auldreekie

I'm thinking about it! Perhaps, when I'm a bit more alert tomorrow morning, I'll try to draw for my own benefit how that description might have worked.... Grateful. auldreekie

Thank you very much. That's very helpful indeed to at least one of us. In particular, your explanation of the beam fills a gap in my knowledge. I'm guessing, then, that the beam is pivoted at a level above the point of contact with the wagon, and counterbalanced by a weight whose level of attachment is above the pivot. That seems quite clear. What is not clear is how the beam then prevents the wagon from plunging into the depths. Perhaps there is some mechanism or structure behind the beam which limits the extent to which it can pivot? auldreekie

From a quick look at images on the web, it could be either, but the shape of the hoppers beneath suggests Carnforth. auldreekie

I always wondered where Barrow Road was! auldreekie

David, Superb once more! Now I see why you've done as you have. I wonder if the original of the Bachmann model was longer, with perhaps more hoppers, than the Haymarket installation. You reckon one of the Bristol sheds. Was there an LMS shed in Bristol? (I believe the GWR didn't go in for these things, as they used friable South Wales coal). Carnforth has been suggested to me. I shall do a bit of delving.... auldreekie

David, Thank you greatly. It's not a question of it not looking good. It looks GREAT. As ever (and it's part of what caused me to pause a few years ago and go off at a tangent) my concern is with how precisely the damned thing worked. I don't know, so I cannot pontificate about your solution. The side-rails for the tippler do appear, from my partial photographic reference, to go into the void. But equally clearly they are anchored very firmly indeed to the main concrete frames at the ends of the structure, as one might reasonably expect. I AM tempted to reactivate this project by attempting a parallel construction, if only because doing so may help to elucidate what really does go on when the wagon is tipped. Nothing like actually having scale replicas of the relevant bits and pieces to hand...... For one thing, those metal (?) structures at the top of the side-rails appear to have curved, rather than segmental, undersides, and careful study of photographs reveals a corresponding projection beneath, with a curved upper surface which looks as if it may have a role in guiding or restraining the deck on which the tipped wagon is carried. But I'm guessing in the dark. Perhaps there's someone out there who can remember operating these enormous contraptions..... auldreekie

David, That looks superb. I had no idea you were so far advanced. What material are you using for extending the Bachmann tower? I was not familiar with the Bachmann tower, and I've no idea what original it is based on. It does look as if it was intended to straddle one track, but I see you have made some at least of the necessary adaptation of the "jigglers" so that they project off to the face opposite the coal tippler. As I said before, I'm not as clear as I wish to be on the precise mechanism of the tippling and on how exactly the coal wagon is restrained from vanishing into the abyss when it is tipped. But I'm a bit doubtful about the way in which the side-rails of your tippler disappear into the void. I sort of expect them to be keyed to the main structural frames of the building, since they must give rise to the maximal stresses which it experiences. And I think, if I remember rightly, that's as suggested by such photographic evidence as I could muster. I'd also like to find out a bit more about how the hoppers are arranged internally in these particular structures at Haymarket and Kittybrewster. It looks as if there might be two of them, and was there any provision of a movable baffle enabling coal to be directed to one or other of them? auldreekie

David, The photograph which I promised. Hope you may find this helpful.... auldreekie

David, Thank you for your very helpful and encouraging reply. The photograph which I posted was dated October 2012, so as you can see this project has suffered a considerable delay whilst I construct such sacred narrow gauge monsters as a Henschel 4-8-2 for a Brazilian mineral line which went broke (the locomotive an absolutely mouth-watering beauty in my book) and the Yugoslav (ex-Bosnian) Class 83 0-8-2 which was the mainstay of much of that country's narrow gauge network (a quirky, even ugly, but anyway very different beast). Since these and other such creatures are absorbing a fair bit of my energy currently, it is likely to be months rather than weeks before the Haymarket scheme springs back to life. Pity you won't be using my coal tower drawings, but the offer remains very much open if you should think otherwise, or if you think that my drawing might help you in your adaptation of the Bachmann model. Just in case it might be of interest, I have taken an indicative photograph of the drawing, which I shall post when I have had an opportunity to set it up on Photobucket. I could be tempted into building the coaling tower as a stand-alone object - just for the hell of having two on the go at once to compare and contrast. The construction process would pose a challenge or two, I have no doubt. A couple of questions: is the wagon hoist and tippler going to be operational on your model and (if so) will you be posting/ publishing details of how you achieved this? Secondly, have you managed success in procuring any details from whatever source of the internal arrangements? I could make a reasoned guess at them, but I must say that I'd prefer to know chapter and verse. I assume that you are familiar with such generic treatments as that given in E S Beavor's "Steam Motive Power Depots": the diagram on his page 20 is most helpful, but it depicts an arrangement in which two coaling roads pass beneath the structure rather (but not exactly) as at Doncaster Carr. The Haymarket/ Kittybrewster setup was, of course, different. auldreekie

