Damage and loss

Source of damage

The lightning current is the primary source of damage. The following sources are distinguished by the strike attachment point (see Table 1):

S1: flashes to a structure;

S2: flashes near a structure;

S3: flashes to a service;

S4: flashes near a service.

Types of damage

A lightning flash may cause damage depending on the characteristics of the structure to be protected. Some of the most important characteristics are: type of construction, contents and application, type of service and protection measures provided.

For practical applications of this risk assessment, it is useful to distinguish between three basic types of damage which can appear as the consequence of lightning flashes. They are as follows (see Table 1):

D1: injury to living beings;

D2: physical damage;

D3: failure of electrical and electronic systems.

The damage to a structure due to lightning may be limited to a part of the structure or may extend to the entire structure. It may also involve surrounding structures or the environment (e.g. chemical or radioactive emissions).

Types of loss

Each type of damage, alone or in combination with others, may produce a different consequential loss in the structure to be protected. The type of loss that may appear depends on the characteristics of the structure itself and its content. The following types of loss shall be taken into account (see Table 1):

L1: loss of human life and permanent injury

L2: loss of service to the public;

L3: loss of cultural heritage;

L4: loss of economic value (structure , content, and loss of activity).

Table 1 – Sources of damage, types of damage and types of loss
according to the point of strike

		Structure		Service
Point of strike	Source of damage	Type of damage	Type of loss	Type of damage	Type of loss
	S1	D1 D2 D3	L1, L42) L1,L2, L3, L4 L11), L2, L4	D2 D3	L`2, L`4 L`2, L`4
	S2	D3	L11), L2 , L4
	S3	D1 D2 D3	L1, L42) L1, L2, L3, L4 L11), L2, L4	D2 D3	L`2, L`4 L`2, L`4
	S4	D3	L11), L2, L4	D3	L`2, L`4
1) Only for structures with risk of explosion, and for hospitals or other structures where failures of internal systems immediately endangers human life. 2) Only for properties where animals may be lost.