Tuesday, August 18, 2020

Engine Balancing

  • To  make  small  adjustments  to  each  unit  make  uniform power  generation
    in every unit.
  • Pmax  by  timing  of  fuel  pump(vit  or  by  shims  to  pump  or  cam  floating
    and readjusting)
  • Pcomp in ME engines by exh valve timing change.
  • Pmax- Pcomp not more than 35 bar to avoid piston ring failure.
    Pi adjusted by fuel index.
    (But limits are The peak pressure difference can't be more than 3 to 5
    for AE And max 10 for ME. Exhaust gas temp diff 40deg C.
    Fuel  rack  should  not  be  adjusted  more  than  10% Otherwise  we  have  to
    change the plunger and barrel)

Saturday, August 15, 2020

Self locking nuts

  • lf-locking nuts provide tight connections that will not loosen under vibrations. 
  • They meet critical specifications as to strength, corrosion resistance, and heat-resistant temperatures. 
  • New selflocking nuts must be used each time components are installed. There are two general types of self-locking nuts. 
  • They are the all metal nuts and the metal nuts with a nonmetallic insert to provide the locking action.
  •  The elastic stop and the nonmetallic insert lock nut are examples of the nonmetallic insert type. 
  • All metal self-locking nuts are constructed either of two ways. The threads in the load-carrying portion of the nut that is out of phase with the threads in the locking portion is one way. 
  • The second way is with a saw-cut top portion with a pinched-in thread. The locking action of these types depends upon the resiliency of the metal.

Thursday, August 13, 2020

4 stages of Ship Construction at yard

  • The block stage
  • Pre-erection stage
  • Erection stage
  • Quayside and commissioning

Advantages of MLC

  • A comprehensive set of basic maritime labour principles and rights
  • Simplification of international requirements
  • A strong enforcement regime, backed by a certification system
  • Verifiable compliance with basic minimum employment and social requirements
  • Application to all ships including those of non-ratifying Members
  • Improved working and living conditions for seafarers
  • A more secure and responsible maritime workforce
  • A more socially responsible shipping industry
  • Improved social dialogue at all levels
  • Seafarers better informed of their rights and remedies
  • Improved supervision at all levels: the ship, the company, the flag state, the port state, and the ILO
  • Global and uniform compliance and verification
  • Improved possibilities of keeping labour conditions up to date
  • Permanent review of maritime labour situation
  • Positive impact on safety at sea
  • Positive impact on the protection of the environment

Wednesday, August 12, 2020

Angle of Repose

  • Angle of Repose is the maximum slope angle of non-cohesive (i.e. free-flowing) granular material
  • It is the angle between a horizontal plane and the cone slope of such material
  • The angle of repose is a characteristic of non-cohesive bulk cargoes, which is indicative of cargo stability, and the purpose of which is to minimize the risk of bulk material shifting; 
  • The cargo should be trimmed reasonably level to the boundaries of the cargo space
    Jn

Tuesday, August 11, 2020

Safe Manning

SOLAS CHAPTER V, REG 14
The principles of minimum safe manning set out in section 3 to ensure the safe operation of ships to which article III of the 1978 STCW Convention, as amended, applies, and the security of ships to which chapter XI-2 of the 1974 SOLAS Convention, as amended,
Principle:
The capability to
  •  Maintain safe navigational, port, engineering and radio watches in accordance with regulation VIII/2 of the 1978 STCW Convention, as amended, and also maintain general surveillance of the ship;
  •  Moor and unmoor the ship safely;
  •  Manage the safety functions of the ship when employed in a stationary or near-stationary mode at sea;
  • Perform operations, as appropriate, for the prevention of damage to the marine environment;
  • Maintain the safety arrangements and the cleanliness of all accessible spaces to minimize the risk of fire;
  • Provide for medical care on board ship;
  • Ensure safe carriage of cargo during transit;
  • Inspect and maintain, as appropriate, the structural integrity of the ship; and
  • Operate in accordance with the approved Ship's Security Plan; and
The minimum safe manning of a ship should be established taking into account all relevant factors, including the following
  • Size and type of ship;
  • Number, size and type of main propulsion units and auxiliaries;
  • Level of ship automation;
  • Construction and equipment of the ship;
  • Method of maintenance used;
  • Cargo to be carried;
  • Frequency of port calls, length and nature of voyages to be undertaken;
  • Trading area(s), waters and operations in which the ship is involved;
  • Extent to which training activities are conducted on board;
  • Degree of shoreside support provided to the ship by the company;
  • Applicable work hour limits and/or rest requirements; and
  • The provisions of the approved Ship's Security Plan

Sunday, August 9, 2020

Maritime TORTS and types

Maritime law torts is a term covering cases where injury, loss or damage is caused to a person or their interests by another party’s action or negligence.
Types of torts 3 types
Intentional torts
An intentional tort is a civil wrong that occurs when the wrongdoer engages in intentional conduct that results in damages to another.
Negligence
Careless conduct that results in damage to another is negligence
Strict liability
Generally, liability because of a tort only arises where the defendant either intended to cause harm to the plaintiff or in situations where the defendant is negligent.  However, in some areas, liability can arise even when there is no intention to cause harm or negligence.
For example, in most states, when a contractor uses dynamite  which causes debris to be thrown onto the land of another and damages the landowner’s house, the landowner

