The area around the shipyards did have a lot of crime problems when GGRM was there but it was pretty secure inside. It was always safe to visit in the day time.
It actually had a couple of buildings with track inside to store and work on 2472 and other cars and engines. I don't know the history of 4450 but some of the SP commuter cars and other equipment arrived in very bad shape and there was never enough money and volunteers to repair and maintain everything. Rebuilding engines to operating condition is very expensive. Some of the collection probably should have gone straight to the scrapyard instead of Hunter's Point but the people that brought it to HP had good intentions. The shipyard and surrounding area is a lot nicer today with new homes going in on the less toxic parts of the shipyard and restoration of some of the older buildings in progress. Some of the old crime ridden projects outside have been torn down and replaced with newer housing so the demographics are changing for the better. If you look at the buildings from the outside you would have no idea that they are subsidized public housing. The new plans call for some "market rate housing" mixed in so there will be more middle class residents in the hood who are priced out of the more expensive areas. Candlestick is being torn down and will be replaced with nicer shops, parks and housing. Mission Bay now has a UCSF hospital and lots of biotech and housing where the old Wye and railyards were. The new Warriors basketball arena will be built on part of the old Kaiser Sand and Gravel plant that used to have rail service