1.2 Fireworks Types and Performance
The design and construction of some of the commonest types of fireworks are given with emphasis on the safe use of fireworks. 1st Galaxy Fireworks Ltd believe that by understanding the basic principals behind the design and construction it will be easier for you to understand and appreciate what they do and to assess their suitability for a given firework display.
Types
The main types of firework used for displays are listed and briefly described below. The names are taken from BS 7114, 1988 under Categories 2, 3 and 4. It must be realised, however, that fireworks may appear under a variety of names, and that they may be described by different generic names within the industry. The only sure way to identify a firework type is by reading the accompanying instructions for use, and a description of the effects.
Also, within the various types, individual fireworks can vary greatly in size, power, and performance.
Bangers
This is a tube containing an explosive composition which produces a single loud report when ignited.
1.2g Gerbs, Drivers and Motors
They can all be described as being from the same family although they are different in their application. How they operate depends on the burn rate and the choke size.
They consist of a tube containing a composition which produces a fountain-shower of sparks and flames, in varying forms and colours usually silver or gold. There may be some sound effect, but not a report. Within this group you can find:
1.2g/h Fountains, Bouquets of Fountains
Fountains are designed to project ornamental and brilliant sparks into the air much like a water fountain.
The composition which is rammed or pressed into the case burns progressively down the tube. The height of the fountain is controlled by the choke. If the diameter of the choke is smaller, the fountain effect reaches higher.
1.2h Wheels
The thrust produced by one or more choked gerbs when attached to a pivoted
piece of wood or a wheel fixed centrally to give a rotating effect. Burning takes place from one end of the firework to the other and provides up to 30 seconds of constant force-called “the driver”. If connected in series could produce 60 seconds burning or more. Where a wheel is set up to rotate in a horizontal plane, this is known as a cascade.
1.2 h Flying Saucers (Crown Wheels)
These are wheels fixed over a spindle in a similar manner to cascades. The wheel is rotated by drivers to spin it and then additional rocket motors lift it in to the air. They need a great deal of space as they can develop a wobble and could travel in unpredictable directions. Bigger ones have a double lift which allows it to lower down and then gain height before burning out.
1.2d Rockets
All rockets, irrespective of size have four main characteristics: i) they have their own propellant charge ii) that this charge is contained in a cartridge or case iii) that this case is fitted with a choke or venturi, iv) that the rocket is fitted with a flight stabilising device.
The rocket is propelled by compacted gunpowder burning over a formed surface (usually a cone with a hollow centre) and the rapid rate of burn (5secs) and thus the large volume of gas quickly created is forced out of a clay, or more usually aluminium, choke or venturi. This provides the force necessary to lift the rocket quickly into the air.
(Flight rockets are of more traditional construction with cardboard case, clay choke and black powder charge).
The head of the rocket (the pot or Star Chamber) contains the stars or other effects and the bursting charge of gunpowder or flash powder. The burning motor flashes to ignite the content of the pot when the rocket reaches the highest trajectory.
The stick of the rocket stabilises its flight.
These fireworks are amongst the most potentially dangerous in a display
The stick and the spent case are going to return to Earth and so the launching tube or frame should be angled away from spectators. In this respect allowance should be made for wind speed and direction and checked again before the display is fired.
It should also be understood that a rocket will have a tendency to turn into the wind. This is because the effect of the wind against the stick is greater than that of the motor and pot.
If a rocket is fired down wind from the spectators it will turn back towards them. Remember this: Allowance MUST be made when considering “fall out zones”.
Wednesday, August 20, 2008
Tuesday, August 19, 2008
Fuse Types, Characteristics and methods of Joining: Part 3
GREEN PLASTIC IGNITER CORD
This fuse burns slowly, at about 25mm (1inch) per second. It is normally used to provide delays at ignition points and in sequences. It sometimes serves as the initial point of ignition for the fireworks.
Connecting green to green is done by twisting 25mm. or so and taping, green to quickmatch by inserting at least 25mm into the core and taping, quickmatch to green by stripping the plastic sleeve (to aid the transmission of the flame use tape wrapped around the plastic sleeve which when pulled back reveals the brown core) and inserting the incendiary into the central core of the quickmatch and then tying with a cable tie if required and/or tape.
