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Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
Call number: ZSP-201-79/8
In: CRREL Report, 79-8
Description / Table of Contents: Sea ice ridging statistics obtained from a series of laser surface roughnessprofiles are examined. Each set of profiles consists of six 200-km-long flight tracks oriented approximately perpendicular to the coastline of the Chukchi and Beaufort Seas. The landward ends of the profiles were located at Point Lay, Wainwright, Barrow, Lonely, Cross Island and Barter Island. The flights were made in February, April, August, and December 1976, and one additional profile was obtained north of Cross Island during March 1978. It was found that although there is a systematic variation in mean ridge height (h) with season (with the highest values occurring in late winter), there is no systematic spatial variation in h at a given time. The number of ridges/km (micron) is also high during the late winter, with the highest values occurring in the Barter and Cross Island profiles . In most profiles, the ice 20 to 60 km from the coast is more highly deformed (higher micron values) than the ice either nearer the coast or farther seaward. The Wadhams model for the distribution of ridge heights gives better agreement with observed values in the higher ridge categories than does the Hibler model. Estimates of the spatial recurrence frequency of large pressure ridges are made by using the Wadhams model and also by using an extreme value approach. In the latter, the distribution of the lagest ridges per 20 km of laser track was found to be essentially normal
Type of Medium: Series available for loan
Pages: iv, 28 S. : Ill.
Series Statement: CRREL Report 79-8
Language: English
Note: CONTENTS Abstract Preface Introduction Data collection and processing Analysis General Variations in ridging Ridge height distributions Occurrence of high ridges The tail of the distribution Extreme values Applications to offshore design Conclusions Literature cited Appendix A. Tabulated ice ridge data ILLUSTRATIONS Location and orien!ation of the laser sampling tracks Mean ridge height has a function of distance from shore for all loca-tions and sampling times in 1976 Number of ridges p per 20-km interval as function of distance fromshore for all locations and sampling times in 1976 p and h values obtained in March 1978 by NASA plotted as a func-tion of distance from shore Ridging intensity I, as a function of distance from shore for all loca-tions and sampling times in both 1976 and 1978 Histograms of predicted versus observed ridge heights separated in-toclassintervalsofo.3m Total x1 values for each ridge sail height class interval The Wadhams ridge height distribution function parameters a and 13 plotted as a function of distance from the shore of Cross Island dur-ing February, April and December 1976 The Hibler ridge height distribution function parameters N0 and Aplotted as a function of distance from the shore of Cross Island dur-ing February, April and December 1976 Plot of log~0 vs ridge sail height Semilog of P,(h), the probability that a ridge encountered at randomwill have a height of at least h meters, versus ridge sail height Ridge sail heights versus spatial recurrence intervals Monte Carlo simulation of the extreme ridge heights generated bythe Wadhams and Hibler models using p and h from the Beaufort Sea February and April tracks TABLES Least-squares constants a, 13 and ~3’
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  • 2
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/26
    In: CRREL Report, 78-26
    Description / Table of Contents: Ice fog suppression experiments on the Fort Wainwright Power Plant cooling pond were conducted during the winters of 1974-76. Baseline information studies occupied a sizable portion of the available ice fog weather in 1974-75. Then hexadecanol was added to the pond and dramatically improved visibility by reducing fog generated from water vapor released by the pond at -14 C. Although this temperature was not low enough to create ice fog, the cold vapor fog created was equally as devastating to visibility in the vicinity of the pond. During the winter of 1975-76, suppression tests were continued using films of hexadecanol, mixes of hexadecanol and octadecanol, and ethylene glycol monobutyl ether (EGME). Suppression effectiveness at colder temperatures was stuided and limits to the techniques were probed. A reinforcing grid was constructed that prevented breakup of the film by wind and water currents. Lifetime tests indicated that EGME degrades much more slowly than either hexadecanol or the hexadecanol-octadecanol mix. The films were found to be very effective fog reducers at warmer temperatures but still allowed 20% to 40% of normal evaporation to occur. The vapor thus produced was sufficient to create some ice fog at lower temperatures, but this ice fog occurred less frequently and was more quickly dispersed than the thick fog that was present before application of the films.
