"They Can't Reach Us Up Here" — How Australians Stormed A Japanese Fortress In Single File

Added: 2026-05-27

[00:00:00]On the morning of the 27th of December 1943, soldiers from B Company of the Second 16th Battalion started climbing a ridge so narrow that two men couldn't stand side by side. The formation was single file, straight up a near vertical slope in the finasterary range of New Guinea with sheer drops falling away on both flanks into cloud forest. Japanese mortar crews on the crest had the trail zeroed and grenades were rolling downhill before the first section cleared the departure point. Every man on that slope was visible to the defenders above and the only cover available was the body of the soldier in front. Shaggy Ridge ran 6 and 1/2 km through the finister range. A razorback spine of kunai grass and exposed rock sitting roughly 5,000 ft above the Ramu Valley floor. At its narrowest, the walking trail shrank to the width of one man's shoulders, open air on both sides, a drop that ended in jungle canopy hundreds of feet below. The Japanese had fortified every null and saddle along the crest with log and earth bunkers sunk below the ridge line connected by communication trenches with fields of fire that overlapped across every approach. The seventh Australian division had been ordered to take this ridge and the only axis of attack was straight up the spine itself. Before B company stepped off, Australian 25p pounder batteries in the valley below fired roughly 3,500 shells into the Japanese positions at the southern end of the ridge. The barrage concentrated on a fortified knob the Australians had named the pimple, the first objective, a raised position at the forward edge that commanded every approach from below. Australian-built boomerang fighters and American Kittyhawks followed with strafing runs along the crest, hitting each identified bunker and trench with bombs and machine gun fire. The southern face of the pimple was torn apart by the time the bombardment lifted, but the reverse slope positions on the far side, the ones the shells couldn't reach at that angle, were still intact. B Company went up at 0900, climbing with hands and feet, rifles slung across their backs, hauling over rock ledges, and through shattered kunai, while the 25 pounders shifted fire further along the ridge.

[00:02:24]Every meter of altitude gained was a meter further from any possibility of retreat. The trail behind was too narrow and too steep for a fighting withdrawal.

[00:02:33]The lead section reached the base of the pimple and found Japanese soldiers who'd survived the barrage already scrambling back into their firing positions from the reverse slope. The fight for the crest started at grenade range and went to bayonets within minutes. B Company took the pimple before midday, but the ground they held was barely large enough for a reinforced platoon, and the ridge stretched another six kilometers to the northwest with every null along it fortified the same way. Japanese forces on the next hill were already forming up for a counterattack, and the Australians, who' just clawed their way up a near vertical slope, had nowhere to dig in on the exposed rock. The seventh division had its foothold on Shaggy Ridge and the price for the remaining 6 km hadn't even begun to be calculated. 3 months before that assault in September 1943, the strategic situation in New Guinea shifted against the Japanese.

[00:03:30]Allied forces captured Lei and Nadzab in a combined airborne and amphibious operation and the Japanese garrison began withdrawing toward its main base areas on the north coast. The ninth Australian division drove along the coast toward Finch Hoffen, grinding through successive rear guard positions.

[00:03:48]The seventh division drew the inland assignment, advanced northwest from the Ramu Valley, cross the Finister Range, reach the coast near Bugajim, and link up with the ninth division to seal the Japanese line of retreat. Shaggy Ridge sat directly across that route, and the Japanese high command understood exactly what losing it would cost. The Ramu Valley delivered its own punishment before the seventh division ever reached the mountains. Temperatures on the valley floor hit 54° C, and the country was flat kunai grassland taller than a standing man, cut by rivers that flooded without warning after each afternoon downpour. Scrub typhus was endemic, a parasitic disease spread by mites that bred in damp, filthy clothing, and it was frequently fatal. The disease evacuated men from the line faster than Japanese fire did during the approach march, and battalion medical officers had limited means beyond isolating the worst cases and hoping. Supply moved forward on foot and by mule train along tracks that dissolved into slurry every afternoon, and the mules themselves were dying from exhaustion and disease at a rate that made every resupply run a logistics calculation about which animals could still carry weight.

[00:05:06]Forward battalions of the 21st brigade, the 2nd 14th, the 2nd 16th, and the second 27th, made contact with Japanese outposts in October 1943 as the division pushed into the Finister foothills. The engagements were small at first, company and platoon actions against rear guard positions the Japanese held long enough to inflict delay and casualties before pulling back. Each rear guard action bought the Nikai detachment more time to prepare the main defensive line on Shaggy Ridge. The Nikai detachment was a brigade strength formation drawn from the Japanese 20th division under Major General Masutaro Nai tasked specifically with holding the Finister passes and it had been digging in for weeks by the time the Australians reached the base of the ridge. The ridge got its name from Lieutenant Bob Clampet of the Second 27th Battalion, whose radio call sign was Shaggy. Clampet's company was the first Australian unit to establish a footing on the southern slopes, and the name attached itself to the entire 6 1/2 km feature. By late October, the Australians had pushed close enough to probe the Japanese defenses directly, and every patrol confirmed the same picture. The crest was held by the second battalion of the 78th Infantry Regiment, reinforced with two companies from the third battalion of the same regiment, backed by guns of the 26th artillery regiment and engineers from the 27th independent engineer regiment.

