What’s the steepest mainline grade on CSX? What % grade is it? How long?
Probably Cranberry Grade on the old B&O from Rowlesburg to Terra Alta, WV. The grade is about 12 miles long and hits 2.84 percent. This is against loaded coal trains.
As always, when you ask about “steepest grade” you have to specify how long. Cranberry conceivably does have a quarter-mile length of 2.8% (tho I got doubts), but if you study the B&O track charts you’ll see the grade never averages much more than 2.2% actual over any mile, so the compensated grade probably can’t exceed 2.35 or 2.4 over a trainlength. They just stuck that 2.84 in to impress the fans.
But yeah, that could be CSX’s steepest main line for all I know.
Seventeen Mile Grade is steeper than Cranberry Grade; however Cranberry is more operationally difficult because (1) as previously mentioned, tonnage traffic ascends it; (2) its curves are more severe; and (3) flange lubricators that are positioned to reduce curve resistance can produce excessive lubrication and significantly reduce adhesion.
Jay Potter
…So from the above figures and data, it appears the CSX route up over the Alleghenies compared to the NS {old Pennsy route}, is the steeper of the two…
Believe we understand the NS route up from Altoona is roughly 1.8% and about 12 miles in length.
Where?
Even if Cranberry isn’t the steepest, it’s an incredible spectacle to see modern diesels on their knees straining to get freight around Salt Lick curve and up that final segment of track. It’s a visual drop-off. Q-316 tends to arrive about 0900 hours.
In response to timz’s question, from slightly east of MP 210 to slightly west of MP 217, with a maximum gradient of 3.31% near MP 216.5.
Jay Potter
Tim, the stretch from Bloomington up thru Bond tends to ascend rapidly. If you follow the road that parallels the savage river and damn, you will see how the railroad “escalates” up the ridge.[2c]
Bond is MP 212.6.
Jay Potter
Can you explain what compensated grade is please? Thanks
…Believe it to be a combination of gradient and curvature.
From the Trains link here TRAINS Magazine - Mountain railroading terminology comes this definition…
Compensated Grade: Because curves add rolling resistance to a train (as opposed to tangent track), mountain grades are usually compensated in curves, that is, the grade is reduced by the same amount that the curve adds resistance. Tighter curves add more resistance, and thus the grade is reduced by an appropriate amount. Thus, the train encounters constant resistance of grade and curvature throughout the climb. The advantage of this is to optimize the climb: if the maximum grade was dictated by the curve, and the tangent track held to the same true gradient, then the mountain climb would be lengthened and the cost of construction would probably be increased significantly. Because curve resistance is empirically derived and not fully understood, most railroads have a different idea of the amount of compensation that is appropriate. Generally, compensation is in the range of a 0.2% to 0.3% reduction in a tight curve. Inexpensively constructed and temporary railroads often dispense with compensation; it’s mostly a feature of main lines and well-constructed railroads.
…Have understood the NS line up from Altoona is generally 1.8% grade and I have read that as the track curves around Horseshoe curve the grade lowers to 1.45% grade…
Seventeen Mile Grade is on CSX’s Mountain Sub I beleive it’s right after the Cheat Grade on the Mountain Sub. If memory serves me right Seventeen Mile is located on the out skirts of Cumberland Maryland, and near the border central Pennsylvania.
Going Westbound from Cumberland on the CSX Mountain Subdivision, the train would climb Seventeen-Mile Grade just west of Keyser to Altamont, then descend the short but troublesome Deer Park Grade, cross the “Glades” slowly ascending to Terra Alta, then descend Cranberry Grade to Rowlesburg and the Cheat River Bridge, climb the Cheat River Grade to Blaser, slowly descend to Tunnelton and Kingwood Tunnel, at West End (West Portal) begin the steep descent of Newberg Grade to Hardman, from there it is easy running to Grafton.
Seventeen Mile Grade is part of the B&O’s famed WEST END. From Cumberland, MD, the track heads southwest (away from PA) into Keyser, WV. Seventeen Mile Grade starts around Bloomington and ends at Altamont, MD. The B&O had to build around the state of PA to get to Pittsburgh, originally ariving via Wheeling,WV.
Like they said, nobody knows for sure what curve resistance amounts to, but it’s customary to assume it’s equivalent to around 0.04 percent per degree of curve sharpness. If we assume that, then each degree of central angle is equivalent to 0.04 ft of “altitude gain”-- so a 180-degree horseshoe adds the same resistance as 7.2 feet of elevation, whatever its sharpness.
That means we can calculate average compensated grades just like we can calculate average actual grades. But we have to remember that curve greasers are alleged to reduce curve resistance well below the assumed 0.04 per degree.
…What is the highest elevation any of these grades attain southwest of Cumberland…? How far west does this Mountain Div. exist…Wasn’t it cut somewhere in this area back a decade or two ago…?
The Mountain Subdivision’s highest elevation is 2629 feet at Altamont; and it extends west through Grafton to Berkeley Run Junction.
Jay Potter