From: <nukeresister@igc.org>
To: <du-list@yahoogroups.com>
Sent: Tuesday, November 06, 2001 7:15
PM
Subject: Re: [du-list] Re: Dai's inquiry
re d.u. in Afghanistan
<< I am not a materials scientist,
but from my understanding of ductile
[Malleable, not brittle, easily drawn
into wire or molded or shaped or
hammered thin.] I would not consider
ductile as a virtue for large
penetrating bombs. >>
Thanks for asking Jack.
I'm not a materials scientist either! But I did check out Jane's
informal reply to my enquiry. I was told that
DU was not strong enough for hard target
penetration. I checked with technical folk who know something about
it and the web links at the end of this message.
[Note: Government specialists who probably monitor this site know the answers already. It must quite amusing for them watching us trying to get nearer to the actual facts. It might save media speculation if they will posted the relevant specifications. They may not have been aware of the contamination issues we are picking up].
Properties of DU I was referring to
Jane's original website quote (see below) that "DU's ductility is suitable
for making penetrators ..." (see References
below). Ductility ranges from
very soft (or malleable) to very hard. The Jane's website reference
in February (since removed) meant
fairly hard. But their recent
phone comments tried to suggest this was unsuitable for targets other than
armour. "Ductility" is a bit
vague but 30 mm DU penetrators (with
some added Titanium) don't seem to bend when they hit armor at high speed.
So how is DU too soft for other hard
targets? We aren't employed to be weapons designers - that's why
I am asking for the facts from
Government. But we need enough
information to avoid being put off with patronising or misleading comments
by politicians or PR
people for manufacturers, the DoD or
MoD. We got enough of that in the Balkans War.
It appears that several different physical
qualities are involved in materials "strength" e.g. Young's modulus, different
hardness ratings,
tensile strength etc. The properties
needed of the "dense metal" in Advanced Unitary Penetrators also depends
on different
manufacturing processes, alloy mixes
and physical design. Its looks as if basic DU comes out a lot harder
and less likely to bend
than a lot of other metals, similar
to the Co/Ni/Fe alloy used for the outer casings. Are these properties
unsuitable for hard targets?
- not on this data.
Only the weapons designers know exactly
what qualities are wanted for specific hard target penetrators. For
non-engineers these
seem to be the main factors:
Properties needed in hard-target penetrators
The main reason for using "dense"
or "heavy metal" in new version hard target bombs and cruise missiles is
the increased kinetic
energy available for an existing delivery
system. High density metal (DU is 2.4 x heavier than Iron)
means that the same weight and
length penetrator can be smaller diameter.
This is important because new upgrades have to fit the same size missile
bodies or bomb
dispensers. See the FAS site
http://www.fas.org/man/dod-101/sys/smart/hdbtdc.htm Research data
on ground penetration
weapons relates penetration effectiveness
to length against cross section area - thinner ones go deeper for the weight,
whatever they
are made of.
The pyrophoric (burns in air) quality
of DU that helps it burn its way through armor is not relevant for the
first stage of hitting hard
targets. Bombs and cruise missiles
go slower than anti-tank shells so DU is less likely to ignite on initial
impact at slower speeds.
Kinetic energy and nose cone design
are most important to go through earth and concrete. Tungsten may
be best for the tip if is not
too brittle. But it would be
far more expensive than DU for the main ballast or liners.
BUT once inside the target (recognised
by the AUP's Hard Target Smart Fuze) and ignited by the weapon's explosive
charge, DU's
pyrophoric quality are likely to make
it an effective incendiary device as in tanks. Tungsten would not
do this.
Incendiary effects may be important
because one requirement for the new generation of penetrators is for use
against suspected
chemical and biological weapons facilities
(see FAS link above). We are not talking GBU-28 technology here (old gun
barrels with
explosives and fins). These are
highly strategic, high value targets. The FAS link above refers to
the AUP (BLU-116) for the GBU-24.
See also http://www.fas.org/man/dod-101/sys/smart/gbu-24.htm
The same AUP technology seems to apply to the AUP-113 used in
the GBU 37 bunker busters http://www.fas.org/man/dod-101/sys/smart/gam.htm
used since 1997 according to FAS.