[00:06:38]The fortifications weren't improvised field positions. They were permanent defensive works built by trained engineers with time and material on their side. Through November and into the first weeks of December, the Seventh Division tried to crack the ridge without committing to a frontal assault.

[00:06:55]Australian 25p pounders hammered the crest daily from batteries positioned in the valley and air strikes went in when weather permitted. Cloud cover rolled across the Finister Range most afternoons and shut down air operations for hours, which meant the bombers had a narrow window each morning to work before the mountains disappeared. Small parties of Australians climbed to within grenade distance of Japanese bunkers, fought brief close-range actions at the cost of casualties the brigade couldn't sustain, and withdrew. The Japanese repaired damaged positions overnight, and replaced their forward troops from reserves further along the spine.

[00:07:34]Flanking patrols found the same answer on every attempt. The slopes on both sides dropped into ravines choked with jungle so thick that moving a platoon strength force through it would take days and arrive exhausted. Weeks of probing and bombardment told the brigade staff what they needed to know and what nobody wanted to hear. Flanking was impossible. The terrain on both sides was vertical jungle. Japanese supply ran along the crest from the northwest beyond effective range of the Australian guns so the garrison couldn't be starved out. Reverse slope bunkers survived the 25-p pounder fire because the shells arrived at the wrong angle to penetrate overhead cover built to withstand exactly that kind of bombardment. That left a direct assault along the ridge itself uphill in single file against a garrison that could watch the Australians forming up and knew exactly where the attack would come. Brigade headquarters issued the order in late December, and the pimple was designated the first objective because controlling it would give the Australians observed fire across the next section of the ridge. The fire plan paired Australian ground forces with the most unusual air asset in the theater. The Boomerang was a light fighter designed and built in Australia. Underpowered for air-to-air combat, too slow to intercept Japanese bombers, but ideal for close air support because its low speed let pilots identify individual bunker positions on a ridge where the gap between friendly and enemy troops was measured in tens of meters. Boomerang pilots flew along the crest, marking targets with smoke, and American Kittyhawks followed the smoke in with heavier ordinance. The entire sequence, artillery barrage, smoke marking, air strike, artillery shift, had to execute within a window tight enough to keep the Japanese in their shelters until the infantry arrived. A short round from a 25p pounder or a misplaced bomb on a ridge this narrow would land on the assault force, and both the gun crews and the pilots knew it. The assault on the 27th put B company on the pimple by midday and the cost of holding it started accumulating within the hour. Resupply had to come up the same single file trail the assault had used with carrying parties making the climb under intermittent mortar fire from Japanese positions further along the ridge. Ammunition, water, rations, and medical supplies went up on men's backs. There was no other method available on terrain this steep and narrow. Wounded came down the same way, carried on stretchers along a track where two bearers couldn't walk a breast, passed from relay team to relay team down the slope. The exposed crest offered no natural cover, and the men who'd taken the pimple spent the rest of that afternoon building sangars from loose rock and the shattered timber of Japanese bunkers, while mortar rounds dropped onto the position at irregular intervals. On the 28th of December, D Company of the Second 16th relieved B Company on the Pimple and pushed the advance further along the ridge. The distance gained that day was roughly 100 m to the next fortified null, a span that took hours of fighting to cross because every step between positions was exposed to fire from bunkers on both sides of the crest. D Company captured two more nles in succession. The furthest point taken was named Makahi's null after the lieutenant leading the forward platoon and it became the new Australian front line on the ridge. On ground this narrow, each captured position eliminated another set of bunkers and pushed the Japanese counterattack start line further back along the spine. But the cost in men and time per 100 meters was steep. Japanese counterattacks came at night. Moving southeast along the ridge toward the Australian-h held nles. Fighting in darkness on a trail barely wide enough for two men was close range and chaotic with grenades the primary weapon on both sides because there was no room to maneuver and no space to set up automatic weapons with clear arcs of fire. The Australians held every counterattack through the last days of December, and the Japanese lost men they couldn't replace as quickly as the Australians rotated fresh companies up the ridge. But the cost was cumulative on both sides. Each company that held the forward position for 24 hours came off the crest with fewer men, and the men who came down carried the fatigue of fighting on a position where sleep meant lying on exposed rock with a grenade in one hand. The conditions on the captured sections of the ridge stripped warfare down to physical basics. Water was the constant problem. There was no source on the crest, and every drop came up from the valley in containers carried on men's backs through the same hours long climb. The heat at the valley floor and the cold at 5,000 ft on the exposed ridge created a temperature swing that left men soaked in sweat at the bottom of the trail and shivering at the top.

[00:12:36]Weapon maintenance was another fight.

