Firework Displays & Safety Dave White Tony Wilkinson Introduction Good afternoon everyone, I’m Tony Wilkinson of Starfire Pyrotechnics and this lecture is intended as an introduction to the science of Pyrotechnics, that’s the chemistry, physics and mechanics of fireworks.   Is there anyone here who thinks I’ve come along here to just blow some things up just for the sake of it? Well… we’ll try not to disappoint you! Seriously…

Just common sense innit? Assessing Risk Regulations Knowledge of the subject “Morbid Imagination” Safety Briefing No-one forward of the line, unless specifically asked to do so There may be the odd bang here and there, though I will always give some warning in case there’s anyone of a particularly nervous disposition… I should also mention that this might make an appearance .. GUN… …it’s a blank-firing replica of an 1851 Colt Navy black powder pistol, not a ‘real’ gun.   There might be some smoke, but hopefully the extractor will take care of that. We won’t be generating any particularly toxic fumes, so you shouldn’t choke to death ! In the very unlikely event of fire, we have two other members of Starfire here: Dave White And Kevin Ford Who will act as fire marshals. To avoid any misunderstandings during demonstrations, an order to evacuate will only be given by Dave, Kevin or myself. Having said that, don’t worry… we do know what we are doing, we are professional firework display operators who take safety very seriously. We’ve done over 50 shows in the last 5 years with no incidents whatsoever. Last, but not least, I must stress that some of the things you’ll see this afternoon are in the DON’T TRY THIS AT HOME category Firstly, they may be extremely dangerous unless you know exactly what you are doing and have the right safety equipment Secondly, any manufacture, modification or disassembly of any firework item is strictly illegal. And it is still the case that a conviction under the Explosives Act would remain with you for life, meaning you would never be able to work in explosives or fireworks and never be allowed a firearms licence. Before we move on…

Lack of common sense! Safety Briefing No-one forward of the line, unless specifically asked to do so There may be the odd bang here and there, though I will always give some warning in case there’s anyone of a particularly nervous disposition… I should also mention that this might make an appearance .. GUN… …it’s a blank-firing replica of an 1851 Colt Navy black powder pistol, not a ‘real’ gun.   There might be some smoke, but hopefully the extractor will take care of that. We won’t be generating any particularly toxic fumes, so you shouldn’t choke to death ! In the very unlikely event of fire, we have two other members of Starfire here: Dave White And Kevin Ford Who will act as fire marshals. To avoid any misunderstandings during demonstrations, an order to evacuate will only be given by Dave, Kevin or myself. Having said that, don’t worry… we do know what we are doing, we are professional firework display operators who take safety very seriously. We’ve done over 50 shows in the last 5 years with no incidents whatsoever. Last, but not least, I must stress that some of the things you’ll see this afternoon are in the DON’T TRY THIS AT HOME category Firstly, they may be extremely dangerous unless you know exactly what you are doing and have the right safety equipment Secondly, any manufacture, modification or disassembly of any firework item is strictly illegal. And it is still the case that a conviction under the Explosives Act would remain with you for life, meaning you would never be able to work in explosives or fireworks and never be allowed a firearms licence.

Today’s Topics Regulations etc. Black Powder (gunpowder) Deflagration Firework Types Estimating Risk Planning an event Firing a show Demonstrations Now… I could go on all day about any one of these, but I’ve chosen a few of the essential elements for some detail:   Burning / Deflagration / Detonation …it’s all gotta burn somehow, so we might as well know why and how it burns ! Not ‘Combustion’ but Oxidation/Reduction Black Powder (gunpowder) … this is part of almost all fireworks and is used as a propellant (like in a gun or in a rocket motor), to make delays and fuses and as an explosive. Effects are a bit complicated and, even now, the exact chemistry is still being argued about! like the strobe material I just showed you, they involve several separate chemical reactions going on at the same time… so I’ll skip this one for today Colours are essential in modern fireworks and, interestingly, have nothing at all to do with gunpowder

Regulations etc. Categories of Firework (BS7114) Category 1 ("indoor") fireworks are for use in extremely restricted areas.  Category 2 ("garden") fireworks are for use by the public in their gardens. Safely viewable from 5m, no debris beyond 3m.  Category 3 ("display") fireworks are for use by the public in larger displays. Safely viewable from 25m, no debris beyond 20m.  Category 4 ("professional") for sale only to fireworks professionals. They have few restrictions, default category for untested fireworks

Regulations etc. UN Hazardous Materials – Class 1 1.1 Mass Explosion Hazard 1.2 Nonmass explosion, fragment-producing 1.3 Mass fire, minor blast or fragment hazard 1.4 Moderate fire, no blast or fragment: a consumer firework is 1.4G or 1.4S 1.5 Explosive substance, very insensitive (with a mass explosion hazard) 1.6 Explosive article, extremely insensitive

Regulations etc. Firework Categories & Classes Consumer Fireworks Usually Cat.3 1.4G Display Fireworks Usually Cat.4 Mostly 1.3G Large shells now 1.1G (ADR)

Black Powder (Gunpowder) Introduction Used for: Propellant (small grain – e.g. Gun) Propellant (large grain – e.g. Rocket) Explosive (burst charge) Fuses, delays etc.

