Monday, 9 May 2011

**Submarines are Safe**

Recently there have been Articles in the Press regarding Submarine Safety my apologies to fellow Submariners but i need to go back to Basic Submarine Quals (BSQ) levels to try and explain the Basics of Submarine operation.

ALL Submarines of  ALL Nations Employ the same Basic Principles in Order to Operate a Submarine Fleet whether they are Diesel /Electric or are Powered By Nuclear Reactors These Principles are as follows:


Neutral buoyancy is a condition in which a physical body's mass equals the mass it displaces in a surrounding medium. This offsets the force of gravity that would otherwise cause the object to sink. An object that has neutral buoyancy will neither sink nor rise.

Archimedes discovered much of how buoyancy works almost 2000 years ago. In his research, he discovered that an object is buoyed up by a force equal to the weight of the water displaced by the object. In other words, an inflatable boat that displaces 100 pounds (45 kilograms) of water is buoyed up by that same weight of support. An object that floats in the water is known as being positively buoyant. An object that sinks to the bottom is negatively buoyant, while an object that hovers at the same level in the water is neutrally buoyant. Scientists later discovered ways to manipulate buoyancy and developed equipment such as the life jacket, which is filled with compressed air and helps to lower a person's average density, assisting in floating and swimming, as well as certain diving equipment (including submarines and submersibles) which have air chamber similar to swim bladders in order to regulate depth.

More about >> Buoyancy


Actually a submarine employs not one, but Four separate hydraulic systems Each one can be Cross connected to power :

1. The steering system, which operates the rudder.
2. The stern plane system, which tilts the stern diving planes to dive or rise.
3. The bow plane tilting system, which tilts the bow diving planes to rise or dive.
4. The main hydraulic system, which operates the following equipment.
a. Flood and vent valves.
b. Main air induction valve.
c. Bow plane rigging.
d. Windlass-and-capstan in bow.
e. Main engine outboard exhaust valves (in some installations hydro-pneumatic).
f. Torpedo tube outer doors.
g. Emergency power for steering system if failure occurs.
h. Emergency power for bow plane tilting system.
i. Emergency power for stern plane tilting system.
j. Periscope hoists.
k. Vertical antenna hoist.

In the case of Complete Hydraulic Failure the Forward and After Planes can be operated by :


Pneumatic power. Since compressed air must also be used aboard a submarine for certain functions, this system, which consists of the compressors, high and low pressure air bottles and air lines, provides another source of auxiliary power. However, pneumatic or compressed-air power also has definite shortcomings. Pressure drop caused by leakage, and the mere fact that air is a compressible substance, may result in "sponginess" or lag in operation. The high pressure necessary for compressed-air storage increases the hazard from ruptured lines, with consequent danger to personnel and equipment. Another disadvantage of air systems is that the air compressors require greater maintenance and are relatively inefficient.


Hand power. Some equipment on a submarine is still operated exclusively by hand, but this practice is rapidly disappearing. This is because the power requirements exceed that which manual effort can provide over long periods of time, and because power operation is faster and can be remotely controlled, thus greatly reducing the communication necessary between crew members.


Click to Enlarge

Click to Enlarge

 Royal Navy Description of  The Pressurised Water Reactor

Pressurised Water Reactor

In simple terms, this is a collection of fissile uranium fuel elements which provide huge amounts of energy to power the vessel (a ton of fissionable material releases the energy equivalent of 2.5 million tons of coal.
The entire process takes place inside a heavy shielded reactor compartment that completely protects the crew from radiation.
The PWR system is based on primary and secondary circuits. Water coolant travels around the primarily circuit, through the reactor pressure vessel (where it is heated by the nuclear fuel elements) and on through the tubes in a steam generator. A high pressure is maintained in the primary circuit to prevent the coolant from boiling.

More info Available Here >> Nuclear Power


How a Submarine is Built and its Components explained


Submarines are complex Vessels  and require specialized and highly trained crews for their operations. Crew members on duty aboard a submarine are known as being on watch. Under normal conditions, only part of the crew is on watch at one time, with watches divided into three rotating shifts of six hours each.
During these times, each crew member is assigned to a specific duty. Under certain conditions (when leaving and entering port, or when the crew is ordered to Action stations) everyone on board the Submarine will have a watch station regardless of his position within the three-shift rotation.

The highly physically and mentally demanding environment of today's modern  Nuclear Submarine requires a unique individual. Submariners traveling at sea and underwater can be out of port for six months or longer. The mental, physical and emotional demands of this job require a highly specialized and special individual.


"A submariner is part of the team. He must be able to be relied upon by his teammates, and he must be individually Trustworthy"



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