THE FRENCH BATHYSCAPH PROGRAM 
Pierre H. Willm 
Ingénieur en chef du Génie Maritime, French Navy 
INTRODUCTION 
The purpose of the third symposium on naval hydrodynamics is to study the latest tech- 
nical developments concerning the means of navigation available to all men. Therefore it 
seemed reasonable to include, among other topics, the survey of a very new achievement 
which enables man to reach the greatest depths actually known, namely, the bathyscaph. 
But it was perhaps less logical to ask France to deal with this subject, since the diving 
record is now held by the U.S. Navy with the bathyscaph TRIESTE, manned by CDR Don 
Walsh and Mr. Jacques Piccard, who reached 11,000 metres in January 1960. I wish to 
express my thanks to the organizers of this symposium who asked me to read this paper, 
thus emphasizing the part taken by France in the development of this system of underwater 
navigation. 
In the short historical account with which I shall begin this paper, I intend to give more 
details about this French participation, and to sum up the different types of bathyscaphs 
actually known. 
In the second part, I will recall the principles involved in this new kind of navigation 
as well as the operational sequence of bathyscaph diving. 
In the third part, I will briefly describe the first French achievement, the FNRS-3, then, 
in the fourth part, the new type now under construction, the Bathyscaph 11,000. 
I will conclude by mentioning a few scientific results obtained during the 80 dives 
made by the FNRS-3 since it was built. 
I regret to have no exceptional announcement to disclose to this honorable assembly as 
regards hydrodynamics: the only new fact concerning propulsion is the essential part played 
by the weight and by the Archimedean principle of buoyancy in vertical movements of the 
craft. All movement in other directions is achieved by means of conventional propellers 
which are entirely satisfactory in every respect. 
HISTORY 
The first attempts at very deep diving were made by two Americans, Professors William 
Beebe and Otis Barton, who in 1934 succeeded in diving to 908 metres, a remarkable depth 
at that time. But the 1.45-metre diameter and 45-mm thick cast steel sphere in which they 
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