One of the perks of working in surveying is occasionally stumbling across or even using cool old maps. Earlier this week I found the coolest type I’ve come across yet, Railway Books.
These are massive table sized books that contain the detailed survey of an entire planned railway route, used back when everything was analogue. An INSANE amount of survey work must have taken place to make these, and then the amount of work to collate it all neatly together makes my head spin. It looks so cool.
Here is one page of one
That little note left on the page in this scan is A4, which gives you a sense of the scale of it.
I don’t know how well you can zoom on that so here are some close ups
You can see the planned bearings of straights, radius of curves, distance makers, how its gonna wind around the terrain.
The elevation profile down the bottom shows the different planned gradients of the track, how that matches up with the terrain, how they are gonna have to cut and fill the terrain to maintain a smooth constant gradient, where and what type of drains they are gonna build where they fill so water can still drain through, I’ll have to grab another page that shows bridges too.
I love all the hand written annotations too
You can see planned level crossings and where roads are to be diverted to make way for the railway, you can also see some funny old units like miles, cus we still used imperial back then and CHS which stands for chains.
side track about chains
which is a literal metal chain of a set length they used to use in surveying. A chain is handy cus it perfectly follows the ground instead of being a measurement in the air. I forget what their length is but a lot of our built world is the size it is cus it was measured in whole chains. eg street corridors are usually 1 chain wide, housing blocks are usually 2 chains deep and x chains long.
In the elevation profile you can see the marking of an old catastrophic flood level noted, where the track will be raised by banking or by bridge.
This rail line is now a rail trail, and I’ve ridden across this bridge in it’s current form many times and defs taken photos of it, but vexingly I cannot find any of the photos for the life of me. I wanted to do a cool thing of the concept of this bridge which started as lines in a book here drawn in the 1880s is now this physical bridge in 2024. I’ll settle for using someone elses pic.
Side track a different cool bridge over the same creek a different rail line still uses today
Sadly we only have access to scans of the books, I’d love to see a proper one. I bet they look even more impressive in person.
Cool railway map! If you liked it let me know what you liked about it. Happy to try and explain any other details I can too if you have questions. ^v^
side track slow math loves cut and fill problems
I particularly like the cutting and filling stuff cus that’s such a fun optimisation problem of trying to equalise the amount you cut into the ground and fill up embankments and the distance between them, so you don’t have to dispose of or bring in as much dirt or move it as far between cut and fill sites, while also taking into account constraints of what the route has to be (gradient vehicles can travel up, curves they can take, directness vs cost saving, etc)
