This article discusses the advantages of Blunt Rod (BR) Lightning Protection over Nonconventional early streamer emission (ESE) and lightning dissipation array (LDA) approaches.

1. Blunt Rod Lightning Protection Advantages
Over Nonconventional Approaches
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Contents
Introduction
Rod Lightning Protection Ad-
vantages Over Nonconventional
Approaches
Background of Lightning
Protection
ESE and LDA Debunked
Legal Precedence
Summary
Acknowledgements
Compliments Of:
Classic Controls, Inc.
Lakeland, FL USA
www.classiccontrols.com
(863) 644-3642

2. 2
Blunt Rod Lightning Protection Advantages
Over Nonconventional Approaches
White Paper
WP043/USA/0416 © Copyright 2016 DEHN Inc.
Introduction
This article discusses the advantages of Blunt Rod (BR) Light-
ning Protection over Nonconventional early streamer emission
(ESE) and lightning dissipation array (LDA) approaches.
The objective of this article is to show the reader that the blunt
end Franklin rod remains the safest and most effective means
of protecting structures from the risk of fire and damage due
to lightning.
Many standards provide excellent insight into best practices,
suggested methods and installation guidelines for lightning
protection systems using BR lightning rod deployment over
the region to be protected. The NFPA 780 and IEC 62305 both
provided fire safety guidance and both adhere to BR practices
with no recognition, suggestion or reference to ESE or LDA
types.
These industry-leading systems always promote a facility-
wide approach addressing, air terminations, down conductors,
earthing electrodes and surge protective devices.
The BR technology developed by Franklin in 1752 remains
the only open peer-reviewed and proven means to assure fire
safety due to lightning. And the insurance underwriters indus-
try only recognizes BR technology. These advantages give en-
gineering and design professionals the confidence needed to
install best measures for lightning risk mitigation.
Background of Lightning Protection
A lightning protection system functions by intercepting the
direct lightning strike energy as it hits near a structure and
safely diverting it to the Earth. Much has been published on
this topic in great detail by academic experts and industry-
leading standards bodies.
Lightning phenomena is roughly based on the discharge of
huge charge regions high in the atmosphere into the Earth.
This discharge initiates high overhead and starts a rapid de-
scent “in the general direction” of Earth with no real high
resolution target. In fact, the actual final discharge pathway is
only established after the charge region is close enough to the
ground to create a finer grained resolution electric field based
influence for small step leader coronas to initiate from all of
the available sources at ground level. Several leaders all “reach
out” to the rapidly descending charge region and the “winner”
establishes the plasma bolt and subsequent return strokes. In
other words, the lightning does not have a real plan when it
starts to fall, but only near the end do the step leaders feel
enough electric field influence to reach up and connect.This all
occurs in 10’s to 100’s of microseconds.
The Franklin rod allows a preferred step leader jump off point
and establishes the discharge path through the rod and down
conductors into the Earth, where the charge is dissipated safe-
ly.This is the only proven means of avoiding lightning damage
and is prescribed by the NFPA and IEC peer-reviewed lightning
standards.
Figure 1 Excerpt from DEHN Lightning Protection Guide(1)
Figure 2 Photo courtesy SCW 2016
leader
Figure 2.1.5

