|Fire Protection of Historic Piers|
Fire Protection of Historic Piers
Piers encompass a
variety of uses. They can be primarily industrial in nature or may be
entirely recreational. Some unusual facilities combine promenade
facilities with extensive assembly use including, in some cases, cruise
ship facilities or sightseeing and recreational craft. In fire
protection terms, such facilities fall in the realm of piers and
wharves. This article will focus on historic piers (Figure 1).
The fire hazard associated with such facilities varies depending on the construction type. More modern piers tend to be of reinforced concrete construction due to the high incidence of severe fires in piers that were wholly or partly of combustible construction. However, whatever the construction, certain problems are unique to piers:
(Credit: Weston and Somerset Mercury)
the case of combustible piers, fire has the potential to involve the
areas below the pier deck. The degree to which this occurs depends upon
the progress of the fire and concentration and extent of combustibles in
the structure. In some cases, fuel may be restricted to combustible
decking. In other instances, the main structural elements may be heavy
timber construction; frequently this consists of creosoted timber.
Often, there is a mixture of construction types (Figures 2 and 3).
(Credit: Gulf of Georgia Cannery Society Archives)
Figure 3. Heavy Timber Sub-Structure under a typical pier.
(Credit: Gulf of Georgia Cannery Society Archives)
prevalence of windy conditions in seaside locations can contribute to
fire spread. Actual fires have demonstrated that fire will spread
against the direction of the wind as well as being assisted in the
direction of the wind. In one relatively recent fire, in an area
involving combustible structure above and below the pier, there was
total destruction in the downwind direction in addition to fire spread
along combustible decking against the direction of the wind.
many cases, piers are relatively inaccessible to fire service vehicles.
Fires below combustible piers are particularly problematic in that
access problems are compounded at low tide by the lack of ‘hard
standing’. In other words, at low tide, fire vehicles, even if they can
access the beach, can become bogged down due to the weight of fire
appliances. This leads to fire service delays that may be critical to
At high tide,
difficulty with the deployment of hoses on the fire, by fire boats for
instance, is compounded by tidal and wave action. Substructure may
effectively screen the fire from direct impingement of water. Although
access is often attempted from above the pier by cutting through the
pier deck, it is usually difficult to determine exactly where the fire
is due to smoke and other factors. If access hatches are not provided,
then fire services have to cut openings into the deck and deploy nozzles
designed to extinguish substructure fires.
It is difficult to extinguish fires in this manner. Water supplies are often limited and the number of openings achievable over a fire area may enable the fire (often aided by lack of water penetration by the nozzles and the prevailing wind) to rapidly spread beyond the area of attack.
Structures above the pier
deck may be of combustible construction or contain sufficient
combustible materials to become involved in a fire and pose a fire risk
to the entire structure. In the case of recreational piers, fires often
start in the above-grade structures and spread to the substructure,
where they burn out of control. Therefore, reliance has to be placed on
automatic suppression to mitigate potential fire damage.
significant piers share many of the typical challenges associated with
other heritage buildings. Notwithstanding the fire problems above – the
challenge is the deterioration of pier buildings and the management of
fire risk over time. Superimposed on the usual problems of achieving an
acceptable level of fire and life safety (in the context of
refurbishment or adaptive re-use) is the so-called ‘moral hazard’
associated with planning and construction in seaside facilities. While
this is a defining characteristic of seaside towns, there is often poor
control of fire hazards, compared to more ‘organised’ jurisdictions. The
transitory nature of business and regulatory controls often allows
uncontrolled construction changes to occur over time. These often
increase the fire risk in probabilistic terms compounded by the
ineffective fire safety management. This is combined with the increased
risk of arson, poor control of recreational fires under piers and other
On a positive note, moves in
the UK to take back ownership of piers either by public or private
agencies – for conservation purposes – is a sign that the heritage value
of certain seaside piers is being recognized. The availability of
grants to introduce recommended fire precaution measures is also
A complication is the
lack of an appropriate standard for property conservation. In England
and Wales, for instance, Approved Document B (ADB)1 to the
building regulations, is primarily a life safety document. It offers
only nominal property protection measures and often relies on
compartmentation and detection to limit fire spread. Compartmentation
may often be breached or nonexistent due to the age of construction.
Extensive combustible concealed spaces may have been created and
modifications made with little regard to fire and life safety. Typical
fire hazards, such as those associated with deep fat fryers or storage
and handling of flammable liquids, are often poorly controlled.
detection relies on effective response to alarms. The assumption that
the size of a fire can be limited by compartmentation and the fire risk
offset by rapid and effective response to a fire must be seen in the
context of access and firefighting limitations on piers. Also, ADB does
not address fires below pier, which are often a contributory factor in
very large fires. The relatively recent fire at Weston super-Mare showed
that the above pier structure itself was so poorly protected that it
could be subject to a total loss. So what is the solution?
first consideration is water supply infrastructure. The use of
recirculating stainless steel mains is one option to prevent freezing of
essential supplies and protecting water supplies from deterioration due
to corrosion. Routinely, such systems should be run on fresh water to
prevent excessive corrosion, but more importantly, to reduce
contamination by marine organisms when saltwater pumps are used.
a recent case, a test of saltwater hydrants was conducted. It was found
that the saltwater system was completely obstructed by fish, seaweed
and other solid matter. This had been pumped into the system under
normal ‘wash down’ of decks, ostensibly to prevent re-ignition of
discarded smoking materials.
Water supplies should include:
terms of the pier substructure and pier buildings, there is no
requirement for the installation of an automatic sprinkler system.
Moreover, there is no national guidance document in the UK for fire
protection of piers. In lieu of this, NFPA 307,2 can be used. It is a robust standard that addresses all the typical conditions encountered in piers and wharves.
sprinkler systems differ in that they typically throw water upwards
rather than downwards in order to reach all pockets in the substructure.
Careful placement of the sprinklers is necessary to achieve effective
wetting of timbers and prevent shielded areas that can permit a path for
fire to spread. NFPA 307 relies on the use of bulkheads to control fire
spread. This can raise planning issues in listed buildings as the
architectural appearance of the pier can be compromised to a degree. In
lieu of this, some consideration could be given to extend the capability
of the sprinkler systems to deal with fire over larger areas.
in above-pier structures require special consideration due to a variety
of factors, including their visual impact on historic interiors. In
most areas with suspended ceilings, sprinklers can be concealed.
the routing of piping has to be designed to r educ e the visual impact
of piping and sprinklers. Where piping has to be exposed, it can
typically be run along beam lines and painted to match adjacent
Professional designers use
a combination of techniques to integrate the system with the building
architecture to provide a fire protection system that is not obtrusive.
This is a result of collective experience on sensitive occupancies, such
as cathedrals and historic houses with decorative ceilings.
challenges may be problematic when undertaking the installation on a
design-build basis. In some instances, contractors may be less concerned
with appearance than achieving system costs in order to win the
contract. For this reason, retention of a fire protection engineer
familiar with pier protection systems and international standards should
be considered before embarking on a program for protection,
restoration, refurbishment or adaptive reuse of an historic pier or
wharf. Most historic buildings benefit from an independent design
followed by a close partnership with the selected sprinkler contractor.
John Ivison is with John Ivison and Associates Ltd.
3/19/2017 » 3/23/2017
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