It does have all the hallmark of a temporary ventilation duct, see all the lifting lug.!From the bottom half up that looks like an axial fan duct and at the very top we have a heavy gauge metal plate that not only adds weight to hold it all down but provide static pressure for the fan motor. The only thing that bothers me is what looks like a motor on the left with electrical conduit running to it, does not look like any IP rated motor that I know and axial fans usually have inline fan motor.Yeah, almost certainly ventilation for the enclosed foredeck.
Did construction of 055 start before or after 001A?
This is supposedly the 3rd 055 under construction at Dalian, just north of where the 052Ds are being built. The picture is dated 2016 November 20 so by now, January, it should be much further along than what is shown.
An older but larger view of the shipyard. A Type 052D can be seen at the bottom of the image.
That is a pleasant surprise. It goes without saying 055 was going to be built at Dalian, but to have work so far along before the first unit at JN has even been launched is a bit unexpected.
I also wonder how the rumours for HPLX also building 055 will turn out...