MSB (Main Switch Board)

In the name of Allah most beneficent and merciful

In this article you will understand how Electricity is “generate and consume” aboard ship. The distribution principal is something same like in domestic purposes but there is a difference, no need of lengthy cable in ship. Only a kilometer / half kilometer is maximum length of cable running across the ship length. So very much high power generation plant system is not required on ship e.g. in MW. There are only some minor losses of electricity on board.

The alternator produces electricity which is then goes to the ECR (Engine Control Room) through bunch of wire from beneath of ECR. These wires then led to the rectangular bar at back of panel known as busbar.

The main advantage of these bars over the cable is that it can easily connect a Motor starter panel or any other kind of load. The main switch board now distribute into several other panel which are listed below.

1.       Feeder panel  No. 1 440 VAC

2.       Feeder Panel  No. 2 440 VAC

3.       Feeder Panel  No. 1 110 VAC

4.       Feeder Panel No. 2 110 VAC

5.       Generator Panel No.1 

6.       Generator Panel No. 2

7.       Generator Panel No. 3

8.       Synchronizing Panel

9.       Group Starter Panel No. 1 (440 VAC)

10.   Group starter Panel No. 2 (440 VAC)

11.   Earth Monitoring Panel

12.   Distribution Box Panel

Now in the bus bar we have 440 VAC coming from generator but for some machinery we required only 110 VAC.  So for this we have usually Air Cooled transformer. 

 Generator Panel No. 1

On Screen

The panel of generator must have essential parameter to display, the figure which are non-essential can be local displayed e.g. RPM, Boost Air (Scavenge air ) pressure, Sea Water pressure, Cooling water pressure, differential pressure. Normally on screen reading are Lube oil Pressure, Lube Oil In/Out, Jacket Water out temperature,

On Vertical Rack

Mostly Alternator side parameters are displayed on it. E.g.  Voltage, Current and Kilowatt. Selector switch for Voltage and current are given so that one can switch to other phase to check voltage and current are present on other phases.  Standby by button is also provided on the panel.

Some two more instrument are provided on the ship e.g. Synchroscope, Synchroscope selector switch, 

Then the electricity which are on bus bar is led to the Feeder panel No. 1, where Group starter panel of are present.

Generator to ACB

ACB to Bus bar

Bus bar to different load/panel (motor, etc)

 

Lubircating Oil

oil which will be carried out on the board.

1. Fuel oil
2. diesel oil
3. lub oil
4. cylinder oil
5. oeht 30 for stearing gear
6. 0s 3 153 for boiler 

Chemical using aboard

The chemical which are using on the tankerz are.

1. ecosphere
2. electroclean
3. coagulant
4. hydrazine (aqeous solution)
5. carbon remover
6. rust oil
7. paroline

Turbocharger Parameter

Gas (turbine) side

Turbocharger

Sight glass (oil level)

Thermostat(oil temp safety)

Thermometer(oil temp)

Comp. side

Sight glass (oil level)

Thermostat(oil temp safety)

Thermometer(oil temp)

Rpm(speed)

On watch i seen the above things on gas  and compressor side.

A three day tour to MT JOHAR

Three day tour on the johar.

I am starting the conversation with my senior from the central point. The question which I asked from the senior are

About the  perfect cylinder lubrication indication.

1. no glassy mirror surface it must be mid b/w shiny and dull
2. spot on the liner
3. not found on stuffing box and scavengine port(ideal condition)

This piece of information is also about the cylinder lubrication. The ball which can be seen in the pipe like test tube are actually work for non-return purpose but also show that part lubrication is running.

the difference b/w the easing gear and safety valve is that safety is being operted by easy ness from a gear which is located at unrestricted location.

About the reverse power is that which is happen when the generator of the ship loose their speed and it on the same busbar will suck power from the other generator. (High to low). Generator which is a very big machine consume very heavy power and also it can injure the prime mover(dangerous speed component can throw away). It is usually done by relay.

The generator is rated in kva (it is the apparent power). Kvar(reactive power- capacitor and inductor)

Kw means the active (real power). The load which I found on the generator is 350-400kw

Inert gas is just like smoke  but have low content of oxygen and high nitrogen. Have smell, white cloud colour. It help us to increase the positive pressure in the tank.

And also when filing the tanks make the tanks in inert conditions while loading it is discharge in air. And also during loading for sake of stability ballasting(pumping seawater in wing tank or center tank) is operated. By pump but in mt johar it is done by fire hose from the above of hole. And manually filling.

Also from the other senior I asked about the difference between the windlass and winches. The difference is offcourse the power and design. Achor is usally lifted up with a windlass and winches for mooring. But the combination can also used on the board ship.

Difference between the nrt and grt and dwt are the followings . dwt is total displacement incuding light weight (only ship not bunker, crew, food items, fuel,). Nrt is volume above the cargo and grt is volume of machine and above cargo

Chlorides, can be found on the board ship, remedy is of course many chemical including hydrazine used to reduced the oxygen content.

Steam and carbondioxide Both can be used in case of scavenging fire. But steam is used which I have read in the book.

Air register is mean to regist (to allow the air infurnance). Note . for purging normal is allow to come in burner of boiler . the boiler of johar is in O-shaped. In the middle there is a fire and steam drum on the above and water drum on below.

Test of lub is conradson carbon residue. Viscosity . ofcourse depend upon the company. Other will carry out in the laboratory. Base Is used to neutraliza it .

Cross head lub is done by screw type pump also the bypass is available. Cross head lubrication is complex as compared to other lubrication.

On the mt johar jerked ignition is employed ( spill valve) and on the other ship we are using common rail . the pump in the one sequence. Like u watch the video in one ship.

On one question I asked about the turbine type which is being using on the shinko manufacturer. But sir don’t know about it.

