Last stage of turnout construction …

Hi all,

I have started adding the checkrails to the UP storage yard turnouts.

First a bit of theory behind the need for a checkrail.

On a prototype turnout, the tip of the vee crossing is quite vulnerable to damage if a wheelset’s flange was to strike it.  This action would most certainly cause a derailment.  The checkrail is there to help guide the wheelset through the crossing so as the flange does not come into contact with the tip of the crossing vee.  The checkrail is gauged off the vee crossing and not from the stockrail.  This measurement is called the Check Gauge.  See my About Proto-87 page.

(The image below is sourced from Greg Edwards’ Trackwork Manual and has been used with permission.)

checkrails

As I am modelling mainline trackwork, I will be using the fifteen foot checkrails.

First a length of code 70 rail is cut to length.  It is then held on it’s side in a piece of timber to allow for the removal of the base of the rail on one side.  Refer to the sectioned drawing above showing the base removed from the checkrail.  The base is then carefully filed away, nearly to the web.

filing away the rail base on one side

Once complete, a slight taper is filed at each end on the same side as the removed base material.  This taper can be seen in the drawing above.

filing slight taper at each end

As can also be seen in the drawing above, the checkrail is bent either side of halfway.  The centre of the checkrail is marked, along with marks 2’6” either side.  At these points, a slight bend is created.

The checkrail is then placed in its location and gauged from the vee crossing with a check gauge.  The centre line of the checkrail is opposite the practical point of the vee crossing.

gauging the checkrail

layout_construction_117

It’s a bit difficult to see in the image above, but it shows the check gauge sitting against the vee and the other end locating the checkrail.  The checkrail is now soldered in position.

Now, a wheelset is test run through the crossing, and with slight pressure against the checkrail towards the vee, the flange should not catch on the tip of the vee.

test running a wheelset through the crossing

The wheelset should run smoothly through the crossing.

I have completed half of the UP yard turnouts, so another eight to go, then I’ll continue on with fitting of the point blades, motors and checkrails in the DOWN yard.

Cheers for now.

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Posted on September 20, 2012, in Trackwork and tagged , , . Bookmark the permalink. 4 Comments.

  1. Hi Ian. Are there air gaps or styrene spacers either side of the crossing vee to insulate the frog?
    Cheers, Lindsay

  2. Looking good Ian!

    How do you find the DD wheelrights gauges to use? Only curious because they are basically scaled down P4 gauges, and are a little different from the sorts of things that are normally used for 3.5 mm scale trackwork.

    Regards,

    Craig W

    • Hi Craig,

      I have found the 3-point triangular gauges very good for tangent track as well as the curves, and this was the first time I had used the Check Gauge. It only just fits over the head of the code 70 rail, but enough to gauge the checkrail OK.

      The checkrails certainly look good once down and enhance the look of the fine flangeway. I can’t wait to get stuck into the detailed turnouts for the scenicked sections.

      Cheers.

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