34theletterbetweenB&D

Surprised, I rather thought it would be Heljan next to be dangling a new tooling Brush type 2. Whatever, looks like my Airfix GMR bodies (now on their 3rd DIY mechanism arrangements, salvaged Hornby mazak rotters superseding HO Athearn PA1, which superseded twin Airfix mechs for that full stereo coffee grinder action) are going to be retired. Unless this newbie doesn't capture the appearance at least equally well...

It's all classically fictional in its Triangness, the well length and bogie wheelbase correct for the 50T rivetted construction Weltrol P, but with the welded frame construction, narrower side members and also a centreline member, from the 55T Trestrol C. Shunt three of the Triang items into Micklehacking wagon works and a little sawing, liberal application of plasticard, cementing and a pair of suitable trestles can result in a credible Trestrol B and C, and a Weltrol P.

The ideal finishing abrasive for the purpose is jeweller's crocus paper or cloth. I think it will now be expensive. (I only have some because my late FiL was a specialist in abrasives manufacture, and I got a chunk of his stash.)

'Sometime' being the significant word. The current disruption to container freight shipping due to events proximate to the Red Sea - Suez Canal - Mediterranean shipping route will be properly biting by then. One might hope that the recent experience of the Suez Canal constipation event will aid the forward planning to minimise disruption, but I wouldn't bank on that.

The fruit of my experience is that standardising on a decoder brand is helpful, only one manual to absorb. As it is I use two, Lenz and Zimo, and operate using a Lenz system, now coming up to 20 years since purchase. Straightforward decoder programming on both brands, bombproof reliability in operation, stable speed control and stopping distances. The caveat, this is solely OO experience, largely using current RTR mechanisms as supplied* with some kit builds with Mashima or similar motors: no traction tyres allowed, and all metal wheels on stock, I don't use sound, and stay-alive is not required on my all live crossing points system, mostly Peco, some SMP and Marcway kits. *Swapped out the bronze wheelsets on an early Heljan product for their nickel silver replacements, various simple rearrangments to improve pick up integrity and gear meshing on RTR product introduced prior to 2013.

The parallel with the more recent strongly promoted Wankel rotor ICE to supplant all them pistons whizzing up and down comes to mind. The experiment that unfortunately doesn't appear to have happened, is the combination of water tube boiler with a steam turbine, the latter an undoubted technical and operational success on rails. The turbine offering much reduced vibration with better use of high pressure steam, as it is the equivalent of a uniflow multi stage compound, should have made life easier for the boiler. A more radical locomotive layout on smaller wheel diameter bogies would present fewer constraints on boiler design, and potentially a better ride with reduced unsprung mass and a smaller reduction ratio requirement from turbine shaft to axle.

It was noticeable that when it came to comments from overseas customers about model railway vendors in the UK, one name dominated. As for access: I recall that earlier the message on this was 'no takers'. Unsurprising, all those currently active in the trade and thus possessing the necessary experience already have their name before the customers, and there's the risk identified here:

Looking further afield, the water tube boiler was tried by major steam rail traction constructors around the world, with limited success. The Stephenson fire tube boiler held out to the end. International comparisons here: http://www.douglas-self.com/MUSEUM/LOCOLOCO/locoloco.htm Scroll down to ' The Pressure is on' and take a look. (You may end up reading the whole site, very interesting altogether.)

I think you will find that WR numbered mk1 CK and BCK were produced, but in choc and cream. However if you can find Bachmann's mk1 CK and BCK in crimson and cream, the lettering comes off very easily with a careful application of white spirit. (This is generally true of Bachmann's product.) Thus removing an E, M or Sc and substituting a W 'converts' them to a WR allocated vehicle. Purists will probably change the numbers too.

Oh yes. And one additional factor, customer confidence. Hattons never put a foot wrong in my s/h purchases. Would like to be able to say the same of their competitors, but poor experiences twenty odd years ago meant that I subsequently only looked in that one place...

This problem lurks in OO product too, whether it is over wide channels or narrow gears, or a bit of both. (And for completeness,the opposite problem of tight channel, wide gear or wide gear boss.) My preference has been to push out the gear shafts and add washers to keep the gears as well positioned as possible for optimal meshing. It's somewhat fiddle-de-dee work, this gear can be positioned with very little slack, but that one needs to be left 'looser than I would have thought optimum' if there's not to be gear noise.

Perfect representation of this large ugly lump then! For my taste it doesn't look sufficiently dented and tatty. Plenty of filth on my disc headcode all over BR green EE type 4, this class swiftly became very mucky as used initially on express traffic.

And now the obvious follow-on question; where's all the s/h RTR model railway traffic formerly handled on this route going to be diverted to? We haven't heard so much from those on the supply side of the s/h jumble sale...

