On Thu, 30 Jul 2009 12:12:51 -0700 (PDT), Andy wrote:

The same is true with the LM Desiros, although the wait is normally so
long that people remove their finger!! The 'rules' on LM state that
the conductor must open their door first to check the position of
train in the platform, hence the delay. I don't know why this rule has
come in, as it certainly adds to the overall journey time without any
major safety advantage over the conductor 'knowing' the train and
platform length from memory.

It's completely ineffective half the time anyway, because at many
stations the platform curves away and at least one end of the train
cannot be seen, so the guard has to rely on this 'knowing' anyway.