The Dnipro River Poses A Large Challenge For The Ukrainian Counter-Offensive

Last week, the Russian military decided to abandon the city of Kherson and retreat to the east bank of the Dnipro River. As part of the operation, they destroyed or damaged every major river crossing including the Antonivsky Bridge, the Darivka Bridge, and the Nova Kakhovka dam. The Russian forces have also established a multi-tier defense on the east banks of the Dnipro River. Although the Russians gave up a strategic city, they have effectively stalled the Ukrainian counter-offensive. For the counter-offensive to continue, the Ukrainian military must now conduct a wet-gap crossing, a difficult military maneuver that involves bridging a river. Indeed, the Russian military lost a full Battalion Tactical Group in a failed wet-gap crossing across the Siverskyi Donets River earlier this year.

The process for a wet-gap crossing starts by establishing security. In an ideal case, the crossing unit would have control of the far-side of the river. Even with control, the bridging site will quickly become a target for artillery and drone strikes, so it is necessary to limit these capabilities. This is done through locating and destroying enemy artillery assets, shooting down the drones, and maintaining covertness with the bridging operation.

Once the threat from enemy artillery and drones have been reduced, the bridging operation can commence. An assault element is staged such that they can rapidly approach the bridging site while still maintaining cover and concealment. The engineer teams then emplace the bridges, which would likely be pontoon bridges given the Ukrainian assets and the length of the river. The Ukrainians have PMP Floating Bridge systems, which are folded up and mounted on the back of a KrAZ-255 truck. The trucks release the pontoons into water, at which point they unfold automatically. Bridging boats then connect to each pontoon, placing it in the proper position. Engineers lock each of the pontoons together to form a secure bridge that can support armored vehicles. For longer bridges, the boats remain attached to the bridge to counteract the river current. A well-trained team could have a bridge constructed in under an hour.

After the bridge is assembled, the assault element must rush across the bridge to secure the bridgehead. The enemy will have placed obstacles, including mines, trenches, and barriers, to limit the effectiveness of the assault element. A follow-up force will then move over the bridge to continue the assault. These operations must be fast because once the enemy identifies the bridging site, the bridge is a target for an artillery or drone strike and will likely be destroyed. When the bridge is destroyed, the units on the far banks will be cut-off from support; as such, it is imperative that a large number of soldiers and vehicles move across the bridge rapidly.

The first challenge faced by the Ukrainians is the amount of coordination required for such an operation. Wet-gap crossings require a substantial amount of training to ensure that the security, bridging, and assault units are in sync with each other. While the Ukrainians have engineer units with bridging capabilities, it is not clear as to how well trained they are. They previously established a short pontoon bridge across an unknown river that was destroyed by a Russian drone on May 7, 2022. Even with trained bridging units, the assault force also requires a large degree of training. Inadequate training results in traffic back-ups and units that cannot rapidly move across the river, resulting in a ripe target for the enemy.

A second challenge is that the Ukrainians are unlikely to establish control of the eastern bank of the Dnipro River prior to a bridging operation. While some of the infantry fighting vehicles, including the BMPs and BTRs, can technically float, the process is not reliable. Indeed, a viral video shows a Russian BMP sinking as it tries to float across a river (note: the video was posted six years ago and is not from the current conflict). Additionally, the Dnipro River would likely not be calm enough for a vehicle to float over. If the Ukrainians attempted to ferry soldiers across the river, they would likely be inadequate for taking the Russian defensive positions which include armored vehicles. As such, the bridging units will likely be under-fire from the opposite shore as they establish the bridge.

Perhaps the largest challenge is the large amount of artillery that the Russians have positioned on the east bank of the river. The river will be under continual surveillance from Russian scouts and from drones. There is low likelihood that the staging for a wet-gap crossing would go unnoticed. As soon as the bridging units enter the water, they will likely come under fire from Russian artillery and loitering munitions. Should the bridge be established, a single Shahed-136, which can carry up to 30 kg of explosives, could destroy a large section of the bridge.

While difficult, the Ukrainians do have several technologies that can help. In particular, they have been very successful at locating and destroying Russian artillery. Their HIMARS missiles have significant range and can precisely destroy Russian targets. Ukrainian counter-drone and air-defense systems have been very successful at striking down Russian loitering munitions. Furthermore, the Ukrainians have their suite of electronic warfare equipment that can disrupt the Russian defensive operations.

Regardless of these technologies, crossing the Dnipro would be challenging for the Ukrainian forces and will take time to plan and orchestrate, slowing down the counter-offensive. In modern times, few armies have successfully completed a wet-gap crossing. The Russians made a smart tactical move in abandoning Kherson, which would have been an urban bloodbath. The question now comes as to whether the Ukrainians will attempt a risky maneuver and cross the Dnipro.