34theletterbetweenB&D

You have to make your own decisions on your required standard: my experience of the situation in RTR OO 60 years past was that the product was NBG, and with support from a club I constructed the models I wanted to what was then termed 'OO finescale'. These models still operate alongside the current RTR OO introduced since the late 1990s, which is to the standard I aimed at by DIY - not always successfully! (A diversion into EM and then P4 while in DIY mode, was easily 'corrected' when supply of good RTR OO kick started my resumption of model railway activity.) And of course those old models built 40 years and more ago are now incredibly low cost...

A useful summary and discussion of what's available in mk1s that can be found second hand.

No, but I have had a couple of the Junior 0-6-0T which was clearly the 'Bachmann Thomas' in plain clothes, just as the 0-4-0T is clearly the 'Bachmann Percy' treated likewise. The problem with the 'Thomas' derived item is that the construction is a PITA, in the that motor and top half of the gear train is captive in the body, which detaches as a piece from the chassis block casting: not too much of a problem to overcome if retaining the body (for the purpose of producing cheap Thomases to amuse small children) not so good if using a different body shell... On a positive note the motor, gear train, chassis casting, wheelsets, pick up wipers are standard Bachmann, gear ratio fairly low because Thomas has to get a move on, but you can obtain realistic performance using DCC or a good feedback controller.

And of practising steam loco engineers, you had to be Andre Chapelon to make a reliable estimate: which ability was then validated by testing. On paper, the 50 sq ft grate area of the respective boilers should generate much the same heat output, with the Coronation's larger superheater area transferring more energy to the steam, and the P2's Kylchap exhaust system extracting more power from any given mass of steam throughput. Where the P2 should possess an operational advantage is a much higher factor of adhesion, which should deliver the ability to put more power down, especially in poor rail conditions.

Some cutting will be involved, whether of the motor casing or its mounting if that's feasible, and/or the cab moulding. To minimise the effect, since a single power bogie is most effective at the rear of loco, choose whichever is the best of the loco ends to lead, and put the power bogie at the trailing end, where any modifications will be less visible

Picture in the LNER Encyclopedia piece about the Y9. https://www.lner.info/locos/Y/y9.php My impression of these wagons converted into tenders is that they were typically old short wheelbase all wooden construction wagons, with 4 plank sides or thereabouts. The illustration of the NBR Jubilee wagon below is the sort of thing, the end door simple to remove to provide easy access, Oxford Rail produced a RTR OO version, and there are plenty of OO kits of like wagons available. https://railsofsheffield.com/products/parkside-ps01-lner-jubilee-coal-wagon?variant=42776042504383&currency=GBP&utm_source=google&utm_medium=cpc&utm_campaign=google%2Bshopping&gad_source=1&gclid=CjwKCAjwnei0BhB-EiwAA2xuBomS29mVvIHs-GwR0eq6M2US4uHBylRmkxViY5o1FXtIDQqnUHTQbRoCA2cQAvD_BwE

Not having ever seen let alone handled this particular model, but with experience of removing screw attached ballast weights in upward of 20 of Bachmann's OO steam models: Sometimes the paint on the ballast block, and/or the surface it sits on, was tacky at assembly, so breaking it out may be required, insert blade in gap and wiggle. Likewise gummed on somewhere with the plastic body assembly solvent, though that's unusual. Inserted exterior detail such as handrail knobs, boiler furniture locators, fouling the ballast block, wiggling it and observing closely for any exterior detail movement; and all else failing simply gently pull out anything potentially fouling. If the ballast is in the smokebox, removing the smoke box door moulding may enable you to see what the obstruction is. And in the case of the WD 2-8-0 this is essential as the ballast weight at the smokebox end can only be removed this way, as it is conical on its long axis. A one off in my experience thus far, but who knows a designer might have felt that it was time for another such? Some ballast weights, especially at the smokebox end of the model, are an essential part of the body assembly, which may not be immediately apparent because the cement is holding. Until suddenly it breaks and parts fall off. Finall, good news, the construction is such that I have never yet had any trouble getting the models reassembled with no sign of having been taken apart.

This was fighting talk in the historic past. That large lump of readily visible rock that orbits our home, supplied a useful indicator of seasonal changes to help with the crucial matter of agricultural planning and more. The term Mo(o)nths isn't an accident, and the quarters led to what is now the week. The arguments over which should take priority, when none of the readily observable cycles resulted in whole number relations (to be expected of a perfect creation) makes very funny reading in the available ancient literature. To truly settle the scale speed argument we need control of gravity, so we are going to need an artificial gravity system in a space station, adjustable for scale, so that a G of 9.8 scale metres per second is produced on our orbiting layout. Run your train above scale speed for the layout curve radii and it will fall off the track. Easy! The beardy absentee billionaire likes running trains and space travel: we should only ask him to take a punt on this project.

Should have mentioned that this also affects the split axle wagon wheelsets in the wagons that were introduced alongside the split axle locos. A sure sign of this is a wagon 'bob-bob-bobbing along'. The spoked wheelsets are useful for pinpoint pick up in BR tenders - OK they lack a spoke but who can spot that behind the frames? - anything to eliminate Hornby wiper drag.

The coning of wheel tyres acting on the running railhead does all that is necessary for pick up; and there is one potential downside from a live checkrail, in that it provides an additional location for a piece of metal (detai) fallen off a model to bridge to a rail at opposite polarity.

That's for the retailers to call. My opinion - based on being able to steadily hoover up Bachmann mk1 at reasonable s/h prices these last 15 years - is that the market is awash with sufficient RTR OO mk1s until the plastic crumbles; what with all the other options from past productions listed above. (And there has been something of a hiatus in new introductions to Bachmann's Mk1range until their recent announcement.)

My immediate thought was that having all the necessary research available, if TT120 'flies' in their opinion, then they can go for the most numerous LNER wide firebox class, that Hornby have long considered beneath them, despite it being the necessary adjunct to the pacifics...

Heljan produced a BR MLV (class 128) with a centre motor all wheel drive mechanism which will do the job very simply inside a coach body. The standard Heljan 14mm dia wheelsets may be substituted for the 12mm dia (DMU size) wheelsets. Obviously there is the task of making the necessary arrangements to mount the coach body on the mechanism: copying the method on the original coach chassis seemed simplest to me. For my own purposes I fitted it inside a full brake coach body: and the usual smooth operation with a DCC decoder on a Heljan centre motor mechanism would simply perform your two proposed applications.

On this specific question, a combination of brittle plastic and tight fits of the stub axle pins, never saw any evidence that oil lubrication had anything to do with this - I used graphite on the unpowered axles - and a great many bogie/pony/tender wheelsets are still in use salvaged from worn out mechanisms. Repair of these as required by use of replacement plastic tubing - as already suggested above - has been a winner, as the plastic goes on degrading . On which subject, be gentle with the keeper plates and other moulded construction pieces used in the bogies and trucks, these can become very brittle and spares are not available.

If it was anything like 'lofts I have known', there will have prolonged high temperatures in summer. Further factors to consider, components of other polymers used in construction and insulation, fluxes used in pipe soldering. In a long ago shared rented house I found a railway layout on the loft flooring, which was some sort of chipboard with a plastic top. The Peco track base was melting in various locations, don't know why. (I salvaged the rail for soldered track construction, the landlord hadn't even known it was there; not too surprising considering the general state of this very low rent accomodation.)