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Zargo9
07-20-2007, 07:39 AM
I need help finding information on what the US used for map coordinates in the South Pacific. I found a site that showed how the British numbered their maps for the BoB and think the USN/USMC used something similar. The only references I seem to find are using strictly lat/long.

Can someone point me in the right direction?

Thanks for the help.

Zargo9
07-20-2007, 07:39 AM
I need help finding information on what the US used for map coordinates in the South Pacific. I found a site that showed how the British numbered their maps for the BoB and think the USN/USMC used something similar. The only references I seem to find are using strictly lat/long.

Can someone point me in the right direction?

Thanks for the help.

Crash_Moses
07-20-2007, 08:54 AM
Good question. I always thought they used latitude and longitude.

What's the URL to the website you mentioned? I'd like to check it out.

Conan_249th
07-23-2007, 10:29 AM
Often times it depended on what was available.

Maps that aviators use when not in support of ground troops are normally:
1:1,ooo,ooo
1:500,000
1:250,000
These maps use Lat/Long coordinate systems in most cases.

Grunts would not find maps of that scale particularly useful. They normally use:
1:50,000
1:25,000
or even 1:12,500 with the "1to50" being predominant. These maps use a UTM projection that has a "false Northing/Easting" that is based on lettered squares of area that are 10 kilometers on a side. Lat/Long can be found on these maps but not very well. The square system means that as you get further away from the one line intersection on the map actually aligned with true North and True East, you get further and further from the "grid North" lines matching true North. But who cares? As long as everybody is on the same map, we can all see what the other guy is talking about.

Each 10X10 grid has an identifier, typically two letters like, say, GM. There may be more letters and numbers before that to identify which of the zones on the globe your map is in, but that is not important unless you are involved in operations near a zone border. At Zone borders, the grid north lines merge like pinstripes at the center seam of your suit jacket. This is because the left side of each zone is true North, while the right side is the greatest deviation caused by forcing a flat reference system onto a spherical surface.

To communicate a point on this type of map you would read something like GM43 which is 4 kilometers East and then 3 kilometers North of the GM reference which is the bottom left of that grid. You can get more exact by adding digits. GM4236 is 4200meters (4.2k) East and 3600 meters North of the origin. GM425368 is 4250 East and 3680 North. GM 42553689 is where my big toe is and GM4255836897 is rediculous unless aiming with a laser!

In WWII, you often just grabbed what was available. The German Army invaded France using copies of the Michelin Road atlas. Many of the islands in the South Pacific had never been mapped by anyone except maybe a missionary.

I hope I didn't confuse things too much.

Cheers,

Zargo9
07-24-2007, 06:55 AM
Crash_Moses:
I unfortunately didn't keep the URL of the site I mentioned but try Googling BBMF or something. I got to a site which showed the inside of the bunker that Winston Churchill was in the night of September 15(?) at what is generally agreed to be the absolute pinicle of that Battle of Britain. He turned to General Somebody-or-other and asked how many reserves there were. "None" was the reply. The other references I have are various books on the Pacific theatre and WW2 in general.

Conan_249th:
Thanks for the info. Do you know if the maps used on the ground would have been used by the aircrews as well? I'm thinking specifically along the lines of Guadalcanal, Guam, Tinian, Saipan etc. Too bad we can't replicate the Solomons campaign and try to take out Buna or Bougainville. Ah well...

Zargo9