Chapter 5— BATHYTHERMOGRAPH 



personnel to select safe convoy routes. Another 

 use is to estimate where the enemy might have 

 his submarines deployed. 



In wartime, routes of each convoy must be 

 planned carefully. If an area in the ocean has 

 consistently poor sonar conditions, the convoy 

 escorts will have difficulty detecting submarines, 

 so the convoy should stay clear. If the average 

 detection ranges between two areas differ notice- 

 ably, it will be necessary to vairy spacing of the 

 escorts. The atlases show these conditions and, 

 because they are available in advance of the 

 actual operation, they can be used to estimate 

 the number of escorts needed to provide ade- 

 quate protection. 



The atlases are prepared from the informa- 

 tion contained on thousands of BT slides, which, 

 for many years, have been forwarded by individual 

 ships to the Oceanographic Office. AttheOceano- 

 graphic Office, the slides are analyzed, and 

 average monthly thermal conditions for areas 

 of the ocean are plotted on ocean charts. The 

 result is a monthly series of charts showing 

 average condition thermal belts. The belts can 

 be consulted to decide which are the dangerous 

 and which are the relatively safe passage routes. 



To guarantee that the slides arrive in good 

 condition, they must be handled with utmost 

 care. They must not be smudged, scratched, 

 or broken. To be useful, they must retain all 

 of the information required by the National 

 Oceanographic Data Center, where the slides 

 now are processed. 



MAILING SLIDES AND LOGSHEETS 



To avoid breakage and to ensure safe delivery 

 of the BT slides, make certain that you carry 

 out the following precautions before mailing the 

 slides to the Oceanographic Office. 



1. Put no material between slides. 



2. Pad the box well, using the same box in 

 which the slides were received. 



3. Put in completed standard mailing label. 

 Copies of this form (NODC-3167/11 (9-61)) may 

 be obtained from the National Oceanographic 

 Data Center (NODC). 



4. Pack slides in a cardboard box. 



5. Wrap the packages securely, and label 

 clearly (type or print legibly) with the following 

 data: ship's name, date of cruise, and sheet 

 number of the BT logsheet. Be sure this infor- 

 mation is on the duplicate standard label inside 

 the box. 



The foregoing procedure is to protect your 

 slides so that NODC has the necessary informa- 

 tion to process them. Fold and staple the BT 

 logsheet so that the mailing format printed on 

 the reverse side is displayed. Mail the BT 

 slides, logsheets, and recorder charts to — 



The National Oceanographic Data Center 



Washington, D.C. 20390 



OBTAINING ADDITIONAL LOGSHEETS 

 AND SLIDES 



Bathythermograph logsheets may be obtained 

 as follows: 



1. All naval activities in the Atlantic area 

 (including the Gulf of Mexico, Panama 

 Canal Zone, European and Mediterranean 

 areas) submit completed Form DD-1149 

 to — 



The Oceanographic Distribution Office 

 U.S. Naval Supply Depot 

 5801 Tabor Avenue 

 Philadelphia, Pa. 19120 



2. All naval activities in the Pacific area 

 (including Antarctic and Indian Oceans) 

 submit completed Form DD-1149 to — 



The Oceanographic Distribution Office 

 U.S. Naval Supply Depot 

 Clearfield, Utah 84015 



3. All other naval activities may request 

 from — 



The National Oceanographic Data Center 

 Washington, D.C. 20390 



Bathythermograph slides are a standard stock 

 item in the electronic system and are obtained 

 through any normal supply support channel. 

 The stock number and description is: NS 6655- 

 67-67-987, Slide Set, Metallic Coated. A set 

 consists of molded plastic box, 50 slides, and 

 telescoping box for shipping. 



BT LOGS 



All BT slides must be accompanied by a 

 BT logsheet (NODC-EXP-3167/lO Rev. 3-66) 

 when sent to the National Oceanographic Data 

 Center. The completed form is essential for 

 processing the BT slides. All items on the 

 form must be filled in. The BT log is designed 

 to provide a standard format for radio trans- 

 mission of synoptic BT data. Its purpose also 

 is to provide NODC with the information required 

 for computer processing of BT data. 



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