Hallade was not alone. His method of track alignment rectification is by far the most used and known but there are quite few other methods for rectification and even proper realignment. One of these methods used a strange curve called involute (or evolvent). It was first described in this book from 1927. Die Absteckung von…
Motto: “I don’t see the code anymore. All I see is blonde, brunette, redhead, negative, adverse.” Cypher Disclaimer: This is not a design guidance. Don’t believe everything you read online. LandXML? LandXML is a non-proprietary data standard on the Extensible Markup Language (XML) format, developed for engineering data exchange. A LandXML file can contain civil and survey…
It was very nice to find this in a standard. Snippet taken from here.
When I hear the name Bernoulli I think about some funny high school experiments of spraying coloured water on paper but also about an infinite loop curve the Roads Professor tormented us in Uni. I would have bet both things were discovered by the same Bernoulli. But no. The more known one, D. Bernoulli, the…
I mentioned in a previous article, The Cubic Parabola – a complicated simplification, that the curvature diagram of the Cubic Parabola increases linearly up to a peak point and then drops down. Only that first section of the parabolic curve can be used as an alignment transition. The curvature diagram of the Clothoid is however…
Prologue One of the giants on whose shoulders stood proudly Isaac Newton, is the French mathematician Renatus Cartesius. He was the first to label the unknowns in equations by the letters X and Y and also he defined the annotation of powers as superscripted labels X2 . Believe it or not, that was a giant…
One alignment design homework I had for my students was to calculate the installation coordinates for a simple alignment. This was a long time ago, before Excel was a thing. We were using scientific calculators back then; a lot of typing. One of the submissions puzzled me. All the coordinates were almost correct. The length…
Ten years ago, one of my first British friends asked me “Why 4°?” The Clothoid is by far the most used transition curve for railway and highway alignment design. I wrote about this marvelous curve in an old article on this blog – here. Although the Clothoid is the ideal transition for linear variation of…
A railway track blog 