Black Powder Solid Grain Progressive Burning of ONE BIG GRAIN SOLID GRAIN LIQUID GAS FLAME

Black Powder Grain Burn

Black Powder Deflagration

Black Powder Confinement There’s 3 important things here: Increased Pressure Increased Temperature Increased Reaction rate

Black Powder Confinement Failure! 50,000psi 50,000psi = more than 1,500 times the pressure of a car tyre !!!! (that’s about 350MPa )

“Flash” Perchlorate and atomised Aluminium Loud reports “Hard Break” shells and rockets High Brisance ‘explodes’ with little confinement >10g = 1.1G

Some types of Firework

Firework: Rocket Construction Stars (with burst charge) BP Grain Nozzle Balance stick Launch tube WHAT WOULD HAPPEN HERE ?

Firework: Rocket Failure modes Cracked Rocket Motor WHAT WOULD HAPPEN HERE ?

Firework: Rocket Failure modes “Groundburst” Also… Failure to fly WHAT WOULD HAPPEN HERE ?

Firework: Rocket Effect of wind “CofG” wind wind WHAT WOULD HAPPEN HERE ? Angling away from wind – make it worse!

Fireworks: Gerbs “Fountains” Kimbolton 7lb Gerb Solid or compressed grain “Fountain with sparks”

Fireworks: Cakes “Multi-shot Battery” Crackle Red Explosive (flash) Red Flare (delay) Propellant (BP) Fuse

Fireworks: Cakes “Multi-shot Battery”

Fireworks: Candles “Roman Candle” Fuse Felt wad Delay Multi-shot 19mm – 65mm + Sidewall can fail Stake, Board or Box

Fireworks: Shells Introduction 3” , 4” and 5” (75,100,125mm) 6” and up 1.1G

Fireworks: Shells Construction 50m+ burst ~100m/sec ~300mph!

Fireworks: Shells Failure Modes No Lift (or zero delay) “Flowerpot” “detonation” Poor Lift Low Break (going up) Long or failed delay Low Break (coming down) “Black Shell” Rack Failure ! Causes: Malfunction, Jam, Loading error

Fireworks: Shells Calculating Distances Rule of thumb: 25m + 10m per shell inch Other Variables: Mortar angle Wind speed & direction Shell spin Mortar type (esp. steel) Note: Normal safety distances do NOT account for disrupted racks 4” Shell

Fireworks: Shells Calculating Distances 4” Shell – 100m burst diameter, burst at 6m, 230m from launch Mortar fallen to 75 degrees from vertical

Fireworks: Fuse & Igniters PIC Green / Brown WASAG Pipe Match (“green”) Electric matches (“dets”)

Don’t forget: Torch and Several lighters! PPE Clothing Hard Hat Eye protection Ear protection (or not) Gloves (or not) Don’t forget: Torch and Several lighters!

A Firework Show Planning the Event Site Visits Safety Distances Roads, Buildings, Airports Responsibilities Event Organiser Marshalling requirements Notification: Police, Fire, CAA (and any other affected parties) Budget etc. Method Statement Risk Assessment

A Firework Show Planning the Display Check material (if possible) Firing Order Equipment Requirements Racks, boxes, boards etc. Material Preparation Fusing Waterproofing Transport ADR

A Firework Show Site Setup Drop Zone Event Organiser Safety Distances Wind Direction Perimeters and Marshalling Layout in firing order Site fusing / wiring Shells Large Cakes Candles Small Cakes Set Pieces Audience

A Firework Show Site Setup Driffield Showground – 24th June 2006

A Firework Show Site Setup Hull University Union – May 2004

A Firework Show Firing the Display Firing Order “Gaffer” Walk-thru Decision to fire Keep lookout Check for ‘duds’ Clearing Up

Lots of links at Fireworks magazine site: More Information: www.hse.gov.uk www.dti.gov.uk/fireworks/ Lots of links at Fireworks magazine site: www.eig.org.uk www.fireworks.co.uk www.bpa-fmg.org.uk Training courses www.kimboltonfireworks.co.uk www.fantasticfireworks.biz

Outdoor Demonstrations Example equipment Types of fuse Black Powder and confinement Fire Fighting