Trains.com

"High Grade" vs. "Low Grade". "Highline" vs "Lowline" parallel railroad lines in RR engineering terms.

6131 views
20 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2020
  • 54 posts
"High Grade" vs. "Low Grade". "Highline" vs "Lowline" parallel railroad lines in RR engineering terms.
Posted by highball6868 on Monday, August 3, 2020 12:55 PM

I have heard these terms on the B&O and Great Northern and Erie. I assume that the low grade lines were built and used for heavy slow coal trains and the high grade lines were for hotshot freight and passenger? The lines would be parallel to each other running at close as 500 feet or within a few miles of each other. The B&O had a "Low Grade" line next to its main line near Keyser WV and runs for about 15 miles or so which locals refer to as the "Low Grade Line ATV Trail" which sits in the Potomac Valley and is very wet and muddy most of the time.

  • Member since
    March 2016
  • From: Burbank IL (near Clearing)
  • 13,540 posts
Posted by CSSHEGEWISCH on Monday, August 3, 2020 1:55 PM

The terms refer more to the terrain and route of the line.  A low-grade line has easier grades and curvature than a high-grade line.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
  • Member since
    February 2008
  • 602 posts
Posted by Bruce Kelly on Monday, August 3, 2020 2:45 PM

In eastern WA, Low Line vs. High Line were and still are taken literally. SP&S between Spokane and Pasco was referred to by some as the High Line because it clung to the higher sides of canyon walls along the Snake River and in Marshall Canyon, even though it had the easiest grades. The NP branch (now long gone) paralleling the SP&S but closer to river level along the Snake was nicknamed the Low Line. BNSF's daily turn between Pasco and Ayer, traveling most of that distance via UP on the opposite side of the river, is still called the Low Line local because it performs the same basic function that NP once did of linking the Lewiston area's former CSP branches with the outside world by way of Riparia.

Out of Spokane, BNSF has two separate lines running southwest through Marshall Canyon, converging at Lakeside Jct. a few miles before the summit at Cheney. The ex-SP&S segment is often referred to as the High Side (it runs mostly at a higher elevation but has much easier grades) while the ex-NP segment is referred to as the Low Side because it drops to a much lower elevation at its crossing of Hangman Creek, with 1 percent grades east and west from there. This is a case where high and low refer to the relative elevation of rail lines, NOT their gradients.

  • Member since
    January 2019
  • 1,693 posts
Posted by Erik_Mag on Monday, August 3, 2020 2:47 PM

The "High Line" when used by the Great Northern was in reference to being north of the Northern Pacific line through North Dakota and Montana.

  • Member since
    January 2001
  • From: MP CF161.6 NS's New Castle District in NE Indiana
  • 2,148 posts
Posted by rrnut282 on Monday, August 3, 2020 3:00 PM

Pennsy also built many low-grade lines.  Some railroads gave them a " xxx Freight Bypass Line" name.  

Many times, the original line was put in as expediently (cheaply) as possible.  Lines that went straight up the hill, or had excessive, sharp turns that slowed down trains, increased operating costs, either by needing helper locomotives or a 2nd crew to get across the division in time.  As the railroads made money, they spent it lowering operating costs by building a lower-grade line that necessitated more grading, bigger bridges, or tunnels (expensive) to reduce curvature and grades, allowing one crew to make it across the division with more tonnage. 

Mike (2-8-2)
  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Monday, August 3, 2020 4:21 PM

highball6868
I have heard these terms on the B&O and Great Northern and Erie. I assume that the low grade lines were built and used for heavy slow coal trains and the high grade lines were for hotshot freight and passenger?

On the Pennsylvania, the terms had specific meaning.  There was no such thing as 'High Grade Line' (especially in the sense of high-grade watch) -- Low Grade lines were built to minimize grades or grade changes to simplify freight handling.  This was usually done without regard to straightening curves at all except insofar as compensating curve and grade together in the civil engineering might be concerned.  The idea was to work the heaviest train at the lowest costs for a given type of power, and PRR had a number of very good examples, like the Atglen & Susquehanna of 1907, that did very well and then still better when electrified.  

A 'High Line' is one built on an elevated grade or trestlework/viaduct, like the PRR low-grade bypass line "behind" 30th St. Station that facilitated freight west from Morrisville.

Now, PRR certainly got into the spirit of low-grade low-curve high-speed design as early as 1923, when they proposed Sam Rea's idea of a new passenger line bypassing the Pittsburgh bottlenecks.  This included quite a bit of heroic earthmoving and a couple of monster tunnels -- but was the line the thinking that culminated in the PRR S1 and T1 was designed to really use.  (Even this has too much curvature to be practical for modern HSR, though, and it (and the connecting extensions at either end) would likely have been a long and expensive disaster from the late '40s on, when even 10-hour trains to Chicago would have become noncompetitive.

