The John Armstrong memorial layout.



In the autumn of 2004 a group of Model railroader near Zurich Switzerland met with the aim of building a modular On3 narrow gauge layout to be displayed at shows and exhibitions in Europe. The search for a room to build and house layout led to a large factory building with an available space of 3821 sqr feet (355 m2) of which we could rent 2/3. With such generous space available we decided to build a permanent instead of a modular layout.

In 1991 the Author had a Sn3 Narrow gauge layout designed by John Armstrong. This plan was now dug out and modified to On3 and the available space. Photo (TB 01-01) shows the original plan by John Armstrong and Photo (TB 01-02) our modified plan. (Stand 2008 not showing the latest additions) The actual size of the layout is 65 x 39 feet the minimum radius 48” and trains climb from 35” to 75” (above eye level). The era is roughly from 1940 to 1950 mainly D&RGW and some RGS. Some members also collect logging and Unitah equipment.



Most of 2005 was used for planning cleaning and painting the room. Then in 2006 we started with construction. Steel girder versus wood L-girder construction was tested. We finally settled for the Wood option. It proofed to be easier to build and more stable. Photo (TB 01-03 and TB 01-03B) shows the initial construction of the underframe. We later changed to the traditional 1x4 L girder style. The stations and yards are build on 3/4“ plywood. The roadbed was built using 0.19 “ x 0.8 “ spliced masonite strips. Ties were hand cut and for rails we used code 100 rail from micro engineering. All turnouts are hand build by Andy Meier using a template. All tracks are hand laid except in the storage yards we used code 100 rails on PCB ties or flextrack from San Juan. All Rails except for the storage yards were weathered before installation.

Scenery is hard-shell over cardboard and/or chicken wire. Scenic material comes from the know producer and includes electrostatic grass.



The layout is run with DCC. We use the ZIMO system with wireless remote control. Most decoders are Tsunami with additional ZIMO function decoders as the Tsunamis lack sufficient outputs. Some ZIMO decoders with Soundtraxx sound only decoders are also in use as well as some ESU decoders. Experiments with QSI decoders were conducted but all removed due to poor performance.

Initially the entire layout was powered by the ZIMO MX-1. Since mid 2010 the layout is divided into blocks. The stations and the sections between stations each being a block. We recently installed DCC circuit breaker and use various track occupancy detectors. The blocks are used to indicate whether tracks between stations are occupied or free. As one can not see one station from the other this is very important to avoid head-on meets.


11 AWG wires are used from the ZIMO central to the various sections. From there 15 – 17 AWG feeder wires run along the tracks. Each piece for rail is connected to the feeder lines by a 22 AWG wire.

The layout contains 3 reversing circuits. One each in the 2 storage yards and 1 in-between Charma and storage yard 1.


Switches are all powered by either Tortoise motors or stall motors with external end-position micro switches powering a relay on either side. All frogs are powered except for the new San Juan switches in yard 2. All switch positions are displayed in various panels by means of yellow LED.


PCB containing 4 latching relays powering 4 turnouts were built. Switches are controlled from a central panel as well as local walk around switching stations. Controls in the central panels have buttons to switch entire groups of switches whilst the local panels allow individual switches to be thrown.


Emergency stop Push buttons and LED every 9 – 12 feet allow the entire layout to be disconnected from the DCC source. These switches need to be disabled during open houses as they proof to much of a temptation for kids to press, since then red LED start to flash all over.

Most stations have modified Kadee Ho electro uncouplers. They are used for switching cars as well as uncoupling engines and cabooses. Every electro uncouple has a red super bright LED installed next to it giving a visual indication for positioning the cars during uncoupling.



Operation is walk-around, whereas an engineer accompanies his train across the layout. It takes about 25-30 minutes for a journey around the layout. 10 or more operators can easily be running trains at the same time.


John Armstrong cleverly designed the layout in such a way, that running from Punnsion via the black canyon, Cimarroon and Pyrite Siding to Cerro Pass we have a maximum grade of 1.6 %. In the other direction from Charma to Cerro pass via Nophire the grades were planned at 3.5 % which we reduced to 2.5%. This allows long trains pulled by one engine to be run in one direction whilst in the other direction trains need to be shorter or long trains must be broken into 2 in Charma or a pusher engine must be used. For this reason we have a turntable and balloon loop in Charma as well as a Wye and holding track up at Cerro Pass. Long trains from Charma can be split in Charma and pulled up the 2.5 % grade to Cerro Pass where the cars are being pushed into the holding track, the engine turned on the Wye and after retrieving the caboose moving back to Charma to collect the 2nd lot of cars. Once all cars are up at Cerro pass, the train gets re-assembled and is ready for the long downhill run.

If pushers are being used, they are uncoupled at Cerro pass wyed and run back to the engine facility in Charma.


Shunting will be introduced at a later stage. We plan to have a few mines as well as a lumber yard with sawmill. Some of these will also be served by On30 feeder lines. Pyrite siding will be a busy place for switching. A large mine with 2 tracks will be placed there. Just ahead of the pyrite tunnel there will be a spur to a large lumber yard / sawmill section. All traffic to this area will be switched and directed in Pyrite. So Pyrite siding will be a busy place as a) trains from Cerro pass to Cimarron meet, the mine must be served and the lumber trains need to be switched.

A second hidden storage yard (yard 2) with 6 tracks is being built just ahead of pyrite siding to take some of the lumber yard and mining trains.

Further mines are planned in Punnision, Cerro Pass and Nophire. Local industries of various sorts will be situated in Punnison, Cimarron and Charma. Charma will also have a large yards for freight cars and passenger cars and some caboose tracks. An oil loading facility, life stock loading track and maintenance of way yard will complete the facilities at Charma.


The heard of operation is the storage yard below Charma. This has been designed by John so that trains can enter from either side be stored in any of the 13 tracks and depart on either side. Trains can also run through. This allows us to have point to point operations from Punnison to Charma or in and out of Yard 1 or run around trains through yard 1.


Rolling stock

We do not have club owned rolling stock. All models are all individually owned. Most engines are either brass or MMI “hybrids” and have their motors replaced by Faulhaber coreless motors and sound decoders installed. We generally illuminate the models. This includes (when available) head- and back-up lights, marker lights, number boards, cab lights and firebox flickering.

Passenger cars have full interior, figures and lights. Wherever possible we use warm-white LEDS for illumination. Whenever possible Caboose have marker lights illuminated by micro LED and switched by a DCC function decoder. All lid caboose have their own address. Engines and caboose address are linked as consist. If you call up the engine the caboose comes up automatically.


We do not standardise on any coupler system. Some use Kadee couplers and some use more prototypical couplers that can however not be uncoupled remotely. We generally encourage the use of plastic trucks with metal wheels to avoid short circuits (specially with brass cars) and allow for smoother operation.


In order to avoid DCC address conflicts, each member has a group of numbers assigned. These are 1000, 1500, 2000, 2500 etc. He then adds the engine number to it to get the address for the model. For example K-36 No 484 owned by the Member with the group 2000 gets the address 2484. This way we can operate the same engine by different members without problems.


Status of construction

As of writing this article (May 2011) all mainline tracks have been completed. The Mines sidings and all yards at Charma as well the engine facilities at Charma and Punnision need to be built. Scenic wise parts of the high line including the long bridge as well as some part of Cimarroon are completed. The Photos show these areas.


Shows News Events etc.


Open House 2024

25+26 Mai

Öffnungszeiten Samstag

11.00 - 18.00


11.00 - 17.00


On3 Trainbuffs...die etwas andere Modellbahn-Gruppe.
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