Professor Calculus, the hard of hearing genius created by Herge built several innovative products and gadgets in various books of Tintin. His biggest achievement was the nuclear powered rocket in “Destination Moon” and “Explorers on the Moon” which took Tintin, Captain Haddock and other characters to the Moon and back. A very ingenious invention of Professor Calculus was the Shark shaped submersible in the “Red Rackham’s Treasure”. What Professor Calculus had built was a shallow diving submersible with an endurance of two hours. This limited endurance coupled with its ability to be navigated only by sight did not allow it to venture too far away from its mother ship.
The submersible had a glass canopy to allow the pilot to look out and navigate. Such manned submersibles are now being built and used for recreational purposes as depicted in the photo.
As a kid, I never bothered to understand or imagine how this submersible would have worked. However, after spending 21 years operating submarines and managing submarine construction projects, I imagined how Tintin’s submersible would work technically. Well, I have put my imagination and knowledge of submarine design to describe how this submersible would have worked.
As the submersible was made up of a not so large set of steel plates; which Professor Calculus managed to smuggle onboard the “Sirius” single handedly; I believe the vessel would have been a single hull design. That is, a single steel pressure hull protecting all the machines onboard. I believe that the tail as well as the snout of the the submersible enclosed a forward and aft ballast tank each. This was required to maintain an even pitch of the submersible when dived. An electric motor would be coupled to the propeller through a gear-box. Or may be a slow speed motor was used. This motor would be a DC motor drawing energy from a set of batteries. based on the period when this submersible was designed, it would be a pretty large and heavy motor placed to the aft of the cockpit. The shaft, supported in at least one journal bearing would have passed through the aft ballast tank and a stern tube to connect to the propeller.
To maintain the weight distribution and to ensure stability of the submersible, the batteries would have been placed in the lower part, in the center of the submersible. I am sure, the batteries would be lead-acid batteries as Li-ion and Metal-Ni Hydride batteries were not invented when this book was written. There would have been a set of HP air bottles, operating at around 100 to 150 bar to expel the water out of the submersible and allow it to surface. In the book when Tintin’s submersible’s propellers were stuck in sea weed, he had de-ballasted the vessel to make it light so that Captain Haddock and Professor Calculus could pull him out.
The gill shaped openings on the hull would have allowed the sea water to the flood the ballast tanks while diving as also expel the water when surfacing. There would be vent valves to allow air to escape from the ballast tanks while diving. These valves would be shut when air was used to expel water out of the ballast tanks while surfacing.
For manoeuvering, the submersible had a rudder behind the propeller. To make it more effective and to ensure it merged with the sharks in the area, the rudder extended above the propeller also. There are two forward planes, shaped as fins provided at the snout. Also, a pair of stern planes were provided near the aft. The stern planes help the submersible to dive and surface by changing its pitch. When the stern planes were put to dive by tintin, they pushed the stern up, thus giving the submersible a down angle. Now the submersible used the propeller thrust to push the submersible under water. For surfacing, the stern planes push the stern down giving the submersible and up angle and thus pushing it to the surface. The forward planes would have been used by Tintin to maintain depth or change depth with a zero down/ up- angle. To operate these planes the submersible would have a hydraulically operated system with hydraulic pumps and a sump maintaining the pressure. There would also be linkages from the hydraulic cylinders to operate these planes.
The submersible definitely carried oxygen cylinders or air cylinders which released fresh air into the cockpit. It carried enough air for a two hour operation. I do not think this submersible carried any navigation equipment and the navigation was done by line of sight only.
The submersible would have needed some turnaround period between each sortie when its batteries would have been charged from the mother ship’s power supply. Also, it’s compressed air bottles would have been charged using a commercial compressor, while a diving compressor would have charged the oxygen cylinder.
In all. it was not as simple a device as Professor Calculus made it look.