MILL CREEK CENTRAL RAILROAD
Track Building & Track Laying Standards
From notes published by Brian Keim in August, 2003
Initially published on website 1/07/2006, last updated 01/12/2006
Introduction
The golden age of prototype railroading was a result of engineering collaboration through the American Association of Railroads. Their efforts helped standardize railroad construction to eliminate problems at connecting railroad interchanges. Standards were developed for railroad construction and materials selection to reduce maintenance costs and to improve safety. Our model Live Steam hobby strives to accomplish these same goals: to eliminate problems with interchanging equipment during open meets, to reduce amount of seasonal maintenance, and to improve safety.
Since our model Live Steam hobby is not governed by an overseeing body such as the A.A.R., it is up to clubs and private track owners to develop and implement their own set of standards. Fortunately, the International Brotherhood of Live Steamers has adopted numerous wheel and track gauge standards that are accepted worldwide. The actual right-of-way design, materials selection, and construction are still left up to the individual club or private track owner. Many articles, speeches, and debates have occurred over the past 30+ years concerning these topics. This is a good thing for it promotes critical thought by numerous persons about a single problem or set of problems. Much information is shared through magazine and newsletter publications and the Internet. Hands-on experience is also shared at open meets, hosted by nearby clubs and owners, where information about what 'has worked for them' is provided. Each club or private layout finds success with varying construction techniques and materials due to their own unique environmental and traffic conditions. For example, a right-of way that is laid entirely within wooded areas and that only sees service for a few weekends per year will likely require very little seasonal maintenance for the construction method employed. However, the same construction method applied to an active club layout that has open field trackage, will likely suffer from constant maintenance requirements throughout the year. With developments in new materials and actual testing of these materials, the standards agreed upon today can be revised in the future. After all, adopted standards are always the evolution and continuous improvement of ideas and practices.
The following standards for building components and assembly technique, are as a result of experience obtained from 30 years of track right-of-way building and maintenance at the North Eastern Ohio Live Steamers layout, formerly located in Copley, Ohio. A substantial amount of information and practices have been introduced to the N.E.O.L.S.. from member experience who themselves are also track owners and operators. This collection of standards is the result of the most current and successful materials selection and assembly techniques for heavily operated right-of-ways and diverse environmental conditions.
The following list of private track owners have been instrumental in supplying experience and insight toward the development of these standards contained within.
Clint EnsworthPA & W RailroadSharon Center, Ohio
Bill HayesMichigan Central RailroadMetamora, Michigan
Ken StemenPennsylvania RailroadMetamora, Michigan
Larry VolzerGreat Northern Ohio & Massillon Eastern RailroadMassillon, Ohio
Charles FairWalden & Lakeshore RailroadJeromesville, Ohio
Richard McCloyMill Creek Central RailroadCoshocton, Ohio
.
Track Work Philosophy
:
It is the goal of everyone involved in our miniature railroad hobby to build a right-of-way on which to operate our model locomotive creations. A successfully designed and built right-of-way must be:
1. Simple to construct.
2. Require very little maintenance.
3. Simple to maintain.
4. Resilient to seasonal. climate changes.
5. Able to accommodate a broad range of locomotive wheel bases, starting with 0-4-0 up through 4-8-4 types.
6. Affordable.
7. Manufactured from readily available and proven materials.
Before any railroad can be built, a determination of the type or service the railroad will be required to provide must be considered. Decisions about the grades and curvatures must take into account the types of motive power and train lengths that will operate over it. A short wheelbase locomotive can easily negotiate very tight curves and somewhat uneven track.. However short wheelbase locomotives tend to lack power and tractive effort, therefore limiting the length of train and maximum grade that they can traverse. A large wheelbase locomotive, such as a 4-8-4 type, is considerably more sensitive to sharp curves and poorly leveled track. The larger size and weight of a 4-8-4 class locomotive make it suitable for hauling longer trains as well as negotiating grades. The logical action to take in designing a right-of-way is to therefore limit the curvature and mean gradients such that all types of locomotives will be able to operate safely.
