Case Study

Lightning Protection & Grounding System Design for a Military Establishment

How ICS designed a Lightning Protection & Grounding System for a Military Facility

10+

Facility Types Protected

5

Coordinated LPS Subsystems

6+

Standards Applied

3-Level

Coordinated SPD Strategy

Introduction

Engineering a Compound-Wide Lightning Protection System for a Military Establishment

This case study presents the design of a Lightning Protection System (LPS) and Grounding System undertaken by ICS Technology Services for a representative military establishment. A properly designed Lightning Protection System is essential to reduce the risk of injury to personnel, structural damage, fire, equipment failure, and interruption of mission-critical services.

ICS engineered a comprehensive, integrated protection solution, from formal risk assessment through system design and standards compliance, tailored to the unique operational, security, and continuity demands of the military environment.

The Lightning Protection System was designed to safely intercept lightning strikes across all structures within the compound, conduct lightning current through controlled paths to earth, and eliminate dangerous voltage differences — protecting personnel, mission-critical systems, classified communications infrastructure, and all operational buildings within the establishment.

A Single Integrated Protection Strategy

The entire military establishment was treated as one coordinated system — every structure, external service connection and sensitive system unified into a single lightning protection and grounding strategy.

The Challenge

A Different Order of Protection Engineering

A military establishment presents lightning protection challenges of a different order from a commercial or institutional facility. Where a hotel's concern is reputational continuity and a hospital's is clinical safety, a military facility's challenge is mission continuity and national security. A lightning event that causes a temporary power disruption in an office building could, in a military context, disable a command communications network, trigger a false alarm in a perimeter security system, damage classified electronic equipment beyond recovery, or create a fire in a fuel-handling area with catastrophic consequences.

Several specific challenges shaped the design from the outset:

Mission-Critical Continuity with Zero Tolerance

Military operations cannot be paused while systems recover from a lightning event. Command and control facilities, communications infrastructure, and security systems must remain fully operational during and immediately after any lightning strike. The LPS was designed not only to protect the physical structure but to maintain the integrity of every critical service throughout a lightning event.

Multiple Structure Types Across a Large Compound

Unlike a single building, a military establishment presents a complex array of structures with varying heights, geometries, construction materials, and internal systems, each requiring an individually assessed and coordinated protection design. The challenge was to deliver a compound-wide integrated LPS that provides verified protection across every structure while maintaining a unified grounding and bonding network that prevents dangerous potential differences between buildings.

Fuel-Handling Areas & Hazardous Atmospheres

Fuel storage, handling, and refuelling areas introduce the possibility of hazardous or flammable atmospheres. A lightning-initiated ignition event in these areas carries consequences that go far beyond equipment damage. The lightning protection design in these zones required strict coordination with applicable hazardous-area regulations, with all metallic components, bonding conductors, and earthing arrangements specified and verified against the relevant hazardous-area standards.

Classified Communications & Data Systems

Military communication, signals intelligence, and data processing facilities contain equipment of high sensitivity and strategic importance. These systems are not only susceptible to lightning-induced transient overvoltages, they also require specific electromagnetic compatibility measures to prevent interference with classified signals and to ensure that surge protection devices do not introduce incompatibilities with proprietary military communication systems. The design required close coordination with the communications systems engineers and applicable military specifications.

Antenna Masts, Towers & Tall Exposed Structures

Communication antenna masts and radar installations represent both a significant lightning attraction point and a critical protected asset. These tall, exposed structures required dedicated air-termination and down-conductor design, with grounding systems that safely discharge the high-frequency, high-amplitude currents associated with direct strikes to elevated metallic structures, while preventing back-flashover into the sensitive receiver and transmitter equipment connected at their base.

Outdoor Personnel & Operational Areas

Military facilities include significant areas of outdoor activity, vehicle parks, parade grounds, outdoor equipment stores, and perimeter areas, where personnel may be present during storm events. Touch and step voltage control in these areas is a life-safety requirement, not a regulatory formality. The grounding design incorporated measures to minimise surface potential gradients across outdoor operational areas throughout the compound.

