CanalOmeters go digital?

How could I productively spend a wet Wednesday afternoon at home?  Well I thought I’d have a go at making a smartphone CanalOmeter.  For those unfamiliar with my CanalOmeters, they are strictly low tech analogue devices for estimating journey times between two points on a canal trip.  You can’t beat cardboard.  Look them up here if you need to see one.

Why bother then with a Smartphone version? Well mainly because it was a bit of a challenge but it does overcome two disadvantages of cardboard ones.

1. Unlike a CanalOmeter, if you do have a smartphone, then there is a good chance it will be in your pocket when you need it
2. On the disc of  the analogue CanalOmeter there is only space for a limited number of locations, whereas the digital version can have every bridge, lock, wharf, visitor mooring etc.

On the other hand, the original CanalOmeter is so quick and easy to use, and don’t be fooled by the seeming precision of the digital version the old disc is just as accurate in the scheme of things because your cruising speed and time to do locks can only be an estimate.  And another thing, printing on cardboard is visible in bright sunlight, which my phone’s screen isn’t!

Anyway, here’s what I came up with.



This one has a hidden table with the entire Oxford canal (South and North) with every bridge  etc. To use it you put a code into the pink and green cells to indicate start and finish, it  looks up the places from its data table and comes up with the full place description, the cruising times, locks and miles come up as shown.  As you might guess, it’s an Excel compatible spreadsheet.  I think most smartphones have free or cheap apps to hold such spreadsheets. You create the spreadsheet on your PC and then download or sync it onto the phone.

I should here mention that the data is exported from Canalplan (everyone genuflect) into the spreadsheet.  The entire thing is self contained and needs no network connection which is a Good Thing as phone signals on the canal are often poor or non existent.  If you did have a good connection of course, you could just log on to Canalplan and use that, although its screen layouts are not good for a phone.

To start with in version 1, I just included bridges and locks, because they had obvious numbers, so I could enter B34 or L27 and so on.  Then spurred on by success I had a go at a vesrion 2 using simple guessable codes for other locations.  This turned out to be much simpler than I thought and I think remarkably easy to learn. For places without numbers I just used the first three letters of the place and then three letters for the canal feature, so we have HEYWHA for Heyford wharf, NAPMAR for Napton marina NEWTUN for Newbold tunnel, HAWJUN for Hawkesbury junction and so on.

I can see a problem on some routes with this approach.  If a route uses more than one canal, you might get duplicate bridge numbers, and on canals like the Birmingham and Fazeley, the bridges have names instead of numbers.

I’ll give it a try when we set off again in September.

So that’s how I passed a rainy afternoon.  As a project it was much simpler than the original analogue version, formatting the data around those discs is sticky. I still prefer the discs though.