Here are some pictures of a dam construction in St. Petersburg.
This "monster" resembling an armored train of the Civil war time, will be used to push one of the barrier leaves preventing ships from entry to the water area of the Neva in case of flood threat.
It has special rails with teeth, the wheels - gears.
A huge "arm" is mounted to the vehicle to push the leaf of the water gate.
That's how it looks like.
The lock preventing ships from entry.