Dr. Ronald B. Standler
Consulting on Lightning Damage or Injury
Copyright 2000 by Ronald B. Standler
Table of Contents
Damage caused by lightning
Warning of lightning
Protection from lightning
My credentials and services
This essay is intended only to present general information about
an interesting topic in law and is not advice for your
specific problem. See my disclaimer.
Lightning is the transient passage of electrical
current between a cloud and either the surface of the earth, another cloud,
or an object in or near a cloud (e.g., an airplane or rocket).
This essay focuses on lightning between a cloud and the surface of
Lightning is most commonly associated with
thunderstorms, but can also occur in snow storms and from the ash
cloud of volcanic eruptions. Thunderstorms can be an isolated cloud,
or part of a line of thunderclouds associated with a front on a map of
surface air pressure. Lightning is most common in the spring and summer
months, but can occur at any time.
Damage caused by lightning
Lightning causes damage to buildings and equipment in three different ways.
- There can be damage as a result of a
direct lightning strike. Such damage includes damage to roofing
materials, structures such as chimneys, heating or air conditioning
units located on the roof or exterior of a building, or fires caused
by lightning igniting combustible material, such as wood-frame
buildings or flammable liquids or vapors.
- Part of the lightning current can be carried inside a building by
electric power, telephone, analog or digital data lines (e.g., closed circuit
television cameras, sensors in an industrial plant, etc.). This
direct injection of lightning current inside a building can cause
immense damage to electrical and especially electronic
circuits and equipment.
- The electromagnetic fields from the current in a
lightning stroke can induce currents and voltage in wire and cables
inside a building. Such surge currents are typically less intense
than direct injection of current, but can easily vaporize integrated
circuits in computers, modems, electronic control circuits, etc.
Electronic equipment is typically designed to operate in a
well-controlled electrical environment. It is the responsibility of
the user to install lightning protection, electrical surge-protective
devices, and power conditioning equipment to mitigate the effects of
disturbances in the electrical voltage waveform. It is well
recognized that the trend toward integrated circuits with more
transistors per unit area, and faster switching speeds, makes these
circuits more vulnerable to both upset and damage.
Upset is a temporary malfunction without any physical change in the
devices or equipment. For example, one might recover from upset by
rebooting a computer; the only loss would be data that was not written
to disk before the upset occurred, and consequential damages from the
interruption of continuous operations. The consequential damages can
be large, for example, in medical equipment used in life-support
Damage is a permanent alteration in the physical properties of one
or more components, that requires repair or replacement before the
equipment can resume normal operation. Examples of lightning damage
to electrical equipment include flashover of insulation inside motors
or transformers, so that the equipment is no longer functional.
Examples of lightning damage to electronic equipment includes
vaporized traces on printed circuit boards, vaporized transistors and
integrated circuits, blown fuses, etc.
Recovery from damage usually takes much longer than recovery from
upset. Prompt recovery from damage requires advance planning,
including local stock of spare parts or redundant systems. Aside from
stocking parts, one must also plan to have an adequate number of
technicians who can diagnose and repair equipment. The lack of
trained repair personnel is generally a bigger bottleneck than the
lack of replacement parts.
A company also incurs expenses for consequential damages
such as overtime pay to do the backlog of work that accumulated while
the damaged equipment was awaiting repair or replacement.
Aside from surge currents that are conducted on wires or cables,
there can also be damage from magnetic fields associated with
lightning currents. For example, lightning current that travels to
earth along reinforcing steel inside a concrete wall or column can
produce a rapidly changing magnetic field that can erase floppy disks
or computer tapes inside a storage cabinet. Further, this rapidly
changing magnetic field can induce a surge current in loops of wire or
cable that are common in computer systems, and such surge currents can
cause damage or upset in the same way as direct injection of lightning
current into wires and cables.
It is well known even to laymen that lightning tends to strike
elevated objects, such as tall trees, tall buildings, water towers,
transmitting antennae for radio or television stations, overhead power
lines, etc. As a result of this knowledge, many people have the
misconception that burying a cable somehow protects it from lightning.
The truth is that when lightning current reaches the surface of the
earth, the current does not magically disappear, but prefers to travel
through highly conducting metal pipes (e.g., buried gas and water
pipes, etc.) and buried cables (e.g., electric power, telephone lines,
cable television, etc.) instead of dry soil or dry rock. In this way,
buried pipes and cables can act like an attractor for lightning
current, in the same way as a tall tower or building.
Lightning current can travel for long distances on overhead power
lines, or in underground pipes and cables, so that a user who
experiences upset or damage may not recognize that it coincided with a
lightning strike some distance from the user.
Warning of lightning
There are many ways that a user can be warned of
thunderstorms: local weather forecasts, listening for thunder from a
line of approaching storms, looking at the locations of
cloud-to-ground lightning on a map provided by the National Lightning
Detection Network, or using a local electronic instrument to detect
intense atmospheric electric fields that indicate the development of a
While such warnings may be useful to mobilize repair personnel, or
to shut down nonessential equipment, it is not economically feasible
to disconnect every electrical or electronic appliance during every
local thunderstorm. Therefore, most businesses must install lightning protection
and surge-protective devices, in addition to power conditioning
Courts in the USA are no longer tolerant of blaming lightning
damage as an "Act of God", as the technology for avoiding such damage
is well known and businesses are expected to use proven technology to
avoid injury to their customers. Furthermore, customers may
reasonably demand continuous service, even during local thunderstorms.
