380John Posted July 23, 2016 Share Posted July 23, 2016 Dear all, without getting to precise, I've been looking this evening behind the maths to creating a realistic gradient for a railway embankment. I'm quite happy with how this is calculated, but what I cannot find is a rough figure in which to raise the track height. I.e from the bottom of the embankment to the track above in an imaginary straight line. (OO gauge) I was thinking around 3" from the bottom to the top, but I did read someone used 4". I was wondering if ready to plant bridges etc designed to be built into the embankment were standard 4" high in oo gauge? I'd like to make my own but I'd like dimensions for the height. Hope this makes sense?! Many thanks in advance! John Link to post Share on other sites More sharing options...
RMweb Premium Kris Posted July 24, 2016 RMweb Premium Share Posted July 24, 2016 The figure you're looking for would be what ever was required by the railway. Some embankments are much lower than others necessitating roads to dip to get under them, The A350 coming out of Westbury Wilts is a good example of this. This road regularly used to flood due to the dip. In other places the bridge carries part of the embankment before getting to the rails. Link to post Share on other sites More sharing options...
Guest 40-something Posted July 24, 2016 Share Posted July 24, 2016 There is no definitive answer to the height of an embankment. In reality chances are if there were 3 overbridges in a half mile, all three would be a different heights from ground level. Work out what your railway is crossing, if its another railway then allow for the height of the tallest piece of stock, track and trackbed, plus a few scale feet clearance to the underside of the bridge deck. More if an OHLE line. If its a road, what is the likely traffic on the road? Artics? Double Decker buses? Again allow for the tallest road vehicle plus a couple of feet. If its a waterway then there really are no rules, especially if its not a navigable waterway Finally, measure in scale, 4mm/ft in this case. OO is a gauge rather than a scale. Link to post Share on other sites More sharing options...
RMweb Premium Ian Smeeton Posted July 24, 2016 RMweb Premium Share Posted July 24, 2016 If its a road, what is the likely traffic on the road? Artics? Double Decker buses? Again allow for the tallest road vehicle plus a couple of feet. If its a waterway then there really are no rules, especially if its not a navigable waterway On the other hand, ask the question "what is the likely traffic on the road?" and set the bridge height a little less for that well known Cameo A bus stuck under a bridge gone.... forgot coat & hat Regards Ian Link to post Share on other sites More sharing options...
380John Posted July 25, 2016 Author Share Posted July 25, 2016 Thank you all for your responses. Ian that cameo sounds great!! Nice simple method of measuring mentioned by using the vehicles intended for the layout. I suppose one good way would be to make a small mock-up and see how they look. Not unless anyone has any examples of how tall their embankments were on their layouts? John Link to post Share on other sites More sharing options...
Judge Dread Posted July 26, 2016 Share Posted July 26, 2016 I have always worked on the maxime "Does it look right?" Here's a photo from "Chessington (Chalk Lane) an EM Southern Electric layout by the then 4mm section of the Hull MRS. Credit to Steve Flint and the Railway Modeller just incase you cannot read the graffiti on the wall above the police Morris Minor. As the average double decker bus height is 14ft 6ins, I reasoned the bridge clearance should be at least 16ft 6ins. Also here is a part of a dimensions sheet by the EM Society which shows embankment sides should be in the range of 1 in 1.5. I hope this helps. Link to post Share on other sites More sharing options...
380John Posted July 26, 2016 Author Share Posted July 26, 2016 Judge dread thank you. This is extremely useful and I must thank you for putting the effort into your response. This has answered my query very well and the added picture and diagram helps me to see the wood for the trees! Thank you, John Link to post Share on other sites More sharing options...
RMweb Premium HillsideDepot Posted July 26, 2016 RMweb Premium Share Posted July 26, 2016 Embankments, and bridges, vary in height according to the landscape, as Kris mentioned. You'd not get an RT double deck under this one. Although an RE single deck fits under the model equivalent The actual bridge, in Chippenham on Brunel's GW main line is marked as having 10' clearance, but that is a cautious figure. I think they way they do it is to take 3 inches off the measured clearance, then round down to the nearest foot or half foot. I suspect its metric now, but that was what a highway engineer told me years ago (when resurfacing and re-signing suddenly meant that we could legally get low-height double deckers under a bridge which had long been a bus route). Incidentally heights over 16' don't need to be signed. I've included a Morris Minor in my picture too for comparison, which I hope doesn't now obscure the wood it more trees! Link to post Share on other sites More sharing options...
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