Mechanical Equipment in Antarctica and The Relation of Laboratory Research to Field Performance by D.L. Pratt M.A., A.M.I.Mech. E. Thesis submitted for the degree of Doctor of Philosophy in the Faculty of Engineering the University of London Department of Engineering, Imperial College of Science and Technology, London, S.W.7. June, 1960. ABSTRACT In the summer of 1957-1953 a vehicle journey was made for the first time across the Antarctic Continent, from the 'ieddell Sea to the Ross Sea, a distance of 2,158 miles. The mechanical engineering aspect of that project forms a large part of the field work of this thesis. The performance of polar vehicle journeys in the past is reviered and requirements for mechanical equipment are assessed. In view of the unknown conditions to be encountered an operational specification temperature of -60°F with storage to -90°F was chosen. An investigation into the main factors affecting performance led to preparatory laboratory research into the fields of : Engines and Lubrication (Startability; economy and altitude performance) Materials (Ferrous; nort4errous; elastomers) Snow Traction and Friction. A theoretical analysis indicated that cranking torque was proportional to the product of cranking speed and oil viscosity. However, the proving of startability appeared essential and the cold clamber was extensively used. Compromise field trials in Norway, together with laboratory research formed a basis for engineering planning and development. The Antarctic field results are analysed under the headings : Terrain Snow Traction and. Friction Engines and Lubrication Materials (Field. Fractures) Human. Snow friction experiments were performed for man-hauling and vehicle sledges and also aircraft on ski. The results form a basis for a proposed mechanism in which there is a mixture of solid and fluid friction. The fluid friction varies between the limits of solid, boundary and hydrodynamic friction and the relationship of the proportion of this friction to the solid friction was shown to depend upon speed, temperature, pressure, material and snow type. Additional laboratory research carried out after the expedition included a clinical examination of a Sno-Cat and ancillary equipment, investigations into the a.c. heating of alkaline batteries and an analysis of used lubricants and carbon deposits. Gear ripple appearing on a Sno-Cat hypoid gear led to the programme of research recorded in the Appendix. Investigations into extreme pressure lubrication and discoveries concerning year phenomena associated with additive oils and a four ball machine are discussed. Gear tooth micro-hardness traverses and X-ray analysis appear to confirm the discovery of a subsurface hardness increase as being due to a martensite transformation. By use of Microscope and Talysurf, controlled wear mechanisms for two additive oils are shown to exist. A mechanism for gear ripple is proeosed and further work suggested. This thesis aims to advance general knowledge of the behaviour and suitability of mechanical equipment for Antarctic conditions and to relate laboratory research to field performance. ACIU101; MEM This thesis and the laboratory work on return from the field has been carried out under the supervision of Professor Hugh Ford without whose promotion this work would not have been undertaken and to whom the author wishes to record his deep gratituaP for many hours of stimulating discussion and guidance. Be thanks Dr. A. Cameron, Mr. N.P.W. Moore and Dr. P.L. Pratt for most useful discussion in their specialised fields. The ninety-six Engineering Organisations who gave so generously of their resources gives some indication of the debt owed to those who so readily proffered their support. The author 'Ashes to express particular thanks to The British Oxygen Company, The British Petroleum Company, The British Welding Research. Association, The Department of Engineering, Cambridge Univers- ity, C.A.V., Eikmaskin, Norway, F.V.R.D.E., i.r.v., I.C.I., Joseph Lucas Ltd., Massey Ferguson Ltd. and S. Smith and Sons Ltd., for their outstanding co-operation. The Finance Committee of The Trans-Antarctic Expedition lent their support for the major period during which the work was undertaken and for this generosity the author acknowledges his thanks. To the leader, Sir Vivian Fuchs, and members of The Trans- Antarctic Expedition, the author expresses his appreciation of their patience and efforts in the care and handling of mechanical equipment. Special mention is due to Assistant Engineer, Howard for his hard work and competence in the field. Particularly to Sir Vivian, the author would like to express appreciation of his trust in delegating the engineering responsibilities and it was with real pleasure that he served, in the field, as a member of his team. Finally, to Imperial College, the author is indebted for the opportunity provided to carry out research in a field so little penetrated by this country. CONTENTS Introduction 1 Chap. I. ANTARCTICA Geography 3 Climate 3 Trans-Antarctic Expedition Project 5 Chap. II. HISTORICAL ANALYSIS 8 Chap. III. ASSESSMENT