A bit of a hold-up

I got there at 9.45 am and there were already about fifty people in the queue. The ticket office was ten minutes late opening but I was kept entertained by Pete 'n' Dud behind me.

'Here, Pete, what are those metal things sticking out?'
'They're part of the stadium, aren't they, Dud?'
'What, to make it look pretty, is it?'
'No, no, Dud, they're part of the engineering, aren't they?'
'Part of the engineering, Pete?'
'Yes, they hold things up.'
'What, is that why it's taking so long for us to get our tickets then?'