This invention relates to detecting devices and more particularly to a new nd improved torpedo detection streamer having a plurality of microphonic detecting devices arranged therein in such a manner as to render the detection streamer substantially directionally and uniformly responsive to sound signals received from torpedoes passing above or below the streamer at any point along the length thereof.
A linear hydrophonic antenna with an associated portside/starboard ambiguity removing device comprises three streamers placed in an equilateral triangle, with a center distance of the order of a third of the wave length which corresponds to the center frequency received. The density of the median streamer is notably greater than the common density of the other two streamers. Channels are formed in a standard way, and the received signals are phase shifted then added up so that the directivity associated with each channel shows a zero, either at portside or at starboard, the direction of which remains fixed despite the roll.
A seal of flexible waterproof material joins two shells, or a shell and its end plate, which are spaced at their edges to have a separation or gap between them into which the seal material loops. The seal material is attached to each shell, or to the shell and its end plate, to effect a watertight seal at the joint. When one joint edge moves radially with respect to the other edge, a low friction rolling action of the seal material accommodates the motion with low frictional resistance and low energy loss.
