THE DRIFT KEEL 



As our tests with models allowed us to anticipate, the Trieste during 

 its trip to Capri exhibited poor course-holding qualities : instead of 

 following its tug in a straight line, it zigzagged from left to right, 

 making angles exceeding 45° with the tugboat's course. These varia- 

 tions produced altogether useless strains, which could even be harm- 

 ful : it was necessary to avoid them. We managed this in a perfect way 



Fig. 20. Cross-section of the float, showing the anti-rolling keels immersed in 



petrol 



by attaching a keel to the back of the bathyscaphe : that is to say, we 

 attached a small vertical keel (see Plate XI). From this moment on,, the 

 Trieste yawed no more. However, I had the impression that this new 

 keel tended to increase the rolling once more. If this observation is 

 correct, this proves that the choice of position for the anti-rolling keels 

 inside the hull was justified. 



[ lô, ] 



