30
BCD SPECIAL REPORT ON
HISTORIC CHURCHES
21ST ANNUAL EDITION
trigger when it should and not when it
should not. It is essential that the product
is reliable and is capable of distinguishing
criminal threat from background activity.
• Simple
: the alarm system should be
as simple to operate as possible as the
majority of churches are cared for by
volunteers and responsibility for the alarm
can change frequently. No church wants
a lengthy instruction manual or intense
training programme, they just want the
alarm to work.
A typical system consists of a control
panel, wireless passive infrared movement
detectors, audio alarm sounders and strobe
lighting. The detectors are battery operated
and communicate with the control panel
via radio signal using a frequency designed
to suit the thick walls, lead roofs and
other features typically found in church
architecture. As a result, the only cabling
required is from the control panel to the
mains power supply and to the sounders,
and a typical installation can usually be
deployed in one day, subject to survey.
The control panel may be installed in the
church or an ancillary building and should
be connected by mobile phone technology
to a 24-hour monitoring and response
centre. On the roof of the church, the audio
alarm typically involves a short burst of a
siren followed by a pre-recorded challenge
warning the intruder to leave immediately
and making clear that people are responding
to the alarm. The message ends with another
short burst of the siren. A sequence like this
which includes a good, clear spoken challenge
has been shown to be far more effective at
deterring intruders than a siren alone.
Despite many similarities, each historic
place of worship is unique, and each alarm
system must be designed on a bespoke basis.
There is no off-the-shelf solution: for the alarm
system to work effectively, each site needs to be
considered on its own merits, and each detector
needs to be tailored to suit the parameters
of its location. Not only are there variations
in design and construction to be taken into
consideration, but there are also variations
in the requirements of the people, usually
volunteers, who look after the building. Both
sets of requirements must always be considered
carefully for an alarm system to be effective.
Where historic fabric is concerned,
it is also important that the alarm system
has been developed in consultation with
historic building professionals, to ensure
that the system is as compatible as possible
with historic fabric. Equipment should be
as small and unobtrusive as possible and
great care must be taken over the fixings.
The positioning of detectors and panels must
be thought through for ease of installation
and operation, as well as for aesthetics.
The alarm system must be based on the
proven catch capabilities of industry-standard
detectors but without the inherent risk of
regular false alarms usually associated with
outdoor installations. The best roof alarm
systems have been developed as roof alarms
from the outset. Adaptations of existing
systems, designed for homes, factories, shops
and the like will not be able to cope with
the unique challenges posed by buildings
with extremely thick walls and a variety of
no-go areas which must be monitored in
isolation from other areas. Detectors often
need to be tailored to suit odd angles, or to
eliminate background radiation or movement,
requiring a range of lenses and sensors.
Monitoring is essential so that there is
a response when the alarms are set off. In
addition, systems should include tamper
protection on all detectors and the control
panel, along with mains power monitoring.
The company monitoring the alarm should
also be alerted in the event that mains power
is lost and not restored. The alarm should have
rechargeable back-up batteries which will run
the system for several days in the event that
mains power is lost. Once power is restored,
these batteries automatically re-charge.
When integrated into a broad strategy
for the protection of churches, dedicated roof
alarm systems provide a simple but highly
effective form of deterrence. At Puddletown
in Dorset, for example, St Mary’s Church
had a spate of attacks in mid-summer 2010,
striking at the lead valley between the nave
and aisles. What was particularly galling
was the fact that the thieves cut out the base
of the gutter near the outlet, so water from
the whole expanse of roof came through
the hole into the church below, causing
extensive damage. It was also very difficult to
make a temporary repair watertight in this
area. An alarm was installed in September
2010. Within two weeks of the work being
completed the PCC was advised that the alarm
had been set off at 2.30am on a Saturday.
On attending the church that morning,
finger marks were found in the anti-climb
paint on a drain pipe and there was evidence
that an attempt at a further theft had been
made, this time without causing any further
damage. Now, four years on, the installation
is still working well and has attracted the
attention of Dorset Police crime reduction
officers and other churches in the region.
Further Information
ChurchCare (the Church Buildings Council’s
website) publishes various leaflets including
one on alternatives to lead:
Ecclesiastical (EIG plc) provides information on
lead theft protection:
English Heritage co-ordinates the Alliance to
Reduce Crime against Heritage (ARCH),
a voluntary national network which
includes churches, police authorities, local
authorities and other organisations:
Hi
ANGUS BROWN
,
founder and managing director
of E-Bound AVX Limited, has held a number of
security-related roles since leaving the British Army
over 20 years ago. He has brought the disciplines
and skills he learned while working for British
intelligence to bear in developing modern security
products and services. Email
Little more than 20 detectors were needed to protect
the roof at Tewkesbury Abbey: these two form part of
the protection for the ambulatory.
A wireless movement detector at St Mary’s, Yelden,
Bedfordshire: for church roofs, movement detectors
often require bespoke lenses and sensors, in this case
background movement from the churchyard below
must be eliminated so that it responds to movement
at parapet level only.
One of the two sounders required at Sheffield
Cathedral. The one shown here with a strobe next to
it, is above the roof of the sacristy and focusses the
sound onto the roof below.
