Categories of SPAD
There are a number of ways that a train can pass a signal at danger without authority, and in the UK these fall into four basic categories;
- A Category A SPAD is where the signalling equipment was working properly, but the train passed the signal at danger even though there was adequate opportunity for it to stop.
- A Category B SPAD is where the signal reverted to danger in front of the train due to an equipment failure or signaller error, and the train was unable to stop before passing the signal.
- A Category C SPAD is where the signal reverted to danger in front of the train due to an emergency, and the train was unable to stop before passing the signal.
- A Category D SPAD is where the train ran out of control and could not be stopped from passing a signal at danger.
Read more about this topic: Signal Passed At Danger
Famous quotes containing the words categories of and/or categories:
“Kitsch ... is one of the major categories of the modern object. Knick-knacks, rustic odds-and-ends, souvenirs, lampshades, and African masks: the kitsch-object is collectively this whole plethora of “trashy,” sham or faked objects, this whole museum of junk which proliferates everywhere.... Kitsch is the equivalent to the “cliché” in discourse.”
—Jean Baudrillard (b. 1929)
“The analogy between the mind and a computer fails for many reasons. The brain is constructed by principles that assure diversity and degeneracy. Unlike a computer, it has no replicative memory. It is historical and value driven. It forms categories by internal criteria and by constraints acting at many scales, not by means of a syntactically constructed program. The world with which the brain interacts is not unequivocally made up of classical categories.”
—Gerald M. Edelman (b. 1928)