Monday, September 8, 2008

Some suggestions for Fireworks Display Material Use

Shell Batteries / Shell Strings

These are generally used for 75mm. and 100mm. shells fired in sequences. They are usually used in groups of 6 shells for 75mm, and 5 for 100mm.

shells.


Such sequences are normally placed in racks specially designed for the purpose.

This allows the shells to be fused together, normally with a time delay between each shell using green PIC. Certain Maroons must not be placed in racks. Always load into individual tubes.


The racks must be secured using wooden stakes or steel pins. If using steel pins

(road pins) or angle irons, then the sledge or club hammer must be protected from the pin to avoid sparks - a piece of cardboard or wood should be sufficient for the purpose. Non- ferrous hammers are available, but are extremely expensive and difficult to procure. If setting up close to where other fireworks have already been prepared, consider placing all the stakes out before fixing the tubes.

Make sure that all fuses are protected whilst securing the stakes and that the racks are angled away from the spectators.


All match fuses must be secured to the top of the mortar tube to prevent it being lifted off by an adjacent shell when fired. This can be difficult to achieve on plastic tubes as they tend to stay damp. In such cases wipe them dry with a rag or paper towel beforehand.

To secure the shell leaders (quickmatch leaders) to the racks use wooden battens tied down using nylon zip ties to pinch the leaders onto the rack frame. You can also use a zip ties on individual leaders, but when using a larger number of shells this is fiddly and time consuming so the former is usually preferred. Another method is to tape the leader down, but this is usually a last option and used if zip ties etc run out as the tape tends not to stick to the racks, but is useful when attaching leaders to the cardboard tubes, simply ensure the surface is as clean as possible giving the tape chance to stick well.


Never use a Stapler to secure shell leaders onto a wooden frame; this can result in premature ignition.


This applies to both batteries and single tubes as the quickmatch fuse can blow itself out when bent over the edge of tubes.


It is important to ensure that the brown paper quickmatch fuse is completely inside the mortar tube and covered as it is particularly sensitive to damp.

The paper fuse will need to be joined to a length of waterproof quickmatch which can be left outside the tube.


Some shells may be pre-fused at the factory. They must not be carried in the tubes in vehicles but unloaded before transport and re-loaded at the display site.


Maroons and Mines

Treat as for shells. Never put maroons in racks. They contain flash powder and if one blows the blast will destroy the whole rack.


Rockets

As a rule Britannia Fireworks do not use Single, Large Rockets in our Displays, but on occasion we are requested to do so. If the site is suitable etc.. we take into account the following :-


The major consideration when setting up rockets is that the empty tubes and sticks will not fall onto spectators. It may seem obvious but the crowd are going to be looking up into the sky! This is where the debris will come from.


Before any firework display it is vital that the wind direction is checked. This is particularly important when considering where to fire rockets. We have already made reference to the fact that rockets turn back into the wind. Plenty of space is required to fire them and an adequate “fall out zone” must be available.


Rockets should be set up in racks specially designed for the purpose. These can take the form of steel tubes welded onto a frame. One alternative is to construct a timber frame made from 1 ½ “ x 1” timber (38 x25mm). The sticks can then be dropped into such suitable guides as large screw eyes, saddle clips, staples of 12mm. diameter or plastic tubes set into spring clips.


Check first of all that the stick of the rocket is firmly fixed to the body and that the stick is not broken or split. Make certain that the rocket is free to rise with no obstructions.


Most rockets have fuse caps. These must be removed for fusing but delay this as long as possible to avoid damp. Rockets are very often fired in a sequence and will therefore need to be fused together. Use green fuse and secure this with tape to each rocket fuse. Be careful the green fuse does not fall away from the rocket as it burns.


Remember to remove all plastic waterproofing before firing rockets!


Rockets – Flights


These are smaller rockets which are fired in groups of 10 or more at the same time and may be fired from a metal cone, an 8” (200mm) tube or a specially constructed box.


Flights are fitted with instantaneous match fuse, unlike their bigger brothers which have delay fuses.


The method for fusing flights is to ensure that all of them fire together. A length of brown fuse or more commonly quickmatch is attached to two rocket fuses and a piece of green fuse is finally attached to the brown or quickmatch to act as the delay fuse. The spread of fire from each fuse will ensure that they will all fire simultaneously.


Roman Candles

Roman Candles, single


These fireworks must be securely fixed to a stake using at least 2 ties, or set firmly in sand or earth. It is important to make sure that they cannot topple as the balls of fire and effects are thrown to a considerable height. When using wire, care must be taken so as not to over tighten and restrict the bore of the tube.


These are very often used in pairs or groups of three to create spectacular effects in fans. In this case they should be fixed as before to specially constructed frames which are in turn attached to stakes. They should be angled away and fixed on the side furthest away from the spectators. If frames are used it will determine the angle of the candles automatically, but if in sand or earth then the maximum permitted angle from the vertical must be no more than 15 degrees.


Candles are fused together using quickmatch. The end of the quickmatch is exposed and is inserted into the open end of the candle. A further short length of black match is used in the end of the candle to aid ignition. All fuses are then secured to the candle using tape. All fuses are then brought to a central point and a 5 second delay using green fuse is finally connected.


Bundles of candles

Small Roman Candles can be tied together to form a bundle of 7 or 19. The bundle is tied together using strong tape or wire provided it is not too tight. These are then secured to a stake or special frame as previously described.


They are fused together by exposing the fuses and laying a generous quantity of black match over the top of them. A delay fuse is attached to the black match and then the top is completely covered with tape to waterproof the items, leaving only the green delay fuse exposed. These can also be linked to others.

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