We start at Baker Street in Central London. Whilst the 'Met Line' actually starts at Aldgate in the City we will start at Baker St as it is where the Met becomes a line in it's own right with the line south being shared with the other sub-surface lines. (I may cover the rest of the line later as a bonus)
Baker Street is probably best known internationally for the 1978 song of the same name and as the home of the fictitious detective Sherlock Holmes. The detective's address, 221b is in fact not a real one however it has been adopted by the Sherlock Holmes Museum near the station, making it the only out of order address in London. Just across the Street itself is TFL's famous lost property office that displays long lost items in the windows Just next door is Baker Street station, the oldest underground station in the world, the original platforms being those used by the Circle and Hammersmith & City Lines. Aside from the Metropolitan it is also served by the Bakerloo and Jubilee Lines. As a interesting side note the Jubilee line north of here was originally part of the Bakerloo and the connection still exists under the station. It is unknown if or why this link has ever been used. The Met line platforms reflect the current service pattern with two through platforms where trains often wait to proceed onto the busy inner circle line . Either side of the through platforms are the bay platforms creating a island platform style arrangement. The two bay platforms are the terminus of most Watford trains as well as some other services in the peak. It was proposed that an expansion of this station would become the terminus of the Great Central Railway but after the falling out the Great Central built their own terminus at Marylebone. The 4 tracks then merge into two heading towards Finchley Road. This is a long stretch of tunnel where trains get to high speeds. The line briefly surfaces to cross the Regent's canal, running parallel to the line out of Marylebone. The entrance to Lord's tunnel can briefly been seen on the left hand side of the train when travelling northbound. Between Baker Street and Finchley Road there are three abandoned stations, Swiss cottage (separate from the Jubilee line station), Lords to serve the cricket ground and Marlborough Road The stations closed in 1940 and 1939. Side note: I suspect Marlborough Road is the inspiration for the scene in Skyfall (2012) where James Bond discovers that an encrypted file on the villan's computer is a map of tunnels under London, Spotting 'Granbourgh Road' which he calls "an old tube station on the Metropolitan line". Granbourgh Road was in fact a real station on the Metropolitan Railway near Verney Junction in deepest Buckinghamshire however calling it a tube station is a stretch. It is likely that the writers mixed up Granborugh Road and Marlborough Road.
On the approach to Finchley Road, The Jubilee line tunnels can briefly been seen on the right hand side heading northbound. Finchley Road has two island platforms with the Metropolitan line tracks on the outside and the Jubilee in the middle. The line continues in this arrangement until Wembly Park. Since 1933 the Met line has run fast through the now Jubilee line stations until Wembly Park. (although Met line services continues until 1950). Some Met line trains however did run over the Jubilee line calling all stations However this ceased in the mid 2000s when the Jubilee line was re-signalled making it incompatible with the A-stock trains on the met. I have heard that Some Met line trains stopped at stations such as Neasden where the platforms on the Met line tracks are still in place but I can't find Strong evidence of this. From just after Finchley Road the alignment is shared with the two track Chiltern mainline from Marylebone to Birmingham (we will cover this line in more detail later). Branching off this line is the Marylebone-Aylesbury line (see below). The Jubilee line leaves the Metropolitan and heads off to Stannmore at Wembly Park. Wembly is a huge interchange designed to handle crowds from Wembly Stadium. Curiously Chiltern trains on the Ayelsbury line do not and never have stopped here which seems strange considering the stations importance. However it could be argued that Wembly is already well served by Chiltern services at Wembly Stadium Station on the other side of the stadium. Special services are put on on event days however as someone who has left from this station at 11 o clock at night after a Coldplay concert I can tell you it gets incredibly incredibly busy despite being the 3rd most important station serving the stadium. That being said the crowd control by British Transport Police and Chiltern staff is phenomenal. Wembly is one of few places (that I can tell) where the Jubilee line is physically connected to the Met. The reason for this is access to the shared Neasden depot where you can occasionally see old stock and maintenance trains parked up in sidings as well as a few other unusual features on the tube such as a train washer and even a level crossing.
Wembly Park: N Chadwick- geograph
From Wembly park the line continues north with a similar tack arrangement. Although the Jubilee line tracks have gone the Fast tracks have emerged on either side. They are used by fast and semi-fast trains to avoid Northwick Park and Preston Road. These two stations are almost identical both having island platforms. In between the two stations The line crosses the West Coast Mainline and Watford DC lines which includes the Lioness line and the Bakerloo line. From Northwick Park the distinctive chimney at Northwick Park hospital towers above the suburban skies. The line then goes into a series of complex junctions that allow access from any of the approach lines to the 6 platforms at Harrow on the Hill. it should also be noted that it is here that Chiltern services to Ayelsbury stop running on separate lines and run on the Metropolitan line. This highly unusual practice of running Mainline trains over a Metro line would be unheard of in many countries however in London it is done in a few places such as on the District line from Wimbledon to Putney where Southwestern Railway empty coaching stock moves (and one timetabled passenger service) run fast over the line using the 4 rail system slightly modified to allow 3 rail trains to use it. another place is on the Bakerloo line between Queens park and Harrow and Wealdstone (technically this is the other way around since Network Rail own this line and Underground trains run over it). Near moor park track-side signs are visible marking the boundary of Network Rail and London Underground track. Chiltern trains are fitted with London Underground tripcock safety systems to allow them to run on LU track. The platform on the south side of the station (the northbound Chiltern line) is occasionally used by Met line trains however the southbound is not as electrification only reaches the south end of the platform meaning that a Met line train could hypothetically run into the southbound platform from the north but would then have to reverse out the same way. The platforms at Harrow are very well arranged with this being the junction with the Uxbridge line cross platform interchange is utilised. North of the station are yet more complex junctions to allow the Uxbridge line to branch of whilst the fast tracks move from being on either side of the slow to being both on the side of the North (down) slow.