AKRAMANUJAN.ORG9TH JANUARY 2020 BLOG243ramanujan1933@gmail.com

NOTE:- Examiners both internal and external mentally categorise the candidates and accordingly put the questions. These questions may be from any function, but the question is supposedly based on the assumption that the candidate is very familiar with the answer, and hence candidates must prepare for these encounters. If the questions are answered correctly and confidently they don’t give room for any cross questions. I Am now spelling out what each experience category candidate is required to be thorough with. This categorization is based on the type of ship you are sailing or your last ship you sailed on.

1 candidates worked on tankers product and crude:-

They should be thorough with the advanced tanker safety course material . Emphasis will be on inert gas systems operations including alarms and safety devices, COW or Butterworth operations. Special fire fighting devices for cargo. Thorough study of annex 1 of MARPOL.

2 Candidates worked on chemical tankers:-

Study the bulk chemical code which is applicable for peculiarities of construction. Categories of noxious substances and methods adopted for diluting or treating residues and the their acceptability by receiving authority

at the at the terminal . Methods adopted for cleaning tanks. Study or revise the notes obtained during your

attendance at the advanced or specialized chemical tanker course. Thorough study of annex 2 of MARPOL.3 candidates worked on bulk carriers with or without cargo gear:-

Study Chapter 6 of SOLAS, ch 12 of SOLAS thoroughly . dangers of grain loading, dangers of iron and nickel ore loading. Candidates must become very familiar with every section of ch 12 SOLAS. Safety requirements of the cargo gear, the issue of the cargo gear certificate and on the tests they are based on. The code of safe working practice. Details of the safety devices fitted on cargo cranes Thorough understanding of the latest circular on BWM and SEEMP. Curves of statical stability, dynamic stability and ship oscillations. LOAD LINE REGULATIONS and SURVEY 4 Candidates worked on container ships:- Special stability requirements due to high extent of cargo . Requirements for hold bilges, special bunkering facility, Torsion box details of construcrtion, details of shaft tunnel construction MARPOL ANNEX 1 AND ANNEX 6 to be thoroughly studied Load line regulations and survey.Cargo securing manual and its contents.5 Candidates worked on car carriers:- Fire fighting aids such as bulk CO2 system and water mist or fog system, construction details of movable dcar decks, shelter deck definition and construction .special stability requirements. Details of car stays. Details of special ballast requirements if provided.

QUESTIONS CONTRIBUTED BY VCISHNU SHANKAR FROM CHENNAI CENTRE

171What are all contents are present in immobilization certificate?Answer:-An immobilization permit is given by the port authorities . The main entries are the duration of immobilization in hours and for the period or dates.172How to change stern tube seal at sea? What all clearances to take in drydock?Answer:- stern tube seals cannot be changed in the open sea , it is done in afloat condition in a shipyard or alongside a pier.

At times occasionally the aft seal starts to leak and develop into a big leak within a few days making it necessary to either dry dock the ship or renew the seals in afloat condition. The reasons for the seals to leak are as follows:

(1) Some gritty matter like sand can get between the seals and the chrome liner and erode the seals and cause grooving of the liner surface leading to leakage.

(2) If the liner has been machined by 1mm during last dry dock, the spring pressure is reduced and can contribute to the leakage.

(3) The viscosity of the oil has reduced caused by using oil of lower viscosity as recommended by the shore office or the oil company.

The procedure adopted in carrying out this repair in dry dock is as follows:

(1) The seal box (aft) is made in two halves to facilitate this repair , and this is dismantled along with the spacing bolts of the seals. The box along with spacer rings are dismantled completely , leaving the seals on the chrome liner.

(2) The old damaged seals can be cut and removed .(3) The new seals one by one are slit , opened and

mounted on the shaft forward of the chrome liner , the slits are vulcanised by a portable vulcanizing tool and then placed on the chrome liner. The process of slitting and vulcanizing is shown in the sketches given bellow. vulcanizing is rubber welding and is commonly used in tyre tube punctures. (Fig 12 and 13)

(Fig 12)

(Fig 13)(4) The three vulcanized seals are mounted on the

chrome liner. The chrome liner is shifted forward after disconnecting it from the propeller . A split liner about 6mm thick is introduced between the propeller boss and the chrome liner so that the locations of the seals on the chrome liner are changed and fit on an unworn surface , avoiding the grooves formed. The split liner is made of

SLIT

bronze to avoid corrosion.(Fig 14) The arrangement is shown in sketch given below. After assembly of the seal box an oil leak test carried out and rope guard fitted back.

(Fig 14)

(5) This same repair can be done in afloat condition, provided the ship is in ballast condition. The ballast can be so arranged to have the aft peak tank empty and forepeak filled up along with the forward D.B. tanks pressed up so that the ship trims by head and brings the stern tube opening out of the water by at least over 15 cms.

A secure stage is built around the stern frame so that workmen can safely stand in the staging work safely. This job has to be done at a repair yard on the repair berth or at any port or repair berth.

