The purpose of 5AT Project is to design and build the first new "new generation" steam locomotive incorporating the best engineering principles while retaining the fundamental characteristics of Stephenson's original concept. The locomotive will incorporate technologies that have been tried and tested in various latter-day locomotive rebuilds, including those developed by Chapelon, Porta, Wardale and others. However this will be the first new locomotive to be designed and built to incorporate these developments. As such, its performance, range, reliability and safety will far exceed the highest standards achieved during the "golden" years of steam, despite the fact that almost all the "new" technologies that will be incorporated in the 5AT were available, or could have been realised, during steam's heyday.

The ideas underlying the 5AT project are many and varied, depending on the person expressing them, but as with all steam projects, they are centered on that indefinable love of steam that has been the foundation of the railway preservation movement. This project, however, has nothing to with preserving the past; it looks entirely to the future and towards an enduring future for steam traction.

The broad aims of the project can be summarised as follows:

1. To demonstrate what steam locomotion could have achieved if greater attention had been paid to the developments in engineering and science that were available during steam's heyday.
2. To produce a locomotive that can travel at adequate speed, over sufficient distance and demonstrating adequate reliability while hauling a commercially viable payload, to ensure the continuation of main-line steam operations in the coming era of higher speed trains and higher track utilization.
3. To produce a financially viable operating plan for the locomotive capable of generating adequate rates of return to warrant commercial funding for the venture, and to justify the construction of additional locomotives to the same design.
4. To set standards for steam locomotive operation that befit the 21st century, and thereby establish a basis for future development of the technology and perhaps the construction of new locomotive designs to meet any future needs or a changing world.
5. To maintain an interest in, study of, and perhaps even a love of, steam traction amongst future generations of children, students and engineers.

Technically there is nothing about this project that cannot be achieved using available engineering technology. Indeed, the steam preservation movement has demonstrated time and again that nothing is impractical let alone impossible when it comes to restoring the most complex of locomotives, or building them from new. Construction of the 2-cylinder "5AT" 4-6-0 locomotive will be technically simpler than construction of the new 3-cylinder A1 Pacific, or the rebuilding the Caprotti-valved Duke of Gloucester.

The Business Plan for the project suggests that commercial viability is not only possible, but is practically achievable. The engineering expertise is available and ready to be put into action. The project costs are relatively small by railway investment standards. The non-financial rewards may be unexpectedly large in terms of recognition, kudos and good will.