Built in 1829, the Carrollton Viaduct is the oldest surviving railroad bridge in the world, and remains in active use, a tribute to its original builders. The viaduct is 297 feet in length and spans the Gwynn's Falls (river).

The B&O wanted to build south out of Baltimore, but politicians feared that doing so would encourage the development of a new, competing port along the Patapsco River, a few miles outside the city. So, they enacted a law specifying that the B&O's route must cross the city line at an elevation of 66 feet above sea level. This forced the railroad to build SW rather than S from Mt. Clare, and cross streams at a higher elevation, thereby necessitating expensive hand-built structures like this viaduct. The viaduct is named in honor of Charles Carroll who owned the land in this vicinity.

Interstate 95 passes about 1000 feet from the viaduct, but you'd never know it. The viaduct is hidden in tree growth and surrounded by industry and a golf course. The best access is by hiking along the western perimeter of the golf course.

Links to older pictures: ~1867, Pic 2, Pic Group

It's a tough climb up a steep embankment to reach the top of the Carrollton Viaduct. This photo looks from the SW side of the viaduct back toward the original location of the B&O's First Stone. Ex-Western Maryland tracks that pass nearby can just be glimpsed at the extreme left side of the image.

The trees in this photo hide an ugly scrap metal facility that operates on the north side of the viaduct. There I dicovered a HUGE (over 10-foot high!) heap of old bottle caps. Not the twist-off kind, the old pry-off kind with cork linings. If these are collectible, there's a real treasure trove hidden here.

Here's the view looking downstream from the top of the viaduct. The golf course is on the left, and the Western MD tracks are hidden in the trees on the right. That's I-95 near exit 51 in the distance. You should be able to glimpse the viaduct from I-95 during non-leaf season if you know where to look.

This bridge just west of the Carrollton Viaduct crosses over the former Western Maryland tracks. If this bridge is numbered 4B, and the Gwynn's Run bridge is 3B, what bridge number is the Carrollton Viaduct?

Figuring out the B&O's bridge numbering scheme has been something of a pet project of mine. The bridges appear to be numbered consecutively as you head west, but there are several oddities, like "A" and "B" suffixes.

Claremont Yard is part of the loop that goes over the Carrollton Viaduct. Long ago the loop was bypassed by a shortcut, but CSX has seen fit to keep the Carrollton ROW as a siding of sorts, and apparently has renamed it Mt. Clare Yard. The original Mt. Clare Yard was between Mt. Clare Junction and Mt. Clare Station (now the B&O Museum).

Here CSX 102 and 731 take on fuel with I-95 in the background. It was here that an interchange with I-70 was going to be built until environmentalists halted work.

Link: connection with PA RR

Now we're looking into the opposite end of Claremont Yard as viewed from the Washington Blvd. overpass in Morrell Park. I-95, which bisects the yard, is visible in the distance.

On a cold, dim February afternoon, a group of derelict engines and cars sits at left awaiting eventual restoral at the B&O Museum.

About a half mile from the south end of Claremont Yard, the OML's looping route over the Carrollton Viaduct (distant engines) joins what is the present day main line (tracks in foreground).

That looping route was a early problem for the B&O, and in 1867 at this location it built a straight shortcut (the foreground tracks) which shaved about 2 miles off the trip to Camden Station, new at the time. This shortcut was known as the Camden Cutoff, and later became part of the main line.

Initially when creating these pages I attempted to list (in the Mile box next to each thumbnail) mileage that corresponded to the original route of the Old Main Line. However, the OML was straightened and shortened in many places, wreaking havoc with my plan. In June 2004 I capitulated, and adjusted all the OML Mile data from here west to agree with the present day mileposts, which appear to use Camden Station as their starting point (mile 0).

Here's Mt. Winans Yards as seen from Patapsco Avenue. The OML is on the extreme left, today's active main line tracks on the right (being negotiated by the coal cars) and the yard in between.

Looking the other direction from the present day Patapsco Avenue bridge we can see the northern end of the Deep Cut. The Deep Cut was made into the ridge between the Gwynns Falls and Patapsco River. The original effort turned out to be much greater than the railroad had anticipated. At 68 feet deep and 3000 feet long, the cut is more impressive when you learn it was all accomplished by hand. Hundreds of men worked with shovels and pickaxes around the clock for well over a year to carve into the sticky clay. It came close to bankrupting the fledgling railroad.

Lansdowne presents the first easy location for active train spotting along the OML. The route is paralleled by Hammonds Ferry Road for some distance. The neighborhood is mostly blue collar residential. This is a comfortable, but not scenic, area to observe CSX action. In the photo, CSX 8770 poses while awaiting a signal to proceed into Baltimore.