BROWN PLASTIC IGNITER CORD
May be worked in a similar fashion to green, however it has a considerably faster burning rate and to avoid confusion should be kept away from the general fusing process unless specifically required.
Other Fuse Joints (Spanish Delays and Pressed Delays)
You can either have a fuse join that finishes at the delay in which case simply reveal 25mm or so of the Quick Match, place this is the end and secure using a cable tie or string. If you wish to join a number of varied time delays together to create several delays from one line of Quick Match then fold the quick match over and cut the end to reveal the internal fuse as shown above.
Once you have done this place the double strand in (exposed end first) and secure in using a cable tie or string.
These fuses can be used to provide delays between sequences of various items or used as a method of delaying shell in the same way as using PIC. Delays are generally more accurate but are more costly, but the benefits can out way when firing to music etc. You must also remember that pressed delays in particular can burn quite viciously and this must be considered when securing them down due to unwanted burning to surrounding fuses, other items and even wooden racks
Safety Considerations When Fusing
The following points must be taken into consideration with regard to fusing before you arrive on site:-
Fusing away from the workshop may only take place on the site of the display,
even though more than one day may be required to prepare the fireworks.
If the weather is poor and you require shelter, fusing may only take place inside a tent or cover of light fabric material or vehicle with a light fabric roof – never in a building.
Only use proper supplied cardboard / fibreboard tubes, high performance
polyprene or UPVC tubes for mortars and shells. Never use steel pipes or
lightweight drainpipes (they also sweat).
Handle quickmatch with care. Cut off what you need and put the rest of the bundle back into the storage container.
When joining quickmatch avoid cutting the incendiary cores. Where cuts must be made, only sharp scissors, nips or very sharp knife may be used. Do not tear fusing apart.
Keep all fusing dry and generally consider total waterproofing of the fireworks display. Bases of buried cardboard tubes should be bagged, open ends of tubes covered with foil or bags secured with rubber bands or tape, cake boxes covered with polythene, flights with thin aluminium foil (which must be taped down to prevent it being dragged off with the first rocket), candles wrapped with polythene etc.
Remember to remove waterproofing from rockets before firing!
Secure all joins so that they cannot be snatched either by accident or during
ignition.
Never use staples to secure fusing. Always use battens with cable ties or the cable ties themselves tape to secure them to the Shell Frame, tape can also be used (gaffer tape) but tends to be less reliable and the PIC can rip stopping the sequence
Do not set green cord along a surface and then cover in tape as it will burn more quickly.
Keep the work site tidy.
Friday, August 15, 2008
Fuse Types, Characteristics and methods of Joining: Part 2
Work on fireworks is only permitted, by law, at a Licensed Factory or on the site of a display.
As much as possible should be carried out at the factory, before going to the site. This has the advantage of working at licensed premises away from the public, and having a good supply of materials to hand.
Wherever you are working, bear the following in mind:-
No smoking, no drinking, no unauthorised use of drugs
Keep the work area tidy, clean up as you go
Use the correct tools for the work
Keep all fireworks not being worked on in covered boxes away from the work area.
Move prepared pieces away from the work area, set them up if possible.
Maintain minimum safety distances at all times. If on site, erect the barriers and keep the public away
Keep track of your tools and sundry materials such as fusing. It is easier to find these in daylight before the firework display than later on in the dark afterwards.
Keep fuses in a suitable container at all times. Handle them as little as possible.
If the prepared pieces are in any risk of becoming damp, they must be protected as an on-going task.
Quickmatch
This usually comes attached to certain shells in the form of plain brown paper and is not waterproof (unless plastic covered quick match is used and tends to be more popular these days). Working quickmatch usually comes in blue, brown or red plastic sleeves but other colours are available. It can be either single or double stranded or multi – cored. It burns at about 15m (50ft) per second and can be treated as instantaneous for practical purposes.
