This leads to the radar signals being diverted in another direction. They also build planes and ships with the walls and wings at specific angles. These are designed to disperse the radar signals in all directions, rather than reflecting it back. This way the the ship becomes visible on the navigation radars of other ships.Įngineers who want to make a large ship invisible also use plastic or other special surfaces. That's why they carry a radar reflector on the mast - an octahedron made out of plated metal. They can also be considered stealth ships - albeit unintentionally. Yachts made out of fiber reinforced plastics reflect radar signals poorly. A radar works by harnessing electromagnetic waves, which are reflected by metallic materials. The biggest danger for ships and planes alike - but that also goes for submarines - is detection by radar. Here are some of the main approaches:Ī stealth bomber: The wings are at an angle that deflects radar signalsĭispersing and diverting waves to avoid reflection Since then, submarine engineers have constantly improved their vessels. Also the idea of reducing the radar signature when surfaced was already a consideration. The main focus of the design back then was to reduce motor sounds as much as possible. The first models were the class VII vessels of the German Navy. The ARA San Juan is no exception.ĭuring World War II Germany built submarines with certain stealth capabilities. In principle, each military submarine is built to make as little sound as possible or emit minimal signals. However, it recently received a substantial retrofitting and modernization, which was completed in 2013. It was built by the German wharf Thyssen Nordseewerke and has been in operation since 1985. Modern generation stealth submarines include the class A212 of the German Federal Navy or the Saab A26 of the Swedish Navy.The development of these types of submarines began in the 1990s and they have been designed to hardly make any noise, emit almost no heat and only minimally reflect radar or sonar signals.īut the ARA San Juan can't be compared to these kinds of submarines. Otherwise, their job is to be as silent as possible.īut what about in the case of an emergency when the vessel actually wants to be found? When this happens, the crew needs to draw attention to themselves - either on the surface with SOS beacons or under water with acoustic signals - such as hammering at the hull of the ship.īut the way modern submarines are constructed may actually cause problems in getting noticed, because the main purpose of design is to suppress any signals from getting out. They rarely surface, except to establish radio contact or perform data communication with their respective headquarters. Military submarines are designed to roam the oceans undetected by enemies or spies.