Link to older pic: station in 1912

CSX's replacement for the B&O CPL signals stands adjacent to Hammond's Ferry Road, guarding access to Mt. Winans Yards.

I'm surprised the design of the CPL signals was not retained. In a CPL, the lights are lit in pairs, green: top and bottom, red: left and right, amber in between. The angle of the pair of lights provided a second way for an engineer to know the state of the signal, something particularly useful when due to distance or weather the color is not easily discerned.

A row of stranded cabooses sits on the east side of the tracks along Hammonds Ferry Road. This is the view from where Sulphur Spring Road had crossed the tracks. A nearby passenger walkway is dated 1967, which probably dates to the closure of the grade crossing. This is also likely the time of construction of the Baltimore Beltway interchange which sits where the Sulphur Spring Road had met Washington Boulevard (US 1).

A plain bridge spans the Baltimore Beltway near exit 9.

Link to older pic: Beltway in 1962

Before the era of centralization, Halethorpe was a major traffic control location. Here south and west bound traffic was switched between the OML and the Washington Branch. HX Tower shown here was built in 1917, closed Oct. 1, 1985, and remains the last surviving tower on the OML. The tower was ideally positioned to witness the Fair of the Iron Horse, B&O's centennial celebration in 1927-1928, which was held here.

Ironically, this was also the site in 1910 of the region's first air show, the transport technology that would supplant rail as the top choice for long distance passenger travel.

Now this area is industrial and very busy. Your best photo opportunities will come on the weekend when things are quieter.

Links: 1927, 1927, 1927, 1927, 1910 Air Show

The B&O's early engineers were overly concerned about keeping their railroad level. They feared the steam engines would not be able to pull loads on steep grades, so they restricted the OML to a mere 0.7% grade. To keep things flat, substantial fills were needed at certain locations, such as Gadsby's Run (also known as Herbert's Run). Here a 57-foot fill was built over a small arched bridge. As at the Deep Cut, all this work was done by hand.

The stone bridge seen here dates to 1828, but was widened to support more tracks in 1875, with additional work done in 1911. In an act of historical preservation, during the widening, the new portion was built inside, and the original stone arch retained and moved outward. It's easy to see this by walking part way into the tunnel. In the foreground, an inexplicably odd assortment of rocks embedded in concrete litters the streambed. This is one of the easiest OML arched stone bridges to access. Simply drive to the end of Hollins Ferry Road, and walk a short distance toward the stream.

The concrete ties and electric catenary indicate these are not B&O tracks. This is the view from the B&O bridge over the ex-Pennsylvania tracks as a high-speed Amtrak Northeast Corridor passenger train zooms toward Washington on Easter Sunday. The B&O and Pennsy were fierce competitors when Pennsy muscled into the region. It would be interesting to hear what must have been tense negotiations for the construction of this crossing. The bridge structure appears to have been rebuilt within the past 60 years, and is quite ordinary.

The 1929-built Vinegar Hill Bridge that carries US Route 1 over the main line provides an excellent vantage point for photos. This view looks back toward Halethorpe as CSX 8528 rumbles past the spot from which the Pennsylvania Crossing photo (above) was taken.

To obtain this view, you must cross US 1 on foot from Selford Road to reach the hidden and now disused pedestrian walkway. Doing so is quite dangerous because of the heavy volume of high speed auto traffic. Be very careful!

The two tracks on the left are the Old Main Line, while those on the right are the Capital Subdivision. Until sometime in the 1950s, the OML was double tracked for its full length, but now the leftmost track terminates here (surprisingly without an abutment or stop of any kind). Despite its appearance, that leftmost track remains in active use to serve the industry at Halethorpe.

What's more interesting: those leftmost rails have date stamps such as "92". That means 1892 (if it were 1992, the full 4-digit year would be stamped). This is likely some of the oldest rail still in use anywhere in the USA.

It's not only CSX that employs this route, MARC (Maryland Area Rail Commuter) trains do as well. This afternoon train is heading away from the camera on its trip from Washington, DC to Baltimore.

Track 3 hosts a mile-long eastbound coal drag, the dual engines in the lead working to pull the heavy load up the small incline. Heat distortion from the engines' exhaust obscures part of the CPL signal bridge as well as HX tower back at Halethorpe. In this view, the engines are crossing over Amtrak's Northeast Corridor lines.

Links to older pictures: (Railfan.net ABPR Archive) 1977, 1982