This page is now to be found at landofinterruptions.co.uk/tram1933
Tram Routes to 1933
Tram route numbers were not introduced until about 1913. For identification purposes on the map, routes existing before that time are given the numbers which they were later allocated. This sometimes causes anomalies where routes were altered before being numbered. All tram routes are MET routes (operated by Metropolitan Electric Tramways) unless otherwise indicated. An exception is the Highgate Hill cable tramway which was independent.
Also in the period from 1913 onwards, a number of MET tramway routes were linked in through services with LCC tramway routes and they then took the LCC route numbers. Some MET numbers, therefore were used only briefly if at all. It may be helpful to note that MET numbers are even numbers and LCC numbers (of the north London series) are odd numbers.
So much for transport nerds, here’s a note for programming nerds: This map is shown using Scaleable Vector Graphics (SVG) with the USE tag with an external link to an SVG file that has been created in Adobe Illustrator. The SVG file uses Illustrator’s Live Trace, Simple option, this cuts out underlying pencil marks on the original hand-drawn map. The SVG tag is inside a container DIV and scrolling is done using the scroll positions on the DIV. I have done it this way, rather than using the TRANSFORM attribute of the SVG elements, as you get scrollbars, which are perhaps more intuitive.
But there’s something very odd happens: on all browsers with the exception of Chrome on the Mac – all those I have tested on pc and Mac – the page has to be loaded twice in order to get the map to display. And not simply loaded twice, it cannot be refreshed for that does not work, and so that the page reload does not have to be done manually I simulate a click on the page using Javascript with a link to a full url, which I do with a submitted form as I don’t think it’s possible to simulate a click on an A tag programatically. Just replacing the href using Javascript doesn’t display the map, relative urls are no good either, it has to be the complete URL with a simulated click. Then it works in all browsers. Naturally a Google search throws up nothing about this and so until someone comes up with a credible solution we carry on with the workaround. It doesn’t appear to be cacheing, for once the map displays you can clear the cache, reload the page and it continues to display fine, that is to say, once the map has displayed using the double-load technique, a single reload of the page will display it fine, even if the cache has been cleared. Strano indeed.
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