The Dagmar is a Landing Ship in the United Nations Navy.
Dagmar is a marine landing and breaching craft. It is able carry and deploy 200 UN Marines onto an enemy space station or ship quickly. It straps onto its target and blows a hole in its hull, allowing the marines to come through.
Marines transit in vertical crash couches, with their weapons locked into quick release clamps next to them. The ships also are equipped with a command and control suite that allows the Landing Force Commander to review the tactical situation and command the assault force.
The ship is most likely named after an actress, Dagmar, who was quite prominent in the mid-twentieth century. There is a long-standing tradition in the shipbuilding trade of fetishizing a ship with a female name or a likeness of the female form (as found on the bow or front or a ship).