Page 1 of 1

Deckungswinkelmesser - Variations - Parts 1-3

Posted: Sat Nov 18, 2017 2:13 pm
by JBaum
Here's Part 1 of a 5 part series.

This deckungswinkelmesser (deckungs = cover, winkel = angle, messer = measurer) is an odd variation that I've only ever seen one of (and this is it). The gauge inside is calibrated in degrees (instead of mils), and percent. The body and outer frame of the deckungswinkelmesser appear to be made of brass, except for the pivot and loop screws, which are steel. The directions plate in this case is made of brass, but some are aluminum. The white on the reverse side is an early type of plastic, which typically shrinks from age, and cracks at the screw (or rivet) corners due to the strain. An oddity which I suspect was used as a form of identification for a deckungswinkelmesser which shows degrees and percent, is that the protective bulge where the lens is mounted is flat instead of curved, as is the matching part of the folding framework. This being flat instead of round is unique to this deckungswinkelmesser, as all the others I've seen had a rounded bulge. The gauge itself reads from 49+ to 19- degrees, and 90% up, to 30% down. I have no idea what the special purpose for this particular deckungswinkelmesser is. Those for the MG34 and MG42 are marked in mils, which corresponds to the calibration of the searching fire device to control elevation.

The deckungswinkelmessers were used by the lafette-equipped MG crews for measuring the relative elevation of an obstruction (cover) to be shot over. This could be a tree line, a building, hillside, or other troops. This measurement could then be dialed into the lafette (could be an artillery lafette, MG lafette, or other, depending on use), and then the projectile (bullet, artillery projectile, etc.) would not hit what you didn't want it to hit. It can also determine, in this case, degrees of elevation (or depression) of a road, river, hill, etc., for a variety of calculations. Most deckungswinkelmessers are calibrated in mils only. They fold as shown in the picture to conserve space in the MG belt pouch.

The loop on the top often had a string or shoe lace tied to it to help prevent dropping. The loop is hinged, and when the deckungswinkelmesser is held by the loop, the deckungswinkelmesser hangs exactly vertical due to gravity. This provides a very accurate reading of a different elevation, since the gauge is certain to be vertical when reading it.

Length when open is 6" (about 15 cm) without the loop. Closed it is about 4-1/4" (10.5 cm). Width, not including the bulged area, is about 1" (2.5 cm).

The manufacturer for this device is Möller / Wedel with the serial number No 13149 Most if not all of the deckungswinkelmessers are stamped with the manufacturer, scale, and number.

The directions read:
"Hold kneeling (to put it at about the same height as the MG on the lafette) in front of one eye, so that the cover and graduation lines can be read at the same time. Read the graduated line number. Mil spacing is 5/64000", which is interesting, because the gauge is calibrated in degrees and percent.

You don't actually look through the deckungswinkelmesser lens (the bulge on the side of the main body). You hold it in front of your eye, just far enough away to be able to see through AND around the lens, and you visually compare the elevation of the obstacle to the lines on the gauge. The white plastic plate is used to write down the number using a pencil, which can easily be erased with a wet thumb after use.

Over the next few days, I'll post pictures of 4 other types of deckungswinkelmessers in my collection.

Click on the picture to enlarge it.

The WWI Deckungswinkelmesser

Posted: Mon Dec 11, 2017 10:51 pm
by JBaum
Part 2:

Here are some pictures of a World War I Deckungswinkelmesser.

This would be appropriate for indirect fire with the MG08 . It has the scale in the little window calibrated in degrees. The scale window is looked through on the side without the centimeter scale, and this has a loop for hanging it vertically made more simply than the later styles.

The small paragraph is German about how to hold and use is only slightly changed on the WWII type. In the parenthesis on the side above the serial number it says that 1° is equal to about 6 mils in the telescope or the RKr, which is the Richtkreis or aiming circle. The celluloid (pale white, plastic-like plate held on with 6 screws) is for writing down the determined angle, and a pencil mark can be wiped clean with a wet finger. It has shrunk over the years and pulled away from the screws on the ends. This is about 100 years old, so a little shrinkage is acceptable.

The WWI deckungswinkelmesser scale window is a little smaller than on the later style, and is a little harder to align for looking through and photographing. There is no protective framework to fold it into for protection, but I would presume that it had some type of small leather holder or pocket to fit into. It would be "unGerman" to have it rattling around getting damaged in the bottom of a tool pouch.

As difficult as the later WWII style is to find, the WWI style is far more rare.

Re: Deckungswinkelmesser - Variations

Posted: Thu Dec 14, 2017 11:17 am
by JBaum
Part 3:

The "standard" WWII Deckungswinkelmesser most commonly found, and the only style that I've found shown in any of the instruction manuals.

This one is calibrated in mils only. A circle is commonly divided into 360 degrees. A mil is 1/6400 of a circle (17.77 mils are in a degree). A degree at 1000 meters distance would be 17.77 meters wide. A mil at 1000 distance is 1 meter wide.

Obviously it is very important to be as accurate as possible if you want to hit your target at a long distance, so for more precise aiming, mils are used for aiming light and heavy weapons at long distances.

The basics are the same as the other deckunswinkelmessers in examples 1 and 2 above. These have a few different manufacturers and a few variations. Some have the aluminum instruction plate, some have a copper finish plate. All have the celluloid white plate on the reverse side to write down the reading, so that it isn't forgotten by the time you get back to the MG or cannon (it's easy to forget a simple number if you're being shot at). I've seen very few that have all four corners of the white plate fully intact. Most at least have cracked corners, some are missing corners, and some have had the plate fall off entirely.

The body, loop, and plate screws of this one are made of steel. Others have the body and plate screws made of brass alloy (they're hard, but non-magnetic), with a steel loop. The steel deckunswinkelmessers have red lead primer under the black paint.