Form Approved
REPORT DOCUMENTATION PAGE
OMB No. 0704-0188
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1. AGENCY USE ONLY (Leave blank)
2. REPORT DATE
3. REPORT TYPE AND DATES COVERED
June 1995
4. TITLE AND SUBTITLE
5. FUNDING NUMBERS
Northern Sea Route Reconnaissance Study: A Summary of Icebreaking
Technology
6. AUTHORS
Devinder S. Sodhi
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)
8. PERFORMING ORGANIZATION
REPORT NUMBER
U.S. Army Cold Regions Research and Engineering Laboratory
72 Lyme Road
Special Report 95-17
Hanover, New Hampshire 03755-1290
9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
10. SPONSORING/MONITORING
AGENCY REPORT NUMBER
U.S. Army Engineer District, Alaska
Anchorage, Alaska
11. SUPPLEMENTARY NOTES
12a. DISTRIBUTION/AVAILABILITY STATEMENT
12b. DISTRIBUTION CODE
Approved for public release; distribution is unlimited.
Available from NTIS, Springfield, Virginia 22161
13. ABSTRACT (Maximum 200 words)
Since the advent of steam power, icebreakers have been built to navigate in ice-covered waters. The hull forms
of early icebreakers were merely an adaptation of open water hull shapes, by sloping bow angles more to create
vertical forces for breaking ice in bending. However, these bow forms were found to be unsuitable for sea-going
vessels because they push broken ice ahead of them. This experience led to construction of all sea-going vessels
with wedge-shaped bows from 1901 to 1979. With the introduction of low-friction coatings and the water-
deluge system, it is now possible to operate ships with blunt bows efficiently in broken ice. New developments
in marine propulsion technology have also been incorporated to obtain better icebreaking efficiency and per-
formance. Both fixed-pitch and controllable-pitch propellers are in use. Nozzles surrounding the propellers are
also used to increase the thrust and to reduce icepropeller interaction. Electrical and mechanical transmission
systems have been used in icebreakers to improve the characteristics of the propulsion system. Though many
types of prime movers are used in icebreakers, medium-speed diesel engines are the most popular because of
their overall economy and reliability. Appendix A is a description of the Russian icebreaker Yamal, which is one
of the largest and most powerful icebreakers of the world today. Appendix B contains an inventory of existing
ships that are capable of navigating in at least 0.3-m-thick ice. Some of the present icebreakers are capable of
14. SUBJECT TERMS
15. NUMBER OF PAGES
239
Auxiliary systems
Icebreakers
Inventory of icebreaking ships
16. PRICE CODE
Hull forms
Icebreaking history
Propulsion system
42
17. SECURITY CLASSIFICATION
18. SECURITY CLASSIFICATION
19. SECURITY CLASSIFICATION
20. LIMITATION OF ABSTRACT
OF REPORT
OF THIS PAGE
OF ABSTRACT
UNCLASSIFIED
UNCLASSIFIED
UNCLASSIFIED
UL
Standard Form 298 (Rev. 2-89)
NSN 7540-01-280-5500
Prescribed by ANSI Std. Z39-18
298-102
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