At dusk on a chilly Chrismas Eve the elves are busy, so instead this dwarf CPL guards the mainline from rail traffic exiting the Route 100 Industrial Park spur.

Since then much taller signals have taken on the job. The distant CPL knows its days are numbered (it was removed later in 2011).

Looking SW beyond the tall signals finds MARC's Dorsey Station, the newest on the mainline.

That's MD 100 traversing overhead.

Speaking of newest, the MARC locomotive fleet now includes 26 Motive Power MP36PH-3C units, a design popular in commuter rail. The Motive Power brand is built by Wabtec Corporation, an American company formed by the 1999 merger of the Westinghouse Air Brake Company (WABCO) and MotivePower Industries Corporation.

CSX operated MARC from inception in 1984 until October 2012; since then Bombardier has taken on the job.

Tucked away beneath Dorsey Station is this small arched concrete bridge.

CSX shares the line with commuter trains between Baltimore and Washington. Here is the new, attractive and quite busy Dorsey Station.

A few plants decorate the station interior, which will soon reopen to greet afternoon commuters.

Here's the view from the platform as CSX 605 scoots under Route 100.

Modern milepost 13 is at the far end of the platform (in fact, before 2011 it was affixed to the platform's railing), but the original stone mile marker is nowhere to be found. I suspect it was removed as part of the construction of either the station or Route 100.

A Conrail engine speeds by atop this attractive stone and brick bridge just south of the Dorsey Station. You can even see it without getting out of your car. Simply drive north on OConnor Drive from Route 176. According to Harwood, this bridge dates to 1870.

This bridge also marks a corner of Howard County. From here south to Laurel, the railroad determines the Howard-Anne Arundel county line. As you might have guessed, the railroad pre-dates Howard county, which split off from Anne Arundel in 1850. I am not sure if the pair of tracks is officially located entirely in one of the two counties, or if the county line runs in between them. The ADC maps indicate the railroad is in Anne Arundel county, but a B&O schedule lists the tracks and stations as being in Howard.

Except for a very short stretch near Mt. Airy, all of Howard County's borders are defined by either railroads or rivers.

Train watching along the Washington Branch is far more productive than along the quiet Old Main Line. Here CSX 8777 roars south (west) past the Dorsey Station with a long line of containers in tow. That's the Rt. 100 overpass in the distance.

Built in 1937, this utilitarian bridge carries the tracks over Dorsey Road, Route 176. Disused stairways on both sides of the road here imply this is where the original Dorsey Station had been located.

Visible despite the glare in the upper right corner is one of the (still-in-use) B&O-style positional signals that are being phased out by CSX.

Several artifacts are to be found at mile marker 14. This turns out to be a very easy spot to access: drive to the end of Ohio/Oak Avenues. The pavement ends right across the tracks from where I'm standing.

Mile 14 is as measured from Baltimore. It's mile 5 on this tour because the Washingon Branch originally began back at Relay, which is mile 9.

The concrete slab in the foreground was probably a signal stand in a former life. In the distance is an S signpost.

Here's a rear view closeup of the S signpost. It looks to be a custom job: it's welded to an old piece of rail. At upper left is where the pavement of Ohio/Oak Avenues ends.

The meaning of the S signpost was something of a mystery, and I received varying opinions: a "speed limit" sign and a "station/stop" sign. But that did not explain why the signs are found only at mileposts.

Fran Giacoma responded with the answer to the puzzle:

"Per the B&O RR Roadway and Track Standards this is a 'Speed Test Sign' to be used at points where the engine speeds are to be checked. They would be placed a mile apart so an engineer could check the accurancy of the locomotive speedometer (if it had one and worked). Sort of like a 'begin measured mile' and 'end measured mile' signs seen on highways and other railroads."

Directly across the tracks from the S signpost is an even nicer surprise: a mile marker which likely dates from the branch's original construction in 1835. It says this spot is 14 miles from Baltimore and 26 from Washington, DC.

With help from paths made by dirt bikers, it's possible to wind your way down from the tracks to this 1835-era culvert. It's been shored up since with concrete (and spray paint), but someone has created a walkway to the entrance. Are people crazy enough to dirt bike through here? The opening is about 4 feet high.

