Detailing Track Part 4: Turnouts
The amount of variation in full-size turnouts is staggering. I admit I had no idea how extensive it was until I began work on the book and I’m still learning about turnouts. This post can’t possible cover all the variations but will look at two common scenarios.
When you study full-size turnouts there is a lot to see beyond the frog and switchpoints. You’ll have specialized tieplates, slide plates, anti-creep rail anchors, rail braces along with clamps and bolts of every description. It all adds up to a wealth of modeling opportunities. The opening photo shows a typical turnout.
Located on the remnant of the GR&I that serves as a switch lead for the Belden Wire And Cable plant in the background, this No. 8 turnout has the traditional features we expect to see. This configuration is typical of low traffic construction having just a head rod and single back rod for the switchpoints. You’ll notice the wear on the open switchpoint and that the throw mechanism has been upgraded to the newer ergonomic handle. Of interest is the rail bound frog with manganese inserts. Referring back to my 1921 Maintenance of Way Cyclopedia, manganese steel inserts came into use around 1900 on turnout frogs in high traffic situations. Whether it’s cast or rolled, manganese steel offers superior resistance to abrasion and wear from wheel impact over carbon steel rail.
All of the turnouts in this area are similar. The GR&I was a separate railroad in the 1800s and later absorbed into the Pennsylvania’s westward expansion. Running north several hundred miles to its namesake city of Grand Rapids Michigan, this was a significant branch with both freight and passenger traffic and I speculate the track was upgraded at some point. During the 1940s -’60s, there were a number of factories in this location and each required considerable switching. This particular frog bears mill marks that indicate it was made by Bethlehem Steel in 1937, which tends to support my speculation.
Also of interest is the cast guardrail. The mill marks give no clear source for the maker but there is a date of 1926, suggesting this may be an original feature.
As a stark contrast, this turnout off the NS main is a study in heavy duty construction. Multiple trains daily pound this turnout with a track speed of 45mph. There are several features to be aware of, first among them being the spring frog.
Spring frogs are favored in heavy traffic situations as they provide a continuous bearing path for the wheel treads along the main route. The wing rail for diverging route is allowed to move by means of heavy springs around a through bolt contained in a housing. Additional spring bolts keep the wing rail aligned to the main route yet allow it to open from the force of passing wheel flanges on the diverging line.
From this view the diverging route to the yard is on the left and the frog is in the normal position for the main. You’ll notice the throat of the frog is offset with the straight closure rail having a smaller gap than the branch near the point of the frog. This not only provides greater running surface but also engages the backs of wheels so they can open the flangeway on the branching route. You can see how the extended guardrail is designed to hold the wheels tightly and guide them through the frog. All along this turnout everything is tightly secured with an abundance of rail anchors and anti-creepers to combat rail movement, while the specialized tieplates spread the load and rolling forces across multiple ties at once.
Looking at the business end, you’ll see that only the switchpoint to the branch is hinged, with the point and closure rail for the main line being a continuous length all the way to the frog. As in the other images, there is an abundance of hardware that ties everything together.
Coming off the main, this turnout features an electric switch lock supported by a third head block tie. Inside is a lever that you turn on physically unlock the switch throw bar. When you move the lever, it sends an electrical current into the signal system to figure out if the block is occupied. This prevents you from opening the switch in front of a train.** (My thanks to Craig Townsend for correcting my error in which I mistakenly described this as a call box.)
The purpose of this series is to encourage a closer study of track, rather than a focus on techniques. The point I want you to take away is that regardless of whether you use commercial products or scratchbuild, once you understand full-size track you’ll see opportunities to enhance the visual qualities of your track. This is not a full blown study of track (that would take volumes) but only a handful of suggestions of things you might consider. You aren’t limited to the level of detail or quality a manufacturer provides. With a bit of work and careful observation, you can enhance the realism of any type of track. Direct links to Parts One, Two and Three are below.