A Unified Engineering Approach

Taken together, these challenges required an engineering approach that treated the entire military establishment as a single integrated protection system — one where every structure, every external service connection, and every sensitive system within the compound is coordinated into a unified lightning protection and grounding strategy.

System Architecture

Main Components of the Lightning Protection System

ICS designed and specified a fully integrated Lightning Protection System comprising five coordinated subsystems, each tailored to the specific structures, hazard profile, and mission-critical requirements of the military establishment.

Air-Termination System

Air terminals and horizontal conductor networks were positioned across all rooftop areas within the compound to provide complete protection coverage over every structure. Terminal placement and mesh configuration were determined using the rolling sphere method, protective angle method, and mesh method as appropriate to each structure's geometry and selected Lightning Protection Level — all in accordance with IEC 62305-3 and NFPA 780.

  • Conductor mesh adopted for large flat-roofed warehouses and accommodation blocks
  • Dedicated air terminals and protective masts for vertical structures, masts and elevated plant
  • Rooftop mechanical plant, HVAC and antenna bases incorporated to prevent uncontrolled side-flash

Down-Conductor System

Multiple down conductors were distributed around the perimeter of each building to provide redundant, low-impedance current paths from the air-termination network to the earth-termination system. Down-conductor routes were selected to provide the shortest and most direct paths to earth while maintaining calculated separation distances from internal electrical, communication, and control services.

  • Test joints at accessible locations enabling periodic resistance testing without structural intervention
  • Natural reinforced-concrete frame components assessed for use as down conductors where continuity is verified
  • Controlled electromagnetic effects on buildings housing sensitive electronic and communications equipment

Earth-Termination System

The earth-termination system provides the discharge point for all lightning current conducted through the down-conductor network. The design incorporates buried perimeter ring earth electrodes around each building, supplemented by driven earth rods at strategic intervals to achieve low earth resistance in all soil conditions.

  • Integrated compound-wide grounding network reduces dangerous potential differences between structures
  • Foundation earth electrodes incorporated where available in new construction
  • Grounding test wells installed for ongoing resistance monitoring, accounting for soil resistivity and corrosion

Equipotential Bonding

Lightning current flowing through the down-conductor and earth-termination network produces electromagnetic fields and voltage differences that can cause flashover between metallic systems within and between buildings. All metallic services and structural elements across the compound were bonded to a common equipotential reference at each building's main bonding bar.

  • Bonded incoming power, water, gas and fuel pipework, cable trays, structural steelwork, shields, feeder systems
  • Compound-wide network provides a unified equipotential plane across all structures
  • Spark-prevention verification at all connection points in hazardous-atmosphere areas

Separation Distance & Electromagnetic Compatibility

In buildings containing extensive electrical, communication, control, and classified electronic systems, the electromagnetic effects of lightning current flowing through nearby LPS conductors represent a significant risk to equipment integrity and signal continuity. Calculated separation distances were maintained between down-conductor routes and internal service runs wherever structurally practicable.

  • Bonding measures implemented in accordance with IEC 62305-3 where required separation could not be achieved
  • LPS conductor routing coordinated with communications layout to minimise mutual induction effects
  • Grounding design assessed for electromagnetic compatibility with sensitive receiver and transmitter equipment
Surge Protection

Surge Protection System — Coordinated, Multi-Level SPD Strategy

External lightning protection alone does not adequately protect the sensitive electrical and electronic systems present across a military establishment. Lightning-induced transient overvoltages can propagate through incoming power lines, communication cables, and data networks into buildings far from the point of strike. ICS designed a coordinated, multi-level Surge Protective Device (SPD) system covering all structures within the compound.

Type 1 / 1+2

Incoming Power Supply Point

Type 1 or combined Type 1+2 SPDs at the incoming power supply point of each building, providing protection against the high-energy direct and induced surges entering via the incoming power infrastructure.

Type 2

Distribution Boards

Type 2 SPDs at distribution boards within each building, providing secondary protection at the point of distribution to critical loads including communications equipment, security systems, UPS systems, and generator control panels.

