Fixing the train track, with some powerful help

I was out in the (English?) countryside, and I needed to make some repairs to a railroad track. The portion that needed fixing was a bridge inside a tight, darkish tunnel. First, I grabbed a couple bolts and washers out from the damaged portion. Then, we (whoever was in charge, and I) decided to adjust the slope of the bridge, because the part where it met up with solid ground had a bit of a lip to it. So the person in charge (for all intents and purposes, the hand of God, because I don't know who else would be doing this) was tilting the bridge from the end behind me, and it was rising and falling, and I got ready to pull it tight when it lined up with the ground. I did, and then I got to work screwing the bolts back in. However, now one-way car traffic was making its way to and through the tunnel (which was now maybe two lanes wide), so I had to keep looking up and making sure I wasn't going to get run over.