Maximum rupture resistance is achieved through two multiple solid ropes reinforced with brackets. Tested for durability and flexibility at temperatures from -30°C to +50°C, these heavy-duty balloons feature high abrasion resistance and high energy absorption (up to 3.8 tons for F-13), making them suitable for vessels up to 1500 tons (F-13). These cylindrical balloons of the F series are widely used by ferries, fishing boats, and commercial ships.