Howard P. Welz

Modular server frame with robust earthquake retention

Adequate retention of computer systems during earthquake events is important because it can not only prevent human injury and potential system damage, but also ensure system availability by limiting to acceptable levels the transmitted accelerations to critical system components such as hard drives. This paper discusses the design of an IBM frame structure and related hardware, and the retention methods used, to provide a robust mechanical installation in both raised- and nonraised-floor environments, capable of surviving severe seismic events. The development of the frame structure and the retention hardware involves extensive earthquake simulation testing, in which the responses of the system under different earthquake test profiles are recorded and analyzed in both the time and frequency domains. Industry standards such as the Bellcore NEBS GR-63-CORE and IBM internal specifications are reviewed and compared, and the transient responses of competing frame designs subjected to various earthquake profiles are investigated to ensure compliance. Finally, the concept of modular design, in which various frame components are utilized to create a flexible family of frames, is discussed.