    Type of Medium: Series available for loan
    Pages: iv, 27 S. : Ill.
    Series Statement: CRREL Report 78-26
    Language: English
    Note: CONTENTS Abstract Preface Introduction Ice fog from cooling ponds Evaporation Relative humidity and cold air Ice fog suppression Air movement 4Plastic films Rafts Injection wells Cooling towers Chemical films Reinforced film experiments Meteorological data collection Floating reinforcement grid Application of the hexadecanol film Hexadecanol, octadecanol mixes Ethylene glycol monobutyl ether Laboratory tests of suppression effectiveness Conclusions Literature cited Appendix A. Design for an automatic thin chemical film applicationsystem Appendix B. Meteorological data ILLUSTRATIONS Figure Low temperature psychrometric chart Cross-section of polyethylene covered raft Location of Fort Wainwright power plant cooling pond Layout of Fort Wainwright power plant cooling pond Rows of 8-ft-diam hoops installed on the cooling pond Pond before application at 0820 hours Overall fog reduction at 0910 hours Large areas with little or no fog at 0920 hours Large clear area upstream of hoops and along west edge of pondprior to applying hexadecanot to the hoops Alcohol film layers accumulating at the leading edge of the hoops,just prior to applying hexadecanol to hoop area Pond 24 hours after application Pond 48 hours after application Effect of chemical films on heat transfer rate from water surfaces Excess water vapor produced vs temperature TABLES Table Cost comparisons for ice fog ruppression
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  • 3
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/22
    In: CRREL Report, 78-22
    Description / Table of Contents: Special environmental factors that influence the design, laying and maintenance of undersea pipelines and cables in polar waters are described. Various approaches to the protection of submarine pipes and cables are considered, and prime emphasis is given to burial techniques for shallow water. A wide range of methods for trenching and burying are discussed, and technical data are given.
    Type of Medium: Series available for loan
    Pages: v, 36 S. : Ill.
    Series Statement: CRREL Report 78-22
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors Introduction Types of pipelines and cables Potential hazards to pipelines and cables Areas of concern Waterdepth Sea ice Icebergs and ice islands Submarine permafrost Ice gouging Seabed erosion by water jets Protection methods Protection of unburied pipes and cables Protection by burial Backhoe digging Wireline equipment Plowing and ripping from the surface Plowing and ripping by self-propelled seabed vehicles Bucket ladder dredges Suction dredging Conventional cutterhead dredges Low pressure water jetting Bottom-traveling cutterhead dredges Explosive methods Novel methods Disc saws, wheel ditchers and m illing drums Ladder trenchers and chain saws Repetitive impulse devices High pressure water jets Flame jets and plasma torches Electrical discharge and electromagnetic radiation Chemical methods Conclusions Literature cited ILLUSTRATIONS Figure Simplified representation of ice gauge depth Penetration of anchor flukes in unfrozen bed sediments Protection arrangements for unburied underwater pipelines Production rates of hydraulic backhoes working in common materials on land Production rates of short-boom draglines working in common materials on land Ladder power as a function of bucket capacity for ladder dredges
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  • 4
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/19
    In: CRREL Report, 78-19
    Type of Medium: Series available for loan
    Pages: iv, 21 S. : Ill.
