These last few weeks I have been playing with some of my Stanier Jubilees. My original Mainline Jubilees ‘Orion’ and’ Leander’ with their suspect quartering have long departed. However ‘Mars’ and ‘Amethyst’ from the second Mainline batch live on with replacement Bachmann chassis.

Ex Mainline Amethyst on Bachmann Chassis

I was inspired by a ‘thread’ on the RMweb site looking for help with lack of tractive effort of the Bachmann model ‘Drake’. The contributions from ‘Alan’ and ’34’ are very useful.

Bachmann ‘Armada’ left, Bachmann ‘Drake’ right

I couldn’t resist the opportunity to have a look inside Drake and it would appear that on my model the bogie spring is a touch longer and made from slightly heavier gauge wire than that used for Armada.

However more telling is a comparison of the weights of the different models. Bachmann Drake weighs 280gm whilst Mainline Amethyst with replacement Bachmann chassis weighs 310gm. I should add that our scales use brass weights and I pretend that they measure to 5gm. (But we don’t have the hassle of batteries or mains supplies.)

Space for decoder

Part of the problem is the space provided for the digital decoder. However since most of the space is in front of the driving wheels packing it with too much extra weight will simply cause the rear driving wheels to lift from the track completely negating any benefits from the added weight. I am not sure how important it is for the engine to be perfectly balanced. For the design of concrete columns I seem to remember it was necessary to keep the centre of thrust within the middle third of the cross section to avoid tensile stresses at the edges. I would say a little bit of out of balance force is no bad thing especially where a tender engine is preferentially driven in one direction and there are gradients to be tackled.

Bachmann Jubilee with 30 gm extra lead

The solution I adopted was to add some pieces of lead as shown above.

2mm sheet lead, A – 13x38, B – 13x16, C – 13x17, D – 28x18mm

The picture above shows the individual pieces of lead together with their nominal dimensions. Item D which has bevelled edges to slot inside the boiler is 28mm long. It is this length because on my models there appears to be a minor obstruction at this distance preventing the lead from lying flat. I would like to have said that it was good planning. However it is was purely by chance that the four pieces of lead weigh 30gm bringing Drake up to 310gm - the same as the earlier split chassis models.

Top of motor

A word of caution – not all my Bachmann Jubilees were wired up the same way. With the added lead the space at the top of the firebox is very tight and I had to re-solder the capacitors on two of the models to ensure a snug fit – why did one model have two capacitors linked together?

Bachmann ‘Drake’ without Detail Parts

A couple of views of the finished product – so to speak. Drake was a ‘bargain’ from Hattons – was it in celebration of the Queen’s Jubilee? Did Bachmann save any production costs by not fitting the cab steps? I also noticed that this was the first ever new engine that I have had that has shed a connecting rod because the retaining screw was not fully tightened. Something else to check for the future.

Bachmann ‘Baroda’

Increasing the engine weight from 280 to 310gm works for me and all Jubilees will now haul any five coaches

My layout is not Digital but I am thinking that the residual space on the Jubilee boiler is probably still big enough to fit the DC chip – so all in all a good solution.