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Blunt Rod Lightning Protection Advantages
Over Nonconventional Approaches
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WP043/USA/0416 © Copyright 2016 DEHN Inc.
ESE and LDA Debunked
Nonconventional lightning protection apparatus fall into ei-
ther the ESE or LDA types. The effectiveness of these appara-
tus over conventional BR systems has been disproved in such
comprehensive work as Uman and Rakov with the University
of Florida, “A Critical Review of Nonconventional Approaches
to Lightning Protection” (2002). This work offers a thorough
investigation of the claims of nonconventional approaches and
shows no actual advantage of these ESE and LDA systems.
This paper from Uman(2) (3) , and many other noted works on
this topic point to the best real world studies conducted in
New Mexico by Moore(4) who found that BR type LPS were
struck 12 times over seven years where as ESE and sharp tip
systems were never struck. This paper also pointed to the FAA
1990 report showing Tampa area airports struck by lightning
even though they were equipped with LDA apparatus intended
to dissipate strikes before they are attracted to a structure.
When compared side by side in a laboratory, Noack et al(5),
testing has shown that blunt tip rods actually attract the strike
with an overwhelming % of strike occurrence. Even when in-
stalled side by side with and ESE, the BR franklin device works
best.And the LDA still was struck a low % of times, and did not
scare away the lightning test discharge.
Here is the basic diagram of an ESE product. The rising ambi-
ent electric field is said to charge up the internal capacitance
to a level that self-initiates an upward bound leader, inducingFigure 3 Excerpt from Noack Testing(5)
Figure 4 ESE Photo courtesy MHD 2016
+ + + +
Result of 420 discharges:
200 to the Franklin lightning rod (47.6 %)
165 to the ESE devices (39.3 %)
55 without puncture (13.1 %)
1 Lightning rod (Franklin)
3 Pulsar 60, Helita, France
4 Prevectron S6, Indelec, France
2 Dynasphere 3000, GLT, Australia
1m
h=2.5m
1 2 3 4
Generator: DC 45 kV
Switching voltage: DC 840 kV
Figure 5 LDA Photo courtesy SCW 2016

4. 4
Blunt Rod Lightning Protection Advantages
Over Nonconventional Approaches
White Paper
WP043/USA/0416 © Copyright 2016 DEHN Inc.
a strike to the ESE and shunting the energy to Earth. No third
party testing has produced any sort of leader advantage or
tendency of the ESE device to be struck in preference to con-
ventional BR protection.
Uman and Rakov have shown rigorously that the time advan-
tage and extra distance coverage claims of ESE supporters are
invalid. The “early streamer” cannot send a step leader up to
the cloud any faster than a BR Franklin rod.
The basic summary drawn from world-leading experts on non-
conventional lightning protection systems does not support
the manufactures claims of those ESE and LDA apparatus.
There is no experimental evidence that ESE apparatus can pro-
tect a larger volume of airspace by virtue of provoking a faster
upward leader speed to attract lightning to itself from farther
away. An LPS system that is deployed using these ESE param-
eters will leave much of the area unprotected when compared
to any conventional evaluation.
Lightning elimination arrays such as the LDA cannot prevent
the initiation of lightning in the thunder cloud and are unprov-
en to be able to avert an imminent lightning strike. These LDA
systems are in fact struck themselves and offer no more pro-
tection than the placement of similar sized BR air terminations.
As illustrated in the photo in figure 5 of an LDA installation
in Fort Pierce, FL. Notice the conventional lightning rods along
building perimeter. It is not clear if these rods were installed
before or after the concrete monopole and wire mesh LDA.
Legal Precedence
There is also a series of legal precedence found against non-
conventional lightning protection vendors related to false
advertising and possible product liability as seen in Federal
District Court of Arizona 2003.
Several manufactures of nonconventional apparatus have em-
ployed legal bullying in a failed attempt to force the NFPA to
acknowledge their products as reported by Mousa(6). This sort
of rubber stamp would have been used as an endorsement
in their strategic marketing campaigns. Fortunately for con-
sumers, engineers and architects, this campaign to forcibly ac-
knowledge the now defunct article 781 was stopped after the
manufactures were unable to present any evidence to support
their product claims. Further, in 2003 these ESE vendors were
convicted of falsely advertising the claimed improvements
over conventional BR technology.
Additional government action was taken in Malaysia and re-
ported by Hartono(7) in 2008 declaring ESE devices must not
be employed due to damage suffered upon buildings while
within the “protection zone” of the ESE devices.
And the worst possible scenario has already come to pass ac-
cording to the professional assessment of industry leaders. A
report released in 2012(8) by Z. A. Hartono and I. Robiah, two
of the world’s leading experts on lightning safety, raises se-
rious questions about the lightning protection equipment in-
stalled at Tampa, FL’s Adventure Island water park.
In September 2011, a 21-year-old Adventure Island lifeguard
was struck by lightning and killed while helping to evacuate
patrons from the Key West Rapids water slide.The outdoor wa-
ter slide is located between two lightning protection installa-
tions, each of which, according to the manufacturer, provides
a zone of protection against lightning strikes extending as
much as 109 meters. The systems rely on a French-made de-
vice, called the Prevectron air terminal, which is not approved
by any U.S. safety code or standard and is not supported by
independent scientific experts or field data.
In commentary related to the death at the park, Bud VanSickle,
executive director for the Lightning Protection Institute (LPI)
said, “The fact that these ESE systems don’t comply with any
U.S. standards should raise serious questions with every ar-
chitect, engineer or facility manager responsible for selecting
lightning protection systems.“
Summary
Blunt Rod lightning protection systems utilizing industry ac-
cepted air terminals, down conductor designs and earthing
systems, along with adequate surge protection on the electri-
cal wiring systems remains the most effective means to assure
equipment and life safety against lightning effects.
Existing U.S. standards that offer guidelines towards the man-
ufacture and installation of lightning protection systems are
developed and updated by Underwriters Laboratory (UL), the
National Fire Protection Association (NFPA) and the Lightning
Protection Institute (LPI). These standards do not authorize
lightning protection for open spaces in the manner employed
at Adventure Island.
This remains a controversial topic and the industry standards
meetings that address the LDA and ESE issues always offer
heated discussions. Engineers and designers are encouraged
to read all available information on the design of best prac-
tice Lightning Protection Systems, and will find the application
of BR technology to be the most scientifically peer-reviewed
industry standards and underwriter insurance accepted ap-
proach.
Only the DEHN high voltage insulated cable and insulated
air-termination rod system can provide conventional blunt tip
Franklin rod protection with an insulated construction to avoid
side flash arcing to the protected structure.
DEHN has provided the industry with a wide range of com-
plaint and certified BR Franklin rod solutions for over 100 years.
DEHN is the only manufacture of these innovative, high volt-
age isolated, blunt tip lightning rod and conductor systems.
These products allow safe down conductor installation and
avoid any touch safety danger of flash over or human shock.
The DEHN lightning protection products are all thoroughly
tested to show the discharge withstand of direct lightning

