Tuesday, 20 October 2015

Eureka 50 Class - adding weight to the tender

My first workings of 5069, the new Eureka 50 class, indicated that there may be few challenges with the tender particularly when operating the locomotive tender first. My first attempt to bring a rake of LCHs and CCHs to the Philip's Creek coal mine tender first resulted in two minor derailments of the tender and some hesitancy of the locomotive when moving through the old Atlas points with about 20mm of dead track on each. The problems that I experienced seemed to confirm. in my mind, my initial impression that the tender needed some extra weight.('Eureka 50 Class - Early Impressions'). However the issue may not be quite that simple!

The pick up arrangement for the tender is shown on the photo opposite. Brass strips fixed to the tender base make contact with lugs on each bogie to convey current from the track to the circuit board and decoder inside the tender. For this arrangement to be effective, there does need to be sufficient weight in the tender to ensure good contact with the track.

Similarly, there also needs to be sufficient weight to ensure that the realistic flanges do their job and keep the wheels on the track as each bogie moves through a point. However, it has been suggested to me that the pivoting of the bogie may be impeded by the friction (albeit ever so slight) between the lugs on the bogie and the metal strip on the tender. So, here we seem to be caught in a dilemma because that contact is necessary for the electrical pick-ups on the tender to function.

I have decided to approach this in two stages, the first being to add additional weight to the tender and then, only if necessary, install an alternate means of electrical contact between the bogie and the tender chassis. This post focuses on the first step only.

Marcus Ammann's very informative web page, Modelling the Main North with DCC (http://www.members.optusnet.com.au/mainnorth/D50)
provides guidance on how to remove the top of the tender. Having done that, my first thought was to add a strip of lead on the inside running the full length of the tender. However, a dummy fit with an equivalent piece of styrene felt as if I was applying pressure to the wires coming out of the top of the circuit board. Instead, I decided to glue a strip of lead into the space provided by the coal moulding. It was glued with super glue and then some blue-tack was added to assist the adhesion. I then glued a strip of very thin styrene beneath it to act as an insulator between the lead and the circuit board should the lead come adrift. I know, probably an overkill with multiple redundancies.

I then added a further strip of lead to the top of the coal in the tender. The photo opposite is a good example of how some colours can change when photographed. The lead is actually a grey colour, not the bronze shade that is shown in the photo. Coal was added to the cover the lead although as can be seen from the photo below some extra coal is still necessary. However, I won't do that until after the locomotive has been weathered. I'll probably make it a fairly full load which may mean moving the apex of the coal more toward the centre of the tender than it is at present.

The results of the early runs after the additional of the extra weight are positive with the instances of the hesitancy reduced and no derailments of the tender bogies to date. However, the real test will come when it's time to move the full coal wagons to Port Waratah.


  1. hi I also have a 50 class from eureka just wondering dose yours make a lot of gear noise when running ?

    1. yes, it is noisy compared to most of my other locomotives. i tried the fix suggested in Marcus' website but without any noticeable change. There is also a periodic clicking noise, the source of which I haven't been able to locate as yet.

      cheers Phil

    2. Hi Phil i found the clicking sound, it was the 2nd set of wheels from the front jumping up and down -- clicks when it slaps on the track, hard to see! but that's what was happening to mine
      thanks, Jim

  2. Jim,

    Thanks for the information. I am currently away from my layout for the next few weeks and will re-look at it when I return. However, I suspect mine will be a similar problem to what you have described.

    From your description, it seems there is probably some slack in the axle mounting for the second pair of wheels. Short of additional lubrication, I'm can't see an easy fix to this.

    cheers Phil