I have been very pleased by the damping out of such oscillations provided by the close coupling mechanisms on those RTR OO models which have the Pullman gangway. Length adjustment of the 'rigid' coupling between the mechanisms is typically required such that all the gangway faceplates are in contact on straight track. The train then moves as one piece and is stable: any deviation from this is an immediate alert to gross contamination on a tyre, usually seen as vertical oscillation. On such (rare) occasions we have the joy of the train halting to enable the faulty vehicle to be detached and set aside. It would be lovely if this might be accomplished without the hand of god, but such refinement has yet to be achieved.

The early releases had by general report a much superior motor with flywheels. All the problems underlined are nothing to do with fitting a decoder, but overall describe a mechanism in a very worn condition; and DCC cannot provide a cure for this. The question this begs is how did the mechanism come to be in this condition? Only you know the answers to these last two questions. The DG is the one Oxford traction model I haven't had hands on, so I cannot offer any direct advice from experience of this model. All of the radial tank, N7 and J27 have competent mechanism designs, and have generally performed equivalently to the comparable RTR OO brand's products that I own, with the N7 - of which I have multiple examples - the standout for its ample traction thanks to the much greater weight of this model. There's no downside to date from the N7's weight, and moreover these get far and away the most running; so if significant wear were to occur it would be on these models. I don't see anything significantly different in the mechanism construction of the DG, based on pictures posted on line. It should work well in my opinion.

I feel you may be up against the limitation of a train set model incorporating multiple vehicle articulation, with none of the stabilisation mechanisms that prototype trains of this type employ, and the slack clearances required for set track curves to boot.

It's only fair to add that the P87 format, HO's equivalent to P4 vs OO is completely feasible for UK steam, but the restriction to applicable prototype radii must be accepted. Exception here! The plenitude of decent RTR OO mechanisms to sling inside loco body kits is very much enjoyed. From the perspective of one that never wanted to run the loco, carriage and wagon works, but rather favoured the happy 'theatrical performance' of timetable operation, the ability to make the required traction class not yet available in RTR a going concern by means of a RTR mechanism has everything to recommend it. The happy fact that many 0-6-0 classes were based on Crewe or Derby wheelbase dimensions, occasionally modified by a few inches, means that there are plenty of 'good fits'.

Irresistible to reply to this. Many years ago I was on a corporate brainwashing management programme at Great Missenden, when P&O were one of the other businesses with a course underway: P&O's was memorably titled 'negotiating to win'. This happily turned out to be a perfect anagram for 'ignite goat in town', the rearrangement facilitated by the course title being displayed on a peg board. Dipsomaniac principle meant we treated all the other course titles likewise late that evening: but I don't recall any of those, including that of the course I was attending. General merriment ensued the following morning. The one exception was the uniformed gent running the P&O course; he had clearly had a very successful humourectomy and let us know about it, frequently, for the remainder of the week.

From my long ago experience it will still be necessary to pre-bend the flexi rail ends to eliminate any 'dog leg' at the join to the set track piece. The set track railjoiners are slack fitting around the rails and thus won't reliably supply the force required for a smooth joint alignment.

Suggests that the vendor isn't aware of the 'auction' concept?

Short answer, if most of the curve will be R3 as you describe, use set track curves. (It takes considerable effort to maintain an accurate constant radius of less than 24"with code 100 flexi, including forming the rails permanently at rail joints to prevent 'dog legs'.)

Rather late seeing this thread, but another possibility is that the piston rod is fouling inside the cylinder moulding.

Parts diagram for the first Bachmann version attached, showing wiper pick ups. It may be possible to track down the catalogue numbers by cross-reference to the names listed? https://Bachmann-spares.co.uk/file/Class-42-original.pdf

This is the crucial piece of information. Because the jerk or stoppage happens in the same place on every rotation of the wheel set it has to be on the wheelsets or coupling rods, 'somewhere' given that the outside motion has been removed. Bends in, or incorrect length of a coupling rod, damage to the crankpins, damage to the axle gear, fixed components snagging on the wheel (pick up wiper on the wheelback for example) are further possibilities, producing equivalent results to a wheelset out of quarter. And just in case this is a new purchase. Was the model showing the problem before a decoder was fitted? If so a return to retailer is indicated. On reading those first two lines I immediately thought the speedo drive representation was the likely bfault, as if this is slightly out of position it runs like a three legged dog. But as you have had all the motion off and it goes tight on the front driver that can be ruled out...

The GNSR had Manning-Wardle 0-4-2T for dock shunting, LNER classes Z4 and Z5. Outside cylinders however, but the overall antiquated appearance might compensate? https://www.lner.info/locos/Z/z4.php