173How to do Welding of two plates with different thickness, angle for edge preparation, distance, how to choose welding rod? What NDT method to be done after welding?Answer:- For joints of plates with difference in thickness of more than 4 [mm], the thickness plate is to be tapered. The taper is not exceed edge preparation after the tapering . Only approved welding procedure are to be used see. All surface to be welded are to be clean, dry and free from rust, scale and greases. The surface and boundaries of each run of deposit are to be thoroughly cleaned and freed from slag before the next run is applied. Before a manual sealing run is applied to the back of a weld, the original root material is to be gouged out to sound metal. All finished welds are to be visually inspected and are to be sound , uniform and substantially free from slag inclusion ,porosity undercutting or other defects. Welds and adjacent base are to be free from injurious arc strikes . Defective section of welds as found by visual or non-destructive examination or leakages under hydrostatic tests, are to be gouged out as necessary and carefully rewelded. For structural repair or renewal welding of the hull plating, no ndt is required ,except a hose pressure test to ensure the repair is not leaking.

The electrodes ro be used will be recommended by the surveyor especially if the two plates to be welded are of two different grades of steel.174Solas requirements of boiler safety valveAnswer:- There are no special rules for boiler safety valves given in SOLAS. Boilers are governed by the classification rules which are approved by the SOLAS which grants the SAFCON certificate if the ship is classed and has satisfactorily completed the special survey or renewal of class certificate.175Under what circumstances you will cut out the main engine fuel pump .Answer:- The fuel pump of any unit is cut out for the following reasons:

If the liner or cyl-head is cracked and this is confirmed.

If piston is seized and running gear (con-rod) disconnected . piston properly supported.

During manoeuvring if cyl air start valve is leaking and ship cannot be stopped.

176What are the safeties present during reversing of main engine?Answer:- During reversing of the engine, the reversing interlock comes into operation and cannot be released unless the engine comes to stop and is not turning.

(b)When the control is operated remote from the local emergency control station say either the Bridge or Engine control room, the reversing interlock which is activated when engine starts to turn can only be unlocked when engine stops. In this condition the reversing lever can be moved to the desired direction. This protective device is provided to safeguard the camshaft and the

cams mounted on the camshaft. This also provides safety to the engine components if reversal is accomplished whilst turning has not stopped . In extreme cases it can cause slippage of journal web shrink fit.

177What action you will take as 2/E during scavenge fire? After scavenge fire you did scavenge inspection. What all reports you make as 2/E?

Answer:- (b) The symptoms of a fire are : (1) continuous surging of the T/C due to the increase of pressure in the scavenge space caused by the burning oil-air mixture. (2) If a pressure relief door is fitted it will activate. (3) In modern ships the particular unit scavenge space temperature alarm will be activated. (5) The paint around the scavenge trunking close to the unit will appear burnt. and will feel hot on touching.

(c) The actions to be taken are as follows: (1)As soon as the temperature alarm is activated rush to the scavenge trunk and confirm it is a scavenge fire from any of the above mentioned symptoms which will be observed..(2) If scavenge space fire extinguishing system is fitted, it should be operated.(3)Inform the bridge and slow down the engine, and inform C/E.(4) Stop engines ,engage turning gear and keep turning engine and operate the particular unit cylinder lubricator manually continuing it till the space has cooled..

If the weather is calm and there is no sign of weather deteriorating for the next 18 hours, the unit may be opened , piston withdrawn and rings renewed as needed. Unit assembled in all respects and proceed on voyage. Ensure that the scavenge space drains under the unit are well cleared. Reduce the cylinder lubrication feed to the particular unit if the feed rate is high .Ensure the scavenge space drains are clear and working. If the weather is not good and likely to deteriorate, then cut off the unit and run at a slower RPM suitable to the conditions which are : vibration free and a smokeless exhaust. Ensure all working cylinders exhaust temperatures are within their normal limits. The unit should be opened and piston rings renewed as soon as the weather improves.

When the unit is opened out , aproper calibration report of liner and piston rings will be made and sent to the shoreoffice. UIf weather does not permit renewal of liner if liner is worn down beyond the limit,

the unit will be assembled with renewed rings replacing the worn and broken rings. Liner will be renewed in port.

178How will you prepare for reentry to machinery space after releasing co2Answer:- after 4 hours after release of CO2, two watch keeping engineers will be sent down after donning the firemen suit with SCBA. They will proceed down to the lowest space and inspect all over , and if they report no trace of fire, the engine room doors,skylights and the blower flaps will be opened to ventilate the engine room. Ventilation has to be done by natural process since power can be made available only after proper entry into the machinery space is established. This may take about six hours.179Daily routines on Oil mist detector, Alarm setting?Answer:- the oil mist detector is normally tested once a week along with other emergency and safety devices.( I may be wrong. Please confirm.)

180CSM survey, where will you find this file onboard? What it is called?

Answer:- The chief engineer has a file for all the quarterly listings of pending surveys issued by class every three months. Surveys which are completed are also mentioned in the listing.