This line is served by the MARC "Brunswick line", as well as by AMTRAK's "Capitol Limited". Unfortunately for the railfan, there is at present only a single MARC train in the middle of the day, leaving Union Station at 2:00 PM for Brunswick. This basically means that a car is required to see much. Our tour will progress west from Union Station in DC to Brunswick; the line continues through Harpers Ferry and Martinsburg on the way to Cumberland, but that's beyond the scope of this. I've included some material on Cumberland simply because it is within reach as a (long) day trip and offers enough to warrant the trip.
If you're willing to take a walk in the evening, head west on Wayne/Second Ave. to Spring St. and turn left. The bridge over the tracks (ex-B&O) is a good place to watch the evening rush. You can also see the Cap. Ltd. here before it gets up to speed. If you stand on the NW side of the bridge (away from DC) you can see the Georgetown Jct. signals in action. You can get down to the track at those signals (under the 16th St. bridge), but there's not a lot of point to it. You can also get to the other end of the junction, legally, by following Brookville Rd. over the tracks and immediately turning left. This road shortly ends up paralleling a sweeping curve, and if you follow it to its end you can see the feeble remnants of the Georgetown Branch. The problem here is that there is no real place to park. Georgetown Junction was the site of the dreadful MARC accident in which the crew and eight passengers were killed.
I have some picture of the station here.
It is possible to get some reasonable pictures here, and there are block signals right in front of the Connecticut Ave. bridge. Beyond the bridge there is a defect detector, but I have never ventured in that direction. The whole area retains a more '40s/'50s appearance, and there are a number of antique shops along Knowles.
You can see some pictures I took in 1984 here.
IF there is some sort of carnival or midway at the county fairgrounds, it's worth taking a peek at the fairground siding to see if they arrived by train, as some do. This is difficult to reach without actually entering the grounds, but it might be possible to go around to the west end of the fairgrounds and get a peek.
Getting to Brunswick is fairly easy; just turn off US 15 before you reach Point of Rocks, where you see the sign. It's not the easiest town to get around in, and the best solution is to park in the commuter lot. The main problem here is being able to see things without trespassing. There are lots of interesting things in the MARC yard, but most of this is concealed by a brushy fence line. If you turn right onto the street that parallels the yards, you will eventually come to a basketball court on your right. You can see through the fence here, although you may not be able to see much. If you have binoculars or a spotting scope, you can look out over the yard from opposite the turntable. You can also follow the C&O canal back along the south side of the yard. Here the problem is that the towpath is much lower than the yard.
The station itself is one of Baldwin's odder products, what with the Palladian windowed gables tacked on the roof. It has been massively restored of late. It sits right next to the yards, with a maze of crossovers in front of it. There is also a tower a bit to the east. In front of the station is a large commuter lot, and I am told that there are tables and such set up by the station and on the far side of the eastbound tracks. There is plenty of traffic to see.
Up the hill from the station and to the left along West Potomac Street is the Brunswick Railroad Museum, which has a huge HO layout among its exhibits. Adjacent to this, and sprinkled around the area, are some remarkably odd antique shops. Brunswick also has a railroad fair in the spring and in the fall, which in the past has featured short MARC excursions up to Martinsburg and back.
The former Western Maryland station is another big Beaux Arts box, much less elaborate than Union Station in Washington, of course. It houses a transportation museum (dealing with both the railroad and the canal) as well as the Western Maryland Scenic RR. The WMSR has a big old steam switcher from the Great Lakes area which they use to haul excursions up to Frostburg and back over the ex-WM main. This trip takes most of a day. They have from time to time run shorter trips using diesels and cabeese, and on some occaisions they offer cab rides (in the diesels, of course).
The CSX yard is huge, and while you can get right up to it, its layout doesn't exactly make viewing easy.
It takes a good chunk of the day just to get to Cumberland from the Balto.-Wash. area, so the best way to see the sights is to stay over a weekend. There is a Holiday Inn in the center of town, within walking distance of the WM station.