When is the cant negative in LandXML?

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…

The other Bernoulli boy and his lemniscate

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…

Hallade’s broken clothoid

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…

Where’s the point?

All the railway networks have design rules for marking the limit from which it is safe to stable a vehicle on a line, without the risk of obstructing the train passage on the other line of an S&C (turnout or whatever other arrangement). In the UK this limit comes in a pair – Fouling Point…

And I wonder, still I wonder, who cut the rails?

Aren’t the adjustment switches some really nice devices? On one side we have rails subjected to thermal stress, tending to seriously expand or contract due to the environment temperature, and on the other side no stress is transferred. Smart! We cut the rails in that funny shape, grease the clamp plates, and we let the…