McMurdo, is the main logistics hub for this end of Antarctica. Virtually anyone doing research in the Ross Sea area to the South Pole to the Vostok Russian Station and back to the ocean comes to Mcmurdo first. Hence the size of the town. Many scientists do their work here, but many more head out to field camps and only do their initial safety training etc at McMurdo.
Summer at Mcmurdo is a hectic wave of thousands of people passing through. 700 to a 1000 or so can be workers at the base. The number peaks at the end of January as summer and winter crew overlap in preparation for the annual ship offload.
Every room is full for most of the summer so it’s rather difficult to shut down buildings for repairs. That work is done mostly in the winter. In the summer everything is patched and in the winter they go back, shut down the building and do a proper repair.
As far as special jobs. We do have snow removal people. Fleet Ops and big loaders. But most towns would have that. We have a Search and Rescue team. Satelite and radio communications people as well as IT and internet.