N-RE

Guideline For Construction And Operation

Module: Roadbed

Release

2.0.2

2007-06-02

In general

Rules:

  1. All tracks must be accessible with wheels after NEM 310.
  2. The clearance after NEM 102/103 must be kept free.
  3. Visible tracks have a rail profile not higher than 1.4 mm (Code 55).
  4. The radius of bended tracks is nowhere lesser than 0.457 m.
  5. Junctions must not be designed to direct the wheel by raising its flange.

Recommendations:

  1. Visible rails are preferably 1.0 mm (Code 40) high.
  2. The radius of route tracks is at least 1.2 m.
  3. The radius of throughout main tracks of stations is at least 0.9 m.
  4. Every 0.5 m an expansions joint is installed.

Wide radiuses and lean junctions not only look good, but also improve the operating safety and lessen the train resistance. Scale radiuses [and junctions] are doomed, even in N-gauge, by the required space. The table below illustrates that fact.
Radius of the originalRadius in N-gaugeRemark
73 m0.457 mAvailable radius for a two track line of industrial products
112 m0.7 mMinimum radius for model railway lines with a distance of 25 mm between the tracks
145 m0.9 mLowest radius of the original without special permit
190 m1.2 mTurnout junction's radius of the original for a driving speed of 40 km/h
300 m1.9 mTurnout junction's radius of the original for a driving speed of 50 km/h
5000 m31 mMinimum radius for new high-speed lines of the German ICE
This means that it is already a painful compromise to permit a radius of 0.9 m for main tracks.

Scale rails are 1.0 mm (Code 40) high. For radiuses after NEM 310 they cannot have fixings. Purchasable track material of this type does not heartened [yet]. Remains to do it yourself (Key technology: Sold rails on the sleepers made from conductor board). This provided free radiuses and all types of junctions, but that's not everybody's piece of cake.

Fortunately, there is at least one manufacture, who offers rails with 1.4 mm height (Code 55), suggests the fixings, promises [implicit] usability for NEM-310, uses electrofrogs which do not direct the wheel by raising its flange, and obtains a quite good stability due to a special shape of the rail. Who accept tight curves (see table above), also gets curved junctions. (We advise against the usage of the double slip and single slip of that manufacture.) In doing so, look and operation safety – matched driving speed assumed – suffer only below average, because geometry and kinematics of model junctions differ from the original. For wiring of that junctions see Module: Electric (junctions).

Other manufactures of appropriate track material may exist. Anyway, there is no good reason to use higher rails, for example the usual products of the large-scale production with 2.0 mm height (Code 80). Only for fiddle yards this material can be used.

To avoid damage by dilatation or drying, an expansions joint in the track should be installed on every module; but it must not be wider than 0.5 mm.

At the profile head

Rules:

  1. The tracks meet the profile ends in a right angle (top view and side view!). That is easily to check with a mirror.
  2. A banking [of the outside rail in a curve] is not permitted.
  3. The ends of the rails are fixed as good as possible so they cannot be damaged. Neither during transport nor at the assembling of the layout.
  4. The rails end approximately 0.2 mm before the edge of the module, in order that they are safely electically disconnected and did not suffer a longitudinal force.

A safe fixation of the rails at the ends of the module is necessary, to avoid damage during the transport or assembling of the layout. For example, they can be sold to cut brass screws at the edge of the module.