    Series Statement: CRREL Report 78-19
    Language: English
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  • 5
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/21
    In: CRREL Report, 78-21
    Description / Table of Contents: This study investigates the possibility of providing estimates of the time of occurrence and length of the freezing season for any location in East and West Germany by using the average Januavy air temperature (AJAT) as an index. The results indicate that reliable values of the mean freezing index can be obtained from the AJAT relationships which are developed for Germany. This association is further verified using data from the northeastern part of the U.S., and the AJAT is then used to determine the average starting and ending dates (and hence the probable length) of the freezing season for stations in Germany. The AJAT and the average dates of snowfall occurrence for numerous locations in the U.S. and Germany are also correlated. Interrelationships between these parameters and the average number of days with snow on the ground for stations up to 3000 m in elevation in Germany are examined. A detailed AJAT map for East and West Germany, in which data from 134 stations, latitude, altitude and regional influences are considered, is developed in order to make the relationships usable. A historical review of the literature on snow studies in Germany and a brief discussion of snow-cover interpretation by satellite photography are included
    Type of Medium: Series available for loan
    Pages: v, 48 S. : Ill. + 1 Kt.
    Series Statement: CRREL Report 78-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Historical literature review Relationships between midwinter temperature and freezing season Mean freezing index 4 Average January air temperature U.S. comparative study Correlation of AJAT and duration of freezing season Relationships between average January air temperature and snow conditions U.S. relationships German relationships Mapping of average January air temperatures Analysis of observed AJ AT data Development of detailed maps Application and discussion Examples Influence of vegetation Literature cited Appendix A. interpretation of snow cover by satellite Appendix B. Contour, station elevation and Aj AT maps for East and West Germany ILLUSTRATIONS Figure Freezing index and freezing season for three stations in Germany Relationship between freezing index and length of freezing season for 17 stations in Germany Average monthly temperature curve for four stations in Germany Relationship between the average January air temperature and the mean freezing indexfor stations in Germany and New England Relationship between the average January air temperature and the average length of the freezing season for 17 stations in Germany Relationship between the average January air temperature and the average starting and ending dates of the freezing season for 17 stations in Germany Relationship between the average date of the first 1-in, snowfall of the season and the average January air temperature for 134 U.S. stations located at elevations of less than 550m Location of 24 stations in the U.S. where average dates of the first 1-in, of snowfall of the season are earlier than at stations with similar AJAT’s Relationship between the date of earliest snowfall of the season and the average Januaryair temperature for stations in East and West Germany Relationship between the date of latest snowfall of the season and the average January air temperature for stations in East and West Germany
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  • 6
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/15
    In: CRREL Report, 78-15
    Description / Table of Contents: This report first discusses the general approach for calculating the horizontal forces an ice cover exerts on a structure. Ice force determination consists of two parts: (1) the analysis of the in-plane forces assuming that the ice cover remains intact and (2) the use of a failure criterion, since an ice force cannot be larger than the force capable of breaking up the ice cover. For an estimate of the largest ice force, an elastic plate analysis and a failure criterion are often sufficient. A review of the literature revealed that, in the majority of the analyses, it is assumed that the failure load is directly related to a 'crushing strength' of the ice cover. However, observations in the field and tests in the laboratory show that in some instances the ice cover fails by buckling. This report reviews the ice force analyses based on the buckling failure mechanism and points out their shortcomings. The report then presents a new method of analysis which is based on the buckling mechanism
    Type of Medium: Series available for loan
    Pages: iv, 13 S. : Ill.
    Series Statement: CRREL Report 78-15
    Language: English
    Note: CONTENTS Abstract Preface Introduction and statement of problem Review of relevant analyses and tests Determination of the largest ice force on an isolated structure Preliminary remarks The buckling analysis of a floating wedge Proposed method to determine Literature cited ILLUSTRATIONS Figure Structures which constrain the movement of the ice cover Ice cover constrained by two parallel rigid walls Analytical model used by Kheishin Observed crack patterns for different shapes of model pier Floating truncated ice wedge Critical buckling loads for floating wedge
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  • 7
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/5
    In: CRREL Report, 78-5
    Description / Table of Contents: The viscoelastic deflection of an infinite floating ice plate subjected to a circular load was solved, assuming the Maxwell-Voigt type four-element model. An effective method of numerical integration of the solution integrals was developed, of which each integrand contains a product of Bessel functions extending to infinity. The theoretical curve was fitted to the field data, but the material constants thus found varied with time and location.