The core is very sensitive and must always be well protected by the sleeve. The waterproof sleeved type burns very violently and must be well tied to any connecting fuse. It must also be well secured to stop it thrashing or blowing away.
All quickmatch burns explosively and the pressure wave that precedes the flame can blow out connecting fuses if they are not well secured by tying with string or tape. It has been known, however, for quickmatch to be extinguished if it is bent too tightly onto a hard object e.g. lip of a mortar tube or cable tie.
Connect quickmatch by exposing the cores and placing in contact. Secure and join by tying and/or taping. Ensure that NO match is left exposed. Alternatively, the core can be connected by inserting into a hole pierced into the sleeve and securing well. Make sure that the core is in contact with the match core and not insulated between layers of the sleeve. Joins should be made “downward” to allow surface water to run off rather than run in. Gaffer or plastic tape should be used to waterproof the joint.
Quick Match to Quick Match – cut open as shown using sharp Stanley knife as shown on the left, then repeat as on the right, then overlay and tape together.
Quick Match to Quick match side joint – cut open each end as shown using a sharp Stanley knife, overlay the strands and tape as shown.
Shell linking is normally done with green plastic igniter cord (PIC) as a delay timer connecting the quickmatch fuses to each other. Keep the main run continuous, with a twist at each connection. The twist can be pushed into the open end of the match and taped over. Alternatively, a pressed powder delay can be used between adjacent shells. It is only used where more accurate timing is required (a Pyro musical or competition).
Shell linking using PIC Green –
Twist the PIC relative to the shell leaders’ placement (which gives the delay between each shell time over distance) then place in the leader and tape over the end to make watertight and secure. Or fold the match strands over the PIC and tape as in the picture above.
Quick Match to PIC -
To link Quick Match to PIC match you MUST strip the plastic coating off to ensure that the quick burning characteristics of the Quickmatch do not go out before lighting the PIC, removing the cover makes it more sensitive to heat/fire in order to transmit the burning successfully.
As much as possible should be carried out at the factory, before going to the site. This has the advantage of working at licensed premises away from the public, and having a good supply of materials to hand.
Wherever you are working, bear the following in mind:-
No smoking, no drinking, no unauthorised use of drugs
Keep the work area tidy, clean up as you go
Use the correct tools for the work
Keep all fireworks not being worked on in covered boxes away from the work area.
Move prepared pieces away from the work area, set them up if possible.
Maintain minimum safety distances at all times. If on site, erect the barriers and keep the public away
Keep track of your tools and sundry materials such as fusing. It is easier to find these in daylight before the firework display than later on in the dark afterwards.
Keep fuses in a suitable container at all times. Handle them as little as possible.
If the prepared pieces are in any risk of becoming damp, they must be protected as an on-going task.
Quickmatch
This usually comes attached to certain shells in the form of plain brown paper and is not waterproof (unless plastic covered quick match is used and tends to be more popular these days). Working quickmatch usually comes in blue, brown or red plastic sleeves but other colours are available. It can be either single or double stranded or multi – cored. It burns at about 15m (50ft) per second and can be treated as instantaneous for practical purposes.
The core is very sensitive and must always be well protected by the sleeve. The waterproof sleeved type burns very violently and must be well tied to any connecting fuse. It must also be well secured to stop it thrashing or blowing away.
All quickmatch burns explosively and the pressure wave that precedes the flame can blow out connecting fuses if they are not well secured by tying with string or tape. It has been known, however, for quickmatch to be extinguished if it is bent too tightly onto a hard object e.g. lip of a mortar tube or cable tie.
Connect quickmatch by exposing the cores and placing in contact. Secure and join by tying and/or taping. Ensure that NO match is left exposed. Alternatively, the core can be connected by inserting into a hole pierced into the sleeve and securing well. Make sure that the core is in contact with the match core and not insulated between layers of the sleeve. Joins should be made “downward” to allow surface water to run off rather than run in. Gaffer or plastic tape should be used to waterproof the joint.
Quick Match to Quick Match – cut open as shown using sharp Stanley knife as shown on the left, then repeat as on the right, then overlay and tape together.
