The value of prototyping in train cab design

This paper draws upon the recent experience of developing trains for the UK rail network. The Hitachi Class 800/801 Intercity Express Train is to be put into service on the East coast and Great Western lines from 2017. An... [ view full abstract ]

This paper draws upon the recent experience of developing trains for the UK rail network. The Hitachi Class 800/801 Intercity Express Train is to be put into service on the East coast and Great Western lines from 2017. An existing Hitachi cab formed the starting point for the design. This was substantially modified by a multidisciplinary design team at DCA (involving designers, engineers, human factors professionals and modelmakers) working in close collaboration with the engineering team at Hitachi.

A wide range of prototyping techniques were employed throughout the projects in order to ensure the usability, feasibility and compliance of the design. These ranged from Computer Aided Design (CAD) models, to low-fidelity paper-based physical prototypes, right through to full-sized visually representative mock-ups. This paper will focus on these different approaches and discuss the individual merits of each. To communicate the approach, the development project will be divided into seven stages:

1. A review of all relevant standards and guidelines relating to human factors requirements and performance (e.g. PRM TSI, LOC & PAS TSI, Group standards, contractual documents) to extract key requirements
2. The development of additional requirements based on analysis of the train user population and the driving task (e.g. reach envelopes)
3. A desk-based assessment of initial train design using 2D drawings and 3D CAD models
4. The design, build and evaluation of low fidelity mock ups (spatial arrangements based on card and paper)
5. Evaluation of full-scale ergonomic mock ups (dimensionally accurate low-fidelity finish)
6. Evaluation of high-fidelity full-sized model (representative fit and finish)
7. Documentation of compliance.

The value of each of these prototype techniques will be discussed and explored along with their limitations. Practical examples will be shared of each of these. For example, the advantages of drawings will be discussed, in that they can be easily transmitted and modified. However, the limitation of scale and representation will also be raised – particularly when shared with stakeholders. Examples will be given of how drawings were judged to be sub-optimal; however, low-fidelity card mock-ups of the same design were liked.

Finally, the importance of visually representative mock-ups will be discussed in the context of stakeholder engagement, detailed simulated task assessments, and glare and lighting studies. Two new assessment approaches developed to assess the cab glare performance and the suitability of the cab against common driving tasks will be covered (published as journal papers). Along with a discussion of the role of more innovative tools such virtual reality headsets.