This is a field bolted moment connection to a column web. The flange plates are welded to the column in the shop and are made to fill the entire space between the column flanges. In this way they can serve as web stiffeners in addition to transmitting the beam flange force into the column. The beam shear is assumed to be carried by the web bolts.
Erection of this connection is simplified by extending the horizontal flange plates and the vertical web plate so that all bolting takes place outside the flanges of the column.