Explain latest developments in Marine ‘Tribology’

Explain latest developments in Marine ‘Tribology’.

  

Tribology is the science and engineering of interacting surfaces in relative motion. It includes the study and application of the principles of

·      friction

·      lubrication 

·      wear

The tribological interactions of a solid surface's exposed face with interfacing materials and environment may result in loss of material from the surface. The process leading to loss of material is known as "wear". Major types of wear include abrasion, friction (adhesion and cohesion), erosion, and corrosion. 

Wear can be minimised by modifying the surface properties of solids by one or more of "surface engineering" processes (also called surface finishing) or by use of lubricants (for frictional or adhesive wear)

There are  world’s two biggest manufacturers of large marine diesel engines, MAN B&W and Wartsila .

Sulzer RTA-series engines now incorporate TriboPack technology -a package of design measures that enable the TBO of the cylinder components, including piston ring renewal, to be extended to at least three years. At the same time, TriboPack allows the further reduction of cylinder lubricating oil feed rate.

The design measures incorporated in TriboPack are:

1. Multi-level cylinder lubrication
2. Liner of the appropriate material, with sufficient hard phase
3. Careful turning of the liner running surface and deep-honing of the liner over the full length of the running surface
4. Mid-stroke liner insulation, and where necessary, insulating tubes in the cooling bores in the upper part of the liner
5. Pre-profiled piston rings in all piston grooves
6. Chromium-ceramic coating on top piston ring
7. RC (Running-in Coating) piston rings in all lower piston grooves
8. Anti-Polishing Ring (APR) at the top of the cylinder liner
9. Increased thickness of chromium layer in the piston-ring grooves.
 

A key element of TriboPack is the deep-honed liner. Careful machining and deep honing gives the liner an ideal running surface for the piston rings, together with an optimum surface microstructure.

The Anti-Polishing Ring prevents the build up of deposits on the top land of the piston which can damage the oil film on the liner and cause bore polishing.

It is also important that the liner wall temperature is adapted to keep the liner surface above the dew point temperature throughout the piston stroke to avoid cold corrosion. Mid-stroke insulation and, where necessary, insulating tubes are therefore employed to optimize liner temperatures over the piston stroke.

Other development

Alpha lubrication (MAN)

•  Electronically controlled cylinder lubrication.
• The lube oil is injected exactly when the piston ring pack is passing the lube oil quills, thus ensuring the best possible utilisation of the costly lube oil.

Anti polishing ring.

Piston ring :-CPR, Gas tight lock and controlled leakage grooves.

New tie rod design (MAN)

Development in Bearing design

• Increase in bearing area
• Shape changed( lemon shaped)MAN
• Bearing temperature monitoring for moving bearing
• On line bearing  wear measurement.
• Thick shell-Flex edge design(MAN)
• Thin shell-Blend edge design

SOPEP ,An emergency preparedness plan and its salient advantages

SOPEP

Q:-   A ship which was bunkering at a foreign port has met with an accident and a substantial amount of oil spillage in water has resulted.

   Draw an emergency preparedness plan for the incident and how best it could be encountered under the provision.

  Describe its salient advantages.

Answer:-

This Plan is available to assist the ship’s personnel in dealing with an unexpected discharge of oil.

Effective planning ensures that the necessary actions are taken in a structured, logical and timely manner.

  -The primary objectives of this Plan are to

·    prevent oil pollution

·    stop or minimize oil outflow when a damage to the ship or its requirements occurs

·    stop or minimize oil outflow when a operational spill occurs in excess of the quantity or instantaneous rate permitted under the present Convention

 The purpose of the Plan is to provide the Master, officers and certain crew members with a practical guide to the prevention of oil spills and in carrying out the responsibilities associated with regulation 37 of Annex I to MARPOL 73/ 78

·        procedures to report an oil pollution incident

·        Coastal State contacts (Focal Points) and Port Contact Lists to be contacted in the event of an oil pollution incident.

·        response actions to reduce or control the discharge of oil following an incident.

·        co-ordination with national and local Authorities in combating oil pollution.

The Plan is designed as a ship-specific tool it must also be considered as an additional instrument and as a link to shore-based plans.

With this the Plans allow an efficient co-ordination between the ship and shore-based Authorities/ Organizations in mitigating the effects of an oil pollution incident.

The Plan includes a summary flowchart to guide the Master through reporting and acting procedures required during an oil pollution incident response.

     The Plan is likely to be a document used on board by the Master and officers of the ship and must therefore be available in the working language used by them.

General procedures for operational spill: (bunkering)

     Operational spill are those which are occur during cargo, bunkering or oil transfer operation.This normally in port or in anchorage.

Immediate action:

1) initiate emergency shut down, stop all transfer operations, close all valves and inform the terminal- in- charge, of your actions.

2) Sound the emergency alarm, inform the Master and initiate the emergency response procedures.

3) inform the Port or local state authority.

Follow Up Action :

1) Identify the source of the spill / leak and initiate measures to stop or minimize the outflow.

2) Drain or transfer the oil from the affected area of the pipeline into empty or slop tanks, taking into account stress and stability of the vessel at all times.

3) The possibility of leakage from sea valves should not be discounted. Pressure on these valves should be relieved, if possible, by draining the lines into a suitable tank on board, if available, or ashore.

4) if there is any possibility of release of flammable vapor or its entry into the accommodation, engine room or cargo holds, its ventilation to these areas must be shut off.

5) Clean up operations must be started using the equipment available on board.

6) All spilled oil that is collected must be carefully stored on board till it can safely be disposed off.

7) Chemicals & dispersants (externally) must not be used unless Prior permission has been obtained from the Port authority.

8) Before resuming normal operations, permission may have to be obtained from the Port authority / Terminal Manager.

Salient advantages of Emergency Preparedness Plan.

  1)     The plan identifies all the activities which may cause oil spillage leading to environmental pollutions.

  2)     It defines clearly, the duties & responsibilities of the master and crew .

  3)     An effective implementation is ensured through specialist teams comprising crew members. These teams are trained on-board through realistic drills carried and on a regular basis thus improving their skill & effectiveness.

  4)     Plan assess the state / condition of tools (cleaning gear) and consumables (cleaning material) provided to clean-up spillage.

     Thus a well prepared EPP will go a long way in dealing with an incidence of oil spill effectively.