Suddenly there's shouting. Engines growl into life. The joking stops. Action.
The quake-stricken Kaikoura residents are glad the army are such patient professionals.
Fresh food, milk, water, baked beans, gas bottles for cooking, hospital supplies, thousands of litres of petrol and diesel, was delivered into the cut-off seaside town today.
The road in isn't easy. Many checks to make. It's out of the army's hands.
"We could just truck through but we have to wait for the green light," one driver said.
While the old cow cocky's ute can trundle through the cracked, beaten roads, two-seater campervans wouldn't make it.
But the NZDF's new MAN MHOV (medium and heavy operation vehicles) - powerful, high-tech eight-wheeled machines - chew it up. Steered by the skilled combat drivers, they streak over cracked roads which are filled with shingle in band-aid repairs. They rumble through landslides, enormous in places, bulldozed aside.
It starts at dawn. In the cool murk at Culverden rugby grounds in North Canterbury, the khaki-clad soldiers do their finally checks, stuffing sausages in their mouths, washing it down with instant coffee. An army marches on its stomach.
Suddenly, there's shouting, jogging, and the roar of diesel engines. Final checks are done and the convoy of 32 vehicles carrying hundreds of tonnes pushes north.
They're worried about aftershocks. But if heavy rain comes too, it could make the slips even more treacherous.
We wind through the hills. Ordinarily this is the scenic route, linking the tourist mecca of Kaikoura and its crays and whales and dolphins with Hanmer Springs and its hot pools and forest tracks.
Today it's slow one-way traffic, the army humping onwards.
Beyond the cordon north of Waiau which has so frustrated locals for the last week or so, we ford the Wandle River. They're building a Bailey bridge for the trip back in some 11 hours time.
The going is good. And then we reach Lyford, the alpine township cut off for so many days after last Monday's giant quake.
The convoy stops. We wait. The message is relayed: the road needs to be checked.
Helicopters usually reconnoitre the road, checking for overnight damage, new perils. But today the fog has slipped low, hugging hilltops, grounding choppers. It's eerie to be in quake country and not hear choppers. If this natural disaster response has had a soundtrack, it's the sound of Robinsons and Squirrels.
It could be some time.
The lodge, which until days ago was a community refuge centre, sells coffee. Starved sandflies descend. The toilets are for emergencies, enquire within.
The troops are getting restless. Let the s***-talking begin. Theological discussions quickly give way to topics as various as mutant chimpanzees, urban drone use, and the death of Happy Hour.
One truckie suggests that earthquakes are "nature's equivalent of sneezing and farting at the same time".
Again, the sudden shouting. The one-hand helicopter signal from a camo-khaki up front and the engines fire up again. We wait some more. The engines are turned off. Two-and-a-half hours later, we're off this time.
We cross damaged bridges one at a time.
At a spot known as Whales Back, the slips are near biblical in scale. Entire hillsides have slipped away, bringing down a slew of earth and debris. Giant boulders as big as a Honda Jazz sit staunchly both sides of the road.
The question of what would happen to us if an aftershock strikes right now is deemed rhetorical.
At spots where the boulders and rocks still teeter above, the convoy spreads out a little. Better to have one or two trucks wiped out than several, it's explained to me. The brutal logic makes sense.
The emergency earthworks by a squadron of various contractors is an impressive operation. Heavy machinery of all kinds - diggers, graders, bulldozers, tractors, screeners - work all day.
Teams of mad abseilers scale the cliffs and dislodge loose offenders.
Once through the hills, the road flattens out. There are still patches of cracks and tears. More than six hours later, we reach the coast, rattled and glad. We stop and regroup in sea air.
The trucks scatter across Kaikoura and deliver the urgent supplies to grateful recipients. But soon after, they gather again at the local horse racetrack. The calls go up, the truckies saddle up, and head back to Culverden. No fuss.
Back through the same dangerzone. A road that can be traversed.
But, for now, and no doubt for a while yet, one which is best left to the pros.