Google 'Sam Rea Line' and revel in the details...

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,330 posts
Posted by selector on Monday, August 3, 2020 5:26 PM

Overmod

 

 
...

A 'High Line' is one built on an elevated grade or trestlework/viaduct, like the PRR low-grade bypass line "behind" 30th St. Station that facilitated freight west from Morrisville.

...

I always wondered why the CPR trestle over the Oldman River at Lethbridge, AB, is formally called the 'high level bridge'.  But, as you say...

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Monday, August 3, 2020 6:18 PM

When originally laid out the early railroads were built on the cheap and dirty - quickest way between A & B undesireable grades and curves be damned.  Considering early locomotives were not 'speed demons' and really couldn't haul much in the way of tonnage - the early alignments filled their rudimentary needs - they got from A to B.

Once RR management began to understand what was necessary to operate the RR AND turn a profit - they began to the see the cost of their line having bad grades and curves and began to utilize some of their profits to implement engineering solutions to ease the grades and curve to increase the tonnage a locomotive was able to handle and ease the curves so the locomotive could handle that increased tonnage at a higher rate of speed.

The 'naming conventions' used by railroaders are very rudimentary - New means it is newer that what was there before.  Low Grade means that there is less gradient on this route than the route that is not the Low Grade.  High Line can mean several things - a line that is build on a 'relatively' high trestle for a extended distance; it can also mean a railroad that is build on the top of ridges and uses high bridges to span the valleys between the ridge tops.

Never too old to have a happy childhood!

              

  • Member since
    March 2016
  • From: Burbank IL (near Clearing)
  • 13,540 posts
Posted by CSSHEGEWISCH on Tuesday, August 4, 2020 10:05 AM

As one example, the C&NW New Line between Chicago and Milwaukee was built around 1900, but it is newer than the original line through the northern suburbs.

The daily commute is part of everyday life but I get two rides a day out of it. Paul
  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Tuesday, August 4, 2020 11:11 AM

It probably won't be long before Ray gets to the term "Air Line" with respect to railroads and wonders if this implies 'high' or 'fast'.  It does not, nor does it imply an absence of grades.  What it means is absolutely ruler-straight in direction, with no horizontal curvature.

  • Member since
    July 2020
  • 54 posts
Posted by highball6868 on Wednesday, August 5, 2020 9:31 AM

Chicago-New York Airline Railroad ("Airline railroad" being a term "as straight as the crow flies") was a early high speed railroad fiasco boondogle that looked great on paper that was to run from a straight line Chicago South Burbs to New York but fell apart when the realityhttp://www.marymaclane.com/airline/ of terrain was that NW Indiana is not as flat as we think it is. https://upload.wikimedia.org/wikipedia/commons/c/cc/CNY_map.png

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, August 5, 2020 9:49 AM

Wasn't so much a 'boondoggle' as a victim of the 1907 financial 'panic'.
 
They did suffer from the problem of choosing to build the whole railroad to high civil standards before getting enough of it open to justify extreme high speed: the Coffee Creek fiasco could easily have been built as a trestle and then filled in as speeds and traffic warranted, and in my opinion a more savvy management might have done so.

The 'other' logical thing that outfit could have done was to co-locate the slightly more ancient high-speed (vaunted to 150mph) parcel 'telpher' system with their ROW.  Even today 8-hour parcel delivery would be an interesting thing to provide... and the telpher could be built before the more expensive passenger ROW and revenue from it used to facilitate improvement and extension.

It is still a bit surprising to me that there wasn't more work on high-speed electric railways of this general kind after 1903; I think there, too, the practical lessons of the 130mph testing were not really recognized before 1907 made it difficult to build them and competition from established railroads both in cost and speed would make it difficult to justify financing them.  It does have to be said that the powerplants and distribution architecture for 100mph trains in the pre-1907 era would have been dramatic especially for those regions that had no great secondary demand for electric power at the time...

  • Member since
    July 2020
  • 54 posts
Posted by highball6868 on Wednesday, August 5, 2020 6:32 PM

https://rogerfarnworth.com/2018/12/07/manchester-victorias-telpher/  is that what you mean by a Telpher which is a kinda of a monorail??

  • Member since
    December 2008
  • From: Toronto, Canada
  • 2,560 posts
Posted by 54light15 on Wednesday, August 5, 2020 7:11 PM

I've never heard of a Telpher. Interesting- it reminds me of the baskets that went through a store on a track about 100 years ago- I seem to recall one in a movie with W.C. Fields. 

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, August 5, 2020 7:56 PM

Look up 'Weems Electric High-Speed Railway'.

