COMMUNICATIONS 



Ice Patrol conmunications included ice reports, environ- 

 mental conditions, Ice Bulletins, special ice advisories, a 

 daily facsimile chart, and the administrative and operational 

 traffic necessary to the conduct of the Patrol. The Ice 

 Bulletin was transmitted by teletype from the Ice Patrol 

 Office in New York twice each day to over 30 addressees, 

 including those radio stations which broadcast the Bulletin. 

 These stations were the U.S. Coast Guard Communications 

 Station Boston/NIK/NMF, U.S. Naval Radio Station Norfolk/NAM, 

 Canadian Coastal Radio Station St. John's/VON and Canadian 

 Forces Maritime Command Radio Station Mill Cove/CFH. 



Coast Guard Communications Station Boston transmitted the 

 Bulletin by CW at 0018 GMT on 5230 and 8502 kHz and at 1218 

 GMT on 8502 and 12750 kHz. After a 2-minute series of test 

 signals the transmissions were made at 25 words per minute 

 and then repeated at 15 words per minute. An abbreviated 

 version of the Ice Bulletin was included in the Western North 

 Atlantic High Seas Broadcast (voice) from Boston on 8765.4 

 (8764.0) kHz upper side band mode at 0130, 0730, 1330 and 

 1930 GMT and on 8764.0 kHz double side band mode at 0200, 

 0800, 1400 and 2000 GMT. During the season a statement was 

 included in every fourth day's voice broadcast requesting 

 comments on the usefulness of presenting ice information in 

 this manner. No replies were received from the maritime 

 community, thus it is anticipated that the use of the Western 

 North Atlantic High Seas Broadcast for dissemination of Ice 

 Patrol information will be discontinued. Coast Guard 

 Communications Station Boston/NIK also transmitted a daily 

 radlofac simile broadcast depicting the locations of icebergs 

 and sea ice at 1600 GMT simultaneously on 8502 and 12750 kHz 

 at a drum speed of 120 revolutions per minute. 



Special broadcasts were made by Canadian Coastal Radio 

 Station St. John's/VON as required when icebergs were sighted 

 outside the limits of ice between regularly scheduled broad- 

 casts. These transmissions were preceded by the International 

 Safety Signal (TTT) on 500 kHz. 



Merchant ships calling to transmit ice sightings, weather 

 and sea surface temperatures were requested to use the 

 regularly assigned international call signs of the Coast Guard 

 Ocean Stations, East Coast AMVER Radio Stations, or Canadian 

 Coastal Radio Station St. John's/VON. All Coast Guard Stations 

 were alert to answer NIK/NIDK calls, if used. 