Regarding the purifier question must be prepared to asked from the seniors. And I havenot seen clarifier where it is located in johar or swat.

How to clean lub oil purifier. For the main engine and for the generator.

A script on Woodward governor

Woodward governor

This electro-hydraulic type of governor is used on many machine eg. Steam turbine to run on a constant revolution per minute, diesel generator to run the alternator on a contant revolution per minute.

It has an output that is linked with the fuel pump for diesel generator and in steam turbine the output is linked with the valve

Maintenance of governor

Following are the point which is dealt with carefully

1. oil of governor is free of foreign particle
2. oil should be of same number that is used previously, eg. Viscosity must be matched
3. clean oil should be used to avoid the malfunctioning of governor.

Common feature incorporate in governor are following

1. speed droop
2. speed limit
3. load limit
4. compensator

speed droop is the time between the maximum load and no load

compensator is used to compensate the variable change for micro seconds.

A script written during my apprenticeship

The working of the steam turbine is very simple. Turbine is of two kind one is impulse and other one is reaction turbine both give rotational output.

Now the question rises what is happening inside the turbine which give rotate the shaft. Let us take a simple real example in our life.

The fan which us air. If the high pressure air is allowed to impinging on the blade the fan will rotate and hence energy will convert from mechanical to electrical.

Same thing is happening inside the steam turbine in which there is a blade mounted on the shaft which can be  rotate. And high pressure is provided through nozzle(diverge).

And the fluid is steam which is impinging on the blade.

Steam have very high enthalpy and with pressure having usually 30 bar is inlet from the nozzle ring which is fixed. There the no pressure drop and when the travel through the blade the a little bit pressure will drop. And so on.

A rough info during my apprenticeship

1. The spindle valve will be order from marine workshop (PNSC). It will be construct of  M/S. The dimension will be provide when ordering.
2. case hardening advantages are ; long life of metal, realibility, can withstand with long fatigue.etc. it is done by several methods ( nitriding, induction hardening, flame hardening, carbodizing,  and nitriding is most commonly used). Example of component are bearing journal, gudgeon pin, shaft.
3. The importance of maintaining the water level in a boiler to prevent the boiler from dehydration. This water is consuming up as steam is producing. So a constant water level is necessary for production of steam at a constant rate. If the water level is drop significantly. The fracture of plate and bending of tube may occur. If the water level is to rise significantly the thermal shock can be happened. steam will not be saturated or we can say that the output of the steam dryness will be effect.
4. reason of using pure water in boiler is to prevent the formation of  ……slag. To have minimum no. of chlorides, phosphate, carbonate.
5. precaution are gas free the vicinity, check any dangerous gas with explosimeter, electric fan is used for free circulation of air. Other wise the person may fatal, ……………..
6. when taking a watch the main point that will be checked as following.

·        Boiler is running normal.

·        Economizer/exhaust gas boiler is running normal.

·        Aux. Generators are running normal.

·        Main engine is running normal

·        Check the level of diesel oil(service tank), fuel oil(service tank), lub oil, fresh water (check also which side port or starboard is on consume)

·         Check that the log book is maintained in the previous watch.

·        And confirm form previous watch officer that every thing is running normal.

7. smoke detector work on principle that smoke can scattered the light. Thus as shown in the figure the photocell is located in another compartment with opaque restriction between the light and photocell. When smoke come, the light will scattered and fall on the photocell. Where it is amplified, and the bell will ring. It can be tested by smoke of a cigarette or butane.
8.  

Piping diagram which is available on a ship

1. BILGE LINE
2. S.W. SERVICE LINE
3. COOL S.W. LINE
4. COOL FRESH WATER LINE
5. F.W. SERVICE LINE
6. T/C & AIR CLR CLEANING LINE
7. F.O. TRANS LINE
8. FUEL OIL PURIFY LINE
9. M/E AUX. BLR & INCINER. F.O. SERVICE LINE
10. GEN. ENG FO SERV LINE
11. LO. TRANS & PURIFY LINE
12. LO SERV LINE
13. STERN TUBE LO LINE
14. 1.6 MPa STEAM LINE
15. 0.95MPa STEAM LINE
16. 0.45MPa STEAM LINE
17. EXHAUST STEAM LINE
18. STEAM DRAIN LINE
19. CONDENSATE WATER LINE
20. FEED WATER LINE
21. COMPRESSED AIR LINE
22. CONTROL AIR LINE ½
23. CONTROL AIR LINE 2/2
24. EXH. GAS & MIST LINE

Note:

These lines are of a tanker Ship

Typical floor (in urdu manzil) on a ship

Main deck

Emg. Generator room (PS)

Hydraulic p/p room (StBd)

Foam room

Laundry, dry cl

Decontamination room

Air conditioning room

Vegetable

Dry provision up room

Pump room enterance

1^st platform

FW tk

Dist W tk

Eng. Wkshp & store

Steering gear

FO settling tk

FO daily service tk

FO boiler tk

FO storage tk

1^st poop deck

Off pantry

Galley

Crew pantry

Crew mess

Crew daily room

Hospital

2^nd poop deck

Oiler

Steward

Ass. Cook

Wiper

3^rd poop deck

Ass. Radio off

Apr engineer

Mess boy

Pump room

Boat swain

4^th poop

2^nd officer

Chief eng. Bedroom-dayroom

Captain

Navigation room

Battery

Radio room

Radio operator

Elevation match

Wheel house

Chart room

2^nd platform

Aft peak water ballast

Ecr

FO storage tk

P/P room

Flooring

Bilge tk

Piston cooling

Daily bilge

DO storage tk

FO service tk

FO overflow tk

Purifiers

Fuel oil storage tk

P/p room