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Flashcards in Dry-Dock Deck (73)
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1

How would you prepare for a Dry-dock Exam?

Verify inspection Intervals: ISE, Hull, Tail shaft, Sea Valves, Integral Fuel Oil Tanks, etc.; Review MISLE back to last Dry-dock and identify damage and temporary repairs that require permanent correction and identify areas for close inspection. Request records of outstanding Conditions of Class; Schedule/attend planning meeting with interested parties to communicate USCG inspection requirements and avoid omissions/interferences/duplication. Ensure the owner/operator understands the criteria for a credit dryocking i.e . hull cleaned, tanks gas free, etc.

2

What are the various inspections normally completed during drydock and where would I find the
cites for each

Intervals for dry-dock, internal structural, and cargo tank internal exams are found in each subchapter as appropriate. These intervals range from 2.5 to l0 years depending on salt/fresh water service, construction or material. Also included in each subchapter is the interval for inspection of integral fuel oil tanks. The number and location of tanks to be opened is dependent on the age of the vessel.

3

Are there any special reporting requirements in advance of the docking of a vessel greater than 20
years of age?

Yes. The traveling inspection staff at CGHQ must be notified as far in advance of such a dry-dock
ins inspection so the ma attend.

4

Briefly describe SOP for confined space entry by marine inspection personnel.

"A certified Marine Chemist shall conduct the initial inspection and certify all confined spaces on merchant vessels "Safe for Workers" before entry by Coast Guard personnel." rules require a Competent Person to reexamine the confined space at least every 24 hours or if conditions under which the certificate was issued under change." "If the competent Person has not properly maintained the Marine Chemist Certificate, the Marine Chemist is required to reissue the certificate prior to entering into the confined space."

5

What are the in intervals for gauging hull structure res including shell plate? Where would you find these requirements ?

Under class rules required thickness measurements other than suspect areas called out by the surveyor generally begin at Special Periodical Survey No. 2. This represents vessels with roughly ten years of service unless grace periods were granted. There are different requirements based on vessel size and service. For instance vessels restricted to the great lakes need not conduct thickness measurements until Special l Periodical Survey No. 7. Considering the routine year of grace dispensation, required thickness measurements for these vessels do not occur until the 42nd year of service. There is also a requirement for periodic gauging of tank vessel mid-bodies more than 30 years old in subchapter D. However, classification with a recognized society is considered equivalent.

6

What is a class 1 structural failure? What are the reporting requirements?

Class I: During normal operating conditions, either
(1) A visible, through thickness fracture of any length in the oil-tight envelope of the outer shell where threat of pollution is a factor; or (2) A fracture or buckle which bas weakened a main strength member to the extent that the safety of the vessel to operate within its design parameters is compromised. Immediate Corrective action must be initiated by the operator with the approval of the OCMI. Temporary repairs may be permitted to allow the vessel to transit safely to a repair facility.

7

What is a class 2 structural failure? What are the reporting requirements?

A fracture or buckle within a main strength member which does not compromise the safety of the vessel to operate within its design parameters and does not create a threat of pollution either by location or containment. Necessity for corrective action
shall be evaluated and agreed
upon between the vessel operator OCMI when the failure is found. Temporary repairs until the next scheduled repair period may be authorized.

8

What is a Class 3 structural failure?

Any fracture or buckle which does not otherwise meet the definition of a Class 1 or 2 structural failure or a fracture which might normally be considered a Class II but is determined not to be detrimental to the strength or serviceability of the effected main hull structural member. Corrective action or notification to the OCMI is not required.
Shall be noted for the record, monitored by the operator if deemed desirable and addressed at the next regularly scheduled repair period.

9

What do you inspect on a bulkhead?

Inspect for watertight integrity and general condition as well as signs of overloading
( warped/deformed).

10

What do you inspect on a deck?

Decks can be part of major longitudinal strength members. Inspect for watertight integrity and general condition as well as signs of overloading (warped/deformed).

11

What do you inspect on a tank top?

Tank tops are the upper boundary of double bottom tanks. Like decks tank tops make up a major part of the hull girder and if wasted or deformed affect hull strength. Inspect for watertight integrity and general condition as well as signs of overloading (warped/deformed).

12

What do you inspect on a Longitudinal?

Generally refers to. smaller structures run longitudinally to stiffen plating (e.g. bottom longs, side shell longs, under deck longs, etc). The term would not apply to larger
strength members such as side keelsons.
? If deflected or deformed, this may indicate impact damage to the side or bottom plating.
? Deflected or deformed members should be examined for cracks and to ensure they have not ''tripped" (web no longer perpendicular with the stiffened/supported plate).

13

What do you inspect on a floor?

A plate used vertically in the bottom of a ship running athwart ship from bilge to bilge usually on every frame to deepen it. in wood ships, the lowest frame timber or the
one crossing the keel is called the floor.
? Deflected or deformed members should be examined for cracks and to ensure they have not "tripped" (web no longer perpendicular with the stiffened/supported plate).

