Technical Feasibility of a Two-Cylinder Entablature Steam Engine with a Parallel Motion Crosshead: An Analysis from Mechanical Engineering

Abstract

In this research, we present the results of analyzing the technical feasibility of an old invention by Henry Muncaster from the perspective of mechanical engineering, specifically focusing on the resistance of materials. The invention is a two-cylinder steam engine with a parallel motion crosshead, for which plans were published in the Model Engineer magazine in 1957. This complex device, composed of 76 elements and lacking descriptive information, has been the subject of a recent article that illustrated its design through the engineering drawing discipline and a 3D CAD model. To provide reliable information and conduct a comprehensive study of its technical feasibility, an extensive linear static analysis was performed. This analysis considered two critical positions of the piston inside the cylinder: upper dead center and lower dead center. We determined the optimal range of working pressures necessary to achieve a safety factor within the optimal design range of two to four. The results include von Mises stresses, displacements, and safety factor distributions, confirming that the optimal working pressure range for steam intake is between 1.885 and 3.550 MPa. This ensures that the safety factor values remain between 2.01 and 3.78.