Quick Match to Quick match side joint – cut open each end as shown using a sharp Stanley knife, overlay the strands and tape as shown.
Shell linking is normally done with green plastic igniter cord (PIC) as a delay timer connecting the quickmatch fuses to each other. Keep the main run continuous, with a twist at each connection. The twist can be pushed into the open end of the match and taped over. Alternatively, a pressed powder delay can be used between adjacent shells. It is only used where more accurate timing is required (a Pyro musical or competition).
Shell linking using PIC Green –
Twist the PIC relative to the shell leaders’ placement (which gives the delay between each shell time over distance) then place in the leader and tape over the end to make watertight and secure. Or fold the match strands over the PIC and tape as in the picture above.
Quick Match to PIC -
To link Quick Match to PIC match you MUST strip the plastic coating off to ensure that the quick burning characteristics of the Quickmatch do not go out before lighting the PIC, removing the cover makes it more sensitive to heat/fire in order to transmit the burning successfully.
Work on fireworks is only permitted, by law, at a Licensed Factory or on the site of a display.
As much as possible should be carried out at the factory, before going to the site. This has the advantage of working at licensed premises away from the public, and having a good supply of materials to hand.
Wherever you are working, bear the following in mind:-
No smoking, no drinking, no unauthorised use of drugs
Keep the work area tidy, clean up as you go
Use the correct tools for the work
Keep all fireworks not being worked on in covered boxes away from the work area.
Move prepared pieces away from the work area, set them up if possible.
Maintain minimum safety distances at all times. If on site, erect the barriers and keep the public away
Keep track of your tools and sundry materials such as fusing. It is easier to find these in daylight before the display than later on in the dark afterwards.
Keep fuses in a suitable container at all times. Handle them as little as possible.
If the prepared pieces are in any risk of becoming damp, they must be protected as an on-going task.
Quickmatch
This usually comes attached to certain shells in the form of plain brown paper and is not waterproof (unless plastic covered quick match is used and tends to be more popular these days). Working quickmatch usually comes in blue, brown or red plastic sleeves but other colours are available. It can be either single or double stranded or multi – cored. It burns at about 15m (50ft) per second and can be treated as instantaneous for practical purposes.
The core is very sensitive and must always be well protected by the sleeve. The waterproof sleeved type burns very violently and must be well tied to any connecting fuse. It must also be well secured to stop it thrashing or blowing away.
All quickmatch burns explosively and the pressure wave that precedes the flame can blow out connecting fuses if they are not well secured by tying with string or tape. It has been known, however, for quickmatch to be extinguished if it is bent too tightly onto a hard object e.g. lip of a mortar tube or cable tie.
Connect quickmatch by exposing the cores and placing in contact. Secure and join by tying and/or taping. Ensure that NO match is left exposed. Alternatively, the core can be connected by inserting into a hole pierced into the sleeve and securing well. Make sure that the core is in contact with the match core and not insulated between layers of the sleeve. Joins should be made “downward” to allow surface water to run off rather than run in. Gaffer or plastic tape should be used to waterproof the joint.
As much as possible should be carried out at the factory, before going to the site. This has the advantage of working at licensed premises away from the public, and having a good supply of materials to hand.
Wherever you are working, bear the following in mind:-
No smoking, no drinking, no unauthorised use of drugs
Keep the work area tidy, clean up as you go
Use the correct tools for the work
Keep all fireworks not being worked on in covered boxes away from the work area.
Move prepared pieces away from the work area, set them up if possible.
Maintain minimum safety distances at all times. If on site, erect the barriers and keep the public away
Keep track of your tools and sundry materials such as fusing. It is easier to find these in daylight before the display than later on in the dark afterwards.
Keep fuses in a suitable container at all times. Handle them as little as possible.
If the prepared pieces are in any risk of becoming damp, they must be protected as an on-going task.
Quickmatch
This usually comes attached to certain shells in the form of plain brown paper and is not waterproof (unless plastic covered quick match is used and tends to be more popular these days). Working quickmatch usually comes in blue, brown or red plastic sleeves but other colours are available. It can be either single or double stranded or multi – cored. It burns at about 15m (50ft) per second and can be treated as instantaneous for practical purposes.
