Machinery

Engine room is the heart and muscles of a ship, providing necessary power and essential “fluids” for a modern vessel. Usually a merchant ship has propulsion and auxiliary power generators in engine room or dedicated compartments as for steering or separators. There are different systems and installations to keep vessel safe and running. They may differ from ship to ship so will mention few tha...

When talking about propellers, they are described in terms of pitch and diameter. Diameter is obviously the distance from tip to tip. Pitch is the distance the prop would travel through water if the water weren't a fluid. Fluid dynamics, induced flow, Reynolds number will show a propeller will never be 100% efficient. Optimizing propeller to get highest efficiency is requiring more than this artic...

An anchor is used by ships, boats, rigs, any other type of floating object to avoid drifting due to current or wind. They are used from ancient times when anchor could be a stone dropped on the bottom until today multitude of anchors' types. There are many types of anchors designed to satisfy specific needs for specific vessels. Heavy anchors, light anchors, stock anchors, stockless anchors and li...

Rudders, in any types and forms are used to maneuver the ship. There are many types of rudders, balanced (compensated), un-balanced (not compensated) and semi-balanced (semi-compensated) when talking about, let’s call them “classic”, rudders. They can be horn type, flap type and spade type. According to shapes and technical solution they can be shilling type, rotating cylinder type, twisted ...

Levers Levers are the basic tools  used in from historic times. Levers were first described  by  Archimedes (287-212 BC). A lever is a simple tool that makes work easier; it involves moving a load around a pivot using a force. Many of our basic tools use levers, including scissors, pliers, hammer claws, nut crackers and many more others. In a Type 1 Lever, the pivot (fulcrum) is between the ef...

Kinematics : linear uniform movement, linear accelerated movement, free falling, rotation. Dynamics : weight, specific weight, friction force, impulse, mechanical power, mechanical efficiency, potential energy, kinetic energy.

A bolt is a bolt. Is that completely true? There are so many kinds of bolts and so many standards, sometimes is difficult to choose the right one. What standard, what diameter, what pitch, what material to choose ? There is huge documentation you can find, here is just a very short guide to help making a choice.   METRIC BOLTS  IDENTIFICATION            INCHES BOLTS IDE...

Torque or moment  = is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist to an object. Mathematically, torque is defined as the cross product of the lever-arm distance and force, which tends to produce rotation.

Calorific value =  The amount of heat produced by the complete combustion of a material or fuel. Measured in units of energy per amount of material, e.g. kJ/kg. Autoignition temperature  = the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark. The temperature at which a chemical will ignite decreases as the pressure increases or oxygen concentration increases.