U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling ... · U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 . 5. Prior to getting underway, the Master

National Maritime Center Serving Our Nation’s Mariners

U.S.C.G. Merchant Marine Exam

Mobile Offshore Drilling Units

Q431 OIM Unrestricted

(Sample Examination)

Page 1 of 12 Q431 OIM Unrestricted

9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0

Choose the best answer to the following Multiple Choice Questions.

1. While in transit, the DEEP DRILLER suffers flooding in the starboard pump room. Both starboard bilge pumps are inadequate to dewater the pump room. You may supplement the performance of the bilge pumps by using the __________.

o (A) starboard saltwater service pump • (B) starboard drill water pump o (C) starboard ballast pump o (D) port ballast pump and crossover system

If choice B is selected set score to 1.

2. A survival craft being used to pick up a person who has fallen overboard from a MODU should approach the person __________.

o (A) at a high rate of speed o (B) with the wind o (C) under oars • (D) against the wind

If choice D is selected set score to 1.

3. While the COASTAL DRILLER is elevated, the out-of-level alarm indicates that hull inclination exceeds 0.3°. What should you do?

o (A) Raise the high corner. o (B) Raise the low corner. o (C) Raise unit to proper air gap and inspect for damage. • (D) Confirm operation of out-of-level alarm.


4. The COASTAL DRILLER is loaded as shown in the Sample Load Form Number 1 (Rig Move). If the contents of 6 and 7 drill water tanks are discharged, what is the new height of the center of gravity corrected for longitudinal free surface effects?

o (A) 48.41 feet o (B) 49.16 feet • (C) 50.79 feet o (D) 51.40 feet

If choice C is selected set score to 1.


9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 5. Prior to getting underway, the Master or person in charge of a MODU must __________.

o (A) conduct a fire drill • (B) log the fore and aft draft marks o (C) test the emergency generator o (D) conduct a boat drill


6. A mobile offshore drilling unit must display obstruction lights when it is on the waters over the Outer Continental Shelf and is __________.

o (A) underway • (B) fixed to the seabed o (C) under tow o (D) All of the above


7. The COASTAL DRILLER, elevated in 150 feet of water with 0 knots current, 10 foot waves, and wind speeds of 70 knots may continue drilling if the maximum leg reaction is less than __________.

o (A) 5,940 kips o (B) 6,020 kips • (C) 6,080 kips o (D) 6,520 kips


8. The sounding in fuel oil tank 4P on the DEEP DRILLER is 8.75 feet. What are the longitudinal moments for this amount of fuel?

o (A) -17,416 ft-long tons o (B) -874 ft-long tons • (C) 3,992 ft-long tons o (D) 17,416 ft-long tons


9. Lowering the hull of the COASTAL DRILLER and refloating should be done in favorable weather conditions with wave heights not more than __________.

o (A) four feet o (B) three feet • (C) five feet o (D) six feet



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 10. When leveling the elevated COASTAL DRILLER, you may raise the low corner instead of lowering

the high corner __________.

o (A) in all cases, it is optional o (B) if a potential punch-through threatens • (C) if lowering the high corner places the unit in the wave action o (D) if proper air gap has been exceeded


11. Repair of structures on a MODU in the vicinity of liquid mud handling areas presents what possible hazard?

o (A) An oxygen-deficient atmosphere may be present. o (B) Liquid muds may flood adjoining spaces. o (C) Toxic gasses may be present. • (D) Flammable gasses may be present.


12. The connected joints of pipe, usually made of three joints of pipe approximately 90 feet long, racked in the derrick when making a trip are called a __________.

o (A) standpipe • (B) stand o (C) joint o (D) string


13. In a severe storm while elevated, the drilling loads on the COASTAL DRILLER must be considered as __________.

o (A) setback loads o (B) hook loads • (C) variable loads o (D) rotary loads


14. In the case of an injury causing a person to be incapacitated, the Master or person in charge of a mobile offshore drilling unit must submit a report to the __________.

• (A) nearest Marine Safety or Marine Inspection Office o (B) nearest hospital o (C) Department of Energy o (D) American Bureau of Shipping

If choice A is selected set score to 1.


9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 15. Why are symmetric mooring patterns frequently used to keep MODU's on station?

o (A) All lines contribute to the holding power of the mooring system. o (B) Governmental regulations require this mooring pattern unless an exemption is issued. • (C) Environmental forces will probably vary in direction during the time the MODU is on station. o (D) Environmental forces will probably come from the same direction during the time the MODU is

on station.