Once the plan of the right-of-way is established, an understanding of how each component interacts and reacts, as a complete section of track is necessary. A typical track section is composed of ballast, cross ties, cross tie screws, rail, rail joiners, and rail joiner bolts. Improper selection and assembly of anyone or combination of components will have a definite and measurable effect upon the stability of an entire track section. It is essential that one does not misinterpret track-building practices utilized by our 1: 1 cousins. The physics of mass, thermal .expansion, static, and dynamic loading as well as environmental effects upon full size railroads are far different from those experienced upon our miniature railroads. Remember that there are no 48' tall giant beings walking all over prototype trackage. A 39' long prototype track section weights about 7700 lbs yet a 1/8 scale section of our model trackage weights less than 15 lbs. Also consider that the rate of thermal expansion of aluminum rail is nearly twice that experienced by steel rail. A properly constructed and installed track section is known to be able to carry a maximum axle loading of 500 lbs.
Understanding the considerations outlined above, we can now identify the functions of each component
utilized in our model track building.
Definitions of Track Building Components
Rail
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. Makes direct contact with locomotive and rolling stock wheels.
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. Distributes load across the supporting cross ties.
Rail joiners
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. Forms a sliding joint that aligns two ends of rail together.
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. Permits a gap between rail ends for thermal expansion and contraction.
Rail joiner bolts and nuts
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Clamps rail joiners and rails together, yet allow for sliding fit of joint.
Cross ties
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Distributes load applied by rail to the ballast.
Cross tie screws
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Holds rail to cross tie surface, while permitting movement of rail along its axis.
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Keeps rails in gauge on cross tie.
Rail Gauge
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Establishes correct distance between adjacent rail heads.
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Must be able to provide reliable and repeatable measurements.
Rail Drilling Jig
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Establishes correct hole location and spacing for drilling holes in rail end that has not been punched.
Ballast
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Supports and distributes load of cross ties.
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Locks position of cross tie, preventing movement.
Tamping Bar
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Designed to properly work ballast under across tie.
Standards For Track Building Components
1) Rail
a) To be made from 6063-T6 extruded aluminum or steel.
b) Dimensions of 'T' head profile areas follows, 1" high, 7/8" wide foot, ~" wide head, 5/32" thick web, supplied in 10' or 12' lengths, reference drawing #2000. See Figure 1.
c) Each end of aluminum rail is to be punched with oblong holes to satisfy thermal expansion requirement.
2) Rail Joiners
For aluminum rail
a) To be made from 6061-T6 extruded aluminum.
b) Dimensions to be 1/8" thick, 1/2" wide, and 4" long, reference drawing #2001. See Figure 2.
c) Must be punched with 4 oblong holes to accept two rail ends.
For steel rail
a) A preformed slip joiner can be .used
3) Rail joiner screws
a) Stainless steel hex head #10-32 x 3/4" long..
4) Rail joiner nuts
a) Stainless steel hex #10-32 Nyloc nut..
5) Cross ties
a) Minimum 1 1/2 x 1 1/2 x 16" long. (Actual measurement of cross tie as sawed from a standard 2 x 4 would be 1 1/2" x 1 5/8").
b) To be cut from pressure treated lumber, rated for ground contact. (Note: the CCA arsenic based treated lumber is preferable to the ACQ treated lumber since it doesn't react with plated steel screws or aluminum or steel rail.)
6) Cross Tie Screws
a) #10 x l " washer head plated self-drilling sheet metal screw for CCA treated wood or stainless steel screws for ACQ treated wood..
7) Rail Gauge
a) To be made out of solid steel or stainless steel bar stock.
b) Minimum gauge between rail heads to be set at 7 5/8", reference drawing #2002. See Figure 3.
8) Ballast.
a) Limestone 617'sor equivalent (57's with fines, etc.). This is a mixture of 3/4" size rock with fines.
9) Tamping Bar
a) Should be a 1" to 1 1/2" wide x 1/16" to 1/8" thick piece of steel attached to a handle.
b) Air tamper with 4" wide blade from Harbor Freight long reach scraper.
Right-Of-Way Preparation
The preparation of a right-of-way roadbed is essential to maintaining the integrity of the finished trackage. Trees, tree roots, rocks, ditches, and creeks are some of the common obstacles that are often in the way of a desired roadbed. Each obstacle will require its own solution for being dealt with. At times, specific obstacles cannot be easily altered therefore requiring revisions to right-of-way plans. The following rules are to be applied when planning, constructing, and maintaining a right-of-way.
1. A minimum of 48" shall be cleared and graded for a single track right-of-way. See Figure 4.
2. A right-of-way which will contain parallel running tracks shall have a width of 24" measured from both outside track centers plus the separation spacing of each adjacent track section. See Figure 5.
