Underway replenishment

Under Seeversorgung (English: Replenishment at Sea / RAS or Underway replenishment / UNREP ) is the supply of in- lake warships with supplies, spare parts, food, ammunition and other supplies and personnel transfer (see Manila- high line ). By Seeversorgungsmanöver the Seeausdauer a warship can be extended considerably.

Standard sequence of a refueling maneuver:

• The fuel -requiring ship runs aft to the utilities and stays on course in parallel at a distance of 30-60 meters.
• Other preparations are usually the installation of the fuel tank filler neck and the dismantling of the rail.
• Making the connection is made first by a leash, which is shot with the " Bola " from one ship to another.
• At this line a wire is brought about, which is stretched between the highest point of the fueling system and the RAS - tree, And thus the fuel hose runs along.

Usually another cable connection between the bugs of both ships is still being manufactured; to this are small colored flags attached, by which the distance between the two ships can be read, the so-called distance line.

In addition to the general hazards associated with fuel or ammunition acquisition ( here refers to the period of the maneuver ban on smoking throughout the ship ) is used for the Replenishment at sea is another added: driving the two ships too close together, the flow rate of between themselves is ships increase water flowing therethrough, whereby the water pressure at that point decreases (Venturi effect). This can cause the two hulls are drawn to each other. Therefore, must be calculated in advance of a RAS maneuver speed and distance of vessels and then adhered to precisely. Here, only highly experienced personnel bridge is used in the rule.

After completion of the supply, the acquiring unit thanks mostly to a specific gesture, such as the playing of the anthem board or other selected piece of music.

In the U.S. Navy and other navies with large supply vessels fixed supplies are often transferred during the transfer of the fuel with helicopters. This technique, known as Vertical Replenishment ( VERTREP ) method is faster than the transfer of pallets by means of dishes.