308 P. Mandel 
Table 1 
Comparison of Characteristics of the Trieste and the Aluminaut 
[ee [me | Te | Si 
Length overall, ft 
Max. Beam, ft 
Draft, before dive, ft 
Inside diameter of pressure hull, ft 
Inside length of pressure hull, ft 
Thickness of pressure hull material, inches 
Total submerged volume at depth 
Internal volume of pressure hull 
Buoyant volume of pressure hull 
Pressure hull structural weight 
Other structural weight 
Volumes 
(cu ft) 
Weights 
(1b) 
21,520 
33,600 
Ballast, permanent and jettisonable 24,6 20 
Propulsion, batteries, pumps, controls ? 
Flotation fluid 157,000 
Scientific payload ~500 
Total submerged displacement 
5 252,000 
Materials Pressure hull material Steel Aluminum 
Flotation fluid Gasoline Silicone 
Performance Operating depth, ft 15,000 
Characteristics | Test 17,000 
Collapse depth, ft 21,000 
Max. horizontal speed, knots 4.7 
Horizontal endurance, miles 96 
Endurance, hours 36 normal 
72 emergency 
Vertical speed, fps 3 normal 
11 max 
Power available for instruments, kwh 64 
Crew Number 3 
*1/2-4 hours at depth depending on time for vertical traverse. 
THE ALUMINAUT CONFIGURATION 
The configuration of a deep-diving submarine is largely determined on the basis of 
structural and arrangement requirements. For the Aluminaut a cylindrical pressure hull with 
hemispherical ends was selected as a good compromise between an optimum structural con- 
figuration and a configuration most suitable for housing people and equipment. The forward 
pressure hull hemisphere and the cylindrical portion of the hull form the basic external hull 
of the submarine since these are not entirely unsuitable from a hydrodynamic point of view. 
For hydrodynamic reasons, however, the aft pressure hemisphere is enclosed within a non- 
pressureproof, almost conical, stern capsule that provides some hydrodynamic fairing and 
also serves to house the electric propulsion motor and control mechanism. This obviates 
the need for large mechanical penetrations of the pressure hull. This capsule is filled with 
a buoyant silicon fluid (specific gravity—0.76) that provides a suitable environment for the 
motor in addition to providing a modest amount of buoyancy (~13 percent). The stern 