The core is very sensitive and must always be well protected by the sleeve. The waterproof sleeved type burns very violently and must be well tied to any connecting fuse. It must also be well secured to stop it thrashing or blowing away.
All quickmatch burns explosively and the pressure wave that precedes the flame can blow out connecting fuses if they are not well secured by tying with string or tape. It has been known, however, for quickmatch to be extinguished if it is bent too tightly onto a hard object e.g. lip of a mortar tube or cable tie.
Connect quickmatch by exposing the cores and placing in contact. Secure and join by tying and/or taping. Ensure that NO match is left exposed. Alternatively, the core can be connected by inserting into a hole pierced into the sleeve and securing well. Make sure that the core is in contact with the match core and not insulated between layers of the sleeve. Joins should be made “downward” to allow surface water to run off rather than run in. Gaffer or plastic tape should be used to waterproof the joint.
Work on fireworks is only permitted, by law, at a Licensed Factory or on the site of a display.
As much as possible should be carried out at the factory, before going to the site. This has the advantage of working at licensed premises away from the public, and having a good supply of materials to hand.
Wherever you are working, bear the following in mind:-
No smoking, no drinking, no unauthorised use of drugs
Keep the work area tidy, clean up as you go
Use the correct tools for the work
Keep all fireworks not being worked on in covered boxes away from the work area.
Move prepared pieces away from the work area, set them up if possible.
Maintain minimum safety distances at all times. If on site, erect the barriers and keep the public away
Keep track of your tools and sundry materials such as fusing. It is easier to find these in daylight before the display than later on in the dark afterwards.
Keep fuses in a suitable container at all times. Handle them as little as possible.
If the prepared pieces are in any risk of becoming damp, they must be protected as an on-going task.
Quickmatch
This usually comes attached to certain shells in the form of plain brown paper and is not waterproof (unless plastic covered quick match is used and tends to be more popular these days). Working quickmatch usually comes in blue, brown or red plastic sleeves but other colours are available. It can be either single or double stranded or multi – cored. It burns at about 15m (50ft) per second and can be treated as instantaneous for practical purposes.
The core is very sensitive and must always be well protected by the sleeve. The waterproof sleeved type burns very violently and must be well tied to any connecting fuse. It must also be well secured to stop it thrashing or blowing away.
All quickmatch burns explosively and the pressure wave that precedes the flame can blow out connecting fuses if they are not well secured by tying with string or tape. It has been known, however, for quickmatch to be extinguished if it is bent too tightly onto a hard object e.g. lip of a mortar tube or cable tie.
Connect quickmatch by exposing the cores and placing in contact. Secure and join by tying and/or taping. Ensure that NO match is left exposed. Alternatively, the core can be connected by inserting into a hole pierced into the sleeve and securing well. Make sure that the core is in contact with the match core and not insulated between layers of the sleeve. Joins should be made “downward” to allow surface water to run off rather than run in. Gaffer or plastic tape should be used to waterproof the joint.
Quick Match to Quick Match – cut open as shown using sharp Stanley knife as shown on the left, then repeat as on the right, then overlay and tape together.
Quick Match to Quick match side joint – cut open each end as shown using a sharp Stanley knife, overlay the strands and tape as shown.
Shell linking is normally done with green plastic igniter cord (PIC) as a delay timer connecting the quickmatch fuses to each other. Keep the main run continuous, with a twist at each connection. The twist can be pushed into the open end of the match and taped over. Alternatively, a pressed powder delay can be used between adjacent shells. It is only used where more accurate timing is required (a Pyro musical or competition).
Shell linking using PIC Green –
Twist the PIC relative to the shell leaders’ placement (which gives the delay between each shell time over distance) then place in the leader and tape over the end to make watertight and secure. Or fold the match strands over the PIC and tape as in picture 3.
Quick Match to PIC -
To link Quick Match to PIC match you MUST strip the plastic coating off to ensure that the quick burning characteristics of the Quickmatch do not go out before lighting the PIC, removing the cover makes it more sensitive to heat/fire in order to transmit the burning successfully.