16. The DEEP DRILLER is loaded as shown in the Sample Load Form #1 (Transit). Weather conditions make it necessary to ballast down to survival draft. It is decided to check the stability at the intermediate draft of 32 feet. If the added ballast has an average VCG of 9.03 feet, and the sum of free surface moments is 56,244 foot-tons, what is the new KGL?

o (A) 54.76 feet o (B) 55.76 feet o (C) 57.22 feet • (D) 61.16 feet


17. The DEEP DRILLER, while loaded as shown in the Sample Load Form #4 (Drilling), suffers damage to the port center column below the waterline. Pumping from tanks 2P and 9P is not sufficient to prevent increasing port list. You should consider counterflooding in tank __________.

• (A) C2BS o (B) C2BP o (C) 2S o (D) 9S


18. The International Oil Pollution Prevention (IOPP) Certificate required by MARPOL is issued to U.S. flag MODUs by the __________.

• (A) U.S. Coast Guard o (B) Environmental Protection Agency o (C) International Maritime Organization o (D) American Bureau of Shipping



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 19. It is proposed to moor the DEEP DRILLER in 600 feet of water in a region in which the effective wind

velocity could reach 80 knots, significant wave height could reach 30 feet, and the current could be 1.5 knots. If these conditions occurred at the same time from the bow, the total environmental force would be __________.

o (A) 620 kips • (B) 595 kips o (C) 475 kips o (D) 425 kips


20. In a storm, the windward lines of a MODU's mooring system provide __________.

o (A) a negative restoring force o (B) a positive righting moment o (C) an increase in KM • (D) a positive restoring force


21. Why must the drilled hole be filled with drilling mud when tripping the drill string out of the hole?

o (A) To keep the mud agitated o (B) To maintain circulation to the mud pits • (C) To prevent reduction of fluid head on the formations o (D) To compensate for MODU heave


22. The DEEP DRILLER is planning to operate while loaded as shown in the Sample Load Form #3 ( Preparing to Drill). What is the margin between KGT and maximum allowable KG?

o (A) 0.66 foot o (B) 2.58 feet • (C) 5.24 feet o (D) 7.87 feet


23. If the low side bilge pump fails and the high side bilge pump has insufficient suction to dewater the low side of the COASTAL DRILLER when afloat, you should use the __________.

o (A) preload pumps • (B) saltwater eductor system o (C) mud pumps o (D) raw water tower pumps



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 24. The motions of the COASTAL DRILLER during a normal transit when wind speeds are less than 70

knots are limited by __________.

o (A) deck edge immersion o (B) wave heights o (C) stability • (D) leg strength


25. When a MODU is inclined at a small angle, the center of buoyancy will __________.

• (A) move toward the low side o (B) remain stationary o (C) move toward the high side o (D) move to the height of the metacenter


26. On offshore drilling units, notification shall be given to the Coast Guard of a casualty if a person is injured and unable to perform routine duties for __________.

• (A) any amount of time o (B) more than 24 hours o (C) more than 36 hours o (D) more than 72 hours


27. A hurricane has recurved to the northeast and its forward speed is 20 knots. Your MODU is located 600 miles northeast of the hurricane's center. How long will it take for the hurricane center to reach your position if it holds its present course and speed?

o (A) 10 hours • (B) 30 hours o (C) 50 hours o (D) 80 hours


28. The DEEP DRILLER is moored in 700 feet of water. The tension on anchor line #3 is 200 kips. What is the vertical component of chain tension for that line?

o (A) 59.1 long tons • (B) 60.9 long tons o (C) 89.3 long tons o (D) 487.2 long tons



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 29. A jack-up with displacement of 10,000 kips has its LCG 100 feet aft of frame zero (AFO). If 200 kips

are loaded at 60 feet AFO and 100 kips are discharged from 20 feet AFO, what is the new LCG?

• (A) 100.0 feet o (B) 100.4 feet o (C) 100.8 feet o (D) 101.2 feet


30. A tool consisting of a handle and releasable chain used for turning pipe or fittings of a diameter larger than that which a pipe wrench would fit is called __________.

o (A) pipe spinner o (B) breakout wrench • (C) chain tongs o (D) makeup tongs


31. Why can a person's sense of smell not be depended upon to detect H2S?

o (A) it is better to rely on eye irritation as a detector • (B) the sense of smell is deadened by the gas o (C) it has a smell similar to petroleum products o (D) hydrogen sulfide gas is odorless


