Service Delivery 4

Explosives

Aim

To make students aware of the operational procedures for dealing with incidents involving explosives and the marking systems in use to identify them.

Learning OutcomesAt the end of the session students will be able to:

• Identify the hazards and risks associated with explosives

• Understand the marking systems used to identify explosives

• Be aware of the operational procedures for

dealing with incidents involving explosives.

Nature of explosives

• All chemical explosives contain fuel and oxygen

• Burn extremely quickly producing large quantities of hot gasses

Nature of explosives

• ‘Low Explosives’ deflagrate at subsonic low velocity up to 100m/sec.

• ‘High Explosives’ propagate at supersonic high velocity 1-10Km/sec producing a blast wave

Classification and Labelling of Explosives Regulations 1983

Based on the UN system of 9 classes of dangerous goods:

Classification and Labelling of Explosives Regulations 1983

• Explosives

• Gases

• Flammable Liquids

• Flammable Solids

• Poisonous & Infectious

•Radioactive

•Corrosives

•Miscellaneous

•Organic Peroxides.

Classification and labelling

Class 1 explosives are sub-divided into hazard divisions;

1.1 Mass explosion hazard

1.2 Projection hazard, no mass explosion

1.3 Fire hazard, minor blast and/or minor projection, no mass explosion.

Classification and labelling

1.4 Substances or articles that present no significant hazard

1.5 Very insensitive substances that have a mass explosion hazard

1.6 Extremely insensitive articles that do not have a mass explosion hazard.

Labelling

• UN Class 1 explosive.

• Hazard division

• Compatibility group

Marking of vehicles

Placarded vehicles may carry up to 16 tonnes of explosives.

Danger signs & subsidiary danger signs (if any)

Exemptions

The Armed Forces are not subject to requirement for placarding but the Ministry of Defence through its Explosives Storage and Transport Committee have voluntarily adopted a similar placarding system.

Transport

• All vehicles carrying explosives must be regarded as potentially hazardous

• Division 1.1 explosives present the major hazard.

Transport

• The incident commander will decided the extent to which fire fighting or rescues might be attempted having regard to the hazard and life risk

• The primary objective must be to evacuate the public to at least 600 metres.

Firefighting

It is vitally important that we differentiate between a fire or risk of fire that is;

• On or near the vehicle but not affecting the load, nor likely to, and;

• An established fire involving the load or

threatening to spread to it.

Firefighting

Where the fire does not involve the load such as a tyre or fire in the vehicle cab priority must be given to extinguishing the fire before it involves the load.

Firefighting

If the fire involves the load or is threatening it;

• Every possible effort must be directed toward evacuating the area

• Only where this is clearly not possible and the rapid application of water would have a good chance should firefighters be committed.

Protection

• Firefighters should not be committed unless they are protected by an earth banking or other substantial structure at some distance from the incident

• An un-buttressed double brick wall may not provide adequate protection.

Effects of explosions

• Vehicle parts

• Packagings

• Explosive debris

• Person being thrown into the air

• Being thrown against a solid object.

Fatal injuries may arise from being struck by;

Effects of explosions

kg tonnes tonnes

50 5 16

99% survive lung damage 6m 38m 80m

1% survive lung damage 27m

50% eardrum rupture 12m 54m 80m

Missiles limit of throw. 150m 250m 2000m

Some examples of the effects of explosions on persons of ‘average’ fitness;

Protection from explosions

To be protected requires;

• Distance

• Substantial cover

• Small buildings or vehicles offer little protection

• Get below ground level if possible

• Or behind thick earth banking.

Radio communications

10 m

50 m

600 m

No Radios Closer Than 10m

No appliance radios closer than 50m

Keep public back at least 600 metres.

The Carriage of Explosives by Road Regulations 1996

• Covers precautions against fire, explosion, theft and unauthorised access

• Prohibits carrying certain explosives

• Suitability of vehicle and freight containers

• Ensures mixed loads carried safely

• Placarding and marking of vehicles.

The Carriage of Explosives by Road Regulations 1996

• Ensures written information carried

• Supervision of vehicles

• Limits and duration of carriage

• Training of drivers and assistants.

Explosives

The driver of the vehicle must carry in writing the following details in a consignment document;

• Division and compatibility group of each explosive carried

• Net mass of each explosive carried

• Name & address of consignor

• If groups C,D or G whether it is a substance or article.

Suspect devices

• Avoid the use of lights or any other warning devices

• A 200m incident zone will have been established within which the use of radio equipment is strictly prohibited.

Suspect devices

• A message should be passed to Brigade Control confirming the type of device e.g. explosive or incendiary device

• If an incendiary then the normal predetermined attendance will be mobilised to the incident.

Bomb alerts

Fire service personnel must not become involved in the search for any suspect devices or packages.

Health and safety

• Personnel should be alert to the possibility of an incorrect marking

system being displayed

• As well as the normal hazards associated with explosives,

personnel should also be aware of the possibility of toxic emissions from burning explosives.

ConfirmationAssessment will be based on this lesson and the corresponding study note

Learning Outcomes• Identify the hazards and risks associated

with explosives

• Understand the marking systems used to identify explosives

• Be aware of the operational procedures for dealing with incidents involving explosives.

THE END