West Australian S Scale Modelling: Z Class

Tuesday, February 12, 2013

Z Class

My Z Class

In December last year I brought along two items for my first show and tell, one of which was a WAGR Z Class and had some requests to follow up with an article so here it is.

The Z class, an 0-6-0 shunting locomotive, entered service at the beginning of dieselisation in November 1953. Three of these locomotives were ordered numbered 1151, 1152 and 1153, to work the jetties of Albany, Bunbury and Esperance. Further information is available here. I was quick to register my interest in a WAGR Z Class following the announcement in June last year that Railwest was seeking interest in doing a rerun, which would consist of the mould and detailing parts and would require a Bachmann BR Class 03. The mould which had originally been developed for an earlier Bachmann BR Class 04? As I’ve always liked these BR shunters I ended up buying both a new Bachmann Class 03 and an older Class 04 in new condition from Ebay, however I decided to go with the new BR 03 after reading an article on fitting DCC to the loco in the July Edition of the Hornby Magazine. The project by Paul Chetter detailed adding a small sugar cube speaker and a Zimo MX 648R decoder loaded with a custom sound project (ZS03) developed from recordings taken from an actual BR Class 03. All of these items were listed as available for purchase from UK based digitrains.

Here is a link to what it sounds like in operation in the BR 03

After doing some research I found both locomotives had Gardner 8 cylinder engines with the BR Classes 03 having the larger 24L 8L3 and the Z class having the smaller 11.2L 8LW. Whilst a little different I really couldn’t hope for more than being able to get a sound project recorded from an actual shunter with the same make of engine and same number of pistons so I went ahead and purchased the speaker and decoder with the installed sound project from digitrains though if you’d prefer to buy locally Richard from DCC Concepts now stocks these speakers.

BR Class 03

Engine: Gardner 8L3

Cylinders: 8

Bore: 5 ½”

Stroke: 7 ¾”

Size: 24L

Z Class WAGR

Engine: Gardner 8LW

Cylinders: 8

Bore: 4 ¼”

Stroke: 6”

Size: 11.2L

Anyhow next step was to modify the chassis to fit in the Z class mould. First, I removed the all the extra electronics including capacitors, LED pickups and 6 pin socket and circuit board. Having no need for the threaded plastic shanks which held the circuit boards down, I cut all of them off.

I continued by trimming up the plastic part of the chassis as shown below in red with a pair of side cutters.

I investigated a number of options for locating the chassis within the body and wanted to get the alignment close to the original as pictured below but in the end opted for a spacing which pushed the chassis slightly further towards the cab end, in order to accommodate the speaker at the front of the chassis.

Actual

My model

To achieve this fit I used a number 115 high speed Dremel cutter to mill down the chassis as shown below. In order to accommodate the kadee couplers I also had to mill between the chassis rails at the rear to increase the width and tidied up the corners with a smaller cutter.

After milling the chassis I glued in a piece of 2mm thick styrene to the front end to close the chassis and provide a tight fit of the chassis between the buffer beams. Initially I found the body sat to high so I milled more off the top side of the ends of the chassis to lower it down.

Extensions were then added to the chassis using 0.02mm thick brass sheet. For the front end chassis extensions a coating of black nail varnish was added to the outside near the pickups to ensure they would be well insulated as they were to be soldered together later. All extensions were fixed with super glue. Later I added some 1mm strips and a t girder which was a piece of rail with the head cut off.

To complete the chassis I added a set of 2 small 2 pin plugs mounted on a PCB, I got from DCC Concepts to connect the decoder to the motor and power pickup whilst allowing the chassis to be easily separated from the body.

With the chassis completed I turned my attention to the body, first gluing in two 2mm strips of styrene to provide more room to screw the chassis to.

I then added all the electronics including the Zimo decoder, sugar cub speaker, a stay alive capacitor, headlights and marker lights. The headlights used proto white Nano LEDs and signal red for the markers from DCC Concepts as was the stay alive.

Now I wanted to be able to potential remove the decoder and used blue tack as I didn’t have double sided tape and that was a mistake as once the small varnished wires for the LEDs got stuck in the blue tack there was no safe way of removing it.