For those interested in some of the technical details about the layout and its operation, here are some points of interest.

The layout utilizes a detection system referred to as Absolute Position Detection (APD) which detects when a train is at an exact position on the layout. This is different than a block detection system where the system only detects that a train is somewhere in a block.

This section describes how the layout functions and is divided into several parts as follows:

1. General Operating Environment (below)
2. DCC Operation
3. Automated Operations Control Centre (AOCC)
4. Scripts
5. Animation
6. Sound
7. Script concepts and organization
8. Signal System

General Operating Environment

RHJ Rail is a DCC (Digital Command Control) layout which means that many engines can be run on the same track at the same time (if extreme care is exercised so that no two engines occupy exactly the same space at the same time!). The particular brand of DCC equipment used is Digitrax.

For more information about DCC, see TECHNICAL Page 2

Much of the layout operation is done using computer control. The Digitrax network is interfaced to a Windows PC and software has been developed to run trains, special effects and other features.

The implementation of a Track Occupancy Status (TOS) system has proceeded smoothly and integrates nicely with the earlier Automated Operations Control Centre (AOCC). Both systems work together to keep track of train locations and to run multiple trains and special effects automatically. Over 20,000 lines of computer code are used to do this!

JMRI (Java Model Railroad Interface) is used and is an "open source" (free) system which provides many features to assist with model railroad operations. Control panels, decoder programming, and scripting are some of the main components.

Many readers will be familiar with Panel Pro and Decoder Pro which are the two main components of JMRI. It is the scripting language of JMRI that provides most of the facilities to control and operate the RHJ Rail layout. Scripts will run under either of the two main JMRI components. RHJ Rail uses Panel Pro as its basic JMRI starting point.

The scripting language syntax is referred to as Jython (a Java implementation of the popular computer programming language, Python). Most, but not all, of the rules of Python apply to JMRI scripting. In addition, JMRI adds some critical components to interface with many of the popular brands of DCC equipment.

Layout Specifications since the main layout was completed.

  RHJ Rail


  19 x 42 feet (over-all)
  Canadian Pacific, with liberal doses of freelance
  present, with significant components of preserved and restored equipment
  Western Canada
Layout Style:
  around-the-walls with walk-in and double-deck elements
Length of mainline run:

double-track mainline with:
- outer mainline: 153.2 feet (2.53 scale miles)
- inner mainline: 151.3 feet (2.50 scale miles)
- historical park mainline: 55 feet (0.73 scale miles)

Total track length:
  main layout: 701.6 feet (11.57 scale miles)
subterranean subdivision: 65 feet (approx.)
off-layout storage and staging: 17 long storage tracks
Layout height:
(above floor)
- base: 49 inches
- maximum: 53 inches
subterranean subdivision:
- 41 inches
  around-the-walls (wall brackets) with peninsula (two legs)
Draped Perimeter:
  72 feet, 6 inches
Viewing area:
  237 sq. ft. (approx.)


  Woodland Scenics foam HO roadbed


  code 100 Atlas flex track, Atlas sectional track, Peco turnouts
Number of turnouts:
  65 (all remote control powered)
Turnout minimum:
  no. 6 (main); no. 4 (historical park)
Minimum radius:
  30 inches (main); 22 inches (historical park and subterranean subdivisions)
Maximum grade:
  2.0 percent
  extruded foam insulation board, plaster cloth, molded foam mountains
Backdrop construction:
  16 inch high hardboard with custom printed photo backgrounds
  Digitrax DCC with JMRI computer interface and many custom-designed components


continued on Technical - Page 2

More details on any of the above can, of course, be obtained by contacting RHJ Rail.

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RHJ Rail is owned and operated by Richard H. Johnson
© Copyright 2022 Richard H. Johnson