After three years of subterranean drilling, the £14.8billion project to transform London's rail network has tunnelled out just five of the 26 miles it will eventually cover.
These incredible pictures show the immensity of the task faced by engineers revamping the capital's creaking transport infrastructure.
The workers are overshadowed by the vast tunnels being drilled for the new Crossrail route.
The project, which is due to open in 2018, will pass through 37 stations and increase London’s rail capacity by 10 per cent.
Subterranean world: Workers appear tiny compared to the vast tunnel being drilled at Whitechapel Station in London
Boring machine: Tunnelling machine 'Sophia' at Crossrail's Plumstead site
Five huge tunnelling machines are now in operation in west, east and southeast London with more than five and a half miles of tunnels now built.
A further 7.5 miles of platform tunnels are also being bored beneath central London station sites.
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Tunnelling work is continuing around-the-clock beneath the capital and later this year two tunnelling machines will pass through the 34.5 metre deep Stepney Green shaft, one of Europe’s largest underground caverns.
Crossrail is an £14.8billion travel infrastructure project that is projected to improve rail links in the capital
Tunnellers: Workers at Canary Wharf (left) and Stepney Green shaft (right)
Monolith: A tunnelling machine at Crossrail's Western tunnels site
Andrew Wolstenholme, Crossrail’s chief executive said: 'With over 5.5 miles of tunnels now completed Crossrail is making good progress in delivering a tunnelling marathon beneath the streets of London.'
According to its website, Crossrail will support regeneration across the capital and shorten journey times, with economic forecasts suggesting the project will add up to £42billion to the UK economy.
New Crossrail stations are being built through the central section of the route at Paddington, Bond Street, Tottenham Court Road, Farringdon, Liverpool Street, Whitechapel, Canary Wharf, Custom House and Woolwich.
Around 200 million passengers will travel on Crossrail each year and station platforms will be 250m in length to accommodate the 200m trains that will pass through each station, as well as enabling longer 240m trains to operate in the future as passenger demand increases.
Crossrail claims the project will add up to £42billion to the UK economy
Shaft: The massive project aims to reduce journey times and increase the capital's rail capacity
A map showing the areas Crossrail will serve. It is expected to put a further 1.5 million people within 45 minutes of central London
THE REBIRTH OF LONDON'S RAILWAYS: CROSSRAIL BY NUMBERS
42 billion - Forecasted pounds the project will bring to the UK economy
14.8 billion - Cost of the project in pounds
200 million - Passengers will travel on Crossrail each year
1.5 million - Additional people that will be within 45 minutes commuting distance of London
2018 - The year it will be open, with completion in 2019
980 - Tonnes each tunnel boring machine (TBM) weighs
20 - Crew work with each TBM
250,000 - Concrete segments will be used to line the tunnels
10 - The percentage increase to rail capacity in the capital
5 - TBMs now in operation in west, east and southeast London