LIGHTNING SAFETY IN WORKPLACES

It is normal for this time of year for Lightningman to be contacted by various organizations who are seeking information as to how they can best manage risks posed by lightning strike, and how to best keep their personnel safe during periods of localized thunderstorms.

This is often easier said than done, as all workplaces will be different, and can cross regions of low and higher lightning prevalence, whilst different workgroups, and different work activities, can often be exposed to differing and various direct, and indirect lightning injury risk mechanisms.

Through this post, I hope to offer some useful insight and perspective into some of the most basic and more appropriate controls that are available to all Australian workplaces, which can significantly impact upon the effective management of lightning hazards during high risk periods.

Lightning is an unpredictable and fatal risk, and it can affect every single workplace across Australia!

Wherever personnel have any activities that are outdoors, they will have a greater exposure and disposition to risk.

The following controls need to be considered wherever personnel may have exposure to lightning, and its varied and unpredictable and injury mechanisms.

1. A Lightning Management Plan (LMP)

A LMP is a vital administrative control that offers a structured framework for;

• detailing the mandatory requirements for the effective management of lightning related hazards, and mitigation of risk.?
• describing how threats posed by lightning strikes can be identified, assessed, and wherever possible controlled/ mitigated.
• detailing the technology controls that can be used for the determination of safe / unsafe conditions.
• assessing the need for, and then detailing safe working procedures for all at risk workgroups
• describing the roles, responsibilities, and accountabilities of all personnel during high risk conditions.

2. A Safe Working Procedure (SWP)

Lightning SWP's are more workgroup specific, and must take into consideration that some workgroups will be undertaking activities that may place them at some greater exposure, or higher disposition to risk factors, than others.

Sometimes an individual workgroups activities and circumstance, will require that they obtain their threat notifications much earlier than any other work groups, so as to make safe any unsafe and incomplete work, or, where they may require additional time in order that they can safely remove themselves form their current location, and then evacuate to the nearest safe shelter.

A Lightning SWP should outline the do's, and the do nots, and dictate when specific workgroup activities should seek a safe shelter, at which alert level, and should describe the most appropriate safe shelter in which to wait out the duration of any lightning threat.

3. Technology Controls - Lightning Detectors

Not all organizations will be in a position to provide the most appropriate professional grade Class 2 Lightning Warning and Threat Notification system, (such as a 'Strike Guard' Lightning Warning System), in which case workplace economics and affordability will often dictate the use of Class 4 'portable/handheld' lightning detectors as the most viable option.

Class 4 lightning detectors are a lower capability detector which are significantly cheaper than the expanded capability, and automation options offered by professional grade Class 2 Warning Systems.

Class 4 detectors have many known limitations and shortcomings such as a very limited threat detection capability, and they can only detect, then notify to historical Cloud to Ground (C-G) lightning strikes, meaning they cannot detect or alert to the more prevalent Cloud to Cloud (C-C) lightning flashes, which are more common than the C-G strikes, but which are still indicative that high risk conditions are current, where the "storm is local".

Class 4 detectors also have a high prevalence to false alarm when used in close proximity to electrical switching, and the operation of common office equipment, (including, laser printers, photocopiers ,mobile phones, radio transmitters, etc.) where the electromagnetic signals from electrical switching and radio frequency bursts, can sometimes trick the detector into believing that the detected signals are lightning.

Moving the detection equipment away from such close proximity to such interference will generally reduce the impost of false alarming!

(Professional Grade Class 2 Warning Systems overcome such false alarming through an inbuilt double positive coincidence and validation between at least 2 independent lightning sensors)

Class 4 detectors will also offer the most basic of visual threat indications, and audible threat notifications, where there is no opportunity to interface/ control the automation of 3rd party threat notifications.

(Professional Grade Class 2 Warning Systems offer 100 % automation of proprietary electronic messaging, audible, and visual threat notification options, via network and wireless communications)

The 100% efficient management/notification of lightning threats is fundamental to operational safety, where any investment in such a technology control will be a wasted investment if those who are tasked to manually administer the management and workplace communication of lightning threat notifications, are unable to hear audible alert notifications over background noise, or are indisposed elsewhere, or are otherwise unable to communicate/ relay threat alerts.

This is where control vetting becomes important, as the correct selection of a Class 4 detector MUST be suitably vetted for use in the intended application, as too often the selection of such a critical technology control to a known fatal risk, is left to non qualified personnel who may be unaware as to the selection requirements, or to the potential downside of their potentially uninformed decisions.

Dr Google offers NO USEFUL ADVICE, and will likely confuse the unwary within the glossy sales material.

