Elevation and grades

An open forum to discuss all aspects of the New Haven Railroad.
NH746EJO
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Joined: 25 Nov 2007, 00:18

11 Sep 2017, 15:03 #11

HIGHEST ELEVATION ON CNE
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This partial view of a large scale CNE profile of the Boston Corners - Winsted - Hartford line may be hard to read in this size.  Start at Canaan on the left which is shown at an elevation of 658 feet above mean high water at New Haven.  The line then climbs to about 810 feet at East Canaan and (going to the bottom of the profile) continues up to1005 feet at Haystack, then going back down the page, the line climbs to about 1330 feet at Summit near Norfolk, which is the highest point on the NYNH&H - Central New England.  The profile is from the office of the Designing Engineer dated Jan. 1, 1922.  Note that grades are steeper than on the Maybrook line -- the climb to Haystack is at a rate of 85.53 feet per mile for about 3.5 miles (grades are the vertical numbers in feet per mile).
Last edited by NH746EJO on 11 Sep 2017, 15:52, edited 1 time in total.
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NH746EJO
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Joined: 25 Nov 2007, 00:18

11 Sep 2017, 15:42 #12

STEEPEST GRADE ON THE NEW HAVEN
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Profile dated January1, 1922 from the office of the Designing Engineer, New Haven.  Grades are shown as rise in feet per mile.  As shown there is a grade of 121.4 feet per mile for about two miles.  Grades at rates of 100 feet per mile or more are rare on the New Haven and they are short.  Between New Haven and Tyler City  there is a 100 foot rate grade but it is less than a mile in length.  On the Litchfield branch there is also a 100 foot per mile grade just east of Hawleyville but only about a half mile in length.
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NH746EJO
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Joined: 25 Nov 2007, 00:18

11 Sep 2017, 16:05 #13

ELEVATION OF PITTSFIELD

At about 1018 feet high, Pittsfield is the highest point on the non-CNE lines of the New Haven.  Note the short half mile grade at an 80.0 foot per mile rate of rise at South Lee.  (Detail of 1/1/1922 profile from Office of Designing Engineer.)
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Statkowski
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Joined: 05 Mar 2003, 09:39

11 Sep 2017, 16:28 #14

Well, looks like Norfolk Summit, Conn. is the highest elevation at 1,330 feet, and the steepest grade was on the Ridgefield Branch at 2.3%.
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NH746EJO
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Joined: 25 Nov 2007, 00:18

11 Sep 2017, 16:34 #15

NEW YORK CONNECTING RAILROAD
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In view of the comments about the NYCRR , here is a profile from the New Haven's Office of Designing Engineer dated 1/1/1922.  The grades shown of 63 feet per mile are the same as the grade on the Maybrook line at Poughquag and just a bit less than the 67.2 grade on the other side of the Poughquag grade on the way down to Towners.
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NH746EJO
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Joined: 25 Nov 2007, 00:18

11 Sep 2017, 16:50 #16

GRADES

I believe the reason that grades are given in feet per mile on engineering profiles rather than a percent such as a 2% grade is that grades are defined by the change in elevation  --  the change in elevation doesn't always mean the grade was steady.  That is, over a mile the track may rise by 50 feet but over the mile the rate of change may fluctuate slightly.  Changes in the grade are generally not abrupt at the bottom and top of a grade.  
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Statkowski
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Joined: 05 Mar 2003, 09:39

11 Sep 2017, 16:58 #17

Most track charts I've seen shows percentage for the affected stretch of track, not feet per mile.  Of course, when showing feet per mile, the mile may or may not be a mile.  And, just as with curvatures, there is a transition - vertical with grades and horizontal with curves.  With your change in elevation process, a rise of 50 feet over a mile (an overall 0.95% grade) could well be interrupted by a brief 7.4% grade, which wouldn't show up.  
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NH746EJO
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Joined: 25 Nov 2007, 00:18

12 Sep 2017, 14:31 #18

TAKE OUT YOUR SLIDE RULE
Saying a grade is 1% would be more understandable for most people than saying the grade is 52.80 feet to the mile.  Of course, if you are British neither would be useful since the British would say the bank (grade) is 1 in 100  -- or 1 in 50 if 2% or 1 in 40 if 2 1/2 %.  And you might need a banking engine rather than a helper.  In the era of the New Haven an electronic calculator would be science fiction so converting grades to the various definitions might require a slide rule (anyone remember slide rules?) or a table.  Following is a railroad construction table which shows grades in percentage and feet per mile.  It also shows how to calculate how much power will overcome the various grades  -- tractive resistance must be exceeded by the tractive force of the locomotive. 
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rsullivan
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Joined: 14 Dec 2016, 20:36

12 Sep 2017, 14:55 #19

Thank you Mr. NH746EJO for this table. I copied it and can see a real use during operating sessions on model railroads with any grade. The conductor (or engineer if alone) must know the weight of his consist and the grades on the assigned route. If the tractive effort of the locomotives assigned to his train are not sufficient to overcome the specific grade(s), the conductor/engineer must either request additional motive power prior to departing with the train, or arrange for helper service if none already are present. While I am modeling the New Haven Division from Oak Point Yard to Cedar Hill Yard, I am going to have to find out the grade at Lower Yard in Bridgeport. If trains departing lower yard don't have enough tractive effort to manage that short grade, than a yard helper would have to be dispatched. Now I have to plan at least two additional below the track uncoupling magnets in the track plan. I love this. For someone modeling the Maybrook, Highland, or any other portion of the New Haven with significant grades (to include me if I can negotiate trackage rights west of Bungay Tower (SS 3) and add Hell Gate with its 1.21% grade (Thanks Mr. Statkowski) it can add more thinking, and as Mr. NH746EJO points out, calculation without any electronic gizmos. It will also give us a chance to show younger modelers a way to figure things out with pencil, paper, and charts. (Don't try to show and explain a slide rule. It's like trying to explain Star Trek to someone who is listening to Fibber McGee and Molly.)
Richard H. Sullivan, Jr.  member #3967
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Statkowski
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Joined: 05 Mar 2003, 09:39

12 Sep 2017, 15:07 #20

When they built the railroad in my neck of the woods, back in 1905, one of the requirements was that main track grades would not exceed 0.8%.  Sure, it had a few 10° curves, and the wye accessing the line had a 12° curve on one leg and a 14° curve on the other.  The line still sees traffic, but the limiting factor for its operation is the 14° curve at the base of a three-mile-long 0.8% descending grade.  Maximum speed on the entire line when new was 25 m.p.h. for freight trains.
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