Commuters caught their first glimpse of the giant structure last week after Network Rail's latest major engineering feat to ease the first piece of the bridge into place to complete the next phase of the station's £850m upgrade.
Contractors spent two nights using hydraulic strand jacks to inch it 28m (19.62 yards), from a construction base north of the station to its place straddling relief tracks, at 3.30am on Sunday, July 8.
The work was completed with four says to spare before suspension of all track engineering until after the Olympics.
Company project director Bill Henry said: "The first part of the new bridge makes a dramatic difference to Reading's skyline and gives passengers a glimpse of how the new station will look when the first phase of the development is opened in May 2013."
When complete the structure will be three times larger than the current passenger bridge and will be linked to new platforms with lifts and escalators. The second and third sections will be constructed on the site before being joined up within the next 12 months.
The upgrade - due to be completed a year ahead of schedule in 2015 - will double the station's capacity and features five new platforms, improved signalling and overhead lines for electric trains.
Contractors are building a new train care depot off Richfield Avenue and will build a viaduct parallel with Loverock Road to filter express trains from slower freight services. The southern Cow Lane bridge was widened at Christmas and the northern one will be widened by 2015 to allow buses and taller vehicles to pass underneath.
Brian Fisher, from principal contractor Costain, said: "We're very proud of what we have achieved on this flagship project. Our work is proceeding steadily to ensure the project continues to run like clockwork."
First Great Western managing director Mark Hopwood said: "We've worked hard with Network Rail to minimise disruption to our customers throughout this project, and they should be commended for completing this challenging piece of engineering work without impacting our services."
To see a time lapse video of the bridge being slid into place see http://youtu.be/i_ACAJm3r2I