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  • 11
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-76/17
    In: CRREL Report, 76-17
    In: Mechanics of cutting and boring, (DE-B103)20210225152525
    Description / Table of Contents: This report, which is one of a series on the mechanics of cutting and boring in rock, deals with the kinematics of machines which utilize a continuous belt as the cutting unit (e.g. coal saws, shale saws, digger-chain trenchers). The discussion and analysis cover the geometry and motion of various components of the cutting system, including such topics as chipping depth, production and conveyance of cuttings, tool trajectories, tool speeds, tool angles, and arrangement of cutting tools on the belt. Worked examples are included to illustrate the application of various equations to practical problems
    Type of Medium: Series available for loan
    Pages: viii, 24 Seiten , Illustrationen
    Series Statement: CRREL Report 76-17
    Language: English
    Note: Contents Abstract Preface Summary Foreword Introduction Terminology Chipping depth Production and conveyance of cuttings Tool trajectories Tool speeds Tool relief angles — kinematic considerations Tool rake angles Belt curvature, slackness and flexibility Tool layout Longitudinal tool spacing Transverse tool spacing Cross-section profiles of the kerf Literature cited
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  • 12
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-77/19
    In: CRREL Report, 77-19
    In: Mechanics of cutting and boring, Part VI
    Description / Table of Contents: Abstract: The report deals with forces and power levels in cutting machines having adisc or drum that rotates about an axis perpendicular to the direction of advance. The forces on individual cutting tools are related to position on the rotor and to characteristics such as tool layout, rotor speed, rotor size, machine advance speed, and rotor torque. Integration leads to expressions for force components acting on the rotor axis, taking into account tool characteristics, cutting depth of the rotor, and rotor torque. These provide estimates of tractive thrust and thrust normal to the primary free surface. For self-propelled machines, this leads to considerations of traction, normal reaction, weight and balance, and power/weight ratios. Specific energy consumption is analyzed and related to machine characteristics and strength ofthe material being cut. Power per unit working area is discussed, and data for existing machines are summarized. Power requirements for ejection ofcuttings are analyzed, and the hydrodynamic resistance on underwater cuttings is treated. A number of worked examples are given to illustrate the principles discussed in the report.
    Type of Medium: Series available for loan
    Pages: vii, 36 Seiten , Illustrationen
    Series Statement: CRREL Report 77-19
    Language: English
    Note: CONTENTS Abstract Preface Foreword Introduction Terminology Forces on individual cutters Torque force and tool force Forces on the rotor axis Tractive thrust and down thrust Alternative tool force formulations Vehicle traction Power/weight ratio Weight and balance Force, torque, speed and power Specific energy Efficiency and performance index Power density Power requirements for ejection of cuttings Hydrodynamic resistance in underwater cutting
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  • 13
    Series available for loan
    Series available for loan
    Hanover, NH : Corps of Engineers, U.S. Army, Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-294
    In: Research report
    Description / Table of Contents: CONTENTS: Introduction. - Test materials. - Testing programs. - Test equipment. - Loading machine. - Environmental chamber. - Platen arrangements. - Stress/strain measurements. - Test procedures. - General. - Uniaxial compressive strength. - Diametral compression tests. - Stress/strain tests. - Test results. - Uniaxial compressive strength. - Brazil tensile strength. - Ring tensile strength. - Stress/strain characteristics. - Discussion. - Strength as a function of water content at room temperature. - Strength as a function of water content at -25°C. - Effect of temperature on the strength of nominally dry rocks. - Effect of low temperature on the strength of water-saturated rocks. - Effect of water on deformability at room temperature. - Deformability of air-dry rock as a function of temperature. - Effect of low temperature on the deformability of water-saturated rocks. - Conclusions and recommendations. - Literature cited. - Appendix A.Test materials for low temperature studies in rock mechanics. - Abstract.
    Description / Table of Contents: Strength tests were made on three types of rock, both "air-dry" and water-saturated, at temperatures from +25° to -195°C, and stress/strain tests were made down to -60°C. Strength of air-dry specimens increased with decreasing temperature at an average rate of approximately 2 x 10^-3 °C^-1, and quasi-elastic moduli increased at comparable rates. Static fatigue mechanisms in air-dry rock were apparently influenced by temperature-modification of adsorbed water. Strength of water-saturated specimens increased dramatically as pore water froze, and continued to increase down to -120°C, where compressive and tensile strengths were greater than room temperature values by factors of 5, 4 and 2 for sandstone, limestone and granite respectively. Compressive stress/strain curves for saturated rocks became steeper after freezing, and initial tangent moduli for saturated high porosity rocks increased by well over an order of magnitude.
