Basements & Underground

FF Mason 0122

Red Watch, Broughton

Types of IncidentTypes of Incident• There are a number of different types of incident the fire service could

attend, which may result in them having to work below ground level.

These can include;• Basements• Cellars• Sewers• Tunnels• Underground Car Parks• Underground Train Systems

• On arrival at a basement fire the following points should be considered when determining the location of the fire;

1. Determine the number of basements within the building.

2. Get information from any member of staff who may have been

in the area.

3. Make use of fire indicator system and/or plans of the premises.

4. Make use if available of specialist equipment.

• There are a number of problems associated with basement fires

• There are 2 principle points which need to be considered when dealing with Basement fires

1. Lack of ventilation

2. Difficulty of access

3. Locating and appraising fire

4. Communication

5. Difficulty in applying extinguishing media

1. When attacking the fire position covering jets above at floors, lift shafts etc..

2. Ventilate as soon as possible

There are a number of different types of openings There are a number of different types of openings at ground level which allow access to at ground level which allow access to underground areasunderground areas

Gratings

Pavement and stallboard lights

Cellar flaps

Chutes

TunnelsTunnels Although there are exceptions, underground tunnels and similar

structures are normally designed and used for transportation, mineral

excavation, car parking and storage purposes.

The structures are often quite old and, as a result, neither designed nor

built with ideal standards of fire protection and fire safety incorporated

Tunnels under construction, railway tunnels, both those with

underground passenger stations and those without, and road tunnels

will give rise to different problems. Tunnels under construction, for

example, present unique difficulties because of their constantly

changing nature

The Risks InvolvedThe Risks InvolvedIt is important to consider carefully the location and structural characteristics of the tunnel or underground complex, such as its depth, dimensions, construction, ventilation, drainage and the potential risk posed by the tunnel's contents or the nature of its traffic. Consideration should also be given to the provision of communications.• The risk underground must be kept to a

minimum. Areas to consider include;1. Site management's knowledge of fire loads, ignition

sources, fire detection and suppression equipment;

2. Site management's knowledge of materials stored or used and their hazards and properties;

3. Site arrangements for environmental monitoring or surveillance;

4. The level of training undertaken by the operator's workforce and the priority given to safety.

5. The arrangements to prevent unauthorised access and malicious ignition.

Others areas fire brigade may also be involved at an incident:

• Enforcing of agreed safety standards. Operators are

expected to follow the Code of Practice for Safety in

Tunnelling in the Construction industry.• Surveys and inspections to identify possible risk areas.• Suggesting improvements and keeping operators

informed of technical advances.• Training of site work-force, observing at fire drills.• Liasing with on-site firefighting teams and an ongoing

programme of realistic training exercises to test

operational procedures.

Access for Fire Appliances and Personnel

In very large underground risks there may be numerous access points, including staircases; lifts and escalators.

There may also be ramp-ways, suitable for pedestrian and vehicular access.

In very large underground complexes rubber tired vehicles or narrow gauge railways are sometimes employed.

Vehicles used to transport firefighters into a tunnel should remain available for their immediate egress.

It is possible that in both rail and road tunnels, the owners may assist by providing a wheeled or tracked trolley for use in conveying equipment to a forward point.

Fire service appliances will not normally enter tunnels except where road or rail tunnels have vehicle access tunnels alongside.

Four-wheel drive vehicles cannot be driven over rail tracks and many tunnels are too small to enter.

It may be possible to adapt a vehicle for use inside a tunnel to assist in the movement of equipment and personnel. In some instances, tunnel operators may assist with the provision of underground transport facilities.

The following points regarding access to underground structures may assist with individual contingency plans:

VentilationVentilation Entering an underground structure where a fire has occurred is extremely

hazardous and any measures that will reduce this hazard should be

considered. The distance from surface level to the floor affected may be

considerable and bridgeheads may be an essential part of the plan.

Additional precautions which can be pre-planned for underground

structures, though not road tunnels, include:

1. Break-in panels to assist ventilation; and

2. External openings for fire brigade smoke extraction units.

An efficient ventilation system is essential. Flashover conditions may occur

with disastrous consequences for firefighting operations. The location of air

shafts and their likely effect on the fire should be borne in mind.

SewersSewers Today's underground systems have developed since the Victorian

period and form a complex underground network of pipes and chambers

By the very nature of the waste products being transported, access and rescue require a certain amount of specialist knowledge.

In most cities and large towns a vast complicated network of sewers has been established for the discharge underground of domestic sewage, trade wastes and rain water.

Sewers form an intricate arrangement of pipes ranging in size from about 150mm diameter to as large as 7 metres in diameter

Local sewers are small in diameter and they discharge into the larger main sewer system which in turn carries the waste materials eventually to one of the purification works for ultimate disposal.

