### Angle of loll

• Intial unstable ship will not be upright. While heeling one side, the angle at which the G & B coincides in neutral equilibrium.
• If GZ=0 then angle of Equilibrium = angle of loll
How to Recognize
• Vessel will not remain upright and will assume a list to either port or starboard.
• Vessel "flops" to port or starboard.
• Vessel will have a very long, slow roll period about the angle of list.
• A small GM is known to exist, plus any of the above.
Angle of Loll
• -ve GM
• Unstable Equilibrium.
• G on the Centreline.
• Corrected by lowering G below M
CORRECTION OF ANGLE OF LOLL
• Moving cargo to a lower position;
• Jettisoning top-weight (in an emergency);
• Reducing FSE by pressing up/emptying tanks;
• Filling low ballast spaces such as DB tanks
• Top up tanks that are already slack.
• Start with the smallest tank on the LOW side first. (If a tank on the high side is filled first, the ship will start to right herself but will then tend to roll over suddenly in an uncontrolled fashion as she passes through the upright. She will then „whip‟ through to a larger angle of loll on the other side. She may even capsize if the momentum gathered is sufficient.) When the low side is filled first, the angle of list will increase initially, but in a slow and controlled fashion. After some time, the weight of the ballast water added will be sufficient to lower the ship’s COG (despite the extra FSE), to cause the angle of list to decrease. By this method the inclining motions of the v/l take place in a gradual and controlled manner
• Now fill the opposite tank on the high side.
• Fill tanks alternately, low side first, until the v/l returns to positive GM.
• Ensure that all tanks are completely filled.

### Differences between MC/MC-C and ME/ME-C engines

The electrohydraulic control mechanisms of the ME engine replace the following components of the conventional MC engine: Chain drive for camshaft Camshaft with fuel cams, exhaust cams and indicator cams Fuel pump actuating gear, including roller guides and reversing mechanism Conventional fuel pressure booster and VIT system Exhaust valve actuating gear and roller guides Engine driven starting air distributor Electronic governor with actuator Regulating shaft Engine side control console Mechanical cylinder lubricators. The Engine Control System of the ME engine comprises: Control units Hydraulic power supply unit Hydraulic cylinder units, including: Electronically controlled fuel injection, and Electronically controlled exhaust valve activation Electronically controlled starting air valves Electronically controlled auxiliary blowers Integrated electronic governor functions Tacho system Electronically controlled Alpha lubricators

### Why is a man hole door elliptical in shape?

Any opening in a pressure vessel is kept to a minimum and for a man entry an elliptical hole  is lesser in size than the corresponding circular hole. More over it is prime concern to have a  smoothed generous radius at the corners to eliminate stress concentration. Hence other  geometrical shapes like rectangle and square are ruled out.  To compensate for the loss of material in the shell due to opening, a doubler ring has to be  provided around the opening. The thickness of the ring depends on the axis length along the  dirrection in which the stresses are maximum and the thickness of the shell. It is important to  align the minor axis along the length of the vessel, as the stress in this direction is  maximum. Longitudinal stress: Pd/2t where P= pressure inside the vessel, d= diameter of the arc, t=  thickness of the shell plating  Circumferential stress: Pd/4t  More over a considerable material and weight saving is achieved as minor is along the  direction of maximum stress.

### Main engine interlocks

Interlocks are provided so that the engine can be started or reversed only when certain conditions have been fulfilled. When there is a remote control of engines, it is essential to have interlocks. This reduces the possibility of engine damage and any hazards to the operating personnel. Turning gear Interlock . This device prevents the engine from being started if the Turning gear is engaged. Running Direction Interlock . This prevents the fuel from being supplied if the running direction of the engine does not match the Telegraph. Starting Air Distributor in end position . This prevents starting from taking place if the shifting of the Distributor has not been completed. Main Lube. oil pressure, Piston cooling pressure, Jacket water pressure, and important parameters must be above the required minimum. Auxiliary Blower Interlock . The Auxiliary Blower is provided in case of Constant pressure turbo charging. Air Spring pressure Interlock . In case of the present generation