Wartime mapping website

A lot of wartime files at TNA use the map number then 6 digit grid reference. This is frustrating as you have to identify which grid or grids the map is in and then convert it to the full Cassini grid reference to then convert it to a current OS grid reference. I use this excellent online converter but when you have hundreds of these to convert it is very time consuming. It also has the Irish Grid converter on another page but luckily the modern Irish grid is the same as the wartime one, only with a single letter prefix.

www.fieldenmaps.info/cconv/cconv_gb.html

I have often wondered if there was a Google overlay for wartime grid reference squares along with modern ones as this will save converting lat/long (in its many forms) into grid references.

That is a very good way of taking the guess work out of it. I still had a couple that defied all attempts to locate, probably due to a typo in the first number or even the wrong set of numbers entirely. I am just starting to build a Cassini overlay for Google Earth - manually - as my skills don't allow me to join the points up accurately so when you zoom in the lines end up being a hundred yards out!

I also found an online overlay of the current OS grid and also the outlines for the Discovery & Explorer series. Sadly I left the machine and the many updates I allowed yesterday rebooted my PC so I lost the pages before bookmarking them and also about 12 grid points I had plotted!

#@#&&**~~ Microsoft

The rings add-on looked good until I tried to use it. It seemed to want me to type in the co-ords each time rather than use those in an existing POI of which I have hundreds! I was going to use it for danger radii in GE. The instructions didn't make much sense as it didn't do what it said. Shame.

Chris, apologies, it does work but only with the current searched location. I just pasted in a converted NGR and opened the "rings" add-on and it assumed that location. I need to play with sector arc next but the wartime angles need conversion for the shift in magnetic north, although they do quote true north which I assume is Manchester?

May have to move this to the Google Earth thread as it might be useful there.

PS I use this to convert my lists of NGRs to GE map locations. gridreferencefinder.com/batchConvert/batchConvert.php

I don't know how to convert the map pin to something else though. It saved me many hours and from my Excel master I just create the whole lot again in seconds after minor updates!