Along the US east coast this gray, featureless sky during January portends snow, except when it doesn't, as was this case this time. The snow seen in the photo below fell two days earlier.

It's so far from the tracks you'd never spot <-- this older mile marker during leaf season. 78 + 18 = 96, and 96 is the milepost at Camden Station in downtown Baltimore. That is a logical reference point for passengers.

Wait, the marker we saw back at milepost 81 --> shows 81 + 9, which is only 90 miles total. Milepost 90 is approximately where the B&O's Belt Line and CSX's Baltimore Terminal Subdivision begin. That is not a sensible reference point since the transition from one branch to another is of no consequence to passengers.

Link: modern utility markers

Autoracks are eastbound from Baltimore lugged by CSX 8610 and CSX 5333 over Gunpowder Falls Bridge.

Link: 1981

I believe the stone to be original 1880s construction but the steel of that era was replaced with that seen here, and concrete added around 1906 to support the demands of faster trains.

It's an uncommon amalgam of stone and concrete.

CSX 733 and CSX 7495 are westbound at Jones Road.

During the 1880s the B&O was still building culverts out of stone though the roof appears to be steel.

Some bridges were revamped later, such as this one in 20th century style.

When 84 Lumber is not expecting delivery via train, their siding becomes convenient storage. This MoW unit is self-propelled.

Link: same model MoW unit on OML

Track insulators, the orange joints, isolate the siding from the main line's signalling system. The yellow item is a derail that blocks a car on the siding from unintentionally rolling onto the main.

This switch is set up for both manual and remote operation. The last time this equipment was updated, the Chessie System had not yet become CSX: the forging date is October 1984.

Track revisions are evident at Little Gunpowder Falls. What had been double track was reduced to single.

These steel beams are not 1880s original but instead exhibit a design the B&O used during the 1920s. Note how at the support the height of the beams changes, as well as that of the wood ties.

Ties on bridges are more difficult to replace and thus to extend their life sometimes have end protectors -- the silvery-white rectangles -- installed to discourage the wood from splintering.

Dusk comes early during cloudy January afternoons. The railroad called these CPLs the East Bradshaw signals.

CSX 2300 is a recently repainted model GP30 that was born December 1962 as B&O 6969.

Links: more CSX 2300 pics, B&O 6969 pics

Grade separation during the years before automobiles meant enough width for horse-drawn carriages to pass, but that's not quite enough room for two at-speed autos to do so safely. Several such underpasses survive on the line in their original form.

westbound at milepost 76...

Near the Joppa Road grade crossing old track ties are staged for pickup and landfilling. Due to their prior chemical treatment, old ties are not burned or chipped. About 700 million wooden ties support the rails of US railroads. Each lasts approximately 40 years, which means about 16 million are replaced every year.

Signals flash at the grade crossing. Note how the fixtures are offset and contain holes for light to escape from the sides so pedestrians can also be alerted. In the distance a B&O CPL is signalling approach.

Link: tie disposal

An uncommon double-culvert is on duty near the crossing. This is only the third I've seen along ex-B&O lines in Maryland.

Piped culverts are more a 20th century expedient therefore I doubt this extracted pipe dates to original 1880s line construction.

The Manley-Reagan siding awaits post-disconnection cleanup. Aerial photos from 2016 show it as yet unremoved.

The G sign (grade) at the Clayton signals advises engineers they can proceed through a stop signal if needed to keep their train moving over the hill.

That hill is more evident when traced by a train. This is the highest spot on the line west of the Susquehanna River.

At photo time the Philadelphia Subdivision had not yet been cleared for double-stacks, so only single-stacks were on the menu.

The concrete left of the train's last car represents the location of Mountain Road's prior bridge.

The line's single-lane underpasses will probably be widened during the 21st century.

The Abingdon Road overpass is a nice platform for train watching.

Readers asked for an overhead view of an engine...

A doll post is the upright arm on a signal pole between the main signal head and a dwarf CPL. It notifies train operators that each signal controls a different track. Masts with doll posts were made taller than others for better visibility from either track.

Here at East Van Bibber the B&O had considered a building a line called the Patapsco and Susquehanna Branch which would have connected to the Old Main Line east of Sykesville near Gorsuch, thus bypassing busy Baltimore and its Howard Street Tunnel bottleneck. The project did not get past the planning stage.

The Van Bibber siding is roughly 2 miles long.

CSX's newer signals do not employ doll posts, instead each track gets a signal on a separate pole.