The journey and transformation that MSL has witnessed during its long history makes for almost unbelievable reading, compared to today’s protective and environmental friendly world.
Back in the 1980’s the vast majority of fire alarm systems were in fact switches (break glass call points) and bells. Very few buildings had detection systems as we know them today.
An early MSL installation in 1985 was to remove some 50 aptly named “rat-cage” heat detectors from an operational warehouse and replace them with beam detection.
The rat-cage was pure science. Imagine something similar to an egg timer glass, now remove the “sand” and replace it with “mercury”, keep the spring loaded tube just under the horizontal with a bi-metal strip. When the bi-metal strip was subjected to heat it released the spring, forcing the “tube” upward allowing the mercury to flow, which shorted the contacts at the other end of the tube, thus making the circuit. Brilliant!
Fire alarm panels were made of wood, how environmentally friendly. Basically a wooden box with coils holding small red & white checked paper squares (flags), above small vision windows - if a coil energised and a flag dropped down into view - you had a fire.
The Big Bang or the deregulation of financial markets in 1986 produced a leap in technology with the buzz words being “electro data processing” = “Halon suppression”. A must have it seemed for almost every building and room in the City of London, let alone the rest of the UK.
The first suppression system installed and commissioned by MSL was in fact a fire alarm control panel (complete with vanished wooden surround) which had a box of tricks called the coincidence unit coupled underneath. From this master set of controls all the smoke detectors and field devices were wired in Mineral Insulated Copper Clad - MICC cable. An installation skill which very few “installers” can complete today.
This magical time saw fire alarm & suppression companies appearing like magic. Perhaps this was not too surprising due to the “testing” of the newly installed suppression systems. All end users would readily and perhaps more importantly be happy to pay for their new systems to be fully discharged. Following this most exiting demonstration and when the dust had settled (literally) a man in a white coat would enter the area and “analyse” the gas concentration. Sometimes the analysis would produce the view that the Halon gas “should” extinguish a fire if ever there was one. Therefore, and now the good bit, replace the Halon and submit the invoice. Ozone layer, what ozone layer!
Innovation after innovation followed and today MSL installs, commissions and maintains: