No.60 Jubilees – of the Bachmann and Mainline varieties
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.
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.
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 up and round the layout. My Bachmann Mk1s tend to be more freely running
and all the Jubilees, both old and new can handle six coaches up the 1:56
gradients.
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.
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