Most portions of the OML were reduced from double to single track during the mid-20th century, however some segments were retained for sidings. This siding, just west of Avalon, sees frequent use, and makes an easy place to find a cooperative photo subject. This location is within Patapsco Valley State Park that can be accessed from US 1 near I-195.

Many people may not realize that diesel locomotives are almost always diesel-electric: they employ diesel engines not to turn the wheels directly, but rather to generate electricity that is then fed to motors at the wheels. Hybrid-variety automobiles have copied this approach.

Bridge 9 over Soapstone Branch is the first significant bridge on the OML west of Relay. It is unique in being the only original stone/masonry bridge left on the OML under which you can (legally) drive (access is via Patapsco State Park).

A 1915 atlas shows B&O's Glenartney Station on the near side of the tracks, right of a grade crossing on the left. As grade crossing elimination, bridge 9 was rebuilt so the road could share the underpass with the stream.

This tour page follows the railroad generally northwest from Avalon Factory at bottom right to the flour mill at upper left.

Several stone bridges will be shown below. Bridge 9 spans the stream that on this map runs through the first R of B&O. R.R. Bridge 10 handles the smaller stream near Montrose Vineyard now reachable via Vineyard Spring Trail. Bridge 11 is near the Maryland Industrial School for Girls.

Within Montrose Vineyard, the map shows some type of cartway, only scattered bits of which survive. I'm told remains do not reach CSX's tracks, so perhaps the cartway faciliated fruit transport within a farm. The valley's sunny slopes were home to orchards. I welcome more info about the cartway, if that's what it was (email me).

Floods from Tropical Storm Agnes during 1972 scoured the Patapsco's banks and exposed the ruins of the Avalon Nail and Iron Works, disused since the flood of 1868 destroyed it beyond repair. Agnes completed the effort by knocking down Avalon Dam (inset, right) that had somehow survived the 1868 calamity. Later during the 1970s, the State of Maryland would remove much of the brick and stone in the foreground. The millrace had began in this vicinity.

Though the railroad is perched higher, it also sustained heavy damage in both floods but each time was rebuilt. Traversing bridge 9 in the background are coal empties.

Links: 1932, 1932

Typical of dozens of stone box culverts along the OML is this one located a short distance west of bridge 9. It has been doing its job quietly since about 1830. To get here, drive to bridge 9 and park, then on foot follow Grist Mill Trail upstream (west). Before this one, you'll first encounter a culvert that around 2020 was shored up with concrete blocks.

Many other culverts and bridges, old and modern, long and short, can be found between mileposts 8 and 11.

Nicely-cut stones were not wasted on culvert interiors. This culvert's outlet end is significantly lower than its input, making for a stair-stepped slope inside. This design is more common than one with exterior stair steps down to the river. I would guess the base stones were laid upon the river bank's natural slope, then fill added on top to create a shelf for the tracks.

Perhaps the most attractive of the bridges along this portion of the OML is bridge 10. The design makes me think the external portion dates from about 1830. The underneath is lined with concrete, which was likely added or redone in the 1900s. The Vineyard Spring Trail crosses under the tracks here. Vineyard Station had been at left, on the near side of the tracks.

By virtue of travelling through a state park, the scenery along this portion of the OML is quite appealing. Coupled with the underused park trails, this is an excellent area for a quiet walk, birdwatching, leaf peeping, etc.

Perhaps all culvert pipes are perforated like this one to allow water to seep in and drain away from the tracks, but this is the first example I've noted.

Its mortared stones indicate Bridge 11 is no longer in original form. Walk under the arch and follow the small stream uphill for about a quarter mile and you'll find a scenic little waterfall with a decent vertical drop. A 1915 atlas shows a path here from what had been Edgewood Road (now the trail) up to the Episcopal Sisters Childrens Country Home on the left.

Somehow these snaking tracks have remained railroad worthy for most of two centuries.

Though this 1830-era culvert seems to have loose stone blocks that require repair, the photo from 1977 (left, courtesy JD Hiteshew) reveals it looked just about the same then as it did in 2000 (above), and more recently (2014, right).

Based on the volume of water, it appears this spot might have deserved an arched bridge.

Eastbound trains enjoyed this autumn 1966 view. What would this area look like about 50 years later? See the next photo...

The seasons and decades change, but the state park and railroad look much the same. Orange Grove Station had been on the left.

B&O's Orange Grove Station nestled in a hillside alcove across the tracks from the flour mill seen in panels below.

The Swinging Bridge recalls the location of Orange Grove.

The park road (River Road until Agnes erased it during 1972) follows the south side of the river to this point, ending in a large parking lot. This makes access to the Swinging Bridge very easy. This is also the location of the Cascades, a scenic waterfall that is popular with visitors.

The original swinging bridge extended to this flour mill. Painted on the side of the mill building behind the workers was

The mill was built in 1856, squeezed rather precariously between the railroad and the Patapsco River. Somehow it survived the flood of 1868 and continued to expand such that by 1900 it was said to be "the largest flour mill east of Minneapolis." Many of the mill's employees lived across the river in Howard County, from where the photo at left (courtesy Pratt Library) was snapped.

