Further to Denis' comment, self propelled split hopper barges are also used to transport sediment (mud, etc) dredged from harbour bottom etc., and dumped further offshore.
victor radio 74 wikipedia link offers a good description of hopper barge.
Below is a link to photo I captured of a split hopper barge** working in the area of the Vancouver seabus terminal entrance (at waterfront station) taken in January 2020.
www.shipspotting.com/gallery/photo.php?lid=3118322
**Since barge non propelled, a tug would tow barge to common dumping ground offshore.

Ah forget it guy's ! i haven't got a clue don't worry about it i am not going to loose any sleep over it ? i just simply don't understand ?

My geuss is what Denis said for perhaps stone break water or some thing like that ??? i will check out that link victor also

Denis see ..https://www.fkab.com/en/references/dredging-2/jan-blanken-2/

Could it be used for stone dumping or only vessels that push stones from deck over board are for that?

Jaybird,in case you are not kidding see Wikipedia
rgds

Guy's can any body tell me what is the purpose of the vessel opening in half i am a bit lost off here is it dropping some thing or picking up some thing am lost off really very strange

Doing the splits!

As if the vessel simply collapsed...