The Russians quadrupled the depth of their defensive minefields, from 120 meters to 500 meters—and also increased the density of mines within the expanded fields. [Earlier, when initially laying the mines]
One notable snippet, given that Ukrainian forces are now past the first line:
All that is to say, the minefields get thinner the farther south you travel from the front line. Ukrainian brigadier general Oleksandr Tarnavskiy told The Guardian Russia devoted 60 percent of its time and resources building the first defensive line and only 20 percent each to the second and third lines. "In my opinion, the Russians believed the Ukrainians would not get through this line of defense.”
this is hugely significant, because it’s how the entire Russian front is organized… the 2nd line is just there to keep the 1st line from running away… the 3rd line is the little bit of reserves they have available… now that the 2nd line is engaged, it won’t take long for what’s left of the 1st line to disappear with their stolen toilets… none of the 2nd or 3rd line troops are ready to face an organized force… they won’t last long…
I don’t specifically know how the Surovikin Line’s defense was planned, but historically, in World War I, the basic idea in trench warfare was that you maintained a substantial reserve. If the line was penetrated, you rapidly counterattacked to regain that section of the line.
I believe that Russia did counterattack, from what I’ve read, but that the counterattack failed to push Ukrainian forces back behind the first line.
Frontline report: Russian counterattacks fail near Robotyne, southern front, as Ukrainians keep pushing south
Ukrainian troops successfully repel multiple Russian counterattacks near Robotyne, an area of paramount importance in the ongoing Ukrainian counteroffensive in southern Zaporizhzhia oblast.
You can also construct more trenches if one trench network is penetrated, limit the losses.
I don’t know if Russia is going to do that. I have not seen discussion of more construction south of the breach, and the open-source-intelligence maps of Russian fortifications from satellite imagery at places like https://deepstatemap.live (click on the little button with a fort) don’t have new lines to the south showing up.
It may be hard to construct them near the front compared to WWI, as they’d be under fire from Ukrainian artillery, and with drones and other reconaissance making construction visible, the trench-digging machines and the like are presumably vulnerable.
Also, if Russia withdraws to a new line on the land bridge, I don’t know if the road network is very amenable to supplying the trenchworks. My understanding from prior reading is that this is why Ukraine is aiming to cut Russian lines to the east of Tokmak, as it makes transportation harder. There’s not a lot of north-south roads off the M14, which is Russia’s remaining safe east-west link.
I have seen recent discussion of construction of fortifications on Crimea, so it may be that that is Russia’s next fallback. I assume that if there was going to be a new main line on the land bridge, that construction resources would be fully directed there, rather than at Crimea.
I will be interested to see if satellite imagery picks up construction of more fortifications on the land bridge, though.
