Cause and Effect

How a series of small incidents can cascade to a major failure situation

The two papers listed were obtained from the on-line Transco library (now National Grid) and are all available for public inspection

They are the reports of two completely separate major failures of the 400kV 'supergrid' supply that occurred in 2003 and are a classic example of how several small incidents can cascade to a major problem.

Note the similaries between each event:
- Equipment out of commission for regular servicing
- A failure that would normally have passed without incident
- A fault that remained unnoticed until it was triggered by other events

London 28 August 2003 - This was the widely publicised event that knocked out the Tube at rush hour and left commuters stranded

Hams Hall 5 Sept 2003 - Less well-known, similar set of causes just a few days later

The National Grid Co. site gives access to many interesting papers on electricity generation and bulk distribution. Look particularly at the "Key Documents" section.