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.