Great vibe outside Soldier Field this afternoon, ahead of the opening night of the tour in Chicago tonight. In fact great vibe in the city in general after yesterday's radio interviews, with acres of press coverage this morning and massed encampments of passionate fans at any and every place the band might be expected to show up.

Soldier Field doors are open at five then it's just a couple of hours till Snow Patrol at 7, with the main attraction expected on stage at 8.30.

Cool collection of photos from rehearsals last night at the Chicago Tribune. which also carries a ton of detail on the Stage production - and while we're waiting for the show, we thought you might like to read them.

Stats on the stage
Designed by Willie Williams (his 10th U2 production)
Architect is Mark Fisher (his 6th U2 production)
Built by Belgian company Stageco using high-pressure hydraulic systems.
Steel structure is 90 feet tall
Center pylon reaches 150 feet
Designed to support 180 tonsVideo screen is made up of 1 million pieces.(500,000 pixels, 320,000 fasteners, 30,000 cables, 150,000 machined pieces).
Takes four days to build
Takes 12 hours to load in screen, stage and universal production equipment
Takes six hours for production to dismantle stage and 48 hours to dismantle and load it out of the stadium.