Astrograph Type A-1

[2banaviator]

Hi All, new to the forum but not the subject matter!

I've been fortunate to acquire a complete, intact, WW2-vintage Astrograph Type A-1. It has the projector, the bulbs, the height gauge, the wooden case, and best of all: each original star chart film in its aluminum canister.

I've been looking for a set of original instructions for the kit. There must have been a technical order document published during the 40's for this instrument, but I've not found it anywhere. It's not even referenced in the Navigators Information File dated July 1945, so it may have been obsolete by then.

Any help is greatly appreciated!

 

[Capt. Vick]

Pictures?

 

[2banaviator]

Pictures uploaded to this album:
Astrograph Type A-1 Kodak | WW2Aircraft.net Forums

 

[2banaviator]

Here are some of the photos:

The projector is affixed to the underneath of the lid by 3 spring-loaded hangers. These hangers are used to suspend the projector over the navigators map table at a height specified by the enclosed height gauge (stored in a slot to the bottom left). The desired star chart (already on a spool) is loaded into the projector and advance by turning the large black wheels. When illuminated, the star chart is projected onto the terrain map on the navigators table.

The 6 round objects in the upper corner are spare lamps for the projector.
Interesting to note that the charts span from 68deg North (just north of the Arctic Circle) to 45 deg South, with some charts that appear to simply be finer resolution of the sky shown in another chart.

There is one star chart film loaded into the projector, you can almost see the black graphics on the clear film, below:

Here is a good image of a star chart, which would be projected onto the terrain map on the navigators table.

 

[Capt. Vick]

Wow! Need machine!

 

[2banaviator]

I was fortunate to find an article from Flight magazine dated Sept 30 1943 (attached here) providing an overview of the Astrograph and how it was to be used. It appears that the concept was initiated by the British Royal Aircraft Establishment, with the final design refinement by Kodak. While the design described in the article is somewhat different than the instrument pictured above, the functions appear to be the same. To our UK members: Anyone ever heard of this instrument being used in RAF aircraft?

Celestial navigation in the 1940's was certainly challenging, but I wonder if this invention contributed much to the cause....

 

[kenneth trevor tutthill]

Astrograph was much used in RAF Bomber Command aircraft from time of its introduction (41,42?) until astro-navigation fell out of general use from 1943 onwards as electronic aids became common - in 1944 RAF decided that sextants were not to be carried as a matter of course, unless a navigator specifically requested one.