502 



[CHAP. 23 



special optical system, permitting a reproduction of the exterior visual field. 

 The displacement will be at least double that of the FNRS-3. The storage 

 batteries will be four to eight times as powerful so as to permit considerable 

 horizontal propulsion. It is expected that the new bathyscaph will be launched 

 in early 1961 followed by test dives in the vicinity of Toulon (see p. 514). 

 Subsequently, it will be converted into an efficient oceanographic research 

 craft for scientific diving, including descents to maximum oceanic depths. 



The Trieste (Figs. 3-5), built by A. Piccard and operated by J. Piccard, was 

 completed in Italy in 1953. Twenty-two dives were completed between that 

 date and 1956 in the Tyrhennian Sea to a maximum depth of 3700 m. Twenty- 

 six more dives were made off Italy under the aegis of the U.S. Navy's Office of 

 Naval Research in 1957. Subsequently the craft was transferred to the U.S. 



r Ifl 



itL 



^TTJSQ 



WATER 

 BALLAST 

 TANK 



GASOLINE TANKS 



GUIDE 

 ROPE 



/ 



BALLAST 

 RELEASE 

 MAGNET 



OBSERVATION 

 GONDOLA 



Fig. 4. Longitudinal section of the bathyscaph Trieste. (Official U.S. Navy photo.) 



Navy operation in the Pacific off San Diego, California, and then to Guam 

 where ultra-deep dives in the hadal depths of the Mariana Trench were under- 

 taken. These abyssal plunges attained depths of 5530 m, 5852 m, 7025 m and to 

 the nadir of the earth with J. Piccard and D. Walsh at 10,910 m (35,800 ft) in 

 the Challenger Deep on 23 January, 1960. As a non-conventional and highly 

 experimental craft the scientific results have been modest (e.g. Piccard and Dietz, 

 1957; Dietz, Lewis and Rechnitzer, 1958; Botteron, 1958; Dietz, 1959; Rech- 

 nitzer, 1959; Mackenzie, 1960; Piccard and Dietz, 1961). In contrast to the 

 largely biological program of the FNRS-3, research from the Trieste has en- 

 compassed gravity, acoustics, marine geology, as well as biology. 



Since the completion of the FNRS-2, bathyscaphs remain the only deep 

 ships which have been fully realized so that a brief description of principle and 

 construction of the Trieste is given here. For a detailed description of the 

 Trieste, the reader is referred to A. Piccard (1956). 