3. Open drainage ditches shall not run parallel along trackage at a distance less than 24" from track center. See Figure 5.
Track Assembly Standards
1) Straight track
a) Track sections are to be constructed in a track jig. This maintains even spacing between ties as well. as provides a flat foundation on which to work.
b) Cross ties are to be spaced at no less than 3 ties per 12" of track (4" spacing).
c) Cross ties should be orientated with the smooth mill cut side to be against bottom foot of rail.
d) Rails are to be gauged using rail gauges. Three or more gauges should be used to ensure parallelism between adjacent railheads. See Figure 6.
e) Rail gauges should not be positioned such that they are more than 2 cross ties apart. See Figure 6.
f) Rails are to be secured to a cross tie, using two cross tie screws per rail, or a total of 4 cross tie screws per tie. See Figure 6.
g) Cross tie screws are to be located in line to each other on opposite sides of the rail foot. See Figure 6.
h) Cross tie screws are to be driven into the cross tie at a slight angle, matching the angle of the rail foot. See Figure 7.
i) Cross tie screws are to be driven into the tie only until the screw makes contact with the rail foot. The screw should never deform or cut into the rail foot, otherwise movement due to thermal expansion of rail will be impeded.
j) When possible, it is good practice to locate a tie directly under a joint. This helps to support both joining rail ends and prevent sags.
k) Track sections or 'panels', to be transported to a remote location for-final assembly to right-of-way, should be assembled with all cross tie screws along one rail properly secured. The adjacent rail is to be secured in four places, (at the ends and two places in the middle). Once the panel is transported to the needed area, the adjacent rail is then loosened and slid into proper position to match the existing rail joint offset. Once the panel is connected to the existing line with rail joiners, the adjacent rail can then be secured to the cross ties.
l) Rail joints, between adjacent rail heads, should be a minimum of 16" apart. This is to help prevent kinks and sags at the joints.
m) Rail joints are to be loose enough to allow for rail movement due to temperature changes. A common rule of thumb is to tighten bolt and nut by hand, then back off by 1/2 turn.
n) A gap between joining rail ends must be maintained. A gap of 1/8" for a 65° F to 85° F rail temperature is recommended. This will allow for sufficient expansion or contraction of the joint for the typical temperature extremes typical of our climate. See Table 1.
o) When required, a section of rail may have bolt holes drilled through web rather than punched. When this is required, holes must be drilled using the rail drilling jig.
p) Ballast should be applied only to sections of joined and secured track. If both rails are not attached to cross ties, then that section should not be ballasted.
q) Ballast should be tamped under the ties at each rail. Ballast should not be excessively tamped at the center of the tie as this will reduce stability of the tie.
r) Track should be checked with a level, ensuring that one rail head is not higher than the other. Straight track should always be level.
s) Track should be checked for sudden rises and falls within each 10' section. Any low spots must be brought up to create a smooth and level profile.
t) If the section is part of a gradient, then any low spots within a 10' section should be brought up to create a uniform transition between the ends of the section.
u) Ballast should be swept level with top of ties.
v) Sections of track that are properly ballasted and leveled will tend to have become several inches above the grade level. These areas of track need to have the edge of the ballast reinforced with earth fill to prevent erosion from weather and foot traffic. See Figure 8.
2) Curved Track
The treatment of curved track sections, as far as the assembly is concerned, follows the same set of rules as outlined in rule 1, a) through v). However, there are specific conditions and considerations unique to curved trackage. These rules are outlined as follows:
a) The minimum radius for mainline right-of-way and passing sidings shall not be less than 60 feet (minimum radius for a 4-8-4).
b) When a curved section of right-of-way must be less than 60 feet, then track gauge must be increased.
c) Rail must be rolled to follow the planned curvature of the right-of-way. A section of curved track should never be 'sprung' into position since the section will tend to work itself back to its original state of curvature.
d) Assembly of a curved track panel should be done on a track jig specifically designed and adjusted to suit the intended rate of curvature along right-of-way.
e) Transitions between straight and curved sections along mainline right-of-way should be planned for and implemented. (A transition is a gradual increase in curvature radius at the intersection of straight and curved sections).
f) Directly connected reverse curves should be avoided. A pair of reverse curves should be separated by a straight section of track no less than 10 feet. The addition of the straight section allows for long wheel base locomotives or truck assemblies to negotiate the change in curvature without binding. The addition of the straight section also prevents coupler swing between two connected cars from being used up, binding, and causing a derailment.
g) Maximum value for super elevation shall be 1/8". The outside rail along a curve should never be below the height of the inside rail. (Super elevation is defined as the condition where the outside rail of a curve is higher than the inside rail).
