they had assessed as holding less than half its defenses in place. They moved off in two columns fast and quiet with the sappers carrying the satchel charges and the Bangalore’s up at the head of the line.

 At 2:30 exactly on the morning of the 13th of May, the barrage opened across Coral. Rockets came in first from the launchers set up in the rubber walking across the helipad and the gun positions in long bursts that lit up the trees behind them. Mortar fire followed and concentrated on the 1 RAR mortar pits and the 102 battery gun line dropping rounds inside the perimeter with practiced accuracy.

Men dived into shallow weapon pits, some of them still not waist-deep, while the radio nets clogged with calls for fire and counterbattery work. By the end of the first 10 minutes, Coral was already taking its wounded out of pits and into the makeshift aid post the medics had set up behind the gun line.

 At 3:30, the infantry hit the wire under the rocket and mortar barrage that had been walking across the base for an hour. Sapper teams led with Bangalore torpedoes through the wire on the southeastern arc, the same arc the North Vietnamese had assessed as the weakest. Behind them came the assault companies of the 141 Regiment, moving fast through the gaps the sappers had blown.

They pushed at the seam between the 1 RAR mortar platoon and the gun line of 102 battery, and they tore both apart in minutes. Within a quarter of an hour, the forward gun pits and the mortar position were inside the North Vietnamese line of advance. First to fall inside the perimeter was the 1 RAR mortar platoon, positioned forward of the gun line in the seam the sappers had picked.

Its men fought from the pits with rifles and grenades, but the sappers were already moving past them, and within minutes the platoon was scattered and its tubes overrun. The forward gun pit of 102 battery was the next position to go. Its detachment was driven out, leaving the howitzer in North Vietnamese hands with rounds still stacked beside it for the next fire mission.

Gunners on the remaining five guns of the battery saw what was happening and turned their barrels in. What followed was the moment Coral turned. The gun crews of 102 battery swung their pieces around until the muzzles pointed inwards across the open ground of their own perimeter, and they loaded Splintex rounds.

Splintex was a beehive shell, an antipersonnel projectile packed with thousands of small steel flechettes that scattered on firing, turning a 105 mm howitzer into something close to a gigantic shotgun. They fired into the assault wave at point-blank range across the open ground inside the wire. The lanyards came down on the firing levers with the gun crews lying flat to avoid the back blast, and the rounds went straight into men who were 30 m away.

 The effect of splintex at that range tore the assault formation apart. North Vietnamese infantry caught in the open between the rubber line and the gun pits had no cover, and the steel needles cut through them in waves. Halfway across the perimeter, the attack stalled and broke up under the canister effect of round after round being fired flat across open ground.

American spooky gunships came in overhead and laid down minigun fire along the tree line behind the assault, cutting off the second echelon before it could reinforce. By first light, the 141 regiment was breaking off and pulling back into the rubber. At dawn, the Australians counterattacked to retake the lost ground.

 A platoon of 1RAR moved through the wire toward the lost gun position, while the remaining batteries kept fire down on the rubber to prevent reinforcement. By the time they reached it, the gun pit was empty with the North Vietnamese sappers pulled back as soon as the splintex started landing and unable to drag the howitzer with them. Their piece was back in Australian hands with its breech intact and its sights still in their mounts after less than 3 hours under enemy control.

Within an hour, the gunners had it dug back in and laid for the next fire mission. Australian losses in the first attack on Coral fell mainly in the gun pits and the mortar platoon, with more wounded across the perimeter. The fallen of the assault companies of the 141 regiment lay in arcs across the open ground where the splintex had caught them, while the rest of the regiment had pulled back into the rubber under their own fire support.

A field count put their losses well into the dozens around the wire alone. The captured gun stood undamaged in its pit, dug back in within hours, and ready to fire again before the next sundown. Coral had held its first night, but the 141 Regiment hadn’t finished with the base. Three days were used by the Australians to make Coral ready for the next attack.

 Engineers dug the gun pits deeper and gave them overhead cover with timber and sandbags stripped out of the supply runs coming in by helicopter. Wire was layered out 50 m or more in front of the gun line, and patrols from 1 RAR cleared the rubber back to the edge of the trees looking for the staging areas the 141 had used on the night of the 13th.

They found bunker complexes and supply caches showing how long the regiment had been biovacking in close before the task force came in. Then on the 16th of May, the 141 Regiment came back. Around 2:30 in the morning, the second attack on Coral opened. Mortars and rockets came in first with the same pattern as the 13th, walking across the helipad and the gun positions.

Behind the barrage, the infantry came on out of the south and east moving in waves through the wire at near regimental strength. This time the wire held them at the obstacle line with the deeper pits and overhead cover keeping the Australian gunners in their fire mission through the worst of the barrage.