14

How do you inspect frames?

A term generally used to designate one of the transverse ribs that make up the skeleton of a ship. The frames act as stiffeners, holding the outside plating in shape and maintaining the transverse form of the ship.
? Deflected or deformed members should be examined for cracks and to ensure they have not ''tripped" (web no longer perpendicular with the stiffened/supported plate).

15

How do you inspect Intercostals?

Situated or fitted between adjacent members of a ship's frame\. Occurring between ribs, frames, etc. The term is broadly applied, where two members of a ship intersect, to the one that is cut.
? Deflected or deformed members should be examined for cracks and to ensure they have not "tripped" (web no longer perpendicular with the stiffened/supported plate).

16

How many double bottom fuel tanks must be internally inspected on a 5 year old subchapter I vessel? Where is the interval found?

None. see 46CFR9 l .43

17

What arc reduced scantlings?

Reduced scantlings means simply that the various internal structures and/or shell plating were approved at sizes below standard rule thicknesses in order to save weight. This reduction in size directly affects corrosion allowances and special coating systems are a requirement of construction. MSM only discusses reduced scantlings in regards to VLCCs and ULCCs. However, NVIC 7-68 indicates that converted LSTs were lightly built and suggests max wastage at 15%. Note: Ballast tank coating systems may be required if reduced scantlings are employed).

18

What factors are used in determining variations in the inspection interval for a cargo tank internal examination?

Variations in CTIE intervals are based on salt or freshwater service, construction (double/single hull, internal /external framed etc. and cargo grade. Intervals run from 2.5-15 years.

19

When are ca cargo tank coatings important?

In certain situations cargo tanks on chemical tankers may require coatings or linings to prevent the rapid corrosion of tank structures. In these instances close inspection of the coating/lining materials is warranted.

20

Why are cargo hatches an important inspection item and what are you looking for?

Answer: Hatch failure has been implicated in a great many total loss casualties and these openings interrupt the hull girder and introduce stress risers at the hatch corners. Inspection should include:
? Dogs or other securing appliances for condition;
? Hatch covers for structural integrity;
? Gaskets for condition;
? Coamings for structural and watertight integrity;
? The deck adjacent to coming comers for signs of cracking or stress corrosion .

21

CG -840 DI mentions ash and rubbish chutes, what is an ash or rubbish chute and what would you inspect?

? Ash chutes are used on coal burning steamers and are essentially a large diameter pipe (4") leading from the ash pit eductor to a skin valve above the waterline. This piping system is subject to abuse due to the abrasive nature of the effluent. The skin valve is susceptible to the same sort of damage as well as fouling. The piping should be examined for wastage and the skin valve for ware and function.
? Rubbish chutes are used to dispose of permissible trash and may represent watertight integrity issues.

22

What are inner bottom drains (Docking Plugs) and what are you looking for?

Docking plugs are specifically mentioned as an inspection item in the MSM and in the CG-840 book. They are installed to allow for draining and cleaning out inner bottom tanks during dry-dock availability. They should be inspected for cracking. erosion or other modes of failure.

23

Describe the following components found in and around rudder assemblies and what might you be looking for during an inspection? Pintles

Pintles: These are the pins in the rudder's hinge. They do not support the weight of the rudder but do provide a stable fulcrum from which it can swing. The pintle is usually a tapered bar fitted into a casting called a gudgeon and secured by a nut.
? The pintle should be inspected for signs of looseness, ware, and cracking.
? Examine locking device (nut weld)

24

Describe the following components found in and around rudder assemblies and what might you be looking for during an inspection?Gudgeons

Gudgeons: Are integrally cast into the stem frame, rudder horn, or shoe piece to receive the pintle. This area is subject to dynamic stress and should be examined for cracking.

25

Describe the following components found in and around rudder assemblies and what might you be looking for during an inspection? Skeg

Skeg: ls a stern ward extension of the keel of boats and ships which have a rudder mounted on
the centre line.

26

Describe the fo llowing components found in and around rudder assemblies and what might you be looking for during an inspection? Stock

Stock: The rudder stock is the piece that physically connects the rudder to the tiller or motor.

27

Describe the fo llowing components found in and around rudder assemblies and what might you be looking for during an inspection?Steadiment Bearings

Steadiment bearings: Bushings or bearings maintaining the rudder stock in position.

28

Describe the fo llowing components found in and around rudder assemblies and what might you be looking for during an inspection? Carrier

Carrier: Bearing mounted on the upper stock to carry the weight of the rudder assembly. ABS 3-
2-1 4117 .3

29

Describe the fo llowing components found in and around rudder assemblies and what might you be looking for during an inspection? Rudder Trunk

Rudder Trunk: Space through which the rudder stock passes through the hull.

30

Describe the fo llowing components found in and around rudder assemblies and what might you be looking for during an inspection? Palm and Palm Bolts

Palm and Palm bolts: Currently referred to as coupling and coupling bolts and are a means to attach the rudder to the rudder stock where such a des ign is used