Fast down the local lines

Hi all, my first post under this username although I did briefly contribute to this forum around 10/11 years ago under the name ‘Metrolander’.  I occasionally ‘lurk’, more so recently, and note that most of the more regular contributors are still familiar names from all those years ago, which is a good sign, as I always found the forum to be such an amazing resource for the sorts of details and insight which so many of us find intriguing.

Anyway, a recent experience travelling on the Met Line has given me cause to ask a question, as it reminds me of something I’m sure was discussed in a thread I looked at many moons ago, namely, what the usual practice is regarding trains running through platforms in service.  As I’ve had to wait for admin approval, I no longer have the exact specifics but on Friday 27th August, I was waiting at HOTH, travelling to Watford having arrived there from Ruislip.  The DMI on platform 3 initially showed a Watford train as arriving first, but then the display changed to a Chesham Fast.  I actually wondered if this meant I would be able to use the old trick of overtaking an all stations Watford between HOTH and Moor Park… however… to my surprise shortly after leaving HOTH (somewhere around 1745), we did not switch over to the fast line. The Train Operator made a PA which wasn’t fully audible but which did mention travelling up the local lines, and this is what we did.  Now, I mentioned above that I have a distant recollection of a thread which covered questions about speed etc when non-stopping a platform, and it’s testing that recollection somewhat but I think Chiltern through Moor Park was discussed, as was the comparative complete crawl through Mornington Crescent, which was closed for some time when I began using the Underground myself in the mid 90s.  It was this recollection which led me to groan somewhat, presuming that even without actually stopping, our passage down the local line would be anything but fast. Turns out, I was wrong! Again, the intervening time period means I don’t recall precisely, but I can do so sufficiently to recount that we didn’t noticeably slow through the stations.

So, I have two questions, firstly, how unusual is this sort of situation? I know that things have been somewhat compromised service-wise recently, so presume that the likelihood of unusual occurrences is somewhat increased.  I am by no means a frequent user of the Underground but have lived at the further reaches of the Met for most of my life, and never known of this before.  Conversely, back in the days when Amersham services always went fast, I can remember numerous instances of them arriving on the usual Watford platform at Moor Park.

Secondly, are there specific practices for running through stations in traffic hours? As I mention, I’m sure I recall that Northern Line trains would have to slow as if stopping at Mornington Crsecent all those years ago, whereas of course Chiltern trains pass through Moor Park apparently at line speed (I know there are far more recent examples of trains passing through closed stations by the way, but the Mornington Crescent memory is vivid as most of my early Underground trips involved visiting Camden Town). I also wonder if the situation is any different at stations/platforms where all trains typically stop, as in the case of North Harrow-Northwood.  I know that the RAT and other Engineering/Departmental trains pass through platforms in traffic hours, but I’ve never seen those going that fast!

Many thanks