As far as I know, David Weems was the first person to extend the telpher idea to long distances, and enlarge it enough to be stable 'outdoors' but not so large that capital and power costs grew large.  This might be thought of as the 1880s version of unmanned space exploration vs. manned colonization -- even today there are few ways to assure 8-hour delivery of business paper except by courier escort, but here it was before the turn of the century...

The thing would not work as described, but it is not that difficult to see how to get it to run.  Several 'lines' of guideway co-located with a double-track 'interurban' progressively given the Sam Rea Line treatment might have made an interesting project in a world not ruined by 1893 and 1907...

  • Member since
    May 2019
  • 1,768 posts
Posted by MMLDelete on Wednesday, August 5, 2020 8:27 PM

Years ago I thought low-grade line meant subpar line. Like a low-grade whiskey or low-grade cut of meat. "Grade" as in quality.

I took it to mean the line was not in good repair. So what I imagined the low-grade line to be was where the slow drag freights ran, the low-priority merchandise.

So I basically had it bass ackward.

  • Member since
    May 2003
  • From: US
  • 25,292 posts
Posted by BaltACD on Wednesday, August 5, 2020 10:00 PM

Lithonia Operator
Years ago I thought low-grade line meant subpar line. Like a low-grade whiskey or low-grade cut of meat. "Grade" as in quality.

I took it to mean the line was not in good repair. So what I imagined the low-grade line to be was where the slow drag freights ran, the low-priority merchandise.

So I basically had it bass ackward.

No you were right for the wrong reasons.

Max tonnage trains will generally use the Low Grade beause the Low Grade's configuration allows more tonnage to be handled - at any speed - than does the alternate line - which can have a multitude of different names depending on local convience.

Never too old to have a happy childhood!

              

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Thursday, August 6, 2020 4:08 AM

BaltACD
Max tonnage trains will generally use the Low Grade beause the Low Grade's configuration allows more tonnage to be handled - at any speed - than does the alternate line

Or, to add a wee dram of Laphroaig, if you want to optimize operations for faster traffic you'll use something like double track and CTC to route the TrucTrains around the ore drags, if you don't want them on the old passenger main with more handling required...

But remember that the old-style low-grade lines involved many preferential compensated curves to limit construction 'spend' over what is required for low-grade limited-curvature (as on the Sam Rea Line) or (horrors!) LGV-style High-speed curve and transition construction gor both horizontal and vertical.  So that 'maximum speed' might be effectively limited even if the equipment itself is capable of safe higher speed.  I suspect the A&S was designed for no more than the PRR peak freight speed of 50mph throughout.  Note that in a modern PSR and fuel-conserving world this is no longer nearly the concern it might have been in an era of reducing times with higher effective train speed... 

I found it amusing that the 'preferred' alternative the DOT/FRA considered for top-down slab-track is simultaneously HAL and Class 9 capable... not that you'd intentionally mix THOSE types of traffic often!

  • Member since
    August 2020
  • 2 posts
Posted by FormD on Friday, August 21, 2020 12:35 PM

What is a "Cutoff" as in the "Lackawanna Cutoff"? I assume that there are other Cutoffs out there and somehow this saved time for the DL&W.

  • Member since
    January 2002
  • From: Canterlot
  • 9,575 posts
Posted by zugmann on Friday, August 21, 2020 4:55 PM

FormD
What is a "Cutoff" as in the "Lackawanna Cutoff"? I assume that there are other Cutoffs out there and somehow this saved time for the DL&W.

PRR had the Trenton Cutoff.  From what I understand it allowed NYC - Harrisburg freights to bypass Philly. 

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Friday, August 21, 2020 7:47 PM

A cutoff is a new line that 'cuts off' from the existing main for some purpose, usually rejoining it at some further point.  This might be done to shorten a convoluted route using better modern grading techniques, as in Truesdale's cutoffs, or to lower peak compensated grades, as in the Morrisville cutoff [note: all the fun started across the river from Trenton...], the Atglen & Susquehanna, etc. on PRR.  (Note that this is slightly but significantly different from cutting off distance or cutting down grades, which is not always what happens...)

There is a slight semantic difference between a 'cutoff' and a whole new main line, like the proposed Sam Rea Line to bypass Pittsburgh, and the west-end connection of it into Ohio.  Arguably the same would exist on the east end of it, which would bypass Philadelphia and probably Trenton to connect more directly to the New York market.  But in a sense these could be considered 'cutoffs' too... just replacing rather than improving a route.  In a sense this was true of the Lackawanna Cutoff as it so thoroughly replaced parts of the Old Main Line that they were regraded for highways.

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

Search the Community

Newsletter Sign-Up

By signing up you may also receive occasional reader surveys and special offers from Trains magazine.Please view our privacy policy