    Type of Medium: Series available for loan
    Pages: iii, 32 S. : zahlr. graph. Darst.
    Series Statement: CRREL Report 78-5
    Language: English
    Note: CONTENTS Abstract Preface Introduction The problem The solution Method of numerical integration Ramp/steady loading Curve fitting to time lapse deflections Asymptotic deflection Deflection profiles Acknowledgement Literature cited Appendix I. Analytical background Appendix II. Computer programs, ramp time profiles and steady time profiles ILLUSTRATIONS Figure Maxwell-Voigt type four element model Definition of the ramp/steady loading Distributed load test by Frankenstein Concentrated load test by Frankenstein Comparison of the calculated curves and measured points of Frankenstein’s con-centrated load test Elements of TE The TE of Frankenstein’s distributed load test The TE of Frankenstein’s concentrated load test Graphs of asymptotic integral Kin (6.4) Deflection profile Asymptotic deflection profile Contour of integrations (B.5) and (B.6) TABLES Table Material constants found by using the time-lapse curves of Frankenstein’s distributedload test Material constants found by using the time-lapse curves of Frankenstein’s con-centrated load test Final time of the three tests
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  • 8
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-78/2
    In: CRREL Report, 78-2
    Description / Table of Contents: Many of the technical questions relating to iceberg transport are given brief, but quantitative, consideration. These include iceberg genesis and properties, the mechanical stability of icebergs at sea, towing forces and tug characteristics, drag coefficients, ablation rates, and handling and processing the iceberg at both the pick-up site and at the final destination. In particular the paper attempts to make technical information on glaciological and ice engineering aspects of the problem more readily available to the interested planner or engineer. Specific conclusions include: (1) No unprotected iceberg, no matter how long or wide, would be likely to survive the ablation caused by a long trip to low latitudes. (2) Icebergs that have a horizontal dimension exceeding 2 km may well be prone to breakup by long wavelength swells. (3) To avoid the dangers associated with an iceberg capsizing, the width of a 200-m thick iceberg should always be more than 300 m. (4) For towing efficiency the length/width ratio of a towed iceberg should be appreciably greater than unity. (5) For a pilot project, the selected iceberg would have to be quite small, if for no other reason than the practical availability of tug power.
    Type of Medium: Series available for loan
    Pages: v, 31 S. : Ill., graph. Darst.
    Series Statement: CRREL Report 78-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sources and properties of tabular icebergs Sources Characteristics of ice shelves near the ice front Characteristics of tabular icebergs Towing Geophysical and engineering considerations Tug characteristics Handling and processing Cutting and boring with thermal devices Penetration with electrothermal devices Electrothermal cutting Making vertical cuts by pre-split blasting Primary fragmentation by blasting Primary fragmentation by mechanical sawing Comminuting ice with machines Slurry pipelines Conclusion Literature cited ILLUSTRATIONS Figure Map of the Antarctic showing the location of the major ice shelves Temperature profiles from Antarctic ice shelves Depth-density profiles of Antarctic ice shelves Representative porosity and specific permeability profiles for Antarctic ice shelves Representative effective thermal conductivity and uniaxial compressive strength pro­ files for Antarctic ice shelves Iceberg sightings from 1773 to 1960 Mean distance between icebergs versus distance from the coast of East Antarctica Iceberg counts made by ship’s radar in the Weddell Sea in February 1977 Histograms showing the freeboard and lengths of icebergs studied by Nazarov Histograms showing the widths of Antarctic icebergs as observed from Landsat imagery Histogram showing observed length to width ratios for Antarctic icebergs Tabular iceberg in the Weddell Sea with horizontal dimensions of approximately 1x6 km The top of a tabular iceberg in the Weddell Sea Crevasses in a tabular iceberg in the Weddell Sea that have apparently been widened by wave action Tabular iceberg in the Weddell Sea View of the sides of a tabular iceberg in the Weddell Sea A small tabular iceberg in the Weddell Sea showing a raised wave-cut terrace on the right and a submerged wave-cut terrace on the left Close-up of the wave-cut terrace shown in the right-hand