3) Grades
a) The maximum mean grade shall be no more than 3% on mainline and 5% on branch line.
4) Bridges, Trestles, and Steaming Bays
a) The primary load bearing beams or stringers shall always be made from steel (Channel, tubing, or 'I' beams, etc.). The size of selected steel shape should be determined based upon a distributed load of 4000 lbs + additional weight of decking and girders per a 10' section of trackage.
b) Vertical supports or trestle bents can be made from steel, concrete, or treated wood.
c) Spacing of vertical supports must be in accordance to the size of beam selected. Smaller beam sections will require closer spacing of supports. Conversely, larger or thicker beam sections will permit greater separation between supports.
d) Vertical supports shall be set in place below frost line (for Ohio, minimum of 36" deep).
5) Switches
a) Points shall be milled from 1" high x 1/2" wide steel 'c' channel.
b) Stock rails shall have the foot and a portion of the head milled out to accommodate the point.
c) The minimum frog size for all mainline switches shall be a #8.
d) Switches shall be of a spring throw type.
e) Cross tie screws may be drilled through the foot of the rail. This is often necessary due to physical limitations (opposite foot milled away for rail point, two rails converging at a frog or end of a point, or where the guard rails interfere with the outside rail).
f) Right-of-way should be designed, when possible, such that the mainline track is to be the straight track through the switch.
6) Diamonds.
a) Construction should incorporate steel materials as much as possible, primarily at the frog where severe impact loading takes place.
b) Cross tie screws may be drilled through the foot of the rail. This is often necessary due to physical limitations (opposite foot milled away for assembly of frog or two rails converging at a frog).
7) Parallel Running Tracks.
a) Mainlines, passing sidings, and yard tracks shall be separated by a distance greater than 40" between track centers.
b) Ballast should be maintained at a constant level between adjacent tracks. This reduces tripping hazards as well as reduces erosion from foot traffic and weather. Another benefit is obtained when re-railing is necessary. Blocking-up of equipment is easier and safer when ballast level is maintained between adjacent tracks. In the case where a derailment occurs, especially with passengers, a level shoulder helps prevent tipping of equipment.
.8) Road Crossings.
a) Where possible road crossings will be of steel rail set in reinforced concrete of sufficient depth to handle traffic. The area between the rails should be lower to allow for easy clean out.
b ) Crossings for mowers and lightweight vehicles can be constructed of longer ties with wood between and outside the rails. The wood between the rails should be no higher than the rail height.
9) Tunnels.
a) Tunnels will be constructed preferably out of steel with a minimum height of 6'.
b) Long tunnels should provide for adequate ventilation.
10) Signals.
a) Signals will be provided for operation of bi-directional single track.
b) Signals will be of a color position design similar to that used on the B&O. This allows for colorblind operators to see the aspect of the signal.
c) Signals will be activated by a limit switch, button, or track circuit.
11) Passing sidings.
a) Passing sidings for bi-directional operations will be located approximately every 500'.
b) Sidings should be of sufficient length to handle the longest normal train.
Appendix
Determination of Rail Joint Gap.
An assembled rail joint section utilizing punched rail ends and punched rail joiners will allow for a considerable gap opening. We would .like to assemble rail joints with a gap wide enough to accommodate an increase in rail length due to a temperature increase. However, we do not want to have a gap opening too wide for this promotes damage or a 'beating down' of rail ends. Instead, we want to find the smallest gap opening for a typical rail temperature that one would encounter during track assembly. The average air temperature in Ohio can vary from -20° F to 100° F. However we want to know what. the rail temperature range that can occur Since rail is heated by conduction from the earth, convection from the air, and radiation from the sun, rail temperatures can vary from -20° F to 140° F. This gives us a mean rail temperature of 80° F. (Extreme temperatures of 180°F have been encountered on particularly hot and sunny afternoons). With this average rail temperature established, now we need to look at how our aluminum rail expands and contracts with temperature to determine a minimum joint gap opening. A metal bar will change in length due to a change in temperature. This change in length, or thermal expansion, is determined by the following equation:
