What is the principal reason for maintaining a boiler plant log book?

The principal reason for maintaining a boiler plant log book is to provide a record of boiler operation and maintenance. This documentation is crucial for several reasons. It serves as an official record that details the day-to-day operations, which can include parameters such as temperature, pressure, water levels, fuel consumption, and any unusual occurrences or maintenance performed.

By having a detailed log, operators can track performance trends, identify issues before they develop into serious problems, and manage the maintenance schedules effectively. Additionally, in the event of an accident or operational failure, the log book provides a vital reference that can help in investigating the cause and ensuring compliance with regulatory standards. This record also supports continuous improvement in operational practices by providing data that can be analyzed over time.

In contrast, aspects like satisfying the Boiler Inspector or the chief engineer may be secondary benefits of maintaining the log but do not encompass the primary purpose of ensuring safe and efficient boiler operation through proper documentation. The notion that the log could provide the operator with an alibi is not a legitimate function of the log book and does not contribute to the safety or reliability of the boiler operation.