Prototype Information.
In 4.1.0 Right of Way I discussed how a railroad company got the land that it operates on. Roadway is defined as the parcel of land which is prepared to receive the track. It starts with with the corporate idea of going from location X to location Y. The Roadway is the engineering decision on what route is chosen to get from X to Y. That decison is impacted by geography, politics, capital, marketing etc., etc. Railroad modeling forcus' on the track engineering aspects of roadway construction.
In this page we will discuss roadway engineering and construction.
Roadway Engineering.
Walter Mason Camp in his book Notes on Track, discusses the subject of roadway engineering. Roadway engineering begins with the reconnoissance or preliminary surveying of a route and follows through the location and the construction of the roadbed, the building of the track proper, and continues with the maintenance and repairs ever afterward; for in no sense can it be excluded during the progress of any of these steps.
In locating the line for a railroad track, it may often happen that a choice may be had between soil or substrata of different kinds, without sacrificing anything in matters pertainrng to right of way, grades or curvature; or the local conditions peculiar to one side of a valley may differ so widely from those of the opposite side, in such respects, for instance, as exposure to wind and drifting snow, slides, falling rocks, surface drainage, springs of water, stream encroachments on the roadbed, the shading of the right of way by steep hills or by forest, as to materially affect the cost of maintenance.
The simplicity of the track structure is the deceptive element in questions relating to maintenance economy, for ideas concerning the stability of track are too frequently confined merely to the question of approved qualities of rails, ties and ballast. To carry traffic, and the machinery of
operation, that is, the weight of locomotives and cars, the length,
number and speed of trains, will govern the amount of business
that the road gets. Certainly the policy of the road should not be to
turn away business and reduce weights of trains to fit the track, but on
the contrary the track should be made to fit the traffic, since it is
the traffic that earns the revenue.
The fact that the track structure lies upon the earth surface, exposed to the extreme action of the natural elements, is a very important consideration in track engineering.
Classification Standards
Classification of Track on a Traffic Basis. The construction and maintenance departments of every railway have certain standards for material and methods. A railway having an extended mileage has a variety of different kinds of track and many different traffic conditions. Thus the maximum freight-train, the fast freight-train, and the high-speed passenger-train, all with excessively heavy axle loads and total weight, have their own requirements for roadway and roadbed.
The American Railway Engineering Association has adopted the following classification of track on a basis of traffic carried:
Class A Track. All districts of a railway having more than one main track. Also all single-track districts where the traffic equals or exceeds a freight-car mileage of 150,000 per mile per year; or a passenger-car mileage of 10,000 per mile per year and a maximum passenger-train speed of 50 miles per hour.
Class B Track. All single-track districts of a railway where the traffic is less than for Class A and is equal to or exceeds a freight-car mileage of 50,000 per mile per year; or a passenger-car mileage of 5000 per mile per year and a maximum passenger-train speed of 40 miles per hour.
Class C Track. All districts of a railway not meeting the traffic requirements of Classes A or B.
Federal Railway Administration
Under FRA regulations, each railroad has primary responsibility to ensure its track meets or exceeds the federal safety standards. This includes railroad inspectors performing track inspections at specified minimum frequencies based on the class of track, the type of track, the annual gross tonnage operated over the track, and whether it carries passenger trains.
According to FRA Regulations:
- Track speed is determined by the class of track.
- Railroads can change the class of track (and thus increase or decrease the track speed) whenever it deems appropriate and without prior notification to, or approval by, the FRA.
- Railroad maintains the track to the appropriate federal safety standards for that class of track.
Class of track (Track speed freight/passenger)
Excepted track 10 N/A m.p.h.
Class 1 track 10 15 m.p.h.
Class 2 track 25 30 m.p.h.
Class 3 track 40 60 m.p.h.
Class 4 track 60 80 m.p.h.
Class 5 track 80 90 m.p.h.
Class 6 track 110 m.p.h.
Class 7 track 125 m.p.h.
Class 8 track 160 m.p.h.
Class 9 track 220 m.p.h.