This stream is unnamed on the ADC maps. A rule of thumb: unnamed streams on the ADC maps are usually spanned via culverts, and named streams are usually spanned via stone arched or steel bridges. An 1860 Martenet's map names this stream "Licking Run".

But the real surprise comes if you employ the wooden walkway to get close enough to the culvert to look inside: many of the granite blocks are recycled stone stringers! These had been used for the initial (circa 1830) track construction on the Old Main Line. I've marked with small circles some of the holes where the iron strap rail had been affixed to the heavy blocks.

In 1830 these blocks had been hewn by hand, and the B&O wasn't one to waste all that effort. When the stringers proved unacceptable as a track bed on the OML, the B&O pulled most of them up, and obviously hauled some here.

This is one of only two known bridges/culverts to have been built primarily with the recycled stringers, but there are likely others waiting to be discovered.

Side note: the built-in flash on my Sony Mavica digital camera rarely works properly: it seems to be uncoordinated with the opening of the lens, resulting in uselessly dark photos. This is the only time the flash has worked. I almost didn't bother trying, but am glad I did.

CSX 7534 barrels south (west) past dirty mounds of snow toward Montevideo Road, one of the busiest grade crossings on the Washington Branch. Plans are in the works to build an overpass for the road.

All the milestones I've located so far are on the Anne Arundel county side of the tracks. This one is tucked away so deep in the brush it's easily missed. To help you find it, look for the more contemporary mile marker on the opposite side of the tracks.

Under a sky of puffy cumulus clouds, CSX 682 heads a westbound train of containers through the Jessup commuter station of MARC's Camden Line. This is a quiet little station with parking room for about 50 cars.

An 1860 map calls this area "Pierceland".

Mr. Carnegie, meet Mr. Illinois.

Two rails, from two different manufacturing plants, from two different years, become one via continuously welded rail, aka "ribbon rail".

Churning a cloud of dust behind, MARC engine 61 pushes this set of 3 commuter cars toward DC during an early autumn afternoon. To reduce the need for turning, MARC engines are designed for remote operation from the end passenger car.

In the foreground is the only concrete whistle sign I've seen surviving on the Washington Branch.

Despite heat-induced atmospheric distortion, with digital camera at max zoom, we can look almost a half mile north back toward Jessup Station to find signals. Color position lights like these are being phased out by CSX, so get out there soon if you want to see some in action.

The bridge in the distance carries MD 175 over the tracks.

The amber signal seen here means "Medium Approach Medium", that is, proceed at medium speed approaching the next signal at medium speed.

Reader Ralph Hough wrote:

"hey steve. i am a conductor for csx and i was looking at your website. very nice site i thought. i really enjoy learning the history of the b&o. one thing i need to bring to your attention is mile 7.2 picture (signals) the amber signal is 'approach' not 'medium approach medium'. i followed your link to mikes signal page and he has it wrong also. again, very nice website. i will be stopping back frequently. thanks...."

Ex-B&Oer Mike Blair added detail:

"Conductor Hough is quite correct that the one displayed in your picture is an approach signal and would require The engineer to immediately reduce to medium speed and approach the signal at Dorsey prepared to stop. ( !! UNLESS his train was greater than 7300 feet long ! In which case he would have to act quickly to stop at Montevideo Road to avoid blocking the roadway, since trains greater than that length will not fit between the road and Dorsey signal.)"

Links to illustrated descriptions of signals: Mike's B&O Signals Page, Todd's CPL Home Page

This arch spanning Dorsey Run is the most modern example I've seen along either the OML or Washington Branch. The brick arched structure dates to 1965, and is numbered 17B. This is the most recent vintage brick arch bridge I have found on any of the routes described on these pages.

The stones in the foreground, near the base of the large tree, are evidence of an older bridge, perhaps that of the pre-1965 alignment.

About 200 feet behind me were the noisy grounds of the Maryland House of Correction (prison) Reformatory for Women. I was a bit surprised no one questioned what your intrepid photographer was doing.