portion of Figure 18 Plot of the change in the freeboard to thickness and draft to thickness ratios with a change in the total thickness of Antarctic shelf icebergs The factor [1 + (A£/£)]2 which gives the adjustment for the presence of wave terraces as a function of £/A£ Acceleration and deceleration curves for an iceberg 1600x400x200 m assuming a form drag coefficient of 0.6, and that the towing force is that required to achieve a steady state towing velocity of « 0.5 m /s Plot of installed power versus displacement tonnage for a wide range of existing tugs Rated bollard pull versus installed power for a wide range of existing tugs Assessed value of existing tugs plotted against tonnage Assessed value of existing tugs plotted against installed power Shear strength of bonded snow versus density Power density versus maximum penetration rate for thermal coring or cutting
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  • 9
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-77/31
    In: CRREL Report, 77-31
    Description / Table of Contents: Ten roofs in Concord, New Hampshire, were surveyed for wet insulation using a hand-held infrared camera. Suspected wet areas were marked on the roof with spray paint and roof samples were obtained to verify wet and dry conditions. Recommendations for maintenance and repair were made based on infrared findings, water contents, and visual examinations. An incremental economic study is presented to serve as a guide in determining the most cost-effective approach.
    Type of Medium: Series available for loan
    Pages: v, 29 S. : Ill., graph. Darst.
    Series Statement: CRREL Report 77-31
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors: US, customary to metric (SI) units of measurement Introduction Infrared camera Core samples StateHouse State House Annex State Library Legislative Office Building Public Health Complex Highway Garage FishandGameOfflces Supreme Court John 0. Morton Building Department of Health and Welfare Laboratory Economics of roof reinsulation Conclusions and recommendations Literature cited ILLUSTRATIONS Figure AGA Thermovision 750 camera system CRREL roof sampler was used to obtain 3-in-diam cores of membrane and insulation Thermogram of dark rectangular area, State House Plan view of State House roof Thermogram showing mottled appearance of the State House Annex roof Photograph of the area shown in Figure 5 Plan view of the State House Annex roof Outline of bright rectangular anomaly showing sample locations 0 and P Ice ½ in. thick was present under the membrane at point 0 Flashing split circled in white spray paint Damaged parapet wall counter flashing Cracked bitumen in a pitch pocket surrounding a vent pipe Thermogram of egg-shaped anomaly on the State House Annex roof Thermogram showing a portion of the only dark area on the State Library roof 815. Plan view, State Library roof The area outlined in spray paint appeared darker than all other portions of the State Library roof The spray painted area coincided with the area on which frost formed The dry brittle membrane was easily damaged during spudding of gravel Large blisters on the State Library roof Skylight caulking needs repair Mastic between the pieces of metal fascia has been split by thermal movements of thefascia, Legislative Office Building Plan view of the Highway Garage roofs
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  • 10
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    Series available for loan
    Hanover, NH : U. S. Cold Regions Res. and Eng. Laboratory
    Call number: ZSP-201-77/26
    In: CRREL Report, 77-26
    Type of Medium: Series available for loan
    Pages: viii, 26 S. : graph. Darst.
    Series Statement: CRREL Report 77-26
    Note: CONTENTS Abstract Preface List of symbols Summary Introduction Recent ice research in Denmark General Structures with vertical faces Wedges with inclined faces Recording of the strength of natural ice Artificial ice — properties and manufacture General Composition of material Order of mixing ingredients Rupture theory Theoretical approach Initial contact Forces acting on wedge Maximum force and actual force Principal stress equations 8Dynamic equations Intermittent nature of force Theoretical curve Verifiction of theory by model tests Description Width of rupture channel Plotting of results Engineering application Comparison with Korahavin’s results Recommendations for future research References Appendix A ILLUSTRATIONS Figure Grading diagram of granulate of plastic described in this report Setting time of plaster of Paris for various salt solutions
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