Engineering, General; Preface; This volume contains the papers presented at the 3rd International Symposium on Multi-body Dynamics: Monitoring and Simulation Techniques. The papers were chosen from a number of submissions made, reviewed by a panel of learned referees and members of the Organizing Committee in a rigorous and fair manner. The quality of the papers are very high, contributing to advancement of knowledge, as well as maintaining the high quality of the Symposium. We would like to thank all the contributors, as well as the members of the Organizing Committee and the learned reviewers. In particular, sincere thanks are extended to the Keynote Speakers, Professors Werner Schiehlen and Ahmed Shabana, and Doctors Gothard Rainer and Heinz Foellinger, for their outstanding contributions to the Symposium. We were all honoured by the presence of the Symposium's Guests of Honour. Firstly, Professor Duncan Dowson (CBE, FRS, FREng) who gave the opening address, and presented our esteemed colleague, Professor Schiehlen, with commemoration for his long standing and significant contributions to the field. Secondly, Professor Richard Parry-Jones for his enlightening speech at the Gala Dinner, held at the Prestwold Hall, Leicestershire. We were also delighted to have many participants from among the members of the Editorial Board of the Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics, particularly Professor Nicolae Orlandea, the Associate Editor and a leading light in the field. The organization of such successful events often requires dedicated and hard working administrative staff, who on this occasion have also dealt with a sizeable exhibition from many leading industrial concerns, logos of many of whom appear on the back-cover of this volume. Sincere thanks are, therefore, due to Jackie Baseley and Christine Biggs. From the outset, in 1997, the Symposium has enjoyed the sponsorship of the Institute of Measurement and Control, for which the Organizing Committee are most grateful. The same is also extended to other co-sponsoring Professional Institutions. The presentation, publication, and dissemination of the Proceedings are a major professional achievement. This task has been carried out from the outset (on three occasions) by the team at the Professional Engineering Publishing. We are very grateful for their painstaking thoroughness, particularly on this occasion by Lynsey Gathercole, Sheril Leich, and Jo Oxford. Homer Rahnejat and Steve Rothberg MBD-MST 2004