For example

1. Environmental and Sustainability

Lightning detectors must be operational at all times, where you cannot activate the equipment after lightning has already struck, which is not an uncommon observation that we see as a specialist in the area of lightning risk mitigation.

                   Strike Alert HD  Battery only Operation         

This will be important when considering the purchase of lower cost detectors which may be battery operation, and non rechargeable, and where the equipment is not equipped to operate from an AC mains, or 12 VDC vehicle adaptor.

Such low cost detectors may offer some impressive sounding features in a glossy brochure, but will also require regular and expensive battery replacement .

This will mean that the real cost of the equipment must also included an amortized annual cost of non rechargeable batteries, which is an unnecessary waste of limited resources, and over time will cost far more than the higher spec rechargeable Class 4 detectors, such as the Skyscan EWS PRO 2 or Thunderbolt2 Lightningman detectors .

1. Suitability of Alert Notifications

Lightning detectors must be selected to suit the intended application, and not be based upon cost issues alone, where a lower cost detector will generally mean reduced capability and features such as the audible horn not being loud enough to be heard over higher background noise, or where the visual alert LEDs may be not be readily visible during the bright light of day.

For example.

Those personnel who work within explosives magazines will generally be considered as having the highest risk from lightning strikes, and who would need to obtain their threat warnings much earlier than any other workgroup , although they will be precluded from carrying any battery powered energy source into and within the confines of the explosives magazine, in which case any control must be located outside the fence of the security compound.

Minimum requirements for a Class 4 detector would require:

• large high intensity colour coded LEDs,
• a very loud (105 dB) audible horn,
• low battery indicator
• rechargeable

Meaning blast crew personnel can confidently leave their detector at the entrance to the magazine, and yet still be able to hear, and visually interrogate the current threat alert, so as to determine their exposure to risk and need to commence TARP.

3. Detection Methodologies

There are several types of Class 4 portable lightning detection methodologies.

Some detection methods (i.e Optical) will not be detailed here , as they are not relevant for personal safety application, especially in high risk workplaces.

The two most common methodologies are :

·????????Instantaneous Ranging and Response Detector (IRRD)

·????????Delayed Response Detector (DRD)

Instant Ranging and Response Device (IRRD)

With an IRRD, every detected C-G lightning strike is ranged and then notified immediately, however this level of detection capability is very limited, where the equipment cannot detect a storms direction or motion, or whether any detected threat may be approaching, is moving parallel , or is on some non-intercepting transect.

                                  Skyscan EWS Pro 2        

The down side of an IRRD is that upon any C-G lightning strike detection (say within 20 kms), there is no indication as to whether the storm is approaching, or moving away from the users location, but trigger action response procedures (TARP) still require that all persons are to make safe any unsafe work, and then seek an immediate safe shelter indoors until 30 minutes have elapsed past the last lightning detected.

As such users of IRDs will suffer from higher levels of false alarming, and extended periods of unnecessary downtime and disruptions.

Delayed Ranging Device (DRD)

With a DRD, every detected C-G lightning strike is stored in memory, where further C-G strikes are then compared with the previous C-G strike data, in order to ascertain whether a storms movement?may be approaching, moving away, or possibly on some non-intercepting transect, unlike the IRRD equipment.

                         Thunderbolt 2 Lightningman Detector         

The Thunderbolt 2” Lightningman” detector users a microprocessor with an LCD display that provides additional levels of threat data not available on the IRRD equipment and includes the following text messaging that is presented via its LCD display;

·????????Detected Strikes

·????????Threat is Local

·????????Distance to storm activity = 'X' km's

·????????Closest Strike = 'X' km's

·????????Estimated Time of Arrival (ETA) = 'X' mins

·????????Estimated Time of Clear (ETC) = 'X' mins

·????????Approach Speed? = 'X' kmh

·????????No Approach Detected

·????????Storm intensity information??????????????????????????

????????

                         Lightningman detector typical LCD messages        

The downside with DRD equipment is that there needs to be a minimum number of data points (C-G strikes) stored in memory, before the microprocessor can then compare previous strike data with later strike data, and then compute the nature of any threat.

In some instances, the delay in waiting for additional C-G strike data can have a situation where C-G lightning can be seen to be visibly striking , without the detector unit alerting.

This is quite normal, and is the trade off for the greater level of threat data being presented via the LCD.

In any such instance operators should know that they must immediately seek a safe shelter.

?Summary

Lightningman are the Australian Specialists in lightning safety and lightning threat detection, and we can assist organizations deal with the technical nuance associated with their workplace activities, and can assist organizations deal with their obligations to ensuring appropriate lightning safety is discreetly embedded within the workplace.

Grant Kirkby -Lightningman