French Bathyscaph Program 479 
submarine hatch, so that it is comparatively easy to handle. Around the porthole ten transit 
holes have been made in the sphere to link the inside with the outside, as follows: electric 
cables (Pyrotenax cables with copper sheathing and insulated with pressure injected magne- 
sia) and pipes for hydraulic fluid and compressed air. 
The float which contains the lifting petrol is made of steel plating 4 to 6 millimetres 
thick. It is divided into a certain number of tanks which only communicate at the bottom (to 
limit the loss of petrol in case of damage). The shot silos and the entry shaft to the sphere 
run vertically through the float. This float has a length of 16 metres and a width of 3.35 
metres. The center part is cylindrical and the ends are in the shape of a truncated cone; 
two stabilizing keels are fitted on each side of the float to improve the dynamic stability 
during vertical movements and in particular in the course of an overrapid ascent. Trials on 
models, undertaken at the trial tank of the Service Technique des Constructions et Armes 
Navales had revealed the existence of oscillations in the course of ascents in a state of 
slightly excessive positive buoyancy (all ballast jettisoned), which might have been dan- 
gerous to the equipment and uncomfortable for the crew. 
To conclude this description of the FNRS-3, it is necessary to mention the outside 
storage batteries housed in two baths filled with oil and exposed to external pres- 
sure. These batteries are used to run the propelling motors and the searchlights and supply 
about 1000 ampere-hours at 28 volts. The two motors are one-horsepower each. They drive 
two horizontal shaft propellers which enable the bathyscaph to be steered and moved hori- 
zontally over an approximate range of 50 metres. There are six searchlights of 1000-watt 
each. The incandescent bulbs which equip them are enclosed in steel cylinders which are 
designed to withstand external pressure. 
All the remote controls of this external equipment are housed inside the sphere. Con- 
tact is maintained with the surface by an ultrasonic transmitting-receiving set, during the 
diving (radio transmission only works while the bathyscaph is on the surface). An echo 
sounder gives the distance from the bottom, a log the vertical speed, and a compass indi- 
cates the bearing of the craft during the descent. Moreover, an air-regeneration plant 
enables two men to live for 48 hours in this confined space; the carbon dioxide is absorbed 
by soda lime; the oxygen consumed is replaced by a fresh supply contained in cylinders of 
compressed oxygen. 
THE BATHYSCAPH 11,000 
The Bathyscaph 11,000 is the name we have temporarily given to the new French craft 
under construction, to indicate the maximum depth for which it has been designed, that is to 
say, eleven-thousand metres. 
The sphere of the Bathyscaph 11,000 is made of forged steel, alloyed with nickel, 
chrome, and molybdenum, with a yield point of 105 kg/mm? after heat treatment. It was 
built by the Compagnie des Ateliers et Forges de la Loire in its works of St. Chamond and 
St. Etienne (France). 
Its internal diameter is 2.10 metres (2 metres in the case of the FNRS-3) and its 
thickness is 15 centimetres (9 centimetres in the case of the FNRS-3). 
The hatch, in the shape of a truncated cone, has an opening diameter of 45 centimetres 
and is located at the upper part, to facilitate the inner arrangement of the sphere. Three 