The system of sewage pipes is arranged in such a way that should work of any kind be required in a section, flow may be diverted by the use of sluice gates and penstocks to alternative routes.

Access to SewersAccess to Sewers To enable repairs and maintenance to be easily carried out,

and to facilitate ventilation, sewage systems are provided

with vertical access shafts. These shafts are accessed via

manholes at street level.

It is from these manholes that any sewer rescue must be

carried out.

Engineers may also gain access from street or footpath

level via manholes. Manholes and shafts are designed

primarily for use by workers carrying only a few tools

The firefighter wearing breathing apparatus will naturally

experience considerable restriction to their movements

when ascending or descending.

Where the invert of a sewer

is more than about 6m below

the surface it is normal for

the ladder climb to be

interrupted by a platform

placed halfway.

Sewer Gas The collapse of workers in sewers is usually caused by the presence of

sewer gas This gas is a mixture of sulphuretted hydrogen and methane, both of

which are toxic and flammable The mixture may burn explosively when mixed in the correct

proportions with air. When the sludge is disturbed or waded through the gas is released and

bubbles up to the surface into the air space above

Light and ventilation• As soon as the probable position of the people to be rescued is established,

manhole covers either side should be removed for light/ventilation and ease

of rescue.

• Due to the sewer gases that are formed during the decomposition of sludge

lying on the bottom of slow moving or stagnant sewers, any firefighter

entering a sewer should wear Breathing apparatus.

• Two firefighters in BA should make their way down the shaft and proceed

along the sewer.

• A third firefighter should descend the shaft to the foot of the ladder while a

fourth remains above ground so that contact may be maintained between

rescuers and surface at all times

• BA must be worn by all four firefighters.

Bacterial Infections• Weil's disease is found in sewers and originates from the urine of rats

• In the early stage Weil's disease is often mistaken for influenza,

pneumonia, tonsillitis or some other common ailment.

Hygiene Precautions

• After working in contact with sewerage hands and forearms must be

washed with soap and warm water

• Clothing, boots and equipment, which are contaminated with sewage,

must be thoroughly washed

• It is essential to bathe on return to the station if contaminated with sewage

Any Questions?Any Questions?

GratingsGratings• Basement windows may often be protected by gratings on the

pavement.

• These gratings are often made to lift up without damage, or may be set (usually with lead) into into the paving stones.

• A sharp blow with the of an axe close to the point where the grating is set will usually free it sufficiently to allow it to be pulled clear.

• With removable gratings which may be held down to an eye bolt by a central chain, it may be possible to lever up the grating and displace it sufficiently to gain access.

Pavements & Stall Board LightsPavements & Stall Board Lights Basements in which goods are stored are often fitted with

pavement or stallboard lights. They are are horizontal and strong enough to be walked on by

pedestrians They may be either used solely for lighting, or may open to

allow for ventilation or for the loading of goods. They may then be placed in the same class as cellar flaps.

Lights which can be opened form the inside may very often have breakable glass panels set near the catches. Sometimes these panels are identifiable by being made from a different coloured glass.

Cellar FlapsCellar Flaps Many premises in which the basement is used for storage have

trapdoors, known as cellar flaps which open to the pavement The doors covering these openings are lifted up when it is

desired to load or unload goods The doors are often made of wood and may be forced open by

removing one of the boards to gain access to the fastenings below.

ChutesChutes The size and construction of chutes varies greatly. Some will permit the passage of a fireman, but others may be to

small. Iron covers which can be lifted up are used for smaller chutes,

but the larger chutes will often have trapdoors which may be fastened in a number of ways.

They will normally open upwards or outwards. Any time when an opening has been opened, a crew member

should be posted by it to worn passers by of the hazard.

Bridgehead.

Bridgeheads are to be used on occasions when it is necessary

for operational reasons to enter a High Rise building so as to

be able to proceed some distance away from the original point

of entry before starting and donning Breathing Apparatus. The

circumstances the Officer in Charge must consider when

assessing whether and where to establish a bridgehead are

detailed in; Section 5.4.3 of OC 13/1/2 (BA Operational

Procedures)

Weils Disease (LEPTOSPIROSIS) Weils Disease is caused by a micro-organism spread by animals (mainly rats, but also pigs and cattle), either directly or indirectly through their urine, which contaminates water and the banks of canals, ponds, rivers and ditches.

The micro-organism enters the body through breaks in the skin and mucous membranes (eyes, nose etc) or from animal bites.

Prevention• Do not enter suspected contaminated area's unless Full Fire Kit and Latex gloves

are being worn.

• Clean and cover all cuts and breaks in the skin immediately with a waterproof dressing and keep them covered when working until they are fully healed.

• Wash thoroughly before eating & drinking after working in a suspected contaminated area.