Question:  Doncaster iPort is connected to the rail network through the main line that is what length?

Context paragraphs:
High-speed rail in Europe: High-speed rail is emerging in Europe as an increasingly popular and efficient means of transport.  The first high-speed rail lines in Europe, built in the 1980s and 1990s, improved travel times on intra-national corridors.  Since then, several countries have built extensive high-speed networks, and there are now several cross-border high-speed rail links.  Railway operators frequently run international services, and tracks are continuously being built and upgraded to international standards on the emerging European high-speed rail network.  In 2007, a consortium of European railway operators, Railteam, emerged to co-ordinate and boost cross-border high-speed rail travel.  Developing a Trans-European high-speed rail network is a stated goal of the European Union, and most cross-border railway lines receive EU funding.  Several countries — France, Spain, Italy, Germany, Austria, Sweden, Belgium, the Netherlands, Russia and the United Kingdom — are connected to a cross-border high-speed railway network.  More are expected to be connected in the coming years as Europe invests heavily in tunnels, bridges and other infrastructure and development projects across the continent, many of which are under construction now.  Alstom was the first manufacturer to design and deliver a high speed train or HS-Train, which ended up in service with TGV in France.  Currently, there are a number of high-level manufacturers designing and building HSR in Europe, with criss-crossed alliances and partnerships, including Canadian company Bombardier, Alstom itself, the Spanish Talgo and the German Siemens.

Rail transport in Israel: Rail transport in Israel includes heavy rail (inter-city, commuter, and freight rail) as well as light rail.  Excluding light rail, the network consists of 1001 km of track, and is undergoing constant expansion.  All of the lines are standard gauge and as of 2016 the heavy rail network is in the initial stages of an electrification programme.  A government owned company, Israel Railways, manages the entire heavy rail network.  Most of the network is located on the densely populated coastal plain.  The only light rail line in Israel is the Jerusalem Light Rail, though another line in Tel Aviv is currently under construction.

London Victoria station: Victoria station, also known as London Victoria, is a central London railway terminus and connected London Underground station in Victoria, in the City of Westminster, managed by Network Rail.  The main line station is a terminus of the Brighton main line to and and the Chatham main line to and Dover via .  From the main lines, trains can connect to the Catford Loop Line, Dartford Loop Line, and the Oxted line to and .  Southern operates most commuter and regional services to south London, Sussex and parts of east Surrey, while Southeastern operates trains to south east London and Kent.  Gatwick Express trains run direct to Gatwick.  The Underground station is on the Circle and District lines between and , and the Victoria line between and .  The area around the station is an important interchange for other forms of transport: a local bus station is in the forecourt and Victoria Coach Station is nearby.

Doncaster iPort: Doncaster iPort or Doncaster Inland Port is an intermodal rail terminal; a "Strategic Rail Freight Interchange", under construction west of Rossington and south of Doncaster at junction 3 of the M18 motorway in England.  It is to be connected to the rail network via the line of the former South Yorkshire Joint Railway, and from an extension of the former Rossington Colliery branch from the East Coast Main Line.

JR Kobe Line: The JR Kobe Line (JR神戸線 , JR Kōbe sen ) is the nickname of portions of the Tokaido Main Line and the Sanyo Main Line, between Osaka Station in Osaka, Osaka Prefecture and Himeji Station in Himeji, Hyōgo Prefecture.  The line, along with the JR Kyoto Line and the Biwako Line, forms a contiguous service that is the main trunk of West Japan Railway Company's Urban Network commuter rail network in the Osaka-Kobe-Kyoto Metropolitan Area.  The line also offers continuous service to the Gakkentoshi Line via the JR Tōzai Line.  It was damaged during the 1995 Great Hanshin earthquake.

Carlingford railway line: The Carlingford railway line is a minor railway line in Sydney, Australia.  Opened in 1888, the line runs north-south between the suburb of Carlingford and the Main Suburban railway line at .  Passenger services on the line form part of the Sydney Trains commuter rail network and are marketed as the T6 Carlingford Line.  The railway line's small catchment, low patronage, short platforms and single track for much of its length mean the T6 generally operates as a shuttle service, with passengers changing at Clyde for T1 North Shore, Northern & Western Line services to the Sydney central business district and Parramatta.  Most of the line is planned for conversion to light rail as part of the Parramatta Light Rail network.  As a result, the line will permanently close.

Biwako Line: The Biwako Line (琵琶湖線 , Biwako-sen ) is the nickname used by the operator of the West Japan Railway Company (JR West) to refer to the portion of the Tōkaidō Main Line (between Maibara Station and Kyoto Station) and the Hokuriku Main Line (between Maibara Station and Nagahama Station).  The section, along with JR Kyoto Line and JR Kobe Line, forms a contiguous service that is the main trunk of JR West's "Urban Network" commuter rail network in the Osaka-Kobe-Kyoto Metropolitan Area.

Dublin–Westport/Galway railway line: The Dublin-Westport/Galway line is a major railway route from Dublin to the towns of Westport in County Mayo and Galway in County Galway.  The line is part of the greater intercity rail network formed by branches of the main line between Dublin and Cork.  The route to Westport and Galway branches away from the main line at Portarlington in County Laois and continues as far as Athlone in County Westmeath, where it splits again, with one branch to Westport and the other to Galway.

East Coast Main Line: The East Coast Main Line (ECML) is a 393 mi major railway link between London and Edinburgh via Peterborough, Doncaster, Wakefield, Leeds, York, Darlington and Newcastle, electrified along the whole route.  Services north of Edinburgh to Aberdeen and Inverness use diesel trains.  The main franchise on the line is operated by Virgin Trains East Coast.

Bell Bay Line: The Bell Bay Line is a freight rail corridor connecting the port of Bell Bay to the main rail network of Tasmania.  The Railway Line was built in 1973 to connect the Longreach sawmill to the rail network, and was extended to Bell bay in 1974.

Supporting paragraphs: Doncaster iPort East Coast Main Line
Answer: 393 mi