Flex Track & Rail Facts

Rail Size: Flex-Track and rail is available in a variety of rail sizes since prototype railways/railroads use different rail sizes. The size used by prototype railways is based primarily on two factors - the size and type of equipment used by the railway, and the function of a particular section of track, that is, mainlines, yards or sidings. Generally, modern, heavier equipment railways use heavier rail than small or branch line railways and all railways use use heavier rail on their mainlines than that used for yards or sidings. Prototype rail is sized according to its weight per yd or metre. Although practice varies widely, the table below lists typical rail weights used.

Type Main Line Yards & Sidings
Modern 110-155 lbs/yd 75-110 lbs/yd
Small or Branch Line 90-110 lbs/yd 60-85 lbs/yd
Early Era, Branch Line 60-85 lbs/yd 32-60 lbs/yd

The greatest realism is obtained when the size of rail used on a layout is based on prototype practice as in the table above. Additional consideration might need to be given to the flange depth of the wheels used (see Flange Clearance table below). ) Model rail is sized by height, represented by its code number, rather than by weight. Thus, Code 82 rail is approximately .082 '' high, Code 55 .055'' high.

The table below gives an approximate correlation of the weight of prototype rail and the size of model rail.

Scale/Code 40 55 70 82 100 125 148 168
O 12 25 35 55 85 100 132 155
S 20 40 65 85 110 155 - -
HO 40 75 100 132 155 - - -
TT 75 115 155 - - - - -
N 115 155 - - - - - -

The tables below show suggested rail sizes by code number for the more popular gauges. The first table is for large modern railways, the second for small or branch lines.

Large/Modern O On3 S Sn3 HO HOn3 N
Main Line 148 125 100 82 82 70 82
Yard Siding 125 100 82 70 70 55 70
Small/Branch O On3 S Sn3 HO HOn3 N
Main Line 125 100 82 70 70 55 55
Yard Siding 100 82 70 55 55 40 40

Flange Clearance: It is often believed that only the largest sizes of rail will provide the necessary wheel flange clearance for good operation. This is true with some flexible tracks but because of extremely small FLEX-TRAK spikes, realistic size rail can be used with most equipment. The Table below lists FLEX-TRAK flange clearance as measured from rail head to spike head.

HO Code 100 0.073" HO/HOn3 Code 70 0.048" HOn2(1/2) Code 55 0.035"
HO Code 82 0.058" HO/HOn3 Code 55 0.035" N Code 70 0.050"
HO Code 70 0.045" HOn3 Code 70 0.048" N Code 55 0.038"
HO Code 55 0.035" HOn3 Code 55 0.036" N Code 40 0.026"
HOn3 Code 40 0.027"

Most HO and HO narrow gauge locomotives and rolling stock in North America use RP-25 wheels having 025 '' and .020 '' flanges receptively. As seen in the table above, this equipment presents no operational problems on any of our HO, HOn3, or HOn21/2 FLEX-TRAK. Some European HO locomotives use .045" or .039 '' deep flanges but even these can be used on FLEX-TRAK with rail as small as Code 70. N gauge wheels have relatively deep flanges ranging from .024 '' to .039 '' depending on the manufacturer, but N Code 70 or 55 FLEX-TRAK is suitable for almost all N equipment.

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Installation: FLEX-TRAK is easily glued down with Fuller's Max Bond, etc, or similar, which generally produce a strong, resilient bond with good sound deadening qualities. Alternatively, drill holes in a few sleepers (ties) and use thin small nails or long spikes If a complete, weathered FLEX-TRAK installation is desired, paint the rail a black/brown colour (acrylic or enamal) or use a metal blackener (such as our Black Magic) and the Sleepers (ties) with brown/grey color (check with photgraphs of your prototype). The paint may be applied with a hand brush or an air brush and the metal blackner with a brush.

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Nickel Silver Rail: MicroEngineering Nickel Silver Rail is designed to be as close to prototype rail in cross section as is practical for adequate strength and economical production. It is manufactured from a high-grade nickel silver alloy which does not form an undesirable oxide film that interferes with electrical conduction as does brass rail.

This particular nickel silver alloy has the added advantage of being a colour which is similar to steel. Rail Craft Rail is produced in three-foot lengths in codes 148, 125, 100, 82, 70, 55, and 40. It is supplied in single lengths or packs of 99 ft. and is available with either as a plain nickel silver finish or a weathered finish (blackened).

