Bridge 481.6 on the Arthur Sub

Discussion in 'Bridges' started by klrwhizkid, Feb 3, 2014.

  1. klrwhizkid

    klrwhizkid Administrator Staff Member Administrator Frisco.org Supporter

    From Karl Brand:
    See Karl's later post that has corrected illustrations.
     
    Last edited by a moderator: Feb 12, 2014
  2. friscobob

    friscobob Staff Member Staff Member Frisco.org Supporter

    Well further north of where I'm modeling, but that would make a very interesting bridge to model. Thanks, Keith and Karl, for sharing!
     
  3. William Jackson

    William Jackson Bill Jackson

    There was a couple like that or similar on the Waldren Branch on KCS. Rail was a common way to make cattle guards also. They used to drive rail into dirt fills to stabilize the slope. Good place to see them was on the lead line.
    Used rail was used for countless items on the railroad. Nice Drawing.
    Bill Jackson
     
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  4. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

    Jeff and I were able to return to the Winding Stair Mountains, and we were able to reach bridge 481.6 for a first hand inspection. See: http://www.frisco.org/shipit/index....ountain-profile-june-30-1909.1361/#post-62846

    DSC_0064_br_481.6_ravine_section.jpg

    DSC_0072_br_481_6_looking_s_chords.jpg

    I intended to redraw the bridge, but I didn't get back to the task until recently. Here is my second attempt to create a drawing of Frisco Bridge 481.6, nee 481.5. Having been able to inspect the remains of the bridge in person, I was able to see my mistaken assumptions.

    From the Bridge Record Nov 1979:

    Spans: 2, 6'-0

    Type: Rail Span

    Number of Bents: 3

    Chord, Ply: 9

    Kind: 90 lbs SH Rail

    Ties: 6" x 8" x 9'-0

    Year: 1938

    Max Panel Length: 6'-0

    Total Length: 13'-0

    In my first interpretation, I used a standard trestle backwall. I misinterpreted the chord description from the bridge record. Eighteen rails were used to form 2 chords of 9 rails instead of the 9 rails that I used to form a single chord.

    The bridge is located on the Frisco’s Arthur Subdivision between Lamberson and Talihina. My 1909 profile shows a rail bridge at this location, albeit MP 481.5. The original structure used stone for the center pier and the two abutments and used 67 lbs rail for the chords. If I had looked at the 1909 profile, I might have had a better idea how the structure looked. I didn't remember I had the profile until after our trip to the Winding Stair Mountains. During 1938, the structure was rebuilt with concrete abutments and a concrete pier. The chord (9 rails/chord) used 90 lbs rail.

    For the bridge deck, the B&B records implied the use of a stand-plan open deck; these are the materials that I used:


    bridge_481_6_plan_view_and_abutment.jpg


    66F7B5AC-4EB6-487A-BC3F-8CB55F5FD5BF.jpeg

    I believe that the rail chords were fabricated off site; the rails were welded to boiler plate, three rail spacers were placed between the chords, and two gauge rods were used to snug everything together. See the photographs. The whole shebang was then loaded on a flat or a gon, and then dropped into place with a Brownhoist. For clarity, the boiler plate and the gauge rods were not shown in my drawing. The prototype bridge is on a 3 degree curve and on a 0.707% grade; I have depicted the bridge as being on a tangent and level.

    The bridge was strong enough to handle everything up to the lighter, 4000-class locomotives.
     
    Last edited: Feb 8, 2019
  5. Coonskin

    Coonskin Member

    Hi Karl:

    Thanks for the info and update.

    You said:

    "The bridge is located on the Frisco’s Arthur Subdivision between Lamberson and Talihina."

    I live about 45 minutes away from Talihina. Using topo maps, I can't for the life of me see a way back toward the roadbed via a county or forest road, either side (west or east).

    Are you hiking up the road bed from Talihina?

    One of my "bucket list" things to do is hike the roadbed (in sections, if needed) from Talihina to Bengal. However, I suspect there will be creeks I won't be able to cross. Unfortunately, I just can't find any roads or trails that touch base with the road bed that would permit vehicular traffic in order to get closer to the road bed.

    Any experience you can share about hiking that area would be much appreciated.

    Andre
     
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