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3. Preheat may be necessary prior to tack welding when the materials to be joined are highly restrained. Special consideration is to be given to use the same preheat as
specified in the welding procedure when tack welding higher-strength steels.
3.1.2 Production Welding Especially Preheat Process
Preheat is giving heat before welding process plates. In all cases, preheat and interpass temperature control are to be sufficient to maintain dry surfaces and minimize the
possibility of the formation of fractures. The preheat requirements is : 1. When welding is performed under high humidity conditions or when the temperature
of steel is below 0°C 32°F, the base metal is to be preheated to at least 16°C 60°F or temperature appropriate to the alloy and the thickness, whichever is higher.
2. When preheat is used, the preheat and interpass temperatures are to be in accordance with the accepted welding procedure and to the satisfaction of the Surveyor.
3.2 DEAD SHIP AND BLACKOUT
3.2.1 Dead Ship
a. The main propulsion plant, boilers, and auxiliary machinery are not in operation due to the loss of the main source of electrical power
b. In restoring propulsion, the stored energy for starting the propulsion plant, the main source of electrical power and other essential auxiliary machinery is assummed to
not be available.
3.2.2 Blackout
Blackout situation means the loss of the main source of electrical power resulting in the main and auxiliary machinery to be out of operation.
3.3 TESTING DURING CONSTRUCTION 3.3.1 Type of Testing
Table 1 : Relationship Between Structure To Be Tested and Type Of Testing
No Structure To Be Tested
Type Of Testing
Hydrostatic Testing Head Or Presure
1 Double Bottom Tanks
Leak and structural
The greater of - to the top of overflow,
- to 2,4 m above top of tank, or - to the bulkhead deck
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2 Double Side Tanks
Structural
1,2
The greater of - To the top of overflow, or
- To 2.4 m 8 ft above top of tank
3
3 Deep Tanks or Cargo Oil
Tanks Structural
1,2
The greater of - To the top of overflow, or
To 2.4 m 8 ft above top of tank
3
- To the top of tank
3
plus setting of any pressure relief valve.
Fuel Oil Bunkers Structural
4 Ballast Hold of Bulk
Carries Structural
1
The greater of - To the top of overflow, or
- To 0.9 m 3 ft above top of hatch
coaming
3
5a Peak Tanks
Structural The greater of
- To the top of overflow, or To 2.4 m 8 ft above top of tank
3
5b Fore Peak Voids collision
bulkhead See Note 4
See Note 4 5c
After Peak Voids Air
6 Cofferdams
Structural
5
The greater of - To the top of overflow, or
- To 2.4 m 8 ft above top of tank
3
7 Watertight Bulkhead
Hose
6
8 Watertight Doors Below
Freeboard or Bulkhead Deck
Hose 9
Double Plate Rudder Air
10 Shaft Tunnel Clear of
Deep Tanks Hose
11 Shell Doors Hose
12 Watertight Hatch Covers
of Tanks on Combination Carriers
Structural
1,2
The greater of - To 2.4 m 8 ft above top of hatch
cover, or - Setting pressure of the pressure
relief valve 13
Weathertight Hatch Covers, Doors and other
Closing Appliances Hose
6
14a Chain Locker and Chain
Pipe aft of collision Structural
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bulkhead 14b
Chain Locker and Chain Pipe fwd of collision
bulkhead Structural
7
15 Independent Tanks Structural
The greater of - To the top of overflow, or
- To 0.9 m 3 ft above top of tank
16 Ballast Ducts Structural
Ballast pump maximum pressure or setting of any relief valve for the
ballast duct if that is less.
17 Hawse Pipe Hose
3.3.2 Application of Coating 1. Final couting may be applied prior to the hydrostatic testing and after the application
of air testing .
2. For all manual or semi-automatic erection weld and fillet weld tank boundary connections
including penetration, final coating is to be applied after air testing. 3. For other weld, final coating may be applied before after testing, provided the
Surveyor, after examination prior to the application of coating, is satisfied with weld.
B. SURVEY ACTIVITIES
3.4 AIR TEST 3.4.1 Reference
Based on ABS Rules 3-7-11.2, 3-7-15.5 and 3-7-37.1 1. Definition and Purpose : Air testing is one of the leak testing for to verify and checked
tightness of the structure such as all boundary welds, erection joint, and penentration including pipe connection.
2. Method : by using air pressure 3. Details of Testing : 1 Pressure value is 0.15 bar 0.15 kgfcm
2
, 2.2 psi. But, It is recommended that the air pressure in the tank be raised to and maintained at 0.20 bar
0.20 kgfcm2, 2.9 psi for approximately one hour, with a minimum number of personnel around the tank, before being lowered to the test pressure. 2 U-tube with a height
sufficient to hold a head of water corresponding to the required test pressure is to be arranged. the cross sectional area of the u-tube is to be not less than that of the pipe
supplying air. In addition to the U-tube, a master gauge or other approved means is to be
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provided to verify the pressure. 3 Air testing must to be applied before painting and final coating.
4. Other Methode Testing : compressed air fillet weld testing or vacuum testing 3.4.2 Procedure of Testing
1. To lose down tank or compartment will to be tested 2. Install the all equipment testing such as pressure gauge and U-tube on the tank cover
manhole. Beside that, prepare also soap liquid. For the height of U-tube minimum 2,03 m.
Intended use of the U - tube is for safety . That is, for testing in areas that have a high temperature such as the engine room , which contains the compressed air tank could
explode . For these conditions , the water pressure in the tank will push the water out of the U - tube
Figure 7 : U-Tube Process
3. Provide the pressure in accordance with ABS Rules see at pressure gauge
Figure 8 : Read The Pressure by Pressure Gauge
4. Wait at least 1 one hour. 5. To spray soapy water to every boundary SIM joint.
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Figure 9 : Spraying Soapy Water
6. Checked for leaks on the SIM Joint. Leakage is characterized by the appearance of
bubbles in the soapy water. 7.
For to ensure the real leak, we must to spray soap liquid again to boundary SIM joint
welding the suspected leak and checked again.
3.4.3 Result and Conclusion of Survey
During air test on WB DW Tank No. 9 P, not found leak on SIM Joint and construction is accept.
Figure 10 : The Resul of Air Testing Process 3.5 VISUAL INSPECTION
3.5.1 Defenition
Visual inspection is checking process for to ensure the compliance of structure in drawing with the actual installed onboard
3.5.2 Procedure visual inspection
1. QC Inspector submit the request to surveyor to obtain RFI Request For Inspection. RFI is a guide of survey because it contains survey time and items to be surveyed.
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2. Based on RFI, surveyor prepare and learning more specific approval drawing. 3. Surveyor come on board and to checked compliance of structure in drawing with the
actual installed on the ship 4. Write the comment on the inspection result
3.5.3 Result and Conclusion of Survey
1. Foundation of Azimuth Thruster Drawing 40448 – 283 - 012 missing face plate on
the bracket. Based on drawing, web shall be W16 + 200 x 20 FF. But actual only used W16 + 200 x 14 FF and contruction is reject and must be changed.
2. Missing bracket on pillar at bottom position and contruction is reject and must be
changed.
Figure 11 : Prepare Drawing Approval Before Survey Onboard
Figure 12 : Missing Face Plate and Bracket
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3.6 UNDERWATER INSPECTION IN LIEU OF DRYDOCKING UWILD 3.6.1 Defenition and Purpose
