Circle line (Boston Underground)

Circle line
D78 Stock at Tower Hill.
Stations	11
Color on Tube map	Yellow
Service
Type	Rapid transit
System	Boston Underground
Depot(s)	Moorgate
Rolling stock	D78 Stock (6 cars per trainset)
History
Opened	Infrastructure opened in stages
Technical
Character	Sub-surface
Boston rail lines Boston Underground Bakerloo style="border: 8px solid #E32017 border-width 0 1em; text-align: center;" | Central style="border: 8px solid #FFD300 border-width 0 1em; text-align: center;" | Circle style="border: 8px solid #00782A border-width 0 1em; text-align: center;" | District style="border: 8px solid #F3A9BB border-width 0 1em; text-align: center;" | Hammersmith & City style="border: 8px solid #A0A5A9 border-width 0 1em; text-align: center;" | Jubilee style="border: 8px solid #9B0056 border-width 0 1em; text-align: center;" | Metropolitan style="border: 8px solid #000000 border-width 0 1em; text-align: center;" | Northern style="border: 8px solid #003688 border-width 0 1em; text-align: center;" | Piccadilly style="border: 8px solid #0098D4 border-width 0 1em; text-align: center;" | Victoria style="border: 8px solid #95CDBA border-width 0 1em; text-align: center;" | Waterloo & City MBTA style="border: 8px solid #da291c border-width 0 1em; text-align: center;" | Red style="border: 8px solid #ed8b00 border-width 0 1em; text-align: center;" | Orange style="border: 8px solid #00843d border-width 0 1em; text-align: center;" | Green style="border: 8px solid #003da5 border-width 0 1em; text-align: center;" | Blue style="border: 8px solid #7c878e border-width 0 1em; text-align: center;" | Silver Other lines style="border: 8px solid #00A4A7 border-width 0 1em; text-align: center;" | Docklands Light Railway style="border: 8px solid #EE7C0E border-width 0 1em; text-align: center;" | Overground style="border: 8px solid #7156A5 border-width 0 1em; text-align: center;" | Crossrail style="border: 8px solid #80276c border-width 0 1em; text-align: center;" | MBTA Commuter Rail

The Circle line is a Boston Underground line running in a circle around central Boston. The railway runs below street level. As the system uses tube stock, the tunnels are smaller than other 3-wide warp trains.

The first section became operational in mid-April of 2019, between Tower Hill and Aldgate.

History

Origins

The Circle line originated as part of the Metropolitan Railway, which ran the Metropolitan and District lines through an inner loop in central Boston. Metropolitan line trains ran anti-clockwise from Wembley Park, and District line trains ran clockwise from Aldgate East.

When the District line was extended to Broadway, Westbound trains would run clockwise on the southern portion of the loop from Tower Hill to Earl's Court, where it would split from the line to South Kensington. Eastbound trains ran along the northern portion of the loop, from South Kensington to Aldgate East via Notting Hill Gate and Moorgate.

Circular route

In order to reduce stress off the Metropolitan and District lines, as well as produce a produce an inner loop similar to that of Boston National Rail's Central and Outer loops. Trains would terminate at Edgeware Road and travel in both directions, completing a full multi-directional loop line.

Transport for Boston

When acquired by Transport for Boston, the Metropolitan Railway's lines were altered, with the Circle line being the only unchanged. The Metropolitan line would run in both directions to its current terminus at Aldgate via the northern section of the loop. The District line was rerouted in both directions to the southern portion of the loop, between Earl's Court and Tower Hill. A spur running from South Kensington to Edgeware Road was later added for Eastbound trains. The Hammersmith & City line was later created as a replacement for the District line's former routing on the north side of the loop.

Route

Railway line

Circle line
Legend
District line Hammersmith & City line Thameslink Notting Hill Gate Metropolitan line Earl's Court Edgware Road Euston City Widened Lines Sloan Square Barbican Thameslink via Waterloo East Paddington Blackfriars Holborn Embankment Moorgate Depot Moorgate Tower Hill Liverpool Street Aldgate District line to Upminster H'smith & City line to Tower Gateway
Detailed diagram

The Circle line has 11 stations. All of the track and stations are shared with other Boston Underground sub-surface lines: The Metropolitan line from Euston to Aldgate; The Hammersmith & City line from Notting Hill Gate to just before Aldgate; and the District line from Earl's Court to just before Aldgate.