Your entire layout absolutely gobsmacks me, as I started out on a very similar course about 4 years ago, but shelved it pro tem, as I became interested in the construction of large and complex narrow gauge locomotives from all ends of the world in 4mm scale. I have by no means given up on my Haymarket project (which, like yours, involved a cutting down of the main shed to about six two windowed bays) since not only have I accumulated most of the necessary materials, and produced some working drawings, but also I have carved out the necessary extensive set of be-windowed gables in 80 thou styrene sheet, to be laminated with the appropriate Slaters' brickwork. This was quite hard on the wrists and thumbs. I don't think my construction techniques will be the same as yours, although it is wonderful to see the ground broken ahead, and to have the opportunity of learning how someone else tackled the challenges. Your initiative to have York Modelmaking cut the windows COULD be a splendid help, although I suspect it comes too late for me, as I believe that I chose to cut to accommodate existing proprietary products which were close to the real thing (but not an exact match). My reason for posting is that I invested considerable effort in arriving at what I believe to be a reasonably accurate 4mm scale drawing of the externals (both sides, roof plan and east end elevation) of the Haymarket coaling tower. I used all the published photographs I could find, plus those of the very similar tower at Kittybrewster. Although I am no sort of a draftsman, I have spent a fair bit of time over the years in scaling buildings and other artefacts from photographs, and I am confident that the results would more than suffice as the basis of a 4mm scale model. One of the reasons I put this project on hold is that I ran into difficulties of access to the technical drawings (which I hoped would elucidate the internal workings) in the possession of the Scottish National Archive. I managed to obtain the grudging admission of the Director that these are not covered by copyright restrictions which at this date would prohibit access to them, but it seemed that I should have to invest in an eight hundred mile round trip in order to consult them in situ. Basically, I've had other things to do than travel to Edinburgh in order further to argue with civil servants whose salary I help to pay..... I don't have scanning facilities, but you'd be welcome to a photocopy of the drawings on which you'd have to do some cut-and-stick. The object is a fair size -- my drawing of it came out at over 33 centimetres tall, by about 18 cm by almost 14 cm (the last including the sloping system of rails on which the coal wagons were raised). Although there would be some inaccuracies in the photocopy-cut-and-paste process, you will appreciate that those would be as nothing compared with fudging a model up from a proprietary product, and they would be no greater than those likely to result from whatever construction method you might adopt from scratch. auldreekie

As a complete neophyte in these matters (but very interested as a modeller potentially using the products of others' CAD-based efforts) , I'm in the midst of tackling one of Bill Bedford's O4/5 boiler/cab units. In the end I shall be pleased with the results, but I must say that my working conclusions are very much along the lines of the "sprued-kit" approach which AJ427 now proposes to try. There seems to me little benefit to be derived from over-complication of the print by inclusion of complex projections such as handrails, ejector pipes, smokebox "darts", which are instinct with the possibility of confusing the 3D printer, and in any case many such objects can readily be fabricated or sourced elsewhere. As regards the UK standard gauge, my interest is focussed on ECML/Scotland and Lothians branches, so my use for the N1 (or the O4 /5 for that matter) is decidedly limited. Bill's O4/5 was the only available 3D printed object of which I was aware remotely in my field of interest, so I was keen to give it a whirl to see what resulted. In the event, it has been well worth the effort, leaving me with a fairly clear picture of the strengths and weaknesses to bear in mind. I am very grateful to Bill for making his somewhat experimental product available. I'm a "possible" rather than a "definite" for your N1 for similar reasons. If anyone was moved to tackle some NB prototypes on your proposed lines (an Atlantic?!; a C15?; a J35 or37?, leaving aside the question of chassis), I'd be right at the head of the queue. I suspect they might have a reasonable "north of the Border" following. Calling all motivated CAD experts..... auldreekie