Introduction<\/strong><\/p>\n In this article we examine the Lotus Mk.VI with special reference to the chassis.<\/p>\n \n Editor\u2019s photograph of Lotus MK.VI taken whilst at Caterham Cars showroom.<\/em><\/p>\n This article performs four significant roles:-<\/p>\n In a serious study of Chapman there is a considerable risk that the student can easily be subsumed in sophisticated science based design calculations .This can block a wider appreciation that Chapman was a considerable conceptual engineer [and Industrial Designer] and that much of the success of his design was adherence to first principles even when production economies would suggest cheaper alternatives although he was totally pragamtic around this and there are many instances where cost\/performance were weighed towards\u00a0 cost saving.<\/p>\n Therefore the editors believe it essential to grasp these first principles. Many textbooks assume level of knowledge and this can compromise a holistic appreciation. \u201cThe Automobile\u201d by Singh Reyat the editors have found extremely useful and covers the mechanical subjects applicable to Chapman design methodology. We paraphrase much of his outline of these fundamental principles.<\/p>\n To date the editors have discussed Chapman\u2019s transition from trials to track in dedicated articles covering the trials cars [Austin Seven Special, Mk\u2019sII, IV and last Trials] and the 750 Formula sports car, the Mk.III. The Mk.VI holds an important role between these and the advanced aerodynamic sports racing cars to follow. There are important technological, commercial and competition dimensions to understand relating to the Chapman\u2019s designs and products. We hope to draw out these and relate them to his products and estimate their significance in the marques development.<\/p>\n Subscribers will find the following A&R articles relevant and integrated with this piece:-<\/p>\n The diagrams provided are illustrative and intended to provide guidance. It\u2019s appreciated that not all subscribers\/ students can access illustrative material and it\u2019s hoped these diagrams will assist in conceptualizing the subject.<\/em><\/strong><\/p>\n Definition of the automobile<\/em><\/strong><\/p>\n \u201cAn automobile is a self-propelled vehicle which is used for the transportation of passengers and cargo over the ground\u201d<\/p>\n Fundamental requirements of the automobile are:-<\/em><\/strong><\/p>\n The fundamental parts of the automobile are:-<\/em><\/strong><\/p>\n Power to weight ratio<\/strong><\/p>\n \u201cThe performance of an automobile much depends on its ratio of power to weight. By keeping the weight down\u00a0 to a minimum and installing engines of higher bhp , the best performance can be achieved \u2026\u2026\u2026.better its climbing abilities, the higher its maximum\u00a0 speed\u00a0 and better its acceleration\u2026\u2026\u2026. A well designed streamlined car having a high power to weight ratio registers a low fuel consumption at a given speed\u201d<\/p>\n Chassis Theory<\/strong><\/p>\n Taken from the net:<\/p>\n The main functions of a frame in motor vehicles are: [1]<\/a><\/sup><\/p>\n These include:<\/p>\n Suspension Theory and Practice<\/strong><\/p>\n This article concentrates on the chassis. In follow up we will examine the suspension arrangements of the Mk.VI in greater detail.<\/p>\n However in relation to suspension and handling it\u2019s important to note that Chapman saw the performance and handling of his designs holistically and primarily as a function of the chassis.<\/p>\n Production cars often adopted the single plane chassis for simplicity, cost etc. Often the overall performance did not warrant a sophisticated design. In such cars the chassis often flexed in use and this in turn impacted negatively on the handling .In an extreme the chassis twisted and in the process strove to steer the vechicle.This obviously has implications for handling, performance, predictability and safety.<\/p>\n Chapman understood this requirement and the Lotus Mk.VI chassis was designed not to flex or bend and thus improve performance.<\/p>\n Design Precedents and Influences<\/strong><\/p>\n We know that Chapman read and researched widely. This directly supported his experience and feedback .In this section we examine some of proven designs that Chapman might have drawn upon. These do not diminish Chapman. From our Design Heroes series we note the constant creative mutation of technologies and materials and in fact how they are effectively reinvented to perform additional purposes. The very act of conceptual design is recognizing the potential within.<\/p>\n The multi tube chassis as we will note was neither new nor totally originated by Chapman. However what he significantly did was cast it into an affordable, democratic available structure that permitted low cost racing on scientific design principles.<\/p>\n Aviation Precedents<\/strong><\/p>\n By the time that the Mk.VI was conceived Colin Chapman was a pilot. He had flown both at university and briefly at the RAF.