Converting Hornby’s 2 BIL to P4 standards

by Ian Sneyd

It is easy to get the body off the chassis but not quite so easy to remove the interior which is clipped in by 6 evil clips.  Converting eight units reinforced my view that this is a superb model and a tribute to the designer and the manufacturer.  The new manufacturing method seemed to me to have only one downside: the lack of lamp brackets.  It also makes it more rugged.  Unlike the Maunsell Coaches, where if you handle them you will need a spare model to break for spares (commode handles and particularly torpedo vents go missing – I write from experience with converting 18 or so), the only vulnerable bits are the gutter downpipes.  Several came off, but were easily replaced.  However 2 broke at the very vulnerable bottom and there is then nothing to be done.  The buffer beams are also poorly attached, which probably accounts for the high incidence of drooping buffers.  Three (out of sixteen) beams became almost completely detached and were Araldited back on.  The bogies came in for an extreme amount of handling with very few problems: a couple of footboards came loose and some shoe beams fell off – a positive, see later.  However, in fact the whole chassis is a huge advance on anything Hornby have done before.  The underfloor detailing is superb, we even get brake rodding now.

The bogies:  The DMBT chassis is one big heavy casting into which clip the bogies.  To get them off it is necessary to unsolder the wires from the bottom of the DCC-ready circuit board.  The sheer weight of this item makes it unlikely that one motor could haul 2 trailers plus an unpowered and de-geared MBT (for four car running with one decoder).  Add to that the impracticality of through wiring and so I have resigned myself to 2 DCC decoders and complicated multiple consisting.

The DTC is completely unpowered so both bogies spring out (relatively ) easily.  To my surprise the dummy bogie is quite different to the unpowered motor bogie from the Bel and the 8′ steam bogie is different to that on the Maunsell coaches.

The 8′ steam bogie is absolutely lovely and a doddle to convert as P4 wheels go straight in.  Just remove the end of the pinpoints as Hornby’s axles would appear to be 25.6 mm rather than 26 mm.  I did not think it remotely practical to remove the plate holding the brake shoes but it is possible to get in there with a small circular file and then bend the shoes out of the way.

The 8′ steam bogie on the DMBT has pick-ups fitted but is otherwise identical to that on the trailer.  If converting to EM or P4 these pickups will reach a solid wheel such as Hornby’s, and those available from Branchlines.  However these are so very expensive and so difficult to paint that Gibson wheels and top acting stylus pickups look a better bet. And indeed work well.

The motor bogie comes apart by levering off the keeper plate (with brute force) and dropping out the wheels.  The keeper plate is attached to the frames which then need the same attention with files as that on the DTC.  When the cross shafts are in, the brake rodding repaired and the whole thing painted it really looks excellent.  Hornby’s bizarrely coloured shoe beams rather detract from a superb piece of modelling.

The wheels pull off the axle leaving the plastic centres behind to be removed with a knife.  The gear wheel is then drifted out.  To my surprise the motor bogie has actually been changed since the Bel to reduce the huge side play.  Using Gibson wheels I secured the gear wheel with Loctite and made 2mm spacers from 1/8 brass tube to take up the side play from “narrow gauge steam rollers” to P4.  New top acting pickups were added as, although this bogie has a much, much better pickup system than the Bel, it is still acting on the backs which is just not practical with Gibson wheels.

With some filing it was possible to get P4 wheels into the dummy power bogie.  With some care I managed to retain all the visible parts of the outside brake rigging although it ends up a bit weak.  As it is necessary to add a cross shaft at each end of the bogie anyway this holds it together.  It is a pity that Hornby could not have engineered 0.5 mm extra space a side as this would have made life very easy of those of the P4 and EM persuasion.  Conversely, the excessive overall width is less of a problem as they do not hit the platform ramps.  On the DMBT the non-powered bogie is identical to the power bogie – incorrectly – but it is not glaringly obvious.  What is obvious is that one of the steps on this bogie is in the wrong place and the footboards look too small to me.  I would not like to have to climb them!  From a trackside view (as opposed to the usual “tethered hot-air balloon” view) the shoe to conductor rail is amazing and gives a whole new dimension to third-rail modelling. Unfortunately………

The shoebeams: There are two problems here: width and height.  The shoes, inboard on the beam, are 32 mm over the outer edges, 31 mm centres.  Correctly spaced conductor rails are 14.7 mm, centre to track centre line.  So the Hornby shoes are consistently outside my conductor rails (so it is not just on OO/HO track then – Modelling Secretary) and worse still, clout any protection boarding.  The shoe height is good (actually lower than my Bel examples) but the heights are very inconsistent, presumably because of manufacturing variations not helped by much handling.  I standardised on a clearance of 1.5 mm when stood on a piece of wood.  Several DTCs needed adjustment, half the DMBTs did.  Do this before painting while you can still get the beams off.  I labour this because watching the shoes on the conductor rail is magic.