    Type of Medium: Series available for loan
    Pages: v, 75 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 294
    Language: English
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  • 14
    Series available for loan
    Series available for loan
    Hanover, NH : Corps of Engineers, U.S. Army, Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-292
    In: Research report
    Description / Table of Contents: CONTENTS: Preface. - General introduction. - A. Pore water freezing data from differential thermal analysis. - Apparatus and technique. - Results. - Discussion. - Conclusions. - B. Indirect determination of pore water freezing data for rocks. - Air penetration tests. - Mercury penetration measurements. - Calculation of unfrozen water content and freezing point depression. - Comparison of calculated and measured freezing characteristics. - Conclusions. - C. Electrical conductivity measurements. - Procedures. - Results. - Discussion of results. - D. Thermal strains in cold rock. - Preliminary tests. - Recording dilatometer. - Test procedure. - Results. - Discussion. - Conclusions. - E. lsothermal compressibility of cold rocks. - Test method. - Test results. - Discussion of results. - Conclusion and recommendations. - General summary of results. - Literature cited. - Appendix A: Water adsorption. - Appendix B: Adsorption and absorption by Rochester shale. - Appendix C: Low temperature conductivity of saturated wood. - Abstract.
    Description / Table of Contents: The phase composition of pore water in three types of rock subjected to temperature below 0°C was explored by a variety of techniques. Freezing point depression was measured as a function of water content by differential thermal analysis, the results yielding relationships between unfrozen water content and temperature. In an effort to avoid the practical difficulties involved in differential thermal analysis, attempts were made to determine freezing characteristics indirectly by air penetration and mercury penetration techniques applied at ordinary room temperatures. Electrical conductivity measurements were made as a function of temperature down to -195° C in an attempt to obtain information on characteristics of interfacial water films at low temperatures. Thermal strain was measured as a function of temperature in order to detect direct mechanical effects associated with phase changes, chiefly strain discontinuities brought about by volume changes in the pore water during rapid freezing and thawing. Finally, isothermal compressibility measurements, with pressures up to 27 kb, were made at - 10°C so as to determine whether the rock underwent step changes in volumetric strain at pressures corresponding to those of the phase boundaries for ice polymorphs.
    Type of Medium: Series available for loan
    Pages: v, 61 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 292
    Language: English
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  • 15
    Monograph available for loan
    Monograph available for loan
    Washington : American Geophysical Union
    Associated volumes
    Call number: AWI G7-96-0035
    In: Antarctic research series
    Type of Medium: Monograph available for loan
    Pages: X, 277 S. : Abb. ; 27 cm
    Series Statement: Antarctic research series 2
    Branch Library: AWI Library
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  • 16
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    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 Seiten , Illustrationen
    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 milling 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
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  • 17
    Call number: ZSP-204-138
    In: CRREL Technical Report
    Type of Medium: Series available for loan
    Pages: v, 38 S. : Ill., graph. Darst.
    Series Statement: CRREL Technical Report 138
    Location: AWI Reading room
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  • 18
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-79/21
    In: CRREL Report, 79-21
    Description / Table of Contents: The report studies the question of whether Great Lakes freighters could move effectively through ice-clogged channels with the aid of tows provided by warping or kedging systems. Ten operational concepts are outlined, and their advantages and disadvantages are noted. The crushing resistance of floating brash ice is then analyzed. The neutral, active and passive states of stress for laterally confined brash ice are considered, and the resistance to horizontal thrusting by a smooth vertical wall is calculated for cohesionless brash ice, and for ice in which there is finite cohesion between the ice fragments. The thickening of the ice cover in the vicinity of a "pusher", and the formation of pressure ridges, are analyzed in order to estimate the amount of pile-up that can occur against a ship hull. The analysis then moves on to consideration of ship resistance by brash ice, taking into account crushing resistance at the bow, tangential friction at the bow, and hull friction aft of the bow section. Comparisons are made between thrust from the ship’s screws and the calculated ice resistance. The next section of the report estimates the force requirements for a warping or kedging system in terms of thrust augmentation for existing vessels. Tow cable requirements are given, and estimates are made for cable anchors and for anchorage of underwater structures. The force and power requirements for winches and windlasses are given, the practical problems involved in the pickup or transfer of cables are mentioned, and the report concludes with a brief appraisal. The conclusion is that a simple warping tug system is appropriate for a full scale experiment, a chain ferry with auxiliary barge seems attractive for an operational system, and a chain ferry plow may be an efficient way to clear ice from channels.
