Ordnance Penetration

[Lenny Siegel <lsiegel@cpeo.org>]

ORDNANCE PENETRATION

At the recent UXO Forum '99 in Atlanta, the U.S. Army Engineering and
Support Center (Huntsville) presented a paper, "Estimating Ordnance
Penetration in Earth." The paper provides a comparison of different
formulas for estimating how far various sizes of ordnance might go into
various soils following impact without detonation.

The comparison is beyond my technical expertise, but one table - based
upon an equation developed by the U.S. Army Waterways Experiment Station
- provides a succinct introduction to the variability in ordnance
penetration. Obviously such information is valuable when determining the
proper level of subsurface clearance at a site. 

The table shows the maximum predicted penetration depth for several
types of ordnance based upon the velocity and weight. The table does
not, of course, take into account vertical migration (frost heave, etc.)
or alterations in the Earth's surface (through grading or erosion).

                        Depth of Penetration (ft) by Soil
Ordnance Item    Limestone     Sand     Vegetation*     Clay
155 mm M107         2.0         14.0        18.4        28.0
105 mm M1           1.1          7.7        10.1        15.4
75 mm M48           0.7          4.9         6.5         9.9
40 mm M822          0.5          3.2         4.2         6.4
37 mm M63           0.6          3.9         5.2         7.9
2.36"  rocket       0.1          0.4         0.5         0.8

Table is formatted for reading with a monospace font.
* = "Soil containing vegetation"

-- 


Lenny Siegel
Director, Center for Public Environmental Oversight
c/o PSC, 222B View St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/968-1126
lsiegel@cpeo.org
http://www.cpeo.org