<\/p>\n From interviews and records we are aware he read widely and absorbed colossal amounts of scientific and engineering material. What\u2019s possibly more important is that he sought to make this knowledge malleable and put it in the service of his designs.<\/p>\n The main structural requirements of aircraft are that they should be lightweight but be able to withstand flight loads, landing loads and a wide range of vibration. In the aircraft structural members are designed to carry load or resist stress. In most cases the structural members are designed to carry end loads rather than side loads i.e. to be subject to tension or compression rather than bending .Ever part of the aircraft must be planned to carry the load imposed upon it.The determination of such loads is called stress analysis.<\/p>\n Within aeronautical engineering and commercial operation lightness is of considerable benefit. Aeronautical engineering therefore produced design philosophy directed towards maximum lightness, the most suitable materials and construction techniques available.<\/p>\n One of the great aircraft designers [Ed Heinmann] is attributed of saying:-<\/p>\n \u201cSimplicate and add lightness\u201d<\/em><\/p>\n Many of the principles of aeronautical engineering like structural are based on Newton\u2019s laws.<\/p>\n When Chapman was conceiving his cars the Second World War was recently ended. Britain had won the war because of many factors not least the science focused disciplines and particularly the quality of the military aircraft.<\/p>\n Chapman would have been aware of this and the examples we believe he might have most appreciated are highlighted here.<\/p>\n Vickers Wellington<\/em><\/strong><\/p>\n This British aircraft made a significant contribution during the Second World War. It\u2019s believed it was designed by Rex Pierson and Barnes Wallis.<\/p>\n From the dedicated Barnes Wallis web site:<\/p>\n \u201cAround this time, Wallis hit upon a revolutionary structural idea \u2013 rather than building an aircraft structure on the principle of a beam, which supports an external aerodynamic skin, he developed a new type of structure which had the structural members formed within the aerodynamic shape itself. This required the structural members to follow the curved outer shape of the fuselage and wings. These members followed geodesic curves in the surface, the shortest distance between two points in the curved surface \u2013 this gave the new structure its name, geodetics. By having the curves form two helices at right angles to one another, the geodetic members became mutually supporting, and the overall framework became immensely strong. In addition to being comparatively light and strong, the fact that the geodetic structure was all in the outer part of the airframe meant that the centre was a large empty space, ready to take payload or fuel.<\/p>\n The fuselage was constructed of a geodesic metal lattice which proved extremely strong and light.\u201d<\/p>\n The design proved an excellent load range to power \u2013ratio.<\/p>\n An example can be seen at the Brooklands Museum, London.<\/p>\n Hurricane, c 1935<\/em><\/strong><\/p>\n It\u2019s believed that the Hawker Hurricane was designed by Sidney Camm.<\/p>\n The primary structural design principle was based on the Warren truss box girder which formed the primary fuselage. See details of Warren Truss used in civil engineering below.<\/p>\n A truss is a rigid framework made up of members such as beams, struts and bars to resist deformation by applied loads. The truss frame fuselage is generally covered in fabric. The truss frame itself is usually constructed of steel tubing welded together in such a manner that members of the truss can carry both tension and compression loads, this type of fuselage normally also has triangular\u00a0 cross\u00a0 bracing .It is based on geometrical form.<\/p>\n See details below.<\/p>\n Automobile Precedent\u2019s<\/strong><\/p>\n The editors provide very brief details permitting subscribers to conduct their own detailed research and comparisons.<\/p>\n Cistalia and Cistalia GP<\/em><\/strong><\/p>\n Two Cistalia are believed to have adopted a space frame chassis: the front engine racing car and the much more advanced and sophisticated Cistalia-Porsche GP 360 designed by Ferry Porsche c 1947-49.This was mid-engine single seat racing car.<\/p>\n Mercedes Benz 300 SLR<\/em><\/strong><\/p>\n \u201cThe Mercedes-Benz 300 SL was one of the first road going cars to be fitted with a high performance chassis .The aim behind its design was to produce an extremely fast touring car\u00a0 with luxurious appointments , and for structural reasons it was decided to use a space frame chassis\u201d<\/p>\n Buckminster Fuller\u2019s Dymaxion cars<\/em><\/strong><\/p>\n Subscribers are directed direct to our dedicated article on Buckminster Fuller in our Design Heroes series. Buckminster Fuller drew up plans for the \u201c4D\u201d Auto [airplane c 1928] and later Dymaxion cars. These were based on aircraft practice and included triangulated space frame chassis and his sketches clearly indicate the tubular frame in three dimensional form proposed.