OF REQUIREMENTS 30 Operational requirements 31 Diesel versus Petrol 33 Air cooling versus liquid cooling 35 Choice of Vehicles 35 Chap. IV. PREPARATORY LABORATORY RESEARCH - ENGINES AND LUBRICATION 39 Startability 39 Cranking Torque 40 Engine Lubrication Batteries 4-9 Fuel 51 Ec mow Performance 52 Altitude Performance 54 Cold Chamber Experiments 58 Transmission Lubrication 67 Field Trials in Norway 70 Chap. V. PREPARATORY LABORATORY RESEARCH - MATERIALS , 73 Materials at Low Temrratures 73 Ferrous Metals 73 Non-Ferrous Metals 79 Elastomers 80 Chap. VI. PREPARATORY LABORATORY RESEARCH - SNOW TRACTION AND FRICTION 83 Snow 83 Traction 83 Friction 87 Chap. XII. CONCLUSIO:T 166 A1' :IDIX GEAR =TIE 172 Four Ball Experiments using Extreme Pressure Lubricants A and B. 175 Four Ball Tests using Maximum Load 180 !.tedium Load Tests 3.EA. Discussion and Conclusions relative to the Experimental Work an Oils A and B. 185 Ilypoid Gear 187 Spiral Bevel Gear 189 Austenite Martensite Transformation and Micro-Hardness Invectif;ation. 193 Hardness 196 X-Ray Diffraction Analysis 199 Required Stresses for Transformation 200 Discussion 201 Conclusion 206 Sugestions for Further ',iork 208 BIBLIOGRAPHY 209 1. INTRODUCTION Nan's attack upon unknown terrain is a two phase operation. The first phase is one of exploration, which consists of reconnaissance and discovery. The second phase is one of exploitation and development. The Antarctic remains in the first phase. This continent, largely unexplored, presents immense political, economic and scientific possibili- ties. Terrain, climate and distance have in the past retarded progress. Nevertheless much valuable work has been slowly accomplished, often under conditions of extreme hardship. The machine age has come slowly to the Antarctic, but with the advent of both ground and air transport a thorough reconnaissance of the interior can be attempted. In 1955, a continental traverse sus planned by Sir Vivian Fuchs, leader of the Trans-Antarctic Expedition. The project to be carried out during 1957-1958 with the dual objective of exploration and scientific research. To carry the necessary weight of equipment for the scientific pro- grammes and especially that of the seismic traverse, vehicles were essential. Inland, operational conditions were unknown and suitable specifications and equipment for operation were not available. SuccessfUl accomplishment placed dependence upon mechanical equipment and thus research and develop- ment programmes were instigated and carried out as thoroughly as time would permit. Preparatory field trials in the Antarctic were not practicable, but 2. compromise field trials were possible in Norway and these with pertinent literature surveys enabled engineering planning, laboratory research and testing to proceed. This Thesis describes the work done in these various aspects, aims to advance general knowledge of the behaviour and suitability of mechanical equipment for very cold conditions and translate laboratory findings into practical terms. Chap. I. 3. ANTARCTICA GEOGRAEHY Some six million square miles of territory, locked in an ice age, lie between the latitudes of 60° and 90° South, cut off from the rest of the world by the Antarctic Ocean and a fringe of pack ice. This Antarctic region consists or a huge inland plateau of rolling snow desert between 9,000 and 13,000 feet high. Here and there mountain peaks pierce the plateau snow fields. These extend in parts to a thickness of over 8,000 feet. From the inland ice sheet, glaciers of immense proportions force their way slowly down into the sea and as these glaciers flow around and aver mountain ranges, giant rifts and crevasses form, making much of the country impassable to present means of surface travel. The interior of the continent supports no animal or bird life. These exist only in the barren coastal areas where there is abundant marine life upon which they can survive. Along the coast, large sections of still floating ice shelf aggravated by the forces of wind and tide, break away to form tabular bergs, some of which have been observed aver ninety miles in length. Whether this territory is a continent or an archipelago is not yet known, since the ice dome obliterates these features. This mass of perhaps four million cubic miles of ice has a strong influence on the weather systems emanating into the Southern hemisphere. CLIMATE Overall snow precipitation in the past has exceeded evaporation and Chap. I. Antarctica. 4. resulted in this immense ice sheet. This mass of ice acts as a refrigerator which in conjunction with the high plateau causes a general system of katabatic winds modified by local topography. The supercooled air meeting warmer moist air from the sea causes the well known severe weather conditions of the Antarctic seabord and explains the extraordinary rates of change in temperature and wind, and resulting low percentage of available working days. On the plateau, it is reasonable to expect that there is a region of high pressure, caused by the intense cold which flows to the low pressure belt encircling the continent.