Quick Match to Quick Match – cut open as shown using sharp Stanley knife as shown on the left, then repeat as on the right, then overlay and tape together.
Quick Match to Quick match side joint – cut open each end as shown using a sharp Stanley knife, overlay the strands and tape as shown.
Shell linking is normally done with green plastic igniter cord (PIC) as a delay timer connecting the quickmatch fuses to each other. Keep the main run continuous, with a twist at each connection. The twist can be pushed into the open end of the match and taped over. Alternatively, a pressed powder delay can be used between adjacent shells. It is only used where more accurate timing is required (a Pyro musical or competition).
Shell linking using PIC Green –
Twist the PIC relative to the shell leaders’ placement (which gives the delay between each shell time over distance) then place in the leader and tape over the end to make watertight and secure. Or fold the match strands over the PIC and tape as in picture 3.
Quick Match to PIC -
To link Quick Match to PIC match you MUST strip the plastic coating off to ensure that the quick burning characteristics of the Quickmatch do not go out before lighting the PIC, removing the cover makes it more sensitive to heat/fire in order to transmit the burning successfully.
Wednesday, August 13, 2008
Fuse Types and Methods of Joining - Part 1
Below we describe the types of fuses and burn speed used in modern day fireworks. This is very helpful to know especially when it comes to firework safety and firework displays.
Types and varieties of fuses
Fuses are lengths of explosive material, mostly in the form of a thin tube containing the material, used to transfer ignition from the firing point, at a safe distance, to the firework device. They can be linked or joined to carry ignition through branches from one initiation point to several fireworks, or from one firework to another. There are two basic types of fuse-
Types and varieties of fuses
Fuses are lengths of explosive material, mostly in the form of a thin tube containing the material, used to transfer ignition from the firing point, at a safe distance, to the firework device. They can be linked or joined to carry ignition through branches from one initiation point to several fireworks, or from one firework to another. There are two basic types of fuse-
· Instantaneous: These transfer the combustion at high speed, at many metres per second. This allows the simultaneous firing of several dispersed items from the same point.
· Delay: These transfers the combustion at a slower rate, to introduce a delay effect, e.g. a series of items connected by delay fuse can be fired in sequence at Predetermined intervals. They are designed to burn at different speeds, according to type. Thus any required time delay can be achieved by a combination of the fuse type, and the length of the run.
Fuse Types
There are many different types of fuse found on fireworks, some of the most common types are explained below:-
QUICK MATCH is the commonest fuse to ignite fireworks. These can be single stranded, double or multi – cored. Ordinary black match is made by impregnating a string with black powder slurry. Once dried it burns readily and relatively slowly. When encased in a plain paper or waterproofed paper ‘tube’, however, the rate of burn becomes practically instantaneous.
A protective cap should be provided to prevent accidental ignition when incorporated into a firework and these can come in differing colours. Quickmatch as obtained for general use does not normally have covers.
PW6 (Slate blue) is manufactured the same way as green, looks similar but is a slate blue. Burns slower however, about 4 secs per inch (25mm) or 172 sec/m.
SPANISH DELAYS Look similar to Pipe Cleaners, constructed from a plastic or fabric outer, this covers a centre core of composition that burns at a constant and accurate rate. These are cut to size according to the length of time required. Spanish Delays are available in all time sequences from 1 second to 1 minute, and more if required..
TAPEMATCH is made by pouring black powder onto the centre of the sticky side of the adhesive tape (sellotape) forming a continuous narrow strip of fuse. Used essentially in the creation of lancework
Summary of Burning Rates:
Quickmatch Instantaneous
Tapematch Instantaneous
PIC Brown 1 sec per foot (3.3sec per metre)
Wasag Green 7 sec per foot
PIC Green 12 sec per foot (1 sec per inch/25mm approx)
PIC Blue 15 sec per foot (1-1/4 per inch)
Bickford 30 sec per foot (variable)
PW6 Slate blue 53 sec per foot (4 secs per inch)
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