Marbelup Valley Railway
Train and Point Control Systems

In August 2004, the Marbelup Valley Railway converted to a Lenz DCC (Digital Command Control) system. While essentially simlar to the previous Infocom system, DCC offers a number of major advantages. Some reasons for making the change include compatibility with other Sn3.5 modellers using DCC, and additional features such as lighting controls and sound. Another big plus is the availability of decoders such as the Lenz LE1035 with back-EMF feedback. This improves low speed control for most locos and, in some cases, the improvement is dramatic with locos that tended towards jack-rabbit performance.

Since 2006, some locos have had sound decoders installed. Initially, one each of the Soundtraxx LC generic steam and diesel decoders were purchased. These provide quite good sound but the motor control was quite noisy and they lacked back-EMF feedback. Both locos (W945 and X1011) were later converted to dual decoder installations with a separate motor decoder. In 2008, most of the remaining steam locos have been fitted out with Soundtraxx Tsunami sound decoders. These have quite good motor control and much improved sound effects over the LC decoder.

In the Freycinet area, points are mechanically controlled using small push-pull buttons on the front edge of the layout. In other areas, points are electrically controlled, most being fitted with Tortoise slow motion point motors. Kojonup, Yelverton and Springdale stations each have two push-button control panels, one at each end of the yard. In addition, remote panels grouped at Freycinet allow remote control of the other stations for single-handed operation or visitor demonstrations. Main line points are also controllable from the CTC system.

Handheld Controllers

Roco Multimouse(left) and LH100 controllers. MVR has four Multimouses and one LH100.

The Multimouse controllers are more user-friendly, especially for visitors, as loco addresses (up to 64) can be saved and easily recalled. Locos can also be assigned a 5-character name, e.g. PM713. The Multimouse has a centre-off speed control knob and can directly control DCC functions 0 to 10 (up to 20 using the shift key). Locos and railcars which are double ended are oriented on the layout to match the direction of the Multimouse control knob, i.e. clockwise (forwards) is to the right. Locos which have an obvious front and rear gnerally run "chimney first" on the mainline and are turned on the turntables as required. The Multimouse is directly compatible with the Lenz ExpressNet controller bus.

Some operators prefer the push-button speed control of the LH100 and it is better for programming decoders.

The four LH90 controllers, originally purchased with the Lenz DCC system, were retired in 2007, as they were not very user-friendly. Two were sold through E-bay and the other two have been retained as extra controllers if needed.

The layout uses 4-digit addressing, which avoids having to remember any abbreviated addresses. For example, W 945 is simply 0945.

The green light on the fascia, between the controllers, shows that track power is on. There is one of these indicators at each station and they show red if the layout power is on but track power is off.

The MVR uses RJ12 connectors for the controller bus (Express Net) and all controllers have curly cords to keep them reasonably tidy.

Locomotive Decoder

Most non-sound locos have Lenz LE1035 DCC decoders which feature back-EMF feedback for precise speed control at low speed. Locos with high top speed have been programmed for a maximum speed of 80-90 km/h, which is typical for WAGR narrow gauge operations. The photo shows a decoder installed in the tender of W 945 (although this loco now has a sound decoder installed).

As part of the changeover to DCC, all locos have been fitted with LED headlights, which are setup for independent front and rear control using functions F0 and F1. The headlights are not set up for directional control as prototype practice when shunting is to have both lights on (dimmed).

Point Controls

The small black push-pull knobs control points at Freycinet station, via a simple mechanical linkage.

This works well in the yard area, as you generally have to be fairly close to the train while shunting. Most of the mechanical parts are standard items made for radio control planes and boats.

The point knobs are located on the fascia, in line with the point being controlled. The "Harbour" knob in the photo controls the point immediately adjacent. The longest are up to 1 metre away. Some control more than one point, e.g. for a crossover.

Uncouplers

There are approximately 30 uncoupler magnets at strategic locations to allow hands-free shunting. The magnets are mounted under the track and are invisible, apart from a splotch of paint on the rail to mark their locations. The magnets drop down when not required to prevent false uncoupling. This is done via a mechanical linkage, using the same knobs as used for point controls.

Uncouplers

Here is the underneath of an uncoupler, showing the hinged magnet (Kadee #308) and the operating mechanism. Here, the magnet is in the down position and has no effect on passing trains.

Uncouplers

The same uncoupler with the magnet raised. Using the delay feature of the Kadee couplers, one uncoupler can serve a number of sidings as, once uncoupled, wagons can be pushed into a siding and left there without recoupling.

The black thing thing behind the uncoupler is a slide switch, which is part of the point controls. A fine wire through the slide switch lever moves the point blades above, while switch contacts control the polarity of the live point frogs. In the Freycinet area, spare contacts are also connected to the CTC system to monitor the status of some points.

Kojonup Panel

Typical push-button panel for local point controls.

Yellow LEDs, connected to auxiliary contacts on the Tortoise point motors, indicate the point positions.

Since the introduction of CTC, point control from the local panels is disabled unless the Train Controller switches the station to shunt mode. A green LED at the top of each panel indicates when shunt mode is in effect.

Remote Panels

The three remote control panels located at Freycinet allow control of the points at the other three stations. This is useful for one-person operation although they are used less since the introduction of CTC.

Each remote panel connects via a 40-way flat cable simply wired in parallel with the local panels at each station.

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Updated 2 June 2008