The bodies:  Running the units round my layout showed that the coupling bars as supplied actually gave an acceptable spacing between coaches, truly excellent when propelling.  But how do I link units together?  I’ll probably run my 8 units as two fours but I think the bar will be rather unsightly between units.  I was going to use Kadees but they are not very prototypical. So at each units end I Araldited in Smith screw couplings which look good and work well. I kept the NEM pockets in case I have a change of mind when I start having to split and join units.

I decided the DTC coach felt too light and, given the vast probable overkill haulage capacity of the power car, decided to add as much weight as I could.

As with the Maunsell coaches they are taxing to renumber as they are using no font known to the HMRS and it is completely wrong for SR anyway.  Unlike, say, the Bachmann N, where you only have to look at it and the lining and numbers fall off, these numbers are very well attached and it took cellulose thinners and a sharp scalpel to get them off.  A touch of matt varnish afterwards and you wouldn’t know they had been played with.

I thought the body detailing was generally excellent though I was dubious about the black rail on the guards van (which I left) and the green wipers (which I didn’t).  Finding there were alarm butterflies which are almost invisible until picked out in red was a real “surprise and delight”.  (Finding alarm butterflies at both ends of a Maunsell coach was the opposite.)  If I am building a coach I never bother with Smoking signs.  But they are there and, even though the mix of Smoking and Non-Smoking is miles wrong for 1938 there is not much I can do about it.  It is just thoughtless putting the same mix on in 1970 and 1938.

I painted the cab interiors cream, except the switch boxes, which looks good.  Crew is a problem when you’re going to run in multiple, but on balance I think better to have in each unit than not.  By chance I was talking to the owner of Falcon Figures at the Horsham show who had just bought a Bil with the intention of producing a motorman specifically for it.  FF are best known for their excellent loco crew (I have dozens) and I went off with 3 suitable looking drivers.

Also on the interiors I added the cream vertical panels that are typical for Maunsell coaches of this period, painted the seats and added passengers and posters etc.  That is the easy bit but makes a vast difference, particularly to the Southern ones.

I do like my headcodes to be correct.  As I did each coach I superglued a small round magnet (very cheap on eBay) behind each headcode panel.  I decide to use the Hornby headcodes (almost) as supplied. These are easily the most authentic looking stencils I have ever come across.  Using one 2 thou feeler-gauge cut into 5 mm by 6 mm panels I made up 21 sets of double stencils to go in the box.  The box should of course be white (not black) when there’s nothing on it so while one end has Hornby’s blanking panel, one has to be painted white.

After initially deciding not to bother I relented on rear lamps and put a hook of 0.45 mm wire though each left side lamp iron.  A Springside tail lamp with a whole drilled in it sits on it when necessary, though looks rather overscale to me.

Reassembling the whole thing, testing as I proceeded, I fitted a DCC chip to save opening it up again.  I used a Digitrax 135 and having removed the blanking plug I pushed 0.5 mm wire into the holes on the chassis socket and soldered the leads to them.

So in summary, this is a really easy conversion.  I have it sat one of my conversions next to one of my Ian Kirk (plastic kit) 2-Bils.  It is very nearly as good.  For RTR that is magic.

Notes from the Modelling Secretary regarding smoking/non smoking accommodation:I compared a Hornby SR 2Bil against monochrome pictures of ex-works new stock in David Brown’s masterwork “Southern Electric, A New History, volume 2” and accommodation diagrams in the June 1956  Electric Stock Appendix to the CWNs.  With a magnifying glass I can make out the writing on the window transfers in the pictures, specifically on pages 106 and 107, in David Brown’s book. I can also make out the writing on the window transfers on the model with the assistance of a magnifying glass. Hornby have the Smoking accommodation transfers in red and No Smoking accommodation transfers in green. I will have to admit to being far more aware of detail matters on BR era rather than on SR stock so I am not sure if this is correct, and this runs contrary to modern “permissive” logic, however I suppose green could be an indication that the air is clearer in no smoking accommodation! This how the comparison works out:

For some reason Hornby’s model DTC has one more smoking compartment than prototype evidence for 1938 and 1956 indicates and on the DMBT the position of the non smoking compartments conform to the 1956 ACWN and not the 1938 picture. I am wondering if smoking/no smoking accommodation was altered between works pictures and introduction to service.  I have so far been unable to find other sufficiently clear pictures of SR units in service, or indeed colour pictures, to be able to provide confirmation one way or another.