Crossrail has started work at a rail underpass close to Acton Main Line station.

This will see 34,000 tonnes of earth removed so it can construct a dive-under, allowing trains from nearby Acton freight yard to pass without disturbing services from Acton Main Line.

Such cargo trains currently arrive and depart by crossing the mainline tracks used for passenger services. When the Crossrail service becomes active, the additional trains would have caused these delays to be more troublesome and disruptive.

Programme director for Crossrail Rob McIntosh said: "The new dive-under will ensure the activities of this important freight yard, which services the London network, are secured when the Crossrail services begin."

He said the dive-under was one of the most complicated structures in the development. It will be managed by Network Rail, as the organisation is responsible for the designs taking place on existing rail lines.

Earlier this month, Crossrail awarded construction firm Vinci and Balfour Beatty a £100 million contract to upgrade 13 stations from Acton Main Line to Maidenhead.

Work is expected to be ongoing until 2016 while Crossrail itself will be fully operational in 2019.