If a segment of track does not meet all of the requirements for its intended class, it is reclassified to the next lowest class of track for which it does meet all of the requirements of this part.
Roadway construction. Roadway is constructed based on the roadway engineering plan. The plan identifies all the issues involving construction, to include:
1) Geography: that is the roadbed, embankment, cuts and fills, drainage, and
2) Track structure: Ballast, Ties, Rails, Turnouts, Track crossings (Special works), and other associated materials.
In Layout Design - 6 - Station Maps I discussed engineering maps that focus on survey information of the right of way, the track
diagram which includes tangent and curvature information and bridge and
building information.
I also discussed the use of mileage maps track diagrams, rail and ballast information, drainage, super-elevation and grade line, bridge and building, and signal and communications information.
The third engineering document of importance is the common standard. It provides a standard of construction for everything the railroad develops. If you're fortunate to have chosen a prototype whose historical society has such maps then you are in luck. I was fortunate to find a Union Pacific Common Standards Book. These standards in this Union Pacific Common Standards book were used to
describe a wide variety of bridges, buildings, tools and track
components all across the Union Pacific system. The collection includes a
large variety standards dating from 1904 to 1985, with numerous updates
replacing obsolete standards, which are also included. Another source is the Pennsylvania Railroad Standard Plans.
Common Standards.
The Class 1 railroads interchanging with the WWSL generally have identified roadway standards based on their unique operational needs. They are called a variety of titles, but essentially are right of way common standards for roadbeds. Here are examples of the roadbed standards for the Class 1's in the WWSL's operational area.
Great Northern
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Northern Pacific
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| Standard Plan by Type of Ballast |
Union Pacific
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Notice that each railroad defines its roadway differently. Great Northern defines by traffic level, Northern Pacific by the type of ballast used during construction, and the Union Pacific by operational activity.
The WWSLThe WWSL roadway is a single track main line with passing sidings. The main line lies primarily along the sides of two narrow river valleys. The WWSL roadway uses embankments, cuts and fills, and various forms of drainage. The WWSL roadway includes a variety of bridges crossing streams and rivers.
The WWSL will use the Milwaukee Road generic roadway template for its right of way, as it applies to electrified operations. See 4.1.0 Right of Way for the template that I will be using.
The WWSL is committed to using the Union Pacific Common Standards for roadway. There are four unique types: single track main line, single track branch line, double track main line and double track branch line.
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The WWSL 1st Division main line was constructed in 1920, upgraded and relayed in 1932. It uses the branch line standard. Construction and/or maintenance after 1932 uses the more recent main line standard maintenance.
The WWSL 1st Division will also have locations with retired, decrepit, abandoned and removed roadbed.
The
WWSL 2nd Division main line was constructed in 1948. It uses the more recent main line standard.
OPLC. The OPLC has their own roadway
standards (again using the Union Pacific Common Standards as a guide). The OPLC was constructed in 1920 and uses the single track main (1923) standard. OPLC roadway at Camp 1 and Sawmill uses the double track (1923) standard. OPLC roadway construction from Coal Grove to Reload uses the single
track (1935) standard.
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The
OPLC is the oldest track on the layout. It will be modeled as Low - or No - profile (Class C ) track.
Saginaw Timber Company. The STC Wickwood Yard is new
track installed in 1948. It will be modeled as medium profile track. There will be a short stretch of no-profile track at the south end
of the line.
Northern Pacific. The
NP 16th Subdivision track is branch line track. I have some photographs
of roadway along the Subdivision. Its definitely not as "formal"
as the NP common standard would indicate and I will model the relaxed
standard.
Milwaukee Road / Union Pacific Railroad. The MILW/UP track is branch line track using the
UP single track branch line common standard.
Modeling Techniques
The WWSL Maintenance Of Way department has identified 10
roadway classes based on roadbed, ballast, tie and rail usage. Each roadway class will have its own modeling technique. See
4.2.11 Roadway Modeling Techniques for additional details.
Federal Railroad Administration Track Safety Standards
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