GOLIATH AND THE GRID
EFFECTIVE COMMUNICATIONS REMAINED A CORNERSTONE OF THE WOLFPACK PRINCIPLE, AS DID NAVIGATION AND LOCATION TECHNOLOGY
rather than relying on standard latitude and longitude positioning for global positioning the kriegsmarine – like the luftwaffe and army – developed their own charts using a grid reference system. the world’s oceans were divided into major areas, generally square though sometimes irregularly shaped near land masses. each of these large areas was identified by a two-letter code (eg ae, cd, eh etc), and further subdivided into a three by three matrix of nine squares, in turn subdivided twice again by the same method.
further complicating the chart for enemy intelligence, these were produced using the standard Mercator’s projection, meaning that squares covering the same actual area became smaller as they neared the equator. this grid chart, which was both complex to decipher for the allies and simple to use for those in possession of it, allowed precise navigational points to be located within an error margin of six miles. for example the location cg9575 would place a U-boat at the entrance of the strait of gibraltar.
such precise navigational instructions were transmitted to U-boats from BDU operations and to complement the installations at nauen and on the french atlantic coast, from 1943 to the war’s end the U-boat service utilised the most powerful transmitter of its time. its antenna required an area of three square kilometres and therefore could not be accommodated at nauen, constructed instead near kalbe in central germany. named ‘goliath’ its Vlf transmissions could be received by submerged U-boats within the caribbean and indian oceans by their use of an extendible loop antenna which functioned underwater while the U-boat could maintain a top speed of 8 knots.
however, by the time that goliath entered service the rudeltaktik had nearly been defeated by allied naval technology, tactics and aircraft. in March 1943 Dönitz concentrated 44 U-boats against convoys hx229 and sc122, 16 of them sinking 22 ships for the loss of a single U-boat in a near perfect pack attack.
Just two months later, energised allied escort forces repulsed repeated group attacks and 41 U-boats were destroyed. conceding defeat with such unsustainable losses, Dönitz was forced to finally withdraw his atlantic wolfpacks.
“FROM 1943 TO THE WAR’S END THE U-BOAT SERVICE UTILISED THE MOST POWERFUL TRANSMITTER OF ITS TIME”