I have recently been doing a lot of reading
up on Zimmerit and the mystery surrounding its
limited time span of use.
Zimmerit was a non-magnetic coating produced for German AFV`s
during WW II for the purpose of combating magnetically attached
anti-tank mines. It was developed by the German company Chemische
Werke Zimmer AG and used from 1943-1944. It was basically a cement
type coating which provided small gaps and uneven ridges on the
outside of the tanks stopping magnetic mines being attached.
Strangely the Germans came up with the idea after inventing a
magnetic mine of their own(the Hafthohlladung 3 Mine) specially
to be used against tanks.
The picture below shows a Hafthohlladung courtesy of the
Bunderarchive.
Unfortunately the Germans believed because
they had created such a mine the allies would surely follow and thus
the invention of zimmerit. In a strange irony the allies never did use
magnetic tank mines.
Zimmerit was applied to tanks as far as I`m aware at the factory and
not in the field. The following description of how zimmerit is applied
is taken from various factual sources including the Haynes Tiger Tank manual,
Military Classic Vehicles, the Bovington archive and the Mike Gibb stug
restoration project.
Zimmerit was made from zinc sulphide, barium sulphate,pine saw dust,
PVA,peeble dust,ochre and pine crystals. The process involves dissolving
the pine crystals in a large quantity of benzene(which is highly flammable and I will come back
to this at a later stage). This creates a sticky golden liquid which
when added to the other ingredients helps the PVA adhere and harden.
Next you are required to trowl on the material to the AFV applying
ridges in a set pattern(they are a number of different patterns). Firstly
a 2mm layer is applied and then from 5cm away a blow lamp is
used to harden and burn off excess moisture. This results in
significant fires. 4 hours or more later a second 4mm layer is
added in the same way. As an example a Stug would require 100kg
of zimmerit to cover it correctly.
Once dry(at least 72hrs) the surface can be painted.
Below is a picture of the zimmerit found on Tiger II.
This is zimmerit on a Stug III
The German high command decided in 1944 to stop applying zimmerit
to AFV`s for various reasons. The obvious being it was not needed
as the allies did not use magnetic tank mines , plus is was costly
and time consuming. A further,discarded reason was that
there were reports coming back from the front that zimmerit was
flammable ?
This is the point that interested me in the subject to start
with and has been frowned apon by the military forums for years
and to me it seemed strange. If reports are coming back from front
line units that zimmerit is flammable and is burning up tanks why
disregard the theory point blank,which is what people have been
doing right up until Mike Gibb put people in the picture.
The key to the issue is the benzene and temperature. The application
of zimmerit as described above only works if its warm. If its cold a
number of issues occur. Cold weather stops the benzene from hardening
properly(this cannot be seen by the naked eye or by touch). This un-
hardened surface is then painted over and the paint locks into the benzene
which has not evaporated. The result is a AFV being sent out into combat
just waiting for a round to ignite the benzene!
Now add to the boiling pot that most of the reports are coming back from
the Eastern Front in 43-44 of zimmerit fires where the temperature is hitting
minus 40 in the winter. Plus Germany is losing the war so the need to rush
tanks out of the factory faster and faster creates a time bomb waiting to
ignite, literally.
A number of nations tested the flammable zimmerit theory after the war
and were unable to get it to burn but they were unaware of the application
problem in cold weather and most likely used a correctly applied zimmerit
vehicle that had seen action. We will never know ?
One other thing about zimmerit that was not intended but was a pleasant
surprise noticed by German and Allied tank commanders alike was its
camouflage characteristics . It naturally created an anti-shine to any
tank that had it and broke up the outline of the tank.
Below is a link to the Weald Foundation and Wheatcroft Collection that
restore AFV`s and collected and tested the info on the zimmerit :
http://www.thetankchannel.com/sdkfzstugiii.html
http://www.wheatcroftcollection.com/
Hope you liked the brief explanation on zimmerit and please get
in touch if you know of any extra information. Its always good
to learn a little more. I would be especially interested in
any information on field application of the stuff as there are
a few suggestions on the net about it but no solid proof as yet.
The model warrior 