5. 5
Blunt Rod Lightning Protection Advantages
Over Nonconventional Approaches
White Paper
WP043/USA/0416 © Copyright 2016 DEHN Inc.
Figure 6 The air-termination products are illustrated here.
Figure 7 HVI touch and clearance safety down conductor products
are illustrated here.
strike energy. The products meet all guidelines for IEC and
UL96A master label protection systems.
The reader is encouraged to review the relevant standards for
their location and requirements and select products that offer
best in class safety and operational assurance.
For more information contact DEHN, Inc. at
www.DEHN-USA.com
Acknowledgements
The Author Mark Hendricks has been in the power quality
industry for 20 years and is the Technical Director with
DEHN, Inc.
(1) DEHN Lightning Protection Guide
(2) Uman, M.A., Rakov,V.A.:A Critical Review of Non-
conventional Approaches to Lightning Protection,
American Meteorological Society, PP1809/2002
(3) UmanAdd Uman references from his book
(4) Moore, C. B., G. D.Aulich, and W. Rison, 2000a:
Measurement of lightning rod response to nearby strikes.
Geophys. Res. Lett., 27, 1487-1490.
(5) Noack, F.: Early Streamer Emission devices – Improved
lightning protection? ETZ, Offenbach (2002)3-4., p. 2 ff.
(6) Mousa,A. M., National Lightning Safety Institute,
Section 5.4.3
(7)(8) Hartono, Z.A.; Mieee a. Robiah, I.: Journal of the
Association of Consulting Engineers Malaysia;
PP2623/1/2008.

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