Saturday, August 8, 2020

Reamer and types

The function of a reamer is to produce a smooth accurate surface in a bore such as that of a bearing or bush, for the shaft, pin or bolt to enter with a very good fit. In engine room Reamers are used for
  • The stern tube hole in stern frame is cast/fabricate roughly under size. When Main Engine is aligned with centre line of the stern frame hole, this hole is reamed to required diameter to fit the stern tube.
  • Fitted bolts on rudder palm and rudder carrier bearing housing for the press fit. They are to be reamed to exact diameter to avoid relative movement.
  • If a hole is drilled for internal threads then before we start with the procedure of making threads (tapping) we have to make sure we get a smooth finish for the threads.
In this respect, a reamer is a much better tool than a drill and can also produce finishes superior to normal machining on lathes. In fact, bores machined on lathes are often finished with reamers to improve the surface and bring them to size. Holes to be reamed must be drilled or machined undersize, the amountof material left depending on the roughness of the surface. Reamers are reaming tools which can be used on lathe machine for drilling purpose.
Total 8 types of reamers are- Adjustable hand reamer, Straight reamer (precision), Hand reamer, Machine reamer, Shell reamer, Tapered reamer, Morse taper reamer & combination reamer.

Thursday, August 6, 2020

How will you repair the coating in FWG & what coating is there on FWG?

  • The internal of the Fresh Water Generator is coated with 2 layers of Nordtec Ceramic 2212 FDA (Food grade coating). 
  • It is developed for Freshwater generators. It is designed as an abrasion resistant and fluid flow ceramic coating. 
  • It coating is reinforced with ceramic and carbide particles to obtain a high level of abrasion and erosion resistance and physical, mechanical strength.
  • The outside of the Fresh Water Generator, is primed and coated with two component paint.
  • As per manual – shell is coated with Neoprene coating and top cover- pure epoxy coating & bottom cover- Neoprene coating

Wednesday, August 5, 2020

Ship security alarm system (SSAS)

International Maritime Organization (IMO) legislation states that the ship’s security alert system shall:
  • Be initiated by pressing a dedicated SSAS button and transmitting a ship-to-shore security alert to a competent authority designated by the administration, which may include the company, identifying the ship, its location and indicating that the security of the ships is under threat or has been compromised
  • Not send the ship security alert to any other ships
  • Not raise any alarm on board the ship, and
  • Continue the ship security alert until deactivated and/or reset.
SSAS is not part of the GMDSS communication requirements but its equipment can be used to support the system.
Ship security alerts can be sent using Inmarsat C and Mini C,
SSAS regulations is that security alerts are required to be routed only to the Company Security Officer and the Flag.
SSAS resetting after take over with change vessel particulars email address and flag contact address

Tuesday, August 4, 2020

Load line survey items in engine room

  • Ship side valves and distance pieces
  • Sounding pipes and its closing arrangement
  • Stern tube sealing
  • Rudder sealing
  • Duct keel manhole water tightness.

Monday, August 3, 2020

High voltage

Voltages up to & Including 1000V is known as Low voltage system and Voltages 1001 and above is called as High Voltage system in maritime practice for ships.
Why High Voltage in Ships
  • Higher power requirements onboard vessels is the foremost reason for the evolution of HV in ships.
  • Higher power requirements have been necessitated by development of larger vessels required for container transort particularly for reefer containers.
  • Gas carriers needing extensive cooling electrical propulsion.
  • For ships with a large electrical power demand it is necessary to utilize the benefits of a high voltage HV installation.
  • The design benefits relate to the simple ohms law relationship that current (for a given power)is reduced as the voltage is increased. 
  • Working at high voltage significantly reduces the relative overall size and weight of electrical power equipment.
As per Ohms law, POWER = VOLTAGE x CURRENT
For a given Power, Higher the Voltage, Lesser is the Current
440 KW = 440,000 watts              
               = 440 Volts x 1000 Amps              
                -1100 volts x 400 Amps              
               -11000 volts x40 Amps 
When large loads are connected to the LV system the magnitude of current flow becomes too large resulting in overheating due to high iron and copper losses.
P= V I cosĪ¦
Copper Loss = I2 R
Advantages:
  • For a given power, Higher voltage means Lower current, resulting in Reduction in size of generators, motors, cables etc.
  • Saving of Space and weightEase of Installation
  • Reduction in cost of Installation
  • Lower losses — more efficient utilisation of generated power.
Disadvantages:
  • Higher Insulation requirements for cables and equipment used in the system.
  • Higher risk factor and the necessity for strict adherence to stringent safety procedures.
  • Trained crew.

Sunday, August 2, 2020

Different types of Ballast water exchange

Sequential:
In this method the ballast tanks are emptied until the ballast pumps lose suction and then the tanks are further stripped by eductor systems. This is followed by taking fresh ballast into the tank.
Flow through method: 
In this method water in pumped into the tank and to allow it to overflow through the air vent or dedicated overflow vents. Three times the volume of the tank is to be pumped through to get a 95 percent efficiency of exchange.
Dilution Method: 
In this method the tank has two openings; water is pumped in from one opening and flows out through the other.

Saturday, August 1, 2020

TriboPack

The design measures incorporated in TriboPack are:
  • Multi-level cylinder lubrication
  • Liner of the appropriate material, with sufficient hard phase
  • Careful turning of the liner running surface and deep-honing of the liner over the full length of the running surface
  • Mid-stroke liner insulation, and where necessary, insulating tubes in the cooling bores in the upper part of the liner
  • Pre-profiled piston rings in all piston grooves
  • Chromium-ceramic coating on top piston ring
  • RC (Running-in Coating) piston rings in all lower piston grooves
  • Anti-Polishing Ring (APR) at the top of the cylinder liner
  • Increased thickness of chromium layer in the piston-ring grooves.