Our chemical weathering process produces a dark colour similar to prototype steel rail which has been exposed to the weather.

After installation, the weathered finish is easily removed from the rail head with an abrasive track cleaner. This will give good electrical conduction and the appropriate appearance of rail that is used regularly.

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Aluminium Rail (G-TRAK only): Rail made of nickel silver becomes very ex- pensive in the large sizes. Aluminum rail is about 1/4 the cost and conducts electricity better. Conductivity is not a problem with brass, nickel silver, or aluminum in any of the common sizes of rail used because of the small current needed. Voltage drop is negligible If feeder wires are attached at intervals on long runs of track. The biggest problem is electrical contact between pick-up wheels and rail and between rails through rail joiners caused by dirt and oxidation.

The tight oxide of aluminum is conductive, loose coatings are not.

Wire contacts need to be cleaned and tightened occasionally. Code 332 aluminum rail is interchangeable with LGB rail and can be used with their track products. It provides an inexpensive way to extend a G Gauge layout. Code 250 rail is a smaller, more to scale for No. 1 gauge (Aster & Marklin 3/8 '' scale standard gauge or LGB or 1/2 '' scale narrow gauge).

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Rail Joiners: A range of nickel silver rail joiners in Code 100, 82, 70, and 55 is available. These rail joiners have been designed to fit snugly over the base of the rail with no crimping necessary, providing perfect rail end alignment. The rail joiners also feature a very low profile making them difficult to detect once in place when weathered.

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Spikes: Micro Engineering spikes have a black finish and are available in three sizes - small, medium, and large. The small size has a .024 '' diameter shank and a head thickness of only .010 ''. This exceptionally thin head makes it possible to use these spikes with smaller rail and still retain good wheel flange clearance. The medium size has a .032 '' diameter shank and a .012 '' thick head. This size is used with Code 125, 148, and some larger rail sizes. The large spike has a .030 '' sq. shank and a .015 '' thick head. It is used with Code 250 and 332 rail.

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Scale Ties (North American): As simple as model ties may seem. a good deal of design effort is incorporated in Micro Engineering ties. Available In both weathered and plain finish, the ties are cut to realistic scale dimensions from fine grained sugar pine which is more resistant to splitting when spiking rail. Our two-step weathering process produces a dull, weathered finish far more realistic than stained tees. Further realism is achieved by using a full profile thickness. This is important since the full thickness of ties is often visible at places of eroded ballast, around head block ties and where loose or stacked ties are molded.

The table below lists the approximate scale dimensions of Micro Engineering ties (length x width x thickness).

HO On3 S
Normal Length 8.5' x 8" x 6" 6.5' x 7" x 5" 9' x 9" x 7"
Turnout Length 16' x 8" x 6" 12' x 7" x 5" 16' x 9" x 7"

Track Gauges: Micro Engineering track gauges are the three point type which will automatically widen the gauge slightly on curves if required. The rail "grippers" or "nibs" are properly spaced for each size rail.Other track gauges are of the roller type which have the advantage of incorporating a flange way gauge as part of their design.

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Rail Cutter: The Micro Engineering Rail Cutter is a high quality cutting plier ideal for cutting FLEX-TRAK and nickel silver or brass rail. A special shaped edge on the blades produces a clean, flush cut on one rail end, requiring a minimum of clean-up. The rail cutter has plastic coated handles and is made of tool steel for a long life. We do not recommend its use with steel wire or rail. The Rail Nipper is a light-weight 5 in. flush side cutting tool for small rail, wires, and plastic trim- ming. It is not recommended for cutting heavier rail (Code 70 and up) or steel.

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Rail Curving Tools: The Rail Craft Rail Curvlng Tool makes it possible to produce smooth constant radius curves on various sizes of rail with the appropriate contoured rollers supplied for each different size of rail. The adjustable centre roll allows the production of a wide range of curves from very broad ones down to those with sharp radii. Calibration lines make It easier to reproduce curves however, because of variations in the temper of the metal and the way the rail is handled in the tool, the amount of curvature may vary somewhat from one rail to another. The final exact curvature is obtained as the rail is spiked in place. Rollers can be interchanged so the same tool base can be used for curving several sizes of rail.

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