On the 25th December 2011 there was a hail storm in the state of
Victoria, Australia, which caused approximately AU$712 million
worth of damage. Some of this damage was caused to passenger
vehicles. The authors conducted a number of inspections of
hail-damaged vehicles as a result of insurance claims being
disputed or rejected on the basis that some, or all, of the alleged
hail damage was not created by hail but instead created
intentionally by the vehicles' owners with the use of different
tools and/or objects. As a result of the inspections and
investigations of potentially fraudulent claims, the authors
conducted a total of 119 tests designed to replicate damage caused
to vehicle body panels by impacting hail and to recreate claimed
hail damage by using tools and other objects. To do so, the authors
created two sizes of hail: Ø20 mm and Ø40 mm hail. A total of 15
impact tests were conducted with Ø20 mm hail. The impact speed for
the Ø20 mm hail varied between 75 km/h and 144 km/h, with the
average being 113 km/h. A total of 50 impact tests were conducted
with Ø40 mm hail. The impact speed for the Ø40 mm hail varied
between 66 km/h and 133 km/h, with the average being 101 km/h.
The testing impact speeds were generally higher than the
terminal velocities of the corresponding hail, so the damage
observed is expected to be an over estimation of the actual damage
caused by hail.
The hail was projected at the test vehicle using a purpose-built
projectile launching device that used a sling-like mechanism to
project hail in a horizontal direction at a test vehicle. The test
vehicle was a white-colored 2001 model Holden Commodore with
non-metallic paint. The body panels tested were: bonnet, roof,
boot, all four doors, the vehicle pillars and cant rail. High speed
cameras were used to determine the impact speed of the hail. Damage
was photographed and recorded. In addition to impacting the vehicle
with hail, a number of different tools and objects were used to
recreate man-made damage. Tools and objects used were: claw hammer
(conventional), welding hammer, ball-peen hammer, mason hammer,
lead ball sink in a sock, golf ball in a sock, ratchet, breaker
bar, crowbar and center punch. The conducted tests revealed the
following findings: 1. hail impacting the vehicle body panels will
not scratch or mark the paint but the paint may chip if hail
impacts the vehicle near a fold or edge of a panel; 2. dents caused
by hail will cause the light to move smoothly and continuously
across the dent and the light will not "break" or crease;
3. where dents were caused by tools and objects the light will
crease into multiple (two or more) distinct areas as it passes over
the dent; 4. scratches and/or markings in the paint were identified
on dents caused by tools and objects; 5. folds and curves on the
panels did not affect the size of the dent caused to the panel;
using the same tool and force to impact two different body panels
(A-pillar and roof) resulted in dents that were very similar in
physical appearance; 6. for the same impact speed the larger Ø40 mm
hail caused more damage than the Ø20 mm hail; and 7. for the same
size hail the higher impact speed hail caused more damage.