1. 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…

2. 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…

3. 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.

4. 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

5. 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

6. 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

7. 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)

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

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

10. Black Powder Grain Burn

11. Black Powder Deflagration

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

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

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

15. Some types of Firework

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

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

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

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

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

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

22. Fireworks: Cakes “Multi-shot Battery”

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

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

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

26. 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

27. 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

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

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

30. 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!

31. 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

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

33. 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

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

35. A Firework Show Site Setup
Hull University Union – May 2004

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

37. Lots of links at Fireworks magazine site:
More Information:
Lots of links at Fireworks magazine site:
Training courses

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