<\/p>\n Jaguar C-Type<\/em><\/strong><\/p>\n From the net<\/p>\n The Jaguar C type used for racing adopted a space frame chassis as opposed to the conventional ladder chassis used on the production road cars. From the net:<\/p>\n Specification<\/strong><\/p>\n The road-going XK120\u2019s 3.4-litre twin-cam, straight-6 engine produced between 160 and 180 bhp (134 kW). The version in the C-Type was originally tuned to around 205 bhp (153 kW). Later C-Types were more powerful, using triple twin-choke Weber carburettors and high-lift camshafts. They were also lighter, and from 1952 braking performance was improved by disc brakes on all four wheels. The lightweight, multi-tubular, triangulated frame was designed by Bob Knight.[1] The aerodynamic body was designed by Malcolm Sayer. Made of aluminium in the barchetta style, it was devoid of road-going items such as carpets, weather equipment and exterior door handles.<\/p>\n The editors deliberately mention the Jaguar as it was British. It would have received considerable publicity and was raced shortly before the Lotus Mk.VI.Its important to study he chassis in some detail and appreciate the car was being raced with an engine almost 3 times the size of the Lotus Mk.VI.<\/p>\n Civil \/Structural Engineering precedents<\/strong><\/p>\n We must note that Colin Chapman qualified in engineering. He might not have been the most dedicated of students and possibly did not wish a career in structural or civil engineering. However he would have completed the syllabus and absorbed all the principles and fundamentals. [One of the most important applications was the Warren Truss \u2013 see below] Significantly he would understand the vocabulary of the discipline and been able to converse with other engineers.<\/p>\n Structural and civil engineers although primarily concerned with utility, function, performance and economy often appreciate that these qualities are the basis of aesthetics.<\/p>\n Colin Chapman had finely attuned aesthetic sensitivities applied to engineering problems.<\/p>\n Structural theory<\/strong><\/p>\n Taken from the net:<\/p>\n Structural engineering depends upon a detailed knowledge of loads, physics and materials to understand and predict how structures support and resist self-weight and imposed loads. To apply the knowledge successfully structural engineers will need a detailed knowledge of mathematics and of relevant empirical and theoretical design codes. They will also need to know about the corrosion resistance of the materials and structures, especially when those structures are exposed to the external environment.<\/p>\n The criteria which govern the design of a structure are either serviceability (criteria which define whether the structure is able to adequately fulfill its function) or strength (criteria which define whether a structure is able to safely support and resist its design loads). A structural engineer designs a structure to have sufficient strength and stiffness to meet these criteria.<\/p>\n Loads imposed on structures are supported by means of forces transmitted through structural elements. These forces can manifest themselves as tension (axial force), compression (axial force), shear, and bending, or flexure (a bending moment is a force multiplied by a distance, or lever arm, hence producing a turning effect or torque).<\/p>\n Warren Truss<\/strong><\/p>\n From the net:<\/p>\n The Warren truss was patented in 1848 by its designers James Warren and Willoughby Theobald Monzani, and consists of longitudinal members joined only by angled cross-members, forming alternately inverted equilateral triangle-shaped spaces along its length, ensuring that no individual strut, beam, or tie is subject to bending or torsional straining forces, but only to tension or compression. Loads on the diagonals alternate between compression and tension (approaching the center), with no vertical elements, while elements near the center must support both tension and compression in response to live loads. This configuration combines strength with economy of materials and can therefore be relatively light. The girders being of equal length, it is ideal for use in prefabricated modular bridges. It is an improvement over the Neville truss which uses a spacing configuration of isosceles triangles.<\/p>\n A preserved original Ansaldo SVA aircraft, showing the Warren truss-pattern interplane wing strut layout<\/p>\n Warren truss construction has also been used in airframe construction for aircraft since the 1920s, mostly for smaller aircraft fuselages, using chrome molybdenum alloy steel tubing, with popular aircraft such as the Piper J-3 Cub. One of the earliest uses for the Warren truss in aircraft design was for the interplane wing strut layout, as seen in a nose-on view, on the Italian World War I Ansaldo SVA series of fast reconnaissance biplanes, which were among the fastest aircraft of the First World War era. Warren truss construction is still used today for some homebuilt aircraft fuselage designs that essentially use the same 1920s-era design philosophies in the 21st century.