 Australian artillery fired on pre-registered defensive targets ringing the base with American medium guns from neighboring American firebases adding heavy support and spooky gunships working over the tree line behind the assault. For nearly an hour, the North Vietnamese pushed at the perimeter. Some sapper teams got close enough to the wire to throw satchel charges, but none made it inside as Australian small arms and machine gun fire chopped them down at the obstacle line.

By dawn, the assault was breaking up under fire from all directions and pulling back into the rubber. Australian patrols pushed out at first light and found the fallen of the 141 regiment stacked in front of the wire and along the assault lanes the Bangalore’s had blown in the previous attack. After two attempts on the same base inside 4 days, the 141 had been bled badly and pulled back to re-fit it deeper in the bush.

 With Coral now anchored, the task force decided to push north. 3 RAR was ordered to set up a second fire support base some 4 and 1/2 km above Coral in the same blocking line that would close the corridor down. The new base was named Balmoral, occupied on the 24th of May deep inside the same corridor that had brought the 141 regiment down on Coral.

Within range of Coral’s guns, Balmoral could draw fire support from the 102 battery. But, the infantry of 3 RAR would have to hold the perimeter on their own ground. By this stage, however, something had changed on the Australian side. C Squadron of the 1st Armored Regiment had arrived.

 Its 60-ton British-built Centurion tanks had moved up from Phuoc Tuy by road and joined the task force at Coral within a few days of the second attack. These were the first Australian tanks to operate in direct support of infantry since the Pacific campaigns of the Second World War and they brought with them the kind of weight the bush warfare in Vietnam hadn’t seen on the Australian side before.

Centurions were dug into hull-down positions at both Coral and Balmoral with their main guns ranged across the wire and onto the rubber lines beyond. They would change what the next attack looked like. Each Centurion mounted a 20-pounder main gun firing 84-mm shells out to a couple of kilometers on open ground, paired with a coaxial machine gun and a commander’s gun on top.

 And the squadron had brought canister rounds along with high explosive stocked in its ready bins. Canister at close range turned the main gun of a Centurion into a weapon that could clear an arc of ground out to 100 m in a single shot. The crews had spent their last months at Puckapunyal training for armored warfare in Europe against Soviet formations, and they were now being asked to fight at close range from dug-in positions in tropical secondary jungle.

They adjusted fast to the conditions on the ground. The first ranging shoots from the Centurion positions at Balmoral were complete within hours of arrival. Against Balmoral, the North Vietnamese moved on the night of the 25th of May into the morning of the 26th. Hanoi committed the 165 Regiment of the 7th PAVN Division, the sister regiment of the bloodied 141, fresh and at full strength.

D Company of 3RAR, dug in on the eastern arc of the perimeter, took the main weight of the assault when it came in. Mortar fire opened the attack at 3:45, and infantry followed within minutes through the wire. They came on in the same disciplined waves that had nearly taken Coral on the 13th. For over an hour, D Company held the wire under direct attack.

 The Centurions at Balmoral lit the ground in front of the perimeter with their main guns and machine guns, firing canister and high explosive into the assault waves at close range with the shells exploding on the rubber tree line behind. Australian 105-mm fire from Coral landed on pre-registered targets in the rubber behind the assault, breaking up the second echelon before it could close.

American spooky gunships came overhead again and worked over the tree line behind, cutting off any chance of reinforcement. By dawn, the 165 Regiment was broken in front of D Company and pulling back into the bush. Over 40 North Vietnamese fallen were counted by Australian patrols in front of D Company’s position alone.

The wire and the killing ground behind it were thick with the 165’s casualties dropped by canister and small arms fire as they came on through the obstacle line. Australian losses in the action stayed lower than at Coral on the 13th, helped by the dug-in defenses and the tank fire that broke the leading wave before it reached the wire.

But, the 165 Regiment hadn’t broken altogether, and intelligence reports from prisoners said another assault was coming within a few days. The Australians at Balmoral used the time to range every weapon they had across the approaches the 165 had used. Their second push came in the early morning of the 28th of May.

The 165 Regiment hit Balmoral again, this time with two battalions in line and supported by mortars and recoilless rifles back in the rubber. At half past two, the attack opened and was committed in waves through the same eastern arc that D Company had held two nights before. By then, the Australians were ready in depth.

 They had ranged their guns and tanks across every approach and brought every weapon on the perimeter into the killing ground with overlapping fields of fire from the Centurions and the infantry positions. Within half an hour, the assault collapsed. Centurion main gun fire and three RAR machine guns broke the leading wave in front of the wire, and the second wave never closed across the open ground behind it.

