Engineers explosively breach wire obstacles surrounding an enemy trench system, under covering fire from two M1A2 Abrams main battle tanks.
Infantry clear the entrance with a barrage of gunfire and grenades, before moving into the tight trench confines.
The lead section advances down the complex with tightly controlled movements up to a switchback, where the point man pauses to clear the next stretch with grenades before taking the corner and continuing the fight.
It's a form of combat which hasn't been the Australian Army's focus for many years, but recent conflicts have brought trench warfare back to the front lines.
Soldiers from 1st Battalion, The Royal Australian Regiment (1RAR) conducted a trench assault exercise - which helped shape new trench warfare doctrine - during Exercise Brolga Sprint, held at the Townsville Field Training Area on June 4-13.
Brolga Sprint progressed from blank-fire runs into non-lethal training ammunition and culminated in a live-fire exercise, with the assault conducted by 1RAR supported by 3 Combat Engineer Regiment (3CER), 4 Regiment, Royal Australian Artillery, and 2 Cavalry Regiment.
It was the first time Lance Corporal Luke Franettovich, of 1RAR, had done trench training in his seven-year infantry career, and he found the new drills exciting.
"As a section commander it's a lot more about controlling the assault rather than conducting the drills," Lance Corporal Franettovich said.
"Due to the threat of grenades, you need to be spread out a lot more, so the communication is a lot harder because the switchbacks can interfere with the soldier's personal radio."
The restricted confines of a trench, increased load and equipment, and the 360-degree threat nature make trench warfare mentally and physically fatiguing.
Soldiers must carry extra ammunition and grenades while navigating cramped positions, which are sometimes littered with obstacles and explosive devices.
'Urban allows a transition of roles quite fluidly, whereas trench relies on people to adopt the same positions throughout the assault, due to specialist equipment and responsibilities.'
Being constantly on the lookout for indirect fire, incoming grenades and Uncrewed Aerial Systems threats means each soldier has to maintain their role vigilantly.
"A lot of the trust is put in your front-four soldiers. They are the ones who make most of the calls, so you have to trust your diggers know what they're doing," Lance Corporal Franettovich said.
For Warrant Officer Class 1 (WO1) Brandon Carey, from Land Combat College, the exercise was a practical challenge for the viability of tactics he developed over the past 12 months.
"Usually you can dig up a pam [instructions] that is pretty similar to what we are doing now. Some of the fundamentals of war don't change, but this was the one thing I couldn't find anything on," WO1 Carey said.
"Apart from very broad-brush trench warfare references, there was only some lessons learnt from World War 1 and 2, which have some similarities in terminology."
WO1 Carey took lessons from the battlefields of Ukraine, doctrine from European allies, and experiences of soldiers returning from Operation Kudu, and adapted them for Australian Army tactics.
"There's elements of our urban doctrine that I am leaning on - trench and urban share some similarities - but they are a very different type of warfare," he said.
"Urban allows a transition of roles quite fluidly, whereas trench relies on people to adopt the same positions throughout the assault, due to specialist equipment and responsibilities."
3CER plant operators made the trenches before Brolga Sprint and shored them up with revetment from combat engineers attached to Combat Team Bravo.
Corporal Oscar Dodd, of 3CER, said the engineers' job was not only in breaching the trench wire obstacles, but to provide mobility and survivability to infantry clearing the trenches.
"When assaulting a trench, engineers either deal with explosive devices or simply conduct a mark and bypass, to maintain the speed and tempo of the attack so the infantry can move forward," Corporal Dodd said.
"Getting to know the infantry we're attached to was really good, and working as engineers in a dismounted environment posed a lot of challenges for us, but it was good to find ways to overcome this."