<\/p>\n Design<\/strong><\/p>\n \n The integral members of a truss bridge<\/p>\n The nature of a truss allows the analysis of the structure using a few assumptions and the application of Newton\u2019s laws of motion according to the branch of physics known as statics. For purposes of analysis, trusses are assumed to be pin jointed where the straight components meet. This assumption means that members of the truss (chords, verticals and diagonals) will act only in tension or compression. A more complex analysis is required where rigid joints impose significant bending loads upon the elements, as in a Vierendeel truss.<\/p>\n In the bridge illustrated in the infobox at the top, vertical members are in tension, lower horizontal members in tension, shear, and bending, outer diagonal and top members are in compression, while the inner diagonals are in tension. The central vertical member stabilizes the upper compression member, preventing it from buckling. If the top member is sufficiently stiff then this vertical element may be eliminated. If the lower chord (a horizontal member of a truss) is sufficiently resistant to bending and shear, the outer vertical elements may be eliminated, but with additional strength added to other members in compensation. The ability to distribute the forces in various ways has led to a large variety of truss bridge types. Some types may be more advantageous when wood is employed for compression elements while other types may be easier to erect in particular site conditions, or when the balance between labor, machinery and material costs have certain favorable proportions.<\/p>\n The inclusion of the elements shown is largely an engineering decision based upon economics, being a balance between the costs of raw materials, off-site fabrication, component transportation, on-site erection, the availability of machinery and the cost of labor. In other cases the appearance of the structure may take on greater importance and so influence the design decisions beyond mere matters of economics. Modern materials such as prestressed concrete and fabrication methods, such as automated welding, and the changing price of steel relative to that of labor have significantly influenced the design of modern bridges.<\/p>\n Note that Isambard Kingdom Brunel adopted this method in his Royal Albert Bridge [see A&R article] and the Forth Bridge.<\/p>\n The 1172 Formula<\/strong><\/p>\n Students will not be able to grasp the fullest appreciation of the Lotus Mk.VI without first understanding the 1172 Formula .We therefore direct subscribers to our dedicated article.<\/p>\n Chapman was an active member of the 750Motor Club that sponsored and generated this formula. It was intended and structured to generate close affordable racing that invited innovation .Chapman had raced the Lotus Mk.III in the 750 Formula and had possibly gone beyond the spirit. In the Lotus Mk.VI he applies considerable care to ensure compliance and the editors believe it was an enormous competition and commercial success as a result.<\/p>\n The 1172 Formula was based on using the Ford side valve components from their utilitarian models dating from the 1930\u2019s.<\/p>\n Understanding Chapman and the Lotus Mk.VI: First Principles<\/strong><\/p>\n Colin Chapman trained and qualified with BSc in engineering. The discipline teaches students to adopt fundamental design criteria \/methodology that includes:-<\/p>\n Colin Chapman therefore approached the problem with considerable holistic conceptual appreciation .Foremost in his mind would be:-<\/p>\n Form and Function of the Lotus Mk.VI<\/strong><\/p>\n In the editors mind the Lotus Mk.VI chassis is a beautiful object in its own right. It possesses a classical architectural order, hierarchy and evident, logical self-articulation.<\/p>\n Throughout there is a logical of multi-use of components.[note other schools of design thought sought to give each function and dedicated perfect separate component]<\/p>\n The editors suggest subscribers might like to look at period photographs of the chassis body-unit .Sources include:-<\/p>\n \u201cThe Lotus\u201d\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Autosport\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2\/10\/1953<\/p>\n \u201cThe Lotus Chassis\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Road & Track\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 June, 1953<\/p>\n Lotus\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Sunburst\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1995<\/p>\n In addition cutaway drawings are also extremely useful. The most obvious being featured in \u201cThe Lotus Project\u201d [see details above]<\/p>\n Other drawings are available on the net.