Type 3

Equipment-Level Terminals

Type 3 or equipment-level SPDs at sensitive electronic terminals, including communications racks, command workstations, signals intelligence equipment, and SCADA and control system interfaces — where the residual transient voltage must meet the equipment's impulse withstand rating.

Coordinated Surge Protection on Service Entries

Coordinated surge protection was also applied on all external communication, data, antenna feeder, and control cable entries to each building, preventing lightning-induced transients from entering through service interfaces rather than the power supply. The SPD system was coordinated at every level with the system voltage, earthing arrangement, upstream protection, short-circuit withstand capability, and the specific requirements of the communication and electronic systems present. SPD connecting conductors were kept as short as practicable throughout, as excessive lead length reduces SPD effectiveness during fast-rise-time transients.

Special Structures

Protection of Special Structures and Areas

Several structure types within the military establishment required individual assessment and specific protection measures beyond the standard LPS design.

Antenna Masts & Communication Towers

Dedicated air-termination, high-current down-conductor design, and isolated grounding arrangements to safely discharge direct strikes while preventing back-flashover into receiver and transmitter equipment at the tower base.

Fuel-Handling Facilities & Storage Tanks

Full coordination with applicable hazardous-area regulations, with bonding, earthing, and SPD specifications verified for spark-prevention requirements in potentially flammable atmospheres.

Large Warehouses & Logistics Buildings

Conductor mesh air-termination to provide uniform roof coverage across large flat-roof structures with multiple internal metallic installations requiring systematic bonding.

Outdoor Electrical Equipment & Vehicle Parks

Surface potential gradient control through extended ring earthing and supplementary earthing measures to minimise touch and step voltage hazards in areas where personnel and vehicles are routinely present.

Perimeter Security & Surveillance Systems

Surge protection on all outdoor camera, sensor, and access control cable interfaces, with bonding of metallic perimeter structures to prevent induced voltage events affecting security system operation.

Standards & Compliance

Designed to Internationally Recognised Standards

The Lightning Protection and Grounding System was designed, specified, and documented in full accordance with the following recognised international and national standards.

IEC 62305-1

General Principles. The foundational standard establishing the framework for lightning protection system design.

IEC 62305-2

Risk Management. Applied to the formal lightning risk assessment that underpins the protection level selection and system specification for the compound.

IEC 62305-3

Physical Damage to Structures and Life Hazard. Applied to air-termination design, down-conductor specification, earth-termination design, and separation distance calculations.

IEC 62305-4

Electrical and Electronic Systems within Structures. Applied to the surge protection design and electromagnetic compatibility considerations for sensitive electronic systems.

NFPA 780

Standard for the Installation of Lightning Protection Systems. Applied to air-termination, down-conductor, and grounding electrode system design where applicable.

NFPA 70 (NEC)

National Electrical Code. Applied to electrical earthing, grounding conductor sizing, and SPD installation requirements.

IEEE Grounding Practices

Applied to the compound-wide integrated grounding network design and the coordination of LPS grounding with the facility's electrical earthing infrastructure.

Documented Assurance Across the Establishment

Compliance with these standards ensures that the lightning protection system delivers verified, defensible performance across the entire establishment — providing the facility authority, engineering officers, insurers, and regulatory authorities with documented assurance that the compound and its occupants are protected to internationally recognised levels. Periodic inspection and maintenance of all LPS conductors, connections, test joints, grounding systems, and surge protection devices are essential to the long-term effectiveness of the system and are built into the maintenance programme as a mandatory requirement.

About ICS

About ICS Technology Services

ICS Technology Services partners with manufacturers, contractors, and institutions to deliver integrated engineering design across a wide range of critical infrastructure disciplines. Lightning Protection Design, featured in this case study, is one part of a broader portfolio of integrated engineering design services that includes:

As facilities across electrification, energy management, industrial automation, digital industries, and smart infrastructure move toward smarter, more connected, AI-driven operations, ICS brings this same standards-first engineering discipline to every project our clients bring us.

Learn more about ICS