New Bachmann Class 47 - P4 conversion and detailing

[Triode]

Hi All.

One of the new Bachmann Class 47s arrived with me in the week leading up to Christmas, but I put it aside to try out on the big day. After amusing myself with all the DCC bells and whistles for a while, I got down to the task of converting it to P4.

The process of conversion is straightforward but not a five minute drop-in exercise. In this regard Bachmann are lagging behind the likes of SLW despite beginning to compete in terms of detail and fidelity with this new model.

I used Gibsons wheels and axles, with the original Bachmann gears and bearings transplanted from the 00 wheelsets after dismantling these. I added 2mm deep packing washers either side of the gears on the outer axles of each bogie to eliminate side slop. I omitted packing washers on the middle axles however to allow them to negotiate curves. Note - I should clarify that at the time of writing I have not actually tested the loco on curves, but this same approach has worked for me on other models.

The main thing which complicates the conversion is that the brake linkages are slightly too thick to allow the wider P4 wheelsets to fit between them. This is solved by gently filing them back from the inside to about half their original thickness. This can be done without removing the brake linkage mouldings from the bogies which does simplify matters.

Despite the brake linkages preventing a simpler P4 conversion out of the box, I have to give Bachmann a big thumbs up for using milled diecast gear towers/gearboxes on this model. This seems to be the emerging norm with their newer releases (the Class 20/0 and Class 158 for example), and is a massive imporvement over the plastic gear towers on the likes of their Class 37 and Class 40 (and presumably their original Class 47, although I don't own one of these). As anyone who has converted one of the older models to P4 will know, the plastic gear towers often have a slight twist in them, which prevents all six wheels lying snugly on the track. The diecast gear towers are significantly more accurate and as I result I haven't had any such issues with the new Class 47.

Overall, a simple enough conversion, but it would have been nice if enough thought had been given in the design to allow finescale wheel sets to fit without any filing being necessary. The fine quality of the plastic parts used elsewhere in the model shows that Bachmann could have manufactured thinner brake linkages if they'd chosen to.

I'll cover detailing and renumbering in future posts. At the moment, the plan is to renumber to 47287, which spent time at Gateshead and Thornaby depots in the 1970s.

I hope this is useful to anyone else thinking of adding this loco to their roster.

Cheers,

Liam

[John Donnelly]

Looks good. I've considered one of these as they were, very occasionally, visitors to Consett but the prices are rather extreme, certainly compared to what Accurascale are charging for their 37 and Deltic...

[bill wilson]

Hi Liam.
Thanks for sharing your experience of converting the 47. I agree, the previous model was an absolute pain and I was wondering what the new model would be like to convert. Pretty sure there will be 1 or 2 in the 2nd release suitable for Queen St.
cheers, Bill.

[Triode]

A further note regarding the P4 conversion: it turns out that the wheels I've fitted are slightly too small in diameter to give the loco the correct buffer height (despite the conversion pack being labelled as suitable for a Class 47). Not a big deal at the moment, but at some point I will probably try to source some slightly bigger wheels to correct this.

Cheers,

Liam

[Crepello]

Class 47 wheels are nominally 3ft 9ins (15mm)
I wonder if the conversion pack was for nominal 3ft 7ins wheelsets?