Russia is set to begin production of floating firing points to guard St. Petersburg from Ukraine’s marine and aerial drones, Leningrad’s regional governor said on August 18.
“We expect to identify samples by October that we can subsequently purchase to protect the Leningrad Region's borders,” Aleksandr Drozdenko said in a Telegram post that included diagrams of a floating sentry post called the PLOT-40. Plot means “raft” in Russian.
Images of the armed raft first emerged in late July when a prototype was displayed at a port in Vyborg.
“After analyzing enemy attacks, it became clear that it was important to strengthen defenses from the water,” Drozdenko said at the time. The unusual vessel “is designed to protect naval bases, port infrastructure, and fuel and energy facilities from modern threats, including unmanned boats and [unmanned aerial vehicles],” the governor said.
Scott Savitz, a senior engineer at RAND, a US-based nonprofit research organization, told RFE/RL that the effectiveness of the rafts would depend on several factors, including how quickly and accurately they can identify and strike incoming drones, and “the floating platforms’ own vulnerabilities to attack.”
Hatches seen on the prototype version do not appear to be heavily armored.
The vessels are equipped with a single remotely controlled autocannon or machine gun fitted with a suite of electro-optical sensors. The prototype raft photographed near Vyborg has five small hatches around its upper hull that could be used as firing ports for soldiers and a larger entry hatch for personnel, though it is unclear if the vessels are designed to be manned.
A small deck around the hull of the raft would enable soldiers to fire shoulder-launched missiles provided conditions are calm.
Savitz pointed out that remotely controlled vessels do not necessarily reduce the number of military personnel required for operation. If the PLOT-40 craft is unmanned, he says, the only advantage would be reduced risk to individual soldiers.
“Personnel aboard a platform can provide a degree of situational awareness and adaptability that are typically greater than those of someone observing and controlling them remotely,” Savitz said, adding that “an unmanned platform can require just as many people, and sometimes more, than a manned one,” due to the requirements of control, maintenance, and resupply.
“In the context of port defense, the main advantage of not having people aboard is that attacks against the platforms would leave humans unscathed; some countries are more concerned about this than others,” he said.
The expert on port defense added that, “manning these platforms for 12-hour shifts doesn’t require many accommodations for habitability.”
Russia’s Plot-40 project is reminiscent in function, if not form, of the Maunsell Forts emplaced in the sea kilometers off the British coastline during World War II.
Unlike the floating Russian raft, the British radar and gun emplacements were fixed to the seabed, but were built with the same purpose: to engage enemy aircraft and naval vessels before they came within range of batteries on land.
Scores of Nazi aircraft and V-1 flying bombs were reportedly shot down by crews on the British forts and one German naval vessel was sunk.
The Russian rafts' chief advantage over a conventional vessel, would be their greater stability at sea, Savitz says. “These platforms may be able to host more and larger weapons than a small vessel could, and they may provide more stability to enable accurate firing.
He added that, "the tremendous innovation that the Ukrainians have continually demonstrated," means mass deployment of the rafts would not alone "negate the Ukrainians’ ability to strike Russian ports.”
Given the chaotic gun and missile fire seen around Russian ports during Ukrainian drone attacks, it is likely the rafts will be anchored far from the coast to minimize risks of friendly fire.