32. If you have to jump in the water when abandoning a MODU, what position should you maintain your legs?

o (A) spread apart as far as possible o (B) held as tightly against your chest as possible • (C) extended straight down and crossed at the ankles o (D) in a kneeling position


33. The marine riser on the DEEP DRILLER should be disconnected if it appears the mooring line tensions will exceed 522 kips or the ball joint angle will exceed __________.

o (A) 4° o (B) 5° o (C) 7° • (D) 10°



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 34. What is the maximum concentration of H2S to which workers may be regularly exposed without

adverse effects?

o (A) 10 ppm • (B) 20 ppm o (C) 40 ppm o (D) 80 ppm


35. In very deep water drilling, it becomes necessary to reduce tension caused by the weight of the riser joints. This is accomplished by using a(n) __________.

o (A) aluminum riser o (B) tapered riser o (C) intermediate tensioner • (D) buoyant riser


36. While drilling at 4,000 feet with casing set to 2,000 feet, the well kicks with mud weight in the hole. Mud pumps are shut down and the blowout preventer is closed. Compared to the drilling situation, the pressure on the casing seat will be __________.

• (A) increased o (B) unchanged o (C) indeterminable o (D) reduced


37. The heavier outboard strake of deck plating on a MODU is called the deck __________.

o (A) doubler • (B) stringer o (C) stiffener o (D) beam


38. A continual worsening of the list or trim of any floating MODU indicates __________.

o (A) negative GM o (B) an immediate need to counterflood • (C) progressive flooding o (D) structural failure



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 39. What is the female section of a tool joint called?

• (A) Box o (B) Pin o (C) Stem o (D) Stand


40. The connected joints of pipe, usually made of three joints of pipe approximately 90 feet long, racked in the derrick when making a trip are called a __________.

o (A) standpipe • (B) stand o (C) joint o (D) string


41. Load line regulations are designed to insure that a MODU has adequate structural strength and sufficient __________.

• (A) stability o (B) mooring tension o (C) riser tension o (D) lifesaving equipment


42. The two courses of action if the underwater hull of a MODU is severely damaged are to plug the openings and to __________.

o (A) dewater the compartment o (B) counter flood to maintain even keel • (C) establish and maintain flooding boundaries o (D) secure power to the compartment


43. The COASTAL DRILLER, while drilling, has a total weight of 15,400 kips. The LCG is 120.00 feet AF0, and the TCG is -0.5 foot to port of the centerline. What is the starboard leg reaction?

o (A) 4,956 kips o (B) 5,063 kips • (C) 5,104 kips o (D) 5,233 kips



9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 44. The DEEP DRILLER is loaded as shown in Sample Load Form #4 (Drilling). While the unit is

deballasting, starboard valve 17 fails in the closed position. You may deballast from tank 8S by pumping from tank 9S and opening valves 18 and __________.

o (A) 35 o (B) 21 • (C) 20 o (D) 17


45. The document that certifies the correctness of the load line marks on a MODU is called the __________.

o (A) SOLAS Certificate o (B) Certificate of Inspection • (C) Load line certificate o (D) Certificate of Documentation


46. While loaded as shown in the DEEP DRILLER Sample Load Form #4 (Drilling), all of the liquid mud is dumped. What is the new location of the longitudinal center of gravity?



47. In a semisubmersible MODU, the columns contain void spaces above the waterline that used principally for __________.

o (A) machinery o (B) equipment storage o (C) elevators • (D) reserve buoyancy


48. While in transit at a draft of 20.5 feet, the DEEP DRILLER has a KGT of 65.00 feet. What is the GMT?




9/10/2019

Q431 OIM Unrestricted U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 49. While loaded as shown in the COASTAL DRILLER sample load form #3 (drilling), 50 kips of tubulars

are discharged from the cantilever starboard pipe racks. What is the change in the vessel's TCG?

• (A) 0.048 foot port o (B) 0.048 foot starboard o (C) 1.020 feet port o (D) 1.020 feet starboard


50. The DEEP DRILLER is loaded as shown in the Sample Load Form #5 (Survival), when an unexpected, slowly increasing port list and bow down trim occurs. A leak in C1P is found. By deballasting from ballast tanks 2P and 3P, the inclination slowly decreases. The increase in the longitudinal free surface correction is __________.

o (A) 0.90 foot o (B) 0.83 foot o (C) 0.57 foot • (D) 0.49 foot



9/10/2019

U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling ... · U.S.C.G. Merchant Marine Exam Mobile Offshore Drilling Units Illustrations: 0 . 5. Prior to getting underway, the Master

Documents