Fireworks Families & Types Part 3

Mines

These can be regarded as similar to shells in the method of use. The important distinction between them is that the firework element is ignited in the tube and is already burning when it exits the tube.

The effect of a mine is therefore instantaneous from the spectator’s viewpoint and always lower, although heights of 100 ft. may still be reached. These produce effects of stars, bombettes, whistles etc. Special care must be given when loading the bag type mines.

It is sometimes extremely difficult to distinguish the difference between some cylindrical mines and cylindrical shells and there are even some spherical mines.

Multi Shot Barrages or “Cakes”

These fireworks known affectionately as “cakes” are actually a collection of other categories of fireworks grouped together in boxes and produce stars, bombettes, whistles, spinners, etc.

They may vary in size from small packages up to large cardboard boxes which can be very heavy to handle.

A cake may contain anything from say 25 x 2.5”” shells in light tubes, 100 x 30mm maroons or even up to 1000 roman candles one shot in each tube.

They are extremely powerful so please be careful! They need to be set up very carefully, with particular attention paid to the surface upon which they stand and secured to a series of stakes. Cakes should always be angled away from spectators.

It is important to ensure that they are the right way up! It is not unknown for them to be labelled upside down or even the larger ones to be packed into their boxes upside down. Please take note !

Due to the size of some Cakes and the calibres used, we recommend moving them at least 50 metres, and in some cases even further (refer to 1^st Galaxy Fireworks Site Policy)

Cakes are boxes containing a number of separate items, fused together so that they are fired in sequence over some period of time, normally much longer than for a single firework. The items may be all of one kind, or a mixture, including small, shells, candles etc.

As with roman candles, once started, the firing continues automatically until the last item is reached.

Batteries are comprised of a number of fireworks, normally of the same type, grouped in a single layout, to be fired as a single unit, individually in sequence, or in any other combination. The effect is the same as from any one firework on its own, enhanced by sequential or multiple firing.

Set pieces

These fireworks are, as their name suggests, used to create a static effect. They can be in the form of waterfalls strung horizontally on string or poles, wheels, flying pigs, fountains or lancework e.g. “Good Night”. These are mini flares linked together with fuse and burn for about 60 secs.

Careful attention needs to be paid to setting these up in order to gain the maximum effect from them, especially with respect to their height. Care must be taken to ensure that the moving fireworks set off in the right direction initially.

Most set pieces are not dangerous if properly assembled, however keep these out of the firing line to avoid premature ignition, especially lancework which must be positioned up wind of the rest of the material on site.

Lancework is a set piece of a special type. They are made up from small fireworks set on a frame which burn simultaneously as individual points of light to present a continuing two-dimensional picture. The picture may be symbolic, such as a badge or crest, or in word form, such as “Good Night”.

More complex effects can be produced by creating different pictures in sequence on the same frame, to produce an impression of motion.

Fireworks Families & Types Part 2

Illumination Pots, Bengal Flares, Lances & Portfires

The compositions used are designed to be slow burning and are contained in light paper cases which burn away with the contents. The commonest encountered are the good old garden volcano, Portfires which are used for ignition purposes, and Lances which are used for making up “Good Night”s etc. Others can be illuminating or strobing, with a duration of anything between 60 seconds and 6 minutes.

Roman Candles

A more complex firework consisting of a tube containing pyrotechnic units alternating with propellant charges. When fired, the units are thrown into the air in sequence from top to bottom. Different effects are obtained by using successive units of varying colour and form. They may also produce sound effects during their trajectory, including a report at the end. Between successive projections, the candle may emit coloured sparks or flame directly from the body.

They are made up to 60mm calibre and can send stars up to nearly 200 ft. The candle must therefore be securely fastened to a stake or candle frame.

It should be noted that as each successive star has further to travel up the case of the candle, it takes longer to exit the tube and is therefore subjected to the lifting charge for longer. The quantity of gunpowder has to be progressively decreased to achieve the same height. Do not use damaged candles – there could be a blow out.

Whilst the styles or effects of roman candles have remained more or less unaltered throughout their history, there have been alterations in the method of activity of achieving the delay between the successive stars.

a) The original Ruggieri design utilised green mix gunpowder and these candles will emit showers of sparks between successive stars. It should be noted that with the exception of any tube products that may be used, all the products are consumed and there is little or no fallout.

b) Typical Chinese candles are used in vast quantities in the fireworks industry. Here a continuous fuse runs down the side of the tube and is designed to burn for the duration of the candle. The delay between successive stars is achieved by alternating them with loose plugs of potters clay. During the course of even a modest display, a considerable amount of clay is thrown into the air. Beware!

c) In recent Years 1^st Galaxy Fireworks Ltd have been using “Typical” Chinese Candles manufactured using similar ideas to the “Ruggieri Technique”, and showers are emitted between each shot, this has enabled slightly better timing and larger stars etc.

d) To overcome the problems of achieving synchronised firing, there have been two developments, the earliest being the substitution of the green mix delay with a felt plug with a pressed delay in the centre. These felt plugs return to Earth unburnt.

