Three-D Modelling for Railways

I wrote about curves previously , but if your curve is a circle - or a section of a circle, an arc, - you have other options. Cylinder The most obvious is to just use a cylinder mesh. Remember to give it enough sides that it will resemble a smooth curve when printed. As a rough guide, at least 2 sides for every millimeter in the diameter. Too many, and you are slowing the computer down unnecessarily, too few and the steps will be visible. If you want a hollow cylinder, create two, one inside the other, with the inner one a bit longer. Then on the outer one add a Boolean modifier, and apply the inner one, I like to put all the meshes that are just there for Boolean operations into their own collection. You can then hide that collection, and see the hole. If you want a section of a circle, you can just delete the vertices you do not want, and add faces as required. However, if you have a move complicated shape composed of several concentric cylinder that gets harder to do, and you are be

Castlefield is in the west of Manchester, and is home to some great bridges. Two canals meet here, and they were here first, so we start with them. The red is the Bridgewater, the first to be built, from coalfields in Worsley. It drew its water from the Medlock, in blue, which became increasingly polluted. When the Rochdale Canal arrived, the Bridgewater could gets its water from there. This necessitated building a tunnel for the river. Some sources indicate this used a siphon to allow the water to get back up to river level, after going deep enough to get under the canals. Further upstream, I guess it has just been culverted. The railways here are more complex - hardly unique in Manchester - due to the vagaries of history. This view is annotated with the lines, based on the Railway Clearing House map of 1910. The blue is the LNWR line from Liverpool, the original Liverpool and Manchester line. The station is now the Museum of Science and Technology. The yellow is rather more recent, i

We stopped briefly at Ribblehead on our way to Durham, so a short post! It is not the fastest route, but makes a nice change. This was the view from the car as we approached from the west (I was not driving). The dominant feature is, of course, the viaduct. There are places along the road on the other side where you can park. It was very busy - a sunny day plus two charity events. A short walk gives a great view of the viaduct. I was surprised how busy the railway was - three trains over the viaduct in the short time we were there. The viaduct was built between 1870 and 1875 as part of the Settle and Carlisle line, to give the Midland Railway its own route to Scotland, in competition with the LNWR route via Preston. This is the view the other way, and you can see all the vehicles lining the road. That is it. I said it was short.