Saying "the computer is down" is a flimsy excuse that indicates
incompetent use of technology and should be a signal for sophisticated
customers to take their business to a more reliable provider.
Protection from lightning
Lightning protection and surge-protective devices can be divided
into three general classes.
- There are air terminals (commonly called lightning rods) on the roof,
which are connected to earth through down conductors.
- There are high-energy surge-protective devices, called arresters,
installed on every electrical and electronic conductor that enters the building,
so that surge currents are diverted to earth.
- There are low-energy surge-protective devices, called suppressors,
installed at each piece of equipment that is either vulnerable to damage
or susceptible to upset.
This kind of patchwork installation often provides incomplete protection,
as there are interactions between these three classes of protective devices.
For example, in some installations the surge suppressor has a lower
voltage protection level than the surge arrester, thereby drawing
surge currents inside a building and creating new problems. Drawing
surge currents inside buildings can create transient magnetic fields
inside the building that can induce surge currents in other loops of
wire or cable, and the surge suppressor may explode when it absorbs a
high-energy surge. As another example, lightning current can travel from a
down conductor, punch through a wall, and enter the electrical power
wiring inside a building.
- a chimney sweep, roofer, or lightning-protection company
installs air terminals,
- a licensed electrician installs a surge arrester
at the main circuit breaker panel, and
- the user installs surge suppressors at every piece of
electronic equipment inside a building.
Also, some installers of air terminals, down conductors, and ground rods
do an ineffective job, which results in a waste of money for
Standard methods for determining lightning protection begin with
an estimate of the number of lightning strikes per square kilometer per year
at the user's site. While this frequency data can be useful in evaluating
the economics of lightning protection, the user must remember that lightning
can, and does, cause immense damage even in regions where lightning is
not common. Therefore, I generally ignore the probability of a lightning
strike to the user's building, since it is foreseeable that lightning
will strike near the building sometime in the next few years.
Instead, I focus on the loss that will be caused by lightning:
- consequential damages:
- loss of business income while equipment is inoperative
- cost of restoring data from backups and paper records
- injuries caused by upset or damage to electronic equipment,
e.g., failure of monitoring equipment in hospital intensive-care ward
- cost of replacing or repairing damaged equipment
- cost of replacing damaged power and data cables
- cost of replacing damaged structure particularly significant if:
- structure contains flammable or explosive materials, so
lightning could cause catastrophic loss
- building has a wood-frame and is located far from the nearest
fire brigade (e.g., a farm house)
- building has historic value and can not be replaced
To design appropriate protection, I suggest hiring an engineer with experience
in both lightning protection, grounding techniques, and
electromagnetic compatibility to design an appropriate protection system for the
building and its contents. This kind of thoughtful planning may lead
to increased survivability of electronic equipment inside the
building, as well as a lower overall cost for protective apparatus.
With the drastic decrease after 1980 in the USA for financial support
of research on lightning and lightning protection technology, the USA
is no longer the world leader in lightning protection. It is
desirable to hire an engineer who is familiar with engineering
standards and research in German-speaking countries, as well as in
Europe and elsewhere in the world.
Protection against lightning can be much less
expensive than repair or replacement of damaged equipment, as well as
consequential damages from loss of use of damaged equipment.
However, merely connecting some surge suppressors inside the
building may result in an improved ability to withstand mild surges,
but is generally inadequate protection and can create significant new
My c.v. gives my credentials, but a terse summary is:
credentials and services
- Ph.D. (physics) 1977, J.D. May 1998
- Professor of Electrical Engineering for 10 years
- Author of one book
and more than 35 published papers in science and engineering
- Attorney in Massachusetts since 1998, who has an international practice of consulting to
litigators on scientific evidence in torts, especially damage or injuries
by lightning or electrical surges
Summary of my experience:
I am interested in the legal obligation of both employers and
operators of recreational facilities (e.g., golf courses, beaches, ski resorts)
to protect their employees and invitees. Such protection might take the
form of surge suppressors on telephone lines, lightning warning systems,
lightning rods, etc.
- During 1971-1979, I was active in scientific research on
atmospheric electricity during thunderstorms,
including a study of the difference between lightning rods
with blunt and sharp tips. In 1974, I triggered lightning
on a mountaintop with a wire-trailing rocket and I measured the
current in the wire, to understand how objects are "struck" by
- I have copies of the current American standards for lightning protection of
buildings and electrical systems and some of the current International
Electrotechnical Commission standards. I am also familiar with the
scientific, engineering, and U.S. Patent literature on lightning
- During 1996-97, I read all of the reported cases in the USA
(back to the year 1894) that involve
injuries or damage by lightning, including lightning currents on
- I am also familiar with the medical literature on injuries from lightning,
including lightning current on telephone lines.
- I know a number of people who can be called as expert witnesses.
I have studied the way that engineering standards can be used to
establish a duty of care in torts. I am also aware of ways in which
a manufacturer, utility, or employer might breach the duty of care,
despite compliance with all relevant engineering standards.
Because of my scientific research experience in lightning and
electrical surges, and my legal education,
I provide consulting to attorneys about legal strategies,
scientific evidence, preparing memoranda of law, drafting briefs, etc.
in this area.
I am particularly interested in assisting attorneys who represent
either victims of lightning injury
or businesses whose equipment was damaged by surges or other
"power quality" problems.
My fees and terms
How to contact me
first posted 8 Aug 1998, revised 1 May 2001
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