<\/p>\n \n \n \n This image is of model the editor constructed using an artist\u2019s mannequin to illustrate form and function. It\u2019s recommended this is seen in context of text and other diagrams provided.<\/p>\n \n This illustrative diagram is not drawn to scale but is hoped indicates the 3 D nature of the multi-tube chassis.<\/p>\n Chassis: Weights & Measures<\/strong><\/p>\n The Lotus Mk.VI is extremely objective and lends itself to vigorous analysis. Not only is it beautiful; it is extremely elementary and capable of very accurate formal structural analysis.<\/p>\n We have noted that in fact the multi-tube arrangement forms when clad with the stressed aluminium panels a chassis-body unit [CBU]<\/p>\n \u201cThe Lotus Project\u201d article September 25th<\/sup>, 1953 observed:-<\/p>\n \u201cThe frame structure is of the multi tubular construction braced and strengthened by flat alloy panels riveted to the main lower tubes 1.7\/8th<\/sup> inch x 18 SWG while the upper ones are 1 inch round and square of the same thickness is employed\u201d<\/p>\n The weight of this in period has been quoted as:-<\/p>\n Autocar \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 25\/9\/1953\u00a0\u00a0\u00a0\u00a0\u00a0 63 lbs.<\/p>\n Autosport*\u00a0\u00a0\u00a0\u00a0 2\/10\/1953\u00a0\u00a0\u00a0\u00a0\u00a0 55lbs\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 90lbs [with all brackets & stressed panels<\/p>\n 120 lbs. with standardized bonnet etc.<\/p>\n *\u201dThe Lotus Project\u201d written by John Bolster.<\/p>\n This article also features a significant photograph of Bolster holding the claimed 90 lb. CBU.<\/p>\n Another photograph that underscores this fact appears in \u201cLotus Seven and Caterham\u201d by Morland which features a photograph with the caption:-<\/p>\n \u201cLotus 6 chassis held by ace Lotus 6\/7 restorer Mike Brotherwood.This demonstrates how light the chassis construction is\u201d<\/p>\n In his text he refers to the chassis as weighing 55 lbs. with main tubes of 17\/8th<\/sup> dia. and 18 g. [90 lbs. with stressed panels]<\/p>\n More recently Kelsey in a magazine article [Thoroughbred and Classic Cars, 1994] quoted that:-<\/p>\n \u201cI experimented with making the chassis lighter by using 20 gauge tube instead of 18 gauge , and 16 gauge sheet instead of 10 for various brackets and components and eventually got down to 36 lbs. for a complete chassis\u201d<\/p>\n The Mk.VI is extremely amenable to forensic analysis.<\/p>\n Many technical publications including Costin & Phipps provide statistics on typical tube weight comparisons.<\/p>\n Examples are:-<\/p>\n Dia or section sq. \/ [in] Profile Sq. \/round Wall thickness \/SWG gauge Weight lb. per ft.<\/p>\n 1\u201d\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Round\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 18\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.488<\/p>\n 1\u201d\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Square\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 18\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.643<\/p>\n 1 3\/4\u201d\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Round\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 18\/16\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.90\/1.15<\/p>\n 2\u201d\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Round\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 18\/16\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1.00\/1.32<\/p>\n Comparable material weights are given in lbs. \/cu ft.<\/p>\n Aluminium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 161<\/p>\n Steel\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 490<\/p>\n Magnesium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 114<\/p>\n Carbon fibre moulding\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 95<\/p>\n Kevlar moulding\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 90<\/p>\n Metal comparison in sheet form [lb. \/wt. per sq. ft.]<\/p>\n SWG\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Magnesium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Aluminium\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Steel<\/p>\n 16\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.73\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1.02\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 3.13<\/p>\n 18\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.54\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.76\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 2.23<\/p>\n 20\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.41\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 0.57\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 1.75<\/p>\n Using this data and the known measurements of the chassis is relatively easy to calculate chassis weights. The chassis is symmetrical in the main and this aids the speed of the exercise.<\/p>\n![\"Mk](\"http:\/\/colinchapmanmuseum.org.uk\/wp-content\/uploads\/2015\/07\/Mk-IV-e1436974499479.jpg\")
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