of the winch motors a more easterly position was obtained and with the 

 decision to attempt to repair the winch motors at Argentia a bathy- 

 thermograph section was run from 41°21' N., 49°34' W., to 44°00' N., 

 51°46' W. The BT section, crossing from the deep water south of the 

 Tail of the Banks to the shoal water of the banks, it was hoped might 

 shed additional light on the current structure. 



Argentia w^as reached on the afternoon of 18 April and the resulting 

 current map was delivered to Commander, International Ice Patrol, on 

 the morning of the 19th. Fortunatety the winch motors did not fail 

 until after a sufficient number of stations had been occupied to permit 

 delineation of the currents westward of the Tail of the Banks. 



With winch motors repaired, the Evergreen departed Argentia on the 

 morning of 5 May to begin a current survey of the area immediately 

 seaward of the eastern slope of the Grand Banks. As the partial survey 

 made in April indicated little likelihood of bergs reaching positions much 

 west of the Tail of the Banks, this survey was to begin there and work 

 northward to the latitude of Flemish Cap. The work of collection of 

 data began on 6 May at station 3600 located at 43°20' N., 50°13' W. 

 With quiet weather work progressed without incident until the afternoon 

 of 9 ^lay at station 3613. Prior to this station the wind drift had op- 

 posed current drift well enough to keep the wire angles within workable 

 limits. At this station, however, the combination of these forces pro- 

 duced a wire angle too great (60°) to permit functioning of the equipment 

 on the deep series. When the gear had been hauled in, the ship was 

 brought into the wind and held there with only sufficient speed to give 

 steerage way while the deep series was repeated. In haufing in this 

 series the winch motor failed after the uppermost bottle had been re- 

 trieved. The remaining wire (103om) and bottles were brought in 

 with the capstan, and while proceeding to the next station the port 

 winch was readied for operation. 



The work at oceanographic stations was continued using the port winch 

 until at station 3616, at 43°07' N., 48°13' W., on the evening of 10 May, 

 the port winch motor burned out. The Evergreen continued to run BT 

 sections along the courses of the proposed survey in the hope of getting 

 current directions and lines of flow from identifying isobaths found in 

 the completed dynamic topography by means of their associated iso- 

 therms at a depth of 100 meters and tracing these isotherms through the 

 successive BT sections. In this area of known contrasts, probable 

 cabbehng, sloping isopycnal surfaces and varj-ing temperature-saUnity 

 relationships, it was realized that an isobathic thermal analysis would not 

 yield accurate results; but it was considered that the resulting estimate 

 of the general pattern of circulation would be superior to that deduced 

 from surface temperatures alone. As soon as the dynamic topography 

 had been completed a dispatch describing the circulation southeastward 

 of the Grand Banks was sent to the cutter on patrol and the Commander, 

 International Ice Patrol. 



69 



