Numerous
different ships systems and controls being maintained by engineer officers are
used on all types of vessels today. These consist of engine room systems such
as lube oil, fuel oil, and seawater, along with deck officer's roles such as
cargo recording and navigation.
Management of the Various Systems Within the Engine
Room and Deck Departments
A ship could
not function without management of the systems incorporated within her hull and
deck. The following sections provide articles on this subject, and I have put
these in their relative groups with a brief description. The subjects have been
divided under general headings and linked to articles written by myself and
other Bright Hub writers in the Marine Engineering channel. We begin with the
various systems and controls within the engine room, before moving onto
examples in the deck department.
Ships Electrical Systems
The
electrical power is supplied from the generators to the main switchboard from
where it is distributed to all parts of the ship through numerous breakers and
relays. It is maintained by the Electrical / Electronics Engineer. There are
normally three generators, one running and supplying power, one on standby, and
one down for maintenance whilst at sea. When maneuvering or alongside working
cargo, two generators share the load with the other on standby.
- Marine Electrical Power Distribution
- Ship to Shore Supplies
- Electrical Grounding on Ships.
- Electrical Power Generator Protection
Lube Oil Systems
The lube oil
system comprises of the main engine sump, suction and discharge filters,
circulating pump, coolers and centrifuge. The sump is the main storage tank,
located under a grill in the crankcase. The suction and discharge filters
remove any particles contained in the oil. (Any pieces of white metal in these
could indicate bearing wiping, and must be investigated)
The cooler
is required to maintain optimum temperature and viscosity and cools the oil
using seawater that passes through tubes or plates depending on the type of
cooler.
Regular
centrifuging of the oil is essential for removing particles and water from the
oil sump; some engines have the centrifuge running twenty-four hours a day;
only being stopped for cleaning.
- Effects of not maintaining Lube oil system.
- Crankcase Lube Oil System
- Lube Oil Used in Marine Diesel Engines
- Lube Oil Cleaning by Centrifuging
- Use of Lubricants Aboard Ship
- Marine Oil Piston Cooling Using Lube Oil
- Treatment of Marine Engine Lube & Fuel Oil
- When Should Lube Oil be Changed
- Operation of Marine Lube Oil System
- Problems in the Lube Oil System
- Boundary and Fluid Film Lube Oil Systems
- Cylinder Liner Lube Oil System
- Wet & Dry Lube Oil Sumps
- Types of Lube Oil Systems
Heavy Fuel Oil System
The majority
of ships engines use heavy fuel oil (HFO) being a by-product of crude oil
refining. It is taken on board ships as bunkers, a sample of which should be
checked by the Chief Engineer, as some suppliers abroad have been suspected of
mixing old sump oil and even scavenge drains with bunker oil.
Before use
in the main engine the HFO must be processed by heating, filtration, purifying,
and clarifying. The heating is to keep the oil from waxing and improve the
usually high viscosity; filtration is carried out at various stages of the
process to remove particles. Purifying removes the water and sludge in the HFO,
and clarification removes the solids.
- Preparation of Heavy Fuel Oil
- Handling, Storage and Use of Heavy Fuel Oil
- Marine Heavy Fuel Oil Contaminants
- HFO from Crude Oil Refining
- Taking on HFO Bunkers
- Marine HFO Management System
- Treatment of Marine Engine Fuel & Lube Oil
- Centrifuging Heavy Fuel Oil
Ship’s Deck Systems and Control
The Deck
Officers use various methods to control the various systems of navigating, tank
cleaning, steering the ship, or control of the cargo. Control of the cargo and
producing a cargo plan is also the duty of the Deck Officers, usually the mate
or Second Officer. It is a very important document required to keep a record of
the type, description, and weights of the various pieces of cargo stored in the
holds or on deck. It also notes its location as well as the sequence of
loading, and thus the reverse order of discharge, in the various ports of call.
Ship’s
Cargo Plan
Navigation System
The bridge
is the Deck Officers domain. When I was at sea as an engineer, I used to go up
to the bridge when off watch and marveled at the sophisticated navigation gear
even in those far off days of 40-odd years ago.
This
consisted of the auto-pilot, gyro-counter, radar screen, ship's speed and
distance run, all neatly arranged on the bridge. The links below provide
further information on this subject.
- Use of Marine Navigation Lights
- Marine Navigation Terminology
- Rules for Ship’s Navigation
- Use of the Magnetic Compass in Navigation
- Electronic Navigation Chart Explained
- Tour of a Ship’s Bridge
- Marine Navigation Using GPS
- Tools used in Celestial Navigation
Cargo Tank Cleaning Systems on Oil Tankers
When I was
an engineer at sea, I used to dread the tank cleaning as the whole ship smelt
like a petrol station forecourt! However it must be done in preparation for the
next cargo. Gas freeing of the tanks is carried out first, with this being a
combination of inert gas flooding and venting of the tanks.
Gas freeing
and tank cleaning is under the remit of the Deck Officers; the Chief Officer
normally being in charge of operations.
Tank
cleaning occurs after discharge of cargo and gas-freeing, usually while on the
sea voyage to the next loading port. The following two links explain the
process involved in these systems.
- Gas Freeing and Tank Cleaning on Oil Tankers
- Inspection of Cargo Tanks on Oil Tankers
Ships Ballasting Systems
This is
under the control of the Deck Officers using their own pumps in the pump-room
or requesting the use of the engine room seawater on deck pump. Ballasting is
carried out as the cargo is loaded or discharged to maintain the ships
stability. There has been a lot of controversy lately regarding taking ballast
on in one port and discharging in another port. This can transport and transfer
alien species that will wreak havoc with the local flora and fauna.
- What is Ballast Water
- Problems Encountered in Discharging Ballast Water
- Ballast Water Management
References
Brighthub: Ships Control Systems
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