    Type of Medium: Series available for loan
    Pages: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 79-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Operational concepts A. Warping tug system B. Chain ferry system C. Chain ferry with auxiliary barge D. Ski tow system E. Dual winch warping system F. Simple kedging G. Trailing-line system H. Above-surface dual winch system I. Pulley systems J. Chain ferry plow Crushing resistance of fragmented ice covers Resistance to ship passage by broken ice Crushing resistance at the bow Tangential friction at the bow Hull friction aft of the bow section Total ship resistance from brash ice Comparison of ship thrust and ice resistance Force requirements for a warping or kedging system Tow cable requirements Anchors and anchorages Force and power requirements for winches and windlasses Pickup or transfer of cable General appraisal Literature cited
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  • 19
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/26
    In: CRREL Report, 81-26
    In: Mechanics of cutting and boring, Part 7
    Description / Table of Contents: Abstract: This report deals with force, torque, energy and power in machines such as drills and boring devices, where the cutting head rotates about a central axis while penetrating parallel to that axis. Starting from a cosideration of the forces developed on individual cutting tools, or segments of cutters, the thrust and torque on a complete cutting head is assessed, and simple relationships between thrust and torque are derived. Similarly, the energy and power needed to drive the cutting head arc estimated and related to tool characteristics. Design characteristics of existing machines are compiled and analyzed to give indications of thrust, torque, power, effective tool forces, nominal thrust pressure, power density, and specific energy.
    Type of Medium: Series available for loan
    Pages: iv, 38 Seiten , Illustrationen
    Series Statement: CRREL Report 81-26
    Language: English
    Note: CONTENTS Abstract Preface Foreword Introduction Terminology Tool forces Parallel motion tools Indentation tools Head thrust, thrust per unit width, and nominal head pressure Power and power density Torque Specific energy Efficiency and performance index Power requirements for clearance of cuttings Minimum power requirements for lifting cuttings in a vertical hole Power consumption and efficiency in continuous-flight augers Air circulation Mud circulation Literature cited Appendix A: Vertical conveyance by continuous-fiight augers Appendix B: Surface areas on a helical flight and its stem
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  • 20
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/17
    In: CRREL Report, 81-17
    Description / Table of Contents: Environmental conditions are described for the continental shelf of the western Arctic, and for the shelf of Labrador and Newfoundland. Special emphasis is given to the gouging of bottom sediments by ice pressure ridges and icebergs, and an approach to systematic risk analysis is outlined. Protection os subsea pipelines and cables by trenching and direct embedment is discussed, touching on burial depth, degree of protection, and environmental impact. Conventional land techniques can be adapted for trenching across the beach and through the shallows, but in deeper water special equipment is required. The devices discussed include hydraulic dredges, submarine dredges, plows, rippers, water jets, disc saws and wheel ditchers, ladder trenchers and chain saws, routers and slot millers, ladder dredges, vibratory and percussive machines, and blasting systems. Consideration is given to the relative merits of working with seabed vehicles, or alternatively with direct surface support from vessels or from the sea ice
    Type of Medium: Series available for loan
    Pages: 38 Seiten , Illustrationen
    Series Statement: CRREL Report 81-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction The western Arctic of North America The continental shelf of Newfoundland and Labrador Burial depth for pipes and cables Degree of protection offered by burial Environmental impact Trenching the beach and the shallows in the western Arctic Trenching beyond the shallows Suction, or hydraulic, dredging Bottom-t raveling cutterhead dredges Plows Rippers Water jets Subsea disc saws and wheel ditchers Subsea ladder trenchers and chain saws Subsea routers and slot millers Bucket ladder trenchers Vibratory and percussive devices Hard rock excavation under water Control and monitoring of subsea machines Vessels and vehicles Trenching from the sea ice Costs of subsea trenching Reference Appendix: Description of waters off Alaska and Newfoundland
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