The tubular structures are post tensioning ducts for the towers. They are upside down here. If you recall from the last post, the tower segments are stacked and then post tensioned (pulled together) with tendons (cables). These extend from the top of the tower to the base and are curved back upward by these ducts. This creates a mechanical advantage.
The two black pipes that are seen sticking up inside of the tub will carry electrical and data cables from the Portsmouth side, across the bottom of the river, to the Kittery side. The existing bridge gets power for the Portsmouth motor from NH and power for the Kittery motor from ME, which has been the source of some issues when one or the other stalls. The new bridge will get all of its power from the same source.
In the final photo, you can see the 8 piers on the Portsmouth side waiting for their tub. Since I took these photos, the tub sections have arrived, and can be seen on barges awaiting installation.