Early history
Over 42 years, CUCC has developed methods for handling such information. Refinements in data management were made necessary by improved quantity and quality of survey; but refinements in data management also helped to drive those improvements. The first CUCC Austria expedition, in 1976, produced only Grade 1 survey for the most part (ref Cambridge Underground 1977 report).
In the 1980s, the use of programmable calculators to calculate survey point position from compass, tape, and clinometer values helped convince expedition members to conduct precise surveys of every cave encountered. Previously, such work required hours of slide rule or log table work. On several expeditions, such processing was completed after the expedition by a FORTRAN program running on shared mainframe time. BASIC programs running on personal computers took over with the release of the BBC Micro and then the Acorn A4. A full history of this period is described in Taking Expo Bullshit into the 21st Century - a story of the data management system up to Spring 1996. [This was less than five years after Tim Berners-Lee published the world's very first web page on 6th August 1991. So the expo website is nearly as old as the web itself.]
Survex - cave surveying
In the 1990s, Olly Betts and Wookey began work on "Survex", a program in C for the calculation and 3-D visualization of centerlines, with intelligent loop closure processing. Julian Todd's Java program "Tunnel" facilitated the production of attractive, computerized passage sketches from Survex centerline data and scanned hand-drawn notes. A history of survex article covering the period 1988-1996 was published in Cambridge Underground 1996.
Initial cave data management
Along with centrelines and sketches, descriptions of caves were also affected by improvements in data management. In a crucial breakthrough, Andrew Waddinton introduced the use of the nascent markup language HTML to create an interlinked, navigable system of descriptions (see "Expo Bullshit"). Links in HTML documents could mimic the branched and often circular structure of the caves themselves. For example, the reader could now follow a link out of the main passage into a side passage, and then be linked back into the main passage description at the point where the side passage rejoined the main passage. This elegant use of technology enabled and encouraged expedition members to better document their exploration.
To organize all other data, such as lists of caves and their explorers, expedition members eventually wrote a number of scripts which took spreadsheets (or comma separated value files, .CSV ) of information and produced webpages in HTML. Other scripts also used information from Survex data files. Web pages for each cave as well as the indexes which listed all of the caves were generated by one particularly powerful script, make-indxal4.pl . The same data was used to generate a prospecting map as a JPEG image. The system of automatically generating webpages from data files reduced the need for repetitive manual HTML coding. Centralized storage of all caves in a large .CSV file with a cave on each row made the storage of new information more straightforward.
HTML and browser incompatibilities
This was a much bigger problem in the past than it is possible to imagine now (most of the early editing is done on an Acorn platform using !Zap). So much so that we have a separate page all about it: "Platform portability - making the website work widely".
Version control
Another important element of this system was version control. The entire data structure was stored initially in a Concurrent Version System repository, and later migrated to Subversion [now using git in 2020]. Any edits to the spreadsheets which caused the scripts to fail, breaking the website, could be easily reversed.
Other types of data
However, not all types of data could be stored in spreadsheets or survey files. In order a display descriptions on the webpage for an individual cave, the entire description, written in HTML, had to be typed into a spreadsheet cell. A spreadsheet cell makes for an extremely awkward HTML editing environment. To work around this project, descriptions for large caves were written manually as a tree of HTML pages and then the main cave page only contained a link to them.
A less obvious but more deeply rooted problem was the lack of relational information. One table named folk.csv stored names of all expedition members, the years in which they were present, and a link to a biography page. This was great for displaying a table of members by expedition year, but what if you wanted to display a list of people who wrote in the logbook about a certain cave in a certain expedition year? Theoretically, all of the necessary information to produce that list has been recorded in the logbook, but there is no way to access it because there is no connection between the person's name in folk.csv and the entries he wrote in the logbook.
The only way that relational information was stored in our csv files was by putting references to other files into spreadsheet cells. For example, there was a column in the main cave spreadsheet, cavetab2.csv , which contained the path to the QM list for each cave. The haphazard nature of the development of the "script and spreadsheet" method meant that every cave had an individual system for storing QMs. Without a standard system, it was sometimes unclear how to correctly enter data.
From " Troggle: a revised system for cave data management", by Philip Sargent and Aaron Curtis, CUCC [with some additions]. Original (2006) paper: " Troggle: a novel system for cave exploration information management", by Aaron Curtis.
History in summary
The CUCC Website, which publishes the cave data, was originally created by Andy Waddington in the early 1990s and was hosted by Wookey. The version control system was CVS. The whole site was just static HTML, carefully designed to be RISCOS-compatible (hence the short 10-character filenames) as both Wadders and Wookey were RISCOS" people then (in the early 1990s). Wadders wrote a huge amount of info collecting expo history, photos, cave data etc.
Martin Green added the survtab.csv file to contain tabulated data for many caves around 1999, and a script to generate the index pages from it. Dave Loeffler added scripts and programs to generate the prospecting maps in 2004. The server moved to Mark Shinwell's machine in the early 2000s, and the version control system was updated to subversion.
In 2006 Aaron Curtis decided that a more modern set of generated, database-based pages made sense, and so wrote Troggle. This uses Django to generate pages. This reads in all the logbooks and surveys and provides a nice way to access them, and enter new data. It was separate for a while until Martin Green added code to merge the old static pages and new troggle dynamic pages into the same site. This is now the live system running everything (in 2019). Work on developing Troggle further still continues (see Troggle intro).
After Expo 2009 the version control system was updated to a DVCS (Mercurial, aka 'hg'), because a distributed version control system makes a great deal of sense for expo (where it goes offline for a month or two and nearly all the year's edits happen).
The site was moved to Julian Todd's seagrass server (in 2010), but the change from a 32-bit to 64-bit machine broke the website autogeneration code, which was only fixed in early 2011, allowing the move to complete. The data was split into separate repositories: the website, troggle, the survey data, the tunnel data. Seagrass was turned off at the end of 2013, and the site has been hosted by Sam Wenham at the university since Feb 2014.
2018
In 2018 we had 4 repositories, 2 mercurial, 2 git
- loser - the survex cave survey data (hg)
- drawings - the tunnel and therion cave data and drawings (git)
- expoweb - the website pages, handbook, generation scripts (hg)
- troggle - the database/software part of the survey data management system - see notes on troggle for further explanation (git)
In spring 2018 Sam, Wookey and Paul Fox updated the Linux version and the Django version (i.e. troggle) to something vaguely acceptable to the university computing service and fixed all the problems that were then observed.
Early 2019
In early 2019 the university computing service upgraded its firewall rules which took the server offline completely.
Wookey eventually managed to find us free space (a virtual machine) on a debian mirror server somewhere in Leicestershire (we think). This move to a different secure server means that all ssh to the server now needs to use cryptographic keys tied to individual machines. There is an expo-nerds email list (all mailing lists are now hosted on wookware.org as the university list system restricted what non-Raven-users could do) to coordinate server fettling.
At the beginning of the 2019 expo two repos had been moved from mercurial to git: troggle and drawings (formerly called tunneldata).