As in 1946, the A2 emission on 480 kilocycles and the Al emission 

 oil 8100 kilocycles were keyed simultaneously. Each broadcast was 

 preceded by a general call on 500 kilocycles after which the trans- 

 mitting station (Radio Argentia, NWP) announced the NIDK ice 

 bulletin with the operating signal to shift to 480 and 8100 kilocycles. 

 After shifting to these frequencies, there followed a 30-second 

 period of test signals to permit receiver tuning. The ice bulletin 

 was then broadcast twice, the first transmission being made at 15 

 words per minute and the second transmission at 25 words per 

 minute, with a 2-minute interval between transmissions. The fol- 

 lowing daily schedule of ice broadcasts was maintained from 1318 

 G.c.t. on 17 March until 0118 G.c.t. on 25 July. 



Time (G.c.t.) Frequency (kilocycles) Emission 



0118 480 A2 



0118 8100 Al 



1318 480 A2 



1318 8100 Al 



Each scheduled ice bulletin followed the general form of giving 

 the most recent information first and listing the ice from south to 

 north and from east to west. As in former years, a distinction was 

 made between ice sighted and ice reported, the former including all 

 ice seen from ships or planes of the international ice patrol and the 

 latter including ice information from all other sources. To avoid 

 possible confusion with reports of ice, when atmospheric conditions 

 produce poor radio reception, reports of other hazards to naviga- 

 tion such as drifting buoys, barges, and liferafts have been placed 

 at the end of the bulletin. An attempt has been made to arrive at 

 an optimum length of ice bulletin by segregating information on 

 conditions south of 49° N., from information from north of that 

 latitude so that ships interested only in southern ice need not copy 

 the complete bulletin, whereas the information on ice conditions in 

 more northerly waters would still be available to those ships which 

 could use such information. Comment and criticism from the per- 

 sonnel of ships operating in this area has been helpful in the past 

 and further suggestions for the improvement of this international 

 service will be welcomed. They should be addressed to the Com- 

 mandant, U. S. Coast Guard, Washington 25, D. C. The cooperation 

 which permits the International Service of Ice Observation and Ice 

 Patrol to render useful service cannot be limited to the national 

 plane on which governments are signatory to the Convention for the 

 Safety of Life at Sea ; but must extend to all individual ships plying 

 the northwestern North Atlantic and all maritime agencies con- 

 cerned with such shipping. Such cooperation was again whole- 

 heartedly given and thanks are expressed here to the many whose 

 participation made possible this international service. 



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