The first tunnel in the Crossrail development has been completed.

A 1,000 tonne drilling machine finished its 6.8 km journey from Royal Oak to Farringdon, commemorating 18 months of tunnelling.

It marks significant progress in the scheme, with around 25 km of the 42 km of new tunnels already constructed.

Commercial secretary to the Treasury Lord Deighton said: "Big projects bring big rewards and Crossrail is another excellent example of the UK delivering on time and on budget to create world-leading infrastructure that will drive our economy."

Even though current routes are not expected to open until 2018, some groups are already calling for expansion, while plans are also underway for Crossrail 2.

Most recently, shadow infrastructure minister Lord Adonis gave his support for extending the development to Reading - it currently stops at Maidenhead.

When it opens, Farringdon station will be a key location with connections to three major airports. Over 140 trains an hour, including 24 Crossrail services during peak times, will pass each hour and 150,000 people will use it daily.