Yes, you have three options:

1. Build your bridge structure on one of our pontoons on a riverbank nearby, then we float it under the bridge and you lift your scaffold structure up underneath. After it is lifted up we take the pontoon away.
2. Build floats into your scaffold structure, float it into position then lift it up underneath with the floats still in place.
3. Lift a pontoon up under the bridge (25m x6.5m pontoon is under 10t) and then use it to work from to install your scaffold structure underneath.

A 4m x 20m pontoon lifted up under a bridge using 4 air hoists.