TABLE 6.1 Current U.S. Coast Guard Polar Icebreakers

Characteristic

POLAR STAR and POLAR SEA

HEALY

Length (feet)

399

420

Displacement (long tons)

13,334

16,165

Cruise speed (knots)

12

12

Endurance (days, nautical miles)

205, 23,000

205, 23,000

Power (SHP)

60,000

30,000

Crew size

134

67

Scientists

20

50

Icebreaking capability

6 feet at 3 knots

4.5 feet at 3 knots

NOTE: SHP = shaft horsepower.

tional by the conclusion of fiscal year 1990…. In preparing such plans, the Secretary shall consult with other interested federal agencies for the purpose of ensuring that all appropriate military, scientific, economic and environmental interests are taken into account.

The design proceeded expeditiously, but delays occurred when a company with Arctic experience proposed to lease an icebreaker to the government. Consequently, OMB denied replacement icebreaker funding in the 1988 budget. An A-104 lease-buy analysis was completed in 1989 and showed that the net present value of a lease would be 10 to 15 percent more expensive than buying the ship. This finding cleared the way for Congress to appropriate funds to procure one ship. Funding was provided in the Defense budget thereby further slowing actual procurement. HEALY, delivered in 1999, was designed with modern science facilities to meet the increasing demand for Arctic research and has proven highly capable in that role. The characteristics of the current fleet are listed in Table 6.1.

THE CURRENT WORLD FLEET OF POLAR ICEBREAKERS

The U.S. Coast Guard generally has used the thickness of ice broken continuously at 3 knots as a simple measure of icebreaking capability. Therefore, icebreaking ships for Coast Guard or military owners are not required to be built to meet classification society requirements. However, requirements for the structural integrity of ice-capable ships are specified in the rules of the various classification societies, for example, the Russian Maritime Register of Shipping, Lloyd’s Register, Det Norske Veritas, American Bureau of Shipping, and Germanischer Lloyd, and national regulatory authorities (Canadian, Finnish-Swedish, and Russian). These requirements are divided broadly into Baltic Rules for ice-strengthened vessels and Arctic Class Rules for icebreaking ships.

Most classification societies have similar requirements for ice-strengthened vessels or ice type ships, which are divided into classes depending on their design ice thickness of up to 1.2 meters. Local structure design ice pressures depend principally on the ice class and hull area.

In contrast, classification society requirements for icebreaking ships have historically varied somewhat in terms of definitions of hull areas, which are strengthened, and design load intensity relative to design ice and operating conditions.

An approximate correspondence between different classification societies’ ice classes is shown in Table 6.2. How-

TABLE 6.2 Approximate Equivalencies Between Classes

Classification Society/ National Administration

Approximate Class Equivalents

Canadian Arctic Shipping Pollution Prevention Regulations

 

CAC 1

CAC 2

CAC 3

CAC 4

Type A

Type B

Type C

Type D

Russian Maritime Register of Shipping

LL1

LL2

LL3

LL4

ULA

UL

L1

L2

L3

Det Norske Veritas

P30

P20

P10 I15

I10

I05

1A*

1A

1B

1C

Lloyd’s Register of Shipping

LR 3

LR 2

LR 2 LR 1.5

LR 1.5

LR 1

1A

1B

1B

1C

Finnish-Swedish Maritime Administrations

 

 

 

 

 

1AS 1A

1B

1B 1C

1C

Germanischer Lloyd

 

 

 

 

 

E4

E3

E2

E1

Bureau Veritas

 

 

 

 

 

1AS

1A

1B

1C

American Bureau of Shipping

 

 

 

 

 

1AA

1A

1B

1C



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