Fire claimed the mill in 1905. Shortly after, Bloede Dam was built about a mile upstream. I have yet to learn when the mill's dam (visible in the photo at left) was removed.

Link: ~1900

Here from the Baltimore County side of the swinging bridge we look up toward the trackside ruins of the Orange Grove Mill. The opening in the stone structure seen here was likely a chute to allow unloading from cars directly into the mill.

Reader Robb Bailey contributed details:

"The chute is located above where the Corliss steam engine was once located in the mill complex, so the chute would have accomodated coal, not grain. Morever, the mill burned in May 1905, long before grain was carried in hoppers. Grain was transported in box cars at the time the mill was in operation. Period photos of the mill in operation clearly show box cars behind the mill complex."

Link: Mill workers

Nature and a blue B&O locomotive conspire to paint a wintry scene. Note the sunburst scheme on the model F7A engine's nose, a style used only on a few units from about 1962 to 1966.

Little of the mill remained on site 60 years after it closed. Agnes floods six years after this photo washed away a bit more.

Back at trackside, the decorative finial at the top of this post attests to both the age and the remoteness of this signal, which had been in use through 2004. I believe such signals had been installed during the 1920s. OML CPLs with a plain cap at the top were added during the 1950s when the line was converted into single-track operation.

A scene that brings a tear to a railfan's eye: B&O's old, signature CPL signals giving way to replacements of less flair. CSX crews were working even on this July weekend to make the exchange.

A little further west of the Swinging Bridge on the Baltimore County side is where you'll find railroad Bridge 12. This is another pretty stone arched structure. The keystone is engraved "1869" which makes it likely this bridge was rebuilt shortly after the disasterous flood the previous year. This is one of only two bridges along the OML that has a dated keystone.

I waited about an hour to add a train to this beautiful autumnal scene, but the daylight was starting to fade so I had to settle for the tiny streak of a plane's contrail. Leaf colors typically peak here a few days either side of November 1st.

The faded digits of an old "mile marker on a rail" claim we're 10 miles from somewhere in Baltimore (Camden Station, I believe). The further west you go on the OML, the more likely you'll find an old marker like this near a modern milepost.

There is a retaining wall west of bridge 12 that is constructed at least partially of stone stringers (disused parts of the original track bed).

Detour: more stringers at this site

At the stringer wall, this trailside sign describes B&O's early track construction techniques.

A panel at the lower left corner of the sign illustrates the three main track designs B&O used before adopting the metal-T-rails-on-wooden-ties approach now ubiquitous. The leftmost design, stone stringers, was, relatively speaking, the most recent of the three as well as the most durable hence its artifacts are found in many spots. Before that, B&O tried the middle design, iron strap rail on wooden stringers, but it quickly proved too flimsy so very little of it was built, and no known artifacts survive. The oldest design is on the right, iron strap rail on wooden stringers on stone blocks. Only with much hunting and luck can one find a remnant of this technique.

What little remains of B&O's block trackage, the oldest of all the track designs tried by the nascent company, is buried under the existing railroad, exposed only when nature or CSX deign to do so. This photo shows one such block. Note the rust stain that, in this photo, traces up/down between the nail holes, perpendicular to the longer side of the stone. That's a fingerprint: had this been part of the stringer design that came later, the rust stains would instead connect the nail holes and trace parallel to the longer side of the stone.

Buzzard's Rock may not look formidable today, but it was a substantial obstacle when all you had was a pickaxe and hammer. This picture hides the size of the rock face, which extends over 100 feet up. Even now, the high cliff above is a favorite place of scavenging birds. You can also see Buzzard's Rock by looking upstream while crossing Swinging Bridge during winter.

Floods from 1972's Tropical Storm Agnes wreaked havoc all along the Patapsco Valley, and the railroad was no exception, such as east of Ilchester Tunnel. The area eroded by the flood had likely been landfilled by B&O when straightening the alignment as part of the tunnel construction. Nature eventually reclaims what man borrows.

I'm surprised the track is jointed as I thought the OML has been continuously welded by 1972. Also note the fresh, gray ballast: B&O had rescued people and equipment isolated by washouts. The OML would lie dormant for several years while repairs were finished.

When a railroad company advertised itself as an "Air Line" this was not what it meant. The Patapsco River is still muddied in this picture, likely taken a week or two after 1972's tragic flooding. Seaboard Air Line Railroad's name boasted of its straighter-thus-quicker route.

By the time of this photo in 1973, the floods had long ago subsided but additional erosion claimed the rails. As seen at right, the B&O laid temporary tracks to skirt around washouts like this. The OML east of Mt. Airy stood on the brink of abandonment and would not see regular train service return until April 1974.

Here's another view of the damage, this time from the Howard County side. Note the struggling railroad utility pole across the river on the left. Agnes cleanup work was underway but the section of River Road underfoot would never be rebuilt.

The first tunnel west of Baltimore is found here at Ilchester. It was built in 1902-3 to bypass a speed-limiting sharp curve, one of many that plagues the OML. At slightly over 1400 feet in length, Ilchester Tunnel is the second longest on the OML east of Harper's Ferry. Trackage through the tunnel was reduced from double to single in the 1960s, perhaps to accommodate the height of trains hauling auto racks.

The next page tours the original alignment that curved left around this hill.