28 IEEE Spectrum | September 2004 | NA

Rock and Rile

September 2004 | IEEE Spectrum | NA 29

For the second time in four years, the Gibraltar peninsulaand the British nuclear attack submarine HMSTireless havefigured in a bitter diplomatic spat between Britain and Spain.This past July, the Tireless paid a six-day visit to Gibraltar,which is claimed by both countries. The visit riled Spanishofficials, still seething over a yearlong stay that started inMay 2000, when engineers repaired a cracked pipe inthe cooling system for the sub’s 70-megawatt (thermal)pressurized-water reactor.

Visible in this photograph, taken in Gibraltar’s porton 9 July, is the sub’s search periscope. It juts up high-est from the sub’s conning tower, more properly knownas the sail. According to Stuart Slade, senior navalanalyst at Forecast International Inc. in Newtown, Conn.,the cone-shaped top of the periscope houses an omni-

directional radar warning receiver, which gives instan-taneous notice of radars operating in the vicinity. In frontof the periscope is the T-shaped radar used for navigatingand avoiding collisions with floating objects.

Two of the sub’s 17 or so sonars are also visible: thematte-looking patch on the side of the ship’s hull is aflank array, which detects other subs at long range;and the bullet-shaped unit that a seaman is hangingon to is the passive-intercept sonar, which fixes anenemy sub’s position for aiming a torpedo at it. Not vis-ible is the antenna unit, which retracts into the top ofthe sail, used to intercept and monitor radio and radaroff foreign coasts. It looks like an oversize beehive withoddly shaped appendages, Slade says.

Photograph by Anton Meres/Reuters