In the morning on August 17, the officer on duty of the Northern fleet said to the reporter of the Russian Red Star daily that the hull of the submarine was being observed with the help of underwater TV equipment. It was determined that all telescopic equipment of the submarine was pulled out, including periscope.
This fact gives a hint to consider one of the versions of the accident. It was suggested by the number of submarine sailors that the sub struck the bottom during a crash dive. The pulled out periscope means that Kursk was at periscope depth at the moment of the dive. Obviously, situation on the surface required the captain to make a decision about crash dive, and diving-rudders were turned into position to dive, the front ballast tanks were filled with water, and then longitudinal trim was created on the front. The bow ballast tanks can take up to 80 tons of water. The distance between the keel and the sea-bottom was 75-80 meters. Suggesting that the submarine had average underwater speed of 8 knots (about 4 meters per second), the contact with the sea bottom could already occur in 15 seconds. Taking into consideration additional impact of inertia on the boat during the dive, bottom streams, turbine spin-up, quick position change of dive-rudders, then the sub could strike the bottom in 7-10 seconds when the captain and the crew were already helpless. This version is indirectly confirmed by the trench left at the seabed. However it would be created in any case, even if there were no strike with the seabed. Anyway the submarine would continue to move through inertia.
It is known that sonic operators of the Northern Fleet ships and Norwegian surveillance ship Marjatta registered two typical sounds (blasts), and the second one was stronger that the first one. One can only guess what had happened and there are several versions. One of them is connected with the presence of the reconstructed torpedoes in the first section. The reconstruction of the torpedo tubes for the new-design torpedoes was carried out at Sevmash plant in Severodvinsk (Archangelsk region) in January 1998. According to one of the admirals who served a few years ago at the Northern Fleet, the industry representatives tried to foist the new torpedo on the navy, although the submarine fleet representatives made attempts to resist. The sailors believed that the new torpedoes were difficult to store and dangerous to handle as the propulsion of the new torpedoes did not use the expensive batteries containing silver but the cheap liquid fuel. The torpedoes were launched with a help of a trigger that produces gas, shooting the torpedo out instead of high-pressure air on the old torpedoes.
If the first blast the sonic operators heard could be the sound of the subs impact with the seabed or a detonated trigger, then the second blast, more powerful, could be a result of explosion of liquid-fuel torpedo.
One cannot deny the possibility that during the shoot the torpedo did not leave the hatch completely and exploded inside it.