Sunday, December 22, 2013

086 The Navajo Mining Railway - Building an Ore Car Fleet #1

Navajo Mine Shaft #1, Mexican Hat, Utah, circa 1928

July 7th, 1928

Dear Mr. Cavenaugh,

     Upon evaluating the needs of all four mines and the establishment of the Cavenaugh Reduction Plant at Mexican Hat, Utah, the railroad has need for larger and more robust railcars for the movement of ore.  The small 16 foot gondolas we are using require manual unloading and can barely carry the weight of the extremely heavy ore.  We have lost seven of them to damage just this month.
     We've been in touch with the Lima Machine Works and they have offered us their Phase Five ore car.  These ore cars are of steel construction for the ore carrying part of the car, but are made of wood for the non-ore parts.  This provides a more inexpensive yet sturdy railcar.  The Gilpin Tramway in Colorado used the Phase Three cars up until 1917 with great success.  They were of two foot gauge construction though so Lima Machine Works designed a Phase Four car for us that is of the 30" gauge variety.
     Due to the weight of the ore we are moving, we thought the Phase Four car would be overloaded and we made some suggestions to Lima for reducing the load area.  They are willing to manufacture one Phase Five car for testing purposes for a fee of $285.  We could expect the car in two months time.
     We'd like your permission to purchase the test car for evaluation.

Yours Sincerely;

Smith and Jones, General Managers


The Gilpin Tram cars have always been interesting to me.  I'm still curios as to how these cars which have a metal bucket bolted between two wood end frames ever lasted so long.  The Narrow Gauge and Short Line Gazette (best magazine ever) published an article in the Sept/Oct 1998 issue on page 30.  The article was written by my Georgia friend and narrow gauge legend Mallory Hope Ferrell.

I'm going to need a lot of cars...but how do you figure out how many?  Here's how I do it...

Using the trackplan located here, I look at the sidings and other car placements such as staging and yards, and figure out about how many it will hold at maximum capacity:

  1. Mine #4 - three cars
  2. Mine #3 - three cars
  3. Mine #2 - closed
  4. Mine #1 - three cars
  5. Crusher - three cars
  6. Tailing Track - three cars
  7. Passing Siding - three cars
  8. Rip Track - one car
  9. Off Line Storage - three cars

Total maximum placements - 22 cars
22 x 75% = 17 cars

I use the percentage calculation to figure out what density of cars I want on the layout at any one time.  For very heavy operations I use 100%.  For very light and slow operations I use 50%.  75% feels right and allows me to have one or two on the work bench for repairs without affecting anything.  Trains are designed to be three cars each, plus caboose and locomotive.

Wow...17 cars is a bunch.  There are no On30 kits for these.  Grandt Line makes a detail parts kit but it is scaled for On2 and doesn't have everything you need to make a car.  Bachmann makes an ore jenny that tips, but these cars look very awkward to me and are really only used at a mine site and not on the open mainline.  They average about $75 for three, which is $25 each.  If I need 17 x $25 = $425.  The evil manager upstairs would never approve that.

My opinion has always been that if you need a bunch of cars, mass produce them!  So that's what we'll do!  Tune in next time when we design the car for manufacturing!


  1. Re: "I'm still curios as to how these cars which have a metal bucket bolted between two wood end frames ever lasted so long." -- I have totally wondered this exact same thing. As far as I'm aware, there aren't any photographs that are taken from above of these cars such that anyone has ever seen the bottom of the "fishbelly" part? Sundance recently published "The Gilpin Railroad Era" which I haven't yet been able to find a reasonably priced copy of, but I've heard there are some not-before published photos in it.

    Anyways, I spent a while on these models because I made some myself. I've seen 7/8n2 guys run the wood frames all the way through the metal body, assuming that the ore went between the wood beams I guess? My version didn't have that. I'm sure you're aware the Gilpin cars had 3 sizes, 0.5 cord, 1 cord and 1.5 cord capacity if I remember correctly. I had focused on the half cord car which I think is the one Grandt produces in On2, except my version was for HOz (1:87 on 6.5mm "Z" gauge). It was a weird and short lived interest of mine, but here's a photo of the car and correct gilpin trucks fresh off the 3D printers:

    The boxcar in the back is a C&S 3ft gauge car in HOn3 for comparison.

    Not sure how true to the original you were planning on being, but I've spotted before that San Juan Car Co's WSL trucks were fairly close to the "pointed" archbar trucks on the gilpin cars (though a bit pricey):

    This comment's going on kinda long so I'll wrap it up here. Will be watching for what you end up doing with these cars.

    1. LOL...make the comments as long as you want! I love 'em! My goal isn't to have a seriously accurate model, but to give the feel of mining in a remote part of Utah. Much later I did figure out that the beams of the car do NOT go through or under the bucket. Each end is a separate piece, and they just bolt on to the one piece bucket. I'm amazed that this every worked, and photos doe show a noticeably sag.

      I ordered the Grandt Line On2 parts kit to get details and ideas...should be here any day. Will post what I find out.

    2. Hey! I love the 3D printed car! That is really fantastic. Since my car is On30, maybe its a 2 1/2 cord car...or 2 with a lower bucket. I've made lots of sketches and mold plans...still haven't ventured into 3D printing. Guess I better learn!


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