DU still seems as functional as Tungsten
for hard-target penetration effect, far more effective for incendiary effect
and far cheaper,
except in health and environmental
costs. In military terms it seems suited to purpose. Whether
environmental consequences are
acceptable, and what precautions are
therefore needed, are political, not military questions.
DU hazards in the Afghan - facts needed
urgently
We are concerned citizens, not munitions
experts. The points above are taken from available websites, comparing
information and
using it to test denials that DU is
being used in the Afghan war. On 1st November the UK Defence Minister
Geoff Hoon told the UK
Parliament on 1st November "It is not
being used at present".
The UK Government has its own definition
of truth - known in UK as "spin". Taken literally Mr Hoon's comment
that DU is not being
used at present literally means "not
at the time I am speaking". It does not answer the questions "has
DU been used in the Afghan
war in the last 4 weeks?" or " Will
it be in the near future?". It does not give the facts needed for
the central question - "What is the
dense metal used in the latest hard-target
smart bomb and cruise missile systems?"
I am an occupational psychologist.
I am concerned about the potential occupational health and safety hazards
of DU for aid workers,
media teams and public health and safety
for civilian communities. There is a special concern for troops sent
to check out targets hit
by hard target guided weapons munitions
- the highest DU risk locations if these suspicions are correct.
Employers including
NGOs and other allied forces
need these facts urgently NOW - to take precautions or increase medical
support. Political
delay will cost more lives.
Political responsibility for answers
Thank you for checking the interpretation
of my data Jack. I hope this is sufficient explanation to keep asking
the main questions. It
is important that we check our case
before going public to politicians or media. The reasons above increase
my suspicions that DU is
most likely to be the dense metal in
the AUP series of hard-target warheads.
Now it is up to our elected representatives,
employers (e.g. NGO's and media companies) and the media to help put these
questions
to the US and UK governments.
We need answers fast. Every day more bombs and missiles are being
used and more ground forces
being sent into the Afghan War.
If DU is being used in some of these systems every day delay will risk
more lives.
Dai Williams, UK
eosuk@btinternet.com
REFERENCES:
Extracts from Jane's Defence website
Depleted Uranium - FAQs (Feb 2001)
DU is a heavy metal that, when alloyed
with titanium (up to 0.75% by weight), becomes a material with a density
(18,600kg/m3) and
ductility suited to making penetrators
for kinetic energy anti-tank munitions, or liners for shaped-charge warheads.
During the Balkans operations from
1992 to 1996, only the US Air Force acknowledges its use in some of its
30mm cannon shells
fired from the GAU-8A cannon.
It is true that some guided weapons
used depleted uranium to increase the penetration effect and that the 20mm
Phalanx
close-in weapon system, used to protect
warships at sea from sea-skimming missiles, also has a percentage of DU
rounds.
Current description at http://www.janes.com/defence/news/jdw/jdw010108_1_n.shtml
(Jane's Depleted Uranium - FAQs, 7
Nov 01 )
What is Depleted Uranium?
Depleted Uranium (DU) is only used
as a penetrator. It is not a warhead, bomb or explosive.
Who used it in the Balkans?
During the Balkans operations from
1992 to 1996, only the US Air Force acknowledges its use in some of its
30mm cannon shells
fired from the GAU-8A cannon. It is
true that some guided weapons used depleted uranium to increase the penetration
effect and that
the 20mm Phalanx close-in weapon system,
used to protect warships at sea from sea-skimming missiles, also has a
percentage of
DU rounds.
Other online sources:
Properties of elements:
http://www.webelements.com/webelements/elements/text/periodic-table/phys.html
see Uranium (238) Youngs modulus
208 similar to Cobalt, Nickel and Iron. Tungsten much higher.
Density very similat to Tungsten.
Hardness (Brinell) similar to Tungsten, 3-4x higher than Co, Ni, Fe.
Properties of alloys: http://www.matweb.com/composition.htm
Enter Uranium 50%+ and submit for data.
See tensile strength for cast, annealed and wrought versions.
Enter Cobalt 5%+, Nickel 5%+ and Iron
5%+ and see properties for some kinds of copper/nickel/steel alloys as
used in the GBU 24
outer casing.
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