Shells

A firework shell is a hollow projectile containing an explosive charge. In Western Europe and the USA the shell may also have an attached lifting charge. It must be remembered that this practice is by no means universal and the presence of a lifting charge would not be considered a defining characteristic by firework technicians. (The presence of a propellant charge is considered a defining characteristic of a rocket!)

The shell is projected from a mortar tube by a charge of gunpowder (the lifting charge) to burst high in the air with whatever effect is incorporated in the shell.

The mortar tube may be made from cardboard, fibreboard or specific types of plastic.

The shells may be made from paper or plastic and are either spherical or cylindrical in shape. It is much easier to contrive multiple breaks or bursts with a cylindrical shell, whereas the spherical shells are required to produce spherical bursts, chrysanthemums, peonies.

Shells which explode with a loud report are called maroons or salutes

The diameter of shells used at 1^st Galaxy Fireworks Ltd are generally anything from 2” to 12” and come in two types:-

a) Bottom fused and

b) Top fused

Bottom fused shells have their lifting charge ignited first. This in turn ignites a delay fuse to the bursting charge.

Top fused shells are fitted with a delay fuse to the bursting charge with a secondary instantaneous fuse to the lifting charge. These are perhaps a little more reliable as there is less risk of the delay fuse being blown out. These tend to be more cylindrical in shape. Care must be taken when installing top fused shells to avoid damage to this lifting charge fuse. It is also essential to ensure that the shell, as with all shells, is inserted into the tube the right way up. Damaged shells should not be used.

Shells can be extremely dangerous if they are not handled and fired in the approved manner. The exit velocity of a shell from the mortar tube could be in excess of 200 mph!

To appreciate the height and effect of a shell, the following can be used as a rough guide

If ‘x’ is the calibre of the shell in inches,

The delay to full height is ‘X’ seconds,

The height reached is ‘X’ x 100 feet,

The spread of burst is ‘X’ x 10 metres.

This will not always apply, however it can be used as a guide for most shells.

Fireworks Families & Types

Fireworks Definitions

The design and construction of some of the commonest types of fireworks are given with emphasis on the safe use of fireworks. 1^st 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 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 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

A tube containing an explosive composition which produces a single loud report when ignited.

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.

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 may be found:

a. Fountains, Bouquets of Fountains

Fountains are designed to project ornamental and brilliant sparks into the air much like a water fountain.

The composition is rammed or pressed into the case burns progressively down the tube. The height of the fountain is controlled by the choke. The smaller the diameter of the choke, the higher the fountain effect.

b. 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.

c. 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.

d. 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 fuel flashes to ignite the content of the pot the instant 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”.

Pro Pyro Fireworks for the Enthusiast

So many people who buy Fireworks like to be able to get hold of something a bit special, a firework with WOW factor or even perhaps something which they shouldn’t get there hands on.

As so many of our Professional Fireworks Displays that we have done over the years we have been asked “where did you get that effect from”, or “can I buy Fireworks like those”. Well of course in most cases the answer is quite simply “No”.

The reason being so many of the fireworks we use in Professional Fireworks Displays are known as Category 4 Fireworks and are specifically for the use of Professionals and its Prohibited in Law that Members of the Public get their hand on them.

Well that got me thinking, another track I was considering at the same time was how we could get the most spectacular Fireworks on our shows whilst keeping under the Threshold of 1.4G, meaning the Fireworks where not 1.3G which in turn enables the movement and storage of fireworks to be made easy.

There are a number of factors that will determine weather a Firework is 1.4G as opposed 1.3G and its not always that the higher hazard (1.3G) is always more spectacular.

So as I thought about killing two birds with one stone (and not by blowing them up) I began to design, in my head, a range of Professional Grade Material that we could use, sell on to our Professional Trade Clients and from that I came up with a range of Cake Barrages and Rocket Volley’s that we now Call “Pro Pyro”.

The Pro Pyro range consists of lots of different Cake Tube Configurations and lots of Effects as well has a selection of small and medium volley’s (which are one of my favourite fireworks). We have loads of quiet effects, animated effects, louder fanned bombette effects and some speciality single effects, single colour and multi effect cakes all under the Pro Pyro brand and ethos.

Now we have the idea and the effects, colours and formations we worked on keeping them to 1.4G, in doing this using our knowledge of what our clients want, the law and the way in which fireworks are made we came up with really stunning fireworks which are Grade A and perfect for all manner of Fireworks Displays, very versatile and lots to choose from.

Well as luck would have it in most cases (not all) many of the Fireworks fitted the legal limitations for Category 3 meaning we could label them for Public Use and carry out the necessary BS7114 Tests for them and put them on sale to the Public.

Now we tested the market with a few last year and our Customers loved them, so please be on the look out this year as we will have even more in the Brochure