Australian artillery from Coral chopped up the rear of the formation as it tried to withdraw into the rubber while Spooky came back and ran the tree line a third time. By sunrise on the 28th, the second regimental attack on Balmoral was finished and the 165 Regiment had been bled out of its battalions twice in three nights.

Patrols pushing out at first light found the same arcs of fallen along the assault lanes with weapons and equipment dropped where the men had fallen. Three regimental attacks on the two bases were over. The Australians stayed in the field for another nine days. They patrolled out from Coral and Balmoral aggressively working through the rubber and the secondary jungle hunting the bunker systems the North Vietnamese had been using as staging areas.

Patrols found bunkers and weapons caches that showed how long the 141 and the 165 had been operating in the corridor before the task force came in. On the 6th of June, the operation was declared finished and the task force pulled out by road and by helicopter back toward Nui Dat. Prisoner debriefs added detail to the field counts.

Captured North Vietnamese soldiers spoke of the Splintex rounds with particular care calling them by their own word for canister and describing what the steel needles had done to the assault waves on the night of the 13th at Coral. They confirmed the 165 had been brought up specifically to finish what the 141 couldn’t on the second attempt.

 They also confirmed that the Saigon corridor was the priority access for the regiments of the 7th PAVN Division through May and June of that year. The Australians on Coral and Balmoral had been sitting on what Hanoi considered the most important ground in the core area. A final count settled the questions about the operation.

 26 Australians had been lost over 26 days of fighting on Coral and Balmoral. The breakdown of those lost showed 16 from 1 RAR, six from 3 RAR, two from 12 Field Regiment, one from 104 Signal Squadron and one from 161 reconnaissance flight, with over 100 wounded across all units. North Vietnamese fallen, counted on the ground in arcs around the wire of both bases, came to 267 confirmed, with estimates running over 300 when the bodies pulled back into the rubber were factored in.

11 North Vietnamese were taken prisoner, the largest haul of regular PAVN prisoners the task force took in any single operation of the war. 36 group weapons and 112 small arms were captured from the fallen and from abandoned bunker positions inside the area of operations. Coral and Balmoral together accounted for the heaviest losses inflicted by the 1st Australian Task Force on regular North Vietnamese Army units anywhere in the war.

Two regiments of the 7th PAVN division had been wrecked in the attempt to overrun the bases. Both pulled back deep into war zone D to refit and rebuild around what survivors they had left. The corridor they had been pushing through was now closed for the rest of the operation. Hanoi’s second wave toward Saigon had been stopped 40 km short of the city by two Australian infantry battalions and their supporting arms working alongside American firepower.

 The Battle of Coral and Balmoral was something Australian planners hadn’t expected to fight. It was a conventional fight at conventional scale. Two regiments of regular infantry against two battalions in Nui Dat firebases, settled by direct artillery and tank fire alongside American air support working overhead. Centurion work at Balmoral became the first time Australian armor had been used in close support of infantry since the Pacific campaigns of 1945.

And the after-action reports went up the chain inside days of the task force returning to Nui Dat. The lesson would shape how Australian armor deployed in Vietnam for the rest of the war, with C Squadron and its successors pushed forward in support of infantry sweeps wherever the core’s area would carry them.

Coral and Balmoral also became the longest sustained engagement the task force fought across its years in Vietnam, and the costliest one measured against the size of the force put on the ground. For the 102 Field Battery, the moment that stayed with them was the loss and recapture of the forward gun pit on the 13th.

That howitzer had been in North Vietnamese hands for less than 3 hours, and they hadn’t been able to remove it or destroy it before the Splintex drove them back into the rubber. Gunners who came back across the wire at dawn found their piece sitting where it had always sat, with its breech and sights still intact in their mounts.

They cleaned it and checked it, then put it back in the fire plan for the rest of the operation. The North Vietnamese had paid roughly 300 fallen to hold an Australian gun for less than half a working shift. No parades met the task force when it came home from the Surfers area. The men of 1 RAR and 3 RAR were back at Nui Dat by the second week of June, and back on regular patrols inside Phuoc Tuy soon after, with the corridor north of Saigon left behind them.

 The Battle of Coral and Balmoral didn’t enter the Australian public memory the way Long Tan had 2 years earlier, or the way Kapyong from Korea had a generation before. And the gunners and infantrymen who had fought there kept the story largely to themselves. It stayed inside the regimental histories and inside the gunner messes, where the men who had served the lost gun on the 13th told the story dry, without embellishment, the way most Australian soldiers tell stories about their war.

The corridor on the way to Saigon had closed, and the fallen of the 141 and the 165 had been counted around the wire of two firebases the Australians had walked into less than a month before.