[00:12:38]Rifles and Bren guns clogged with the red mud of the Finister slopes, and cleaning gear was one more item that had to be humped up the trail. The men on the ridge ate cold rations because cooking fires would draw mortar fire, and they slept in 2-hour rotations when they slept at all. A pause between late December and mid January gave the seventh division time to reorganize.

[00:13:01]Battalions of the 21st Brigade had carried almost the entire fight so far, and the brigade was worn down. Fresh units from the 18th Brigade moved into the line for the next phase. A coordinated assault intended to clear the remaining Japanese positions along the full length of Shaggy Ridge rather than grinding forward one null at a time. Simultaneous attacks along the main spine and up secondary spurs would hit the Japanese defenses from multiple directions and prevent the garrison from concentrating its remaining strength against a single axis of advance. The renewed offensive began in mid January 1944 and the fighting followed the established pattern at a larger scale.

[00:13:44]Each null still had to be taken individually. Each advance still played out in tens or hundreds of meters, and each captured position became an immediate target for counterattack. The 18th Brigade pushed along the main ridge, while elements of the 21st Brigade worked up secondary ridge lines that intersected the spine. Coordination between the two brigades was complicated by terrain. Radio communication was unreliable in the mountains. Visual signals were blocked by cloud and jungle canopy and runners crossing between positions moved over ground that was frequently under fire. The advances were measured by nles taken and bunkers cleared and each day's progress was visible only on a large-scale map where the names of individual hills and saddles could actually be read. The Nakai detachment fought a disciplined defense for weeks, but the arithmetic of attrition was working against the Japanese garrison. By mid January, the forward companies of the 78th Infantry Regiment had been thinned to a fraction of their starting strength. Replacement troops had to come forward along the same narrow crest the Australians were attacking, and that route was now under observed fire from 25p pounder batteries that had the ridge registered to the meter. Every resupply run and every reinforcement column the Japanese pushed southeast along the spine took casualties before it reached the forward positions. The Australians could rotate exhausted companies out of the line and bring fresh ones up from the valley. The Japanese could only feed men forward along a corridor that was shrinking by the day. Canio saddle sat at the northwestern end of the ridge system, and it was the last Japanese defensive position that mattered. Losing it would cut the garrison's withdrawal route and leave the remaining defenders trapped between advancing Australian infantry and sheer terrain on both flanks. During the third week of January, the assault went in and the close-range pattern held grenades and small arms at distances where the combatants could hear each other moving. Japanese defenders fought with the same discipline they'd shown along the entire ridge. But they were outnumbered, cut off from effective resupply, and facing troops who'd been doing this for a month and had learned every trick the terrain allowed. On the 23rd of January 1944, the last organized Japanese resistance on Shaggy Ridge collapsed. Surviving elements of the Nikai detachment withdrew northwest along mountain tracks leading deeper into the Finister Range, leaving behind bunkers full of their dead, abandoned equipment and the wreckage of a defensive position that had held for 4 months. Australian patrols swept the length of the ridge and found that the Japanese fortifications were built to a standard that explained why so many had survived weeks of shelling. Log and earth bunkers with overhead cover thick enough to absorb anything short of a direct hit from heavy caliber artillery, firing slits cut to cover specific sections of the approach trail, communication trenches deep enough for a man to move between positions without exposing himself above the crest. The seventh division's butcher bill for the entire Shaggy Ridge campaign came to 46 killed and 147 wounded. Japanese dead confirmed on the ridge and in the surrounding area totaled 244 with total Japanese casualties estimated at up to 500. The ratio reflected the weight of the Australian artillery and air support.

[00:17:18]3,500 shells and repeated air strikes on a frontage measured in meters had done damage that the infantry then exploited.

[00:17:27]But the casualty figures alone didn't capture what the fighting had cost in endurance. Four months of operations in terrain that punished every movement, every resupply, every casualty evacuation with the same grinding physical effort had worn the division down to a degree that numbers on a page couldn't convey. capturing Shaggy Ridge and Canurio Saddle broke open the route through the Finister Range to the north coast. From there, the seventh division continued toward Bugajim to complete the linkup with the 9inth Division pushing from the coast. Japanese forces left in the Huan Peninsula had lost their viable route for organized withdrawal through the mountains and the Finister Range, the barrier that had protected the North Coast garrison for months, was now in Australian hands. Every operational objective that had driven the campaign was achieved, and it had been achieved by infantry companies climbing a ridge, one man at a time. Shaggy Ridge stayed on the maps long after the war, named for a lieutenant whose radio call sign stuck to 6 and a half kilometers of rock because his company happened to get there first. The men of the second 16th and the second 27th, who'd fought their way up it, one behind the other, carrying everything on their backs up a trail wide enough for one pair of boots, went on to more of the same mountains, the same jungle, the same war that wouldn't end for another 18 months. It became another place they'd been, and another hill they'd taken, filed alongside all the others. Most of them didn't talk about it