Anomalies in Thermodynamics Draft Text Only – Readers’ suggestions and inputs are welcome Thermodynamics is not an easy subject to master and there are many instances where it defies intuitive judgement. The following examples are offered by way of enlightenment and perhaps education: Steam viscosity: it is intuitive knowledge that liquids become less viscous as […]
8ATT 2-8-4T Tank Locomotive The 8ATT 2-8-4 tank engine concept is another possibility for modern steam traction incorporating some of the AT (advanced technology) features of the 5AT. Whilst being similar in principle to 8AT conceptual design, the tank engine configuration, having no tender, is lighter and less costly than a tender engine. Furthermore, it […]
8AT 2-8-0 Locomotive The idea of developing a 2-8-0 version of the 5AT first arose in 2004 after the 5AT Group received an enquiry from a coal railway investment group in Indonesia who were seeking to procure a fleet of steam locomotives to operate their railway. Chris Newman, an engineer with experience in materials handling […]
Alternative Project Strategies The fundamental aim of the 5AT Project was to ensure the continuation of steam locomotive development. In preparing the Feasibility Study for the 5AT Project, the 5AT Group looked at several possible locomotive developments that might have evolved from the 5AT design. Perhaps the most immediately attractive of these was an 8AT […]
5AT Project Summary The background to the 5AT Project begins with the classic work of the French engineer André Chapelon (1892 – 1978) and the improvements he achieved in both the efficiency and performance of the steam locomotive. By taking a rational scientific approach to steam locomotive development Chapelon was able to incorporate improvements into rebuilds of existing […]
5AT Technical Specifications The 5AT technical specifications have been outlined by David Wardale as follows: Maximum axle load: 20 metric tons (same as BR Class 5MT). Engine weight in working order: 80 ~ 90 metric tons (the load on the leading bogie will be determined at the detail design stage, hence precise weight cannot now […]
Fundamental Design Calculations for 5AT Advanced Steam Locomotive Introduction: Funding was obtained at the start of the project for undertaking the Fundamental Design Calculations (FDCs) for the 5AT locomotive. This task was completed by David Wardale in 2004 after some two and a half years of work. It is instructive to read Dave Wardale’s summary […]
Engineering of the 5AT The 5AT Group included professional engineers with experience in designing, building, operating and maintaining steam locomotives. Until the suspension of the project, their efforts were directed at developing preliminary designs for the locomotive, including Fundamental Design Calculations, Detail Design and Engineering Drawing. Other aspects of the engineering effort undertaken in relation […]
Principles of Modern Steam Additional pages in this section have still to be compiled. Please contact Chris Newman at webmaster@5at.co.uk if you would like to assist by contributing text to any pages in this section or anywhere else on this website. Pages currently available in this section are: “Second Generation Steam” GPCS Combustion Air Preheating Porta’s Water […]
Modern Steam Miscellany This section includes miscellaneous pages relating to the broad subject of “Modern Steam”. It may later be expanded into a separate section if enough material is collected to warrant it. Currently the pages included are: SAR Class 26 4-8-4 The Red Devil SAR Class 19D 4-8-2 No 2644 The American Coal Enterprise’s […]
Twin Valves and Large Steam Chests Unusually if not uniquely, the 5AT will be fitted with twin valves above each cylinder combined with large volume steam chests. Valves must be sized to ensure that the total port area through which the steam flows into and out of the cylinders, is sufficient to keep pressure drops […]
Thermal Efficiency The “thermal efficiency” of any engine is defined as the amount of useful energy output divided by the amount of energy input . It is not a fixed quantum but varies according to the engine’s load and conditions of operation. Three types of efficiency are described here: Cylinder or Indicated Efficiency; Drawbar Thermal Efficiency; […]