Most readers know something about the No- match system for firing fronts, b u t it's not clear that everyone u n d e r s t a n d s how it is actually used in prepping a show, nor its benefits. Nomatch is an ignition system t h a t u s e s the ultra fast signal speed (6500 ft./sec.) of shock tube to distribute an internal non-destructive, bright light shock signal along the 1/8" diame- ter plastic t u b e to terminate inside a Nomatch all purpose igniter (API). These igniters are 5/32" o.d.. x 3/4" long a l u m i n u m t u b e s specially crimp connected to various lengths of shock tube leaders. The a l u m i n u m t u b e s are first formed with an air tool to close one end, then charged with a small a m o u n t of ignition pow- der, and t h e n crimped onto the shock tube out- p u t end. The new a t t a c h m e n t crimping tool (recently designed for 1999) improves overall performance, prevents powder from leaking back into the shock t u b e , a n d eliminates the vent hole of the older version API. By eliminat- ing the vent hole of the older design API, any possible contamination of the shock signal p a t h by foreign material entering the vent hole, is eliminated. Also, removing the vent allows for 100% of the shock energy to concentrate inside the API, improving performance a n d reliability. The user inserts the API into the black powder, or quickmatch of the device to be ignited. Suc- cess h a s also been found with directly inserting the API into clay chokes of gerbes a n d drivers that have a first fire ignition priming to receive the energetic s p a r k s of the API. This h a s only been tried on gerbes t h a t have a plastic end cap to hold the shock t u b e centered a n d secure. The API m u s t also be held tight inside the choke hole of the clay nozzle. The alternate method is to relay the API ignition into the gerbe with a short piece of quickmatch. The API functions instantaneously with the shock sig- nal, and performs m u c h like an electric match- head, producing a spit of flame a n d sparks. The API differs from an electric m a t c h h e a d in t h a t it is more energetic a n d the flame/spark tempera- ture is hotter at 3000°C.
Performance of all electric match-fired fronts is typically achieved by first prepping all fire- works devices of the front with electric matches inserted into the ignition element of the devices,
then taping a n d / o r tying the wires, etc. This work is usually accomplished days or weeks before the show at the fireworks shop. The front materials are t h e n carefully packed in shipping boxes a n d labeled, t h e n p u t away in a magazine until the display date. During field set-up of the display fronts, time consuming, a n d sometimes complex, wire connections are necessary, with circuit testing to finish the set-up. Electric m a t c h fronts also require special high voltage capacitive discharge type firing boxes to deliver enough energy to overcome total circuit resis- tance presented by series wiring of the match- h e a d s a n d cable wire. This presents a limit to the length of the front depending on the charge voltage of the CD box. Even with the highest voltage CD box available, there is a limit to the length of the front a n d the n u m b e r of electric m a t c h e s t h a t c a n be fired in series. Not so with Nomatch fired fronts.
Assembly of Nomatch fired fronts varies slightly b u t with great time savings benefits. As with the electric m a t c h fronts, shop preparation ahead of the display is also typical a n d neces- sary. Short lengths of shock t u b e leaders with attached API's are assembled to the front fire- works devices pretty m u c h the same as would be done with an electric m a t c h . In addition, soft silicone rubber couplers are attached to tees, and the shock t u b e leaders are t h e n plugged into the bottom leg of the plastic tee signal splitters. The shock t u b e is p u s h e d into the sili- cone rubber coupler until it touches the barb on the tee. Inexpensive, b u t necessary rubber finger covers for the index finger a n d t h u m b , are available in the Nomatch catalog. These fin- ger tip covers are u s e d to grip the slick surface of shock tube which allows for effortless inser- tion of shock t u b e into the rubber couplers. (This is a tool no one using Nomatch should leave home without. But if you do, they are available at all office supply stores). After the Nomatch API leaders are assembled to the front devices, they are packed into shipping boxes a n d p u t away in a magazine until the display date, j u s t as with electric matched devices. During field assembly of the display fronts, the tees (already assembled to the API shock tube leaders at the shop) are interconnected with shock tube taken from spools, again plugging
the e n d s of the interconnecting shock t u b e s all the way into t h e r u b b e r couplers until they bottom o u t against t h e b a r b on the tees. All connections a r e checked at this time to m a k e sure none of the API leaders have pulled back from the tees during previous handling. If the interconnection lengths between tees are prede- termined a n d known, shock t u b e t a k e n from spools c a n be precut at the shop with the e n d s capped with vinyl protection c a p s (available in the catalog). This is necessary to prevent dirt a n d moisture from contaminating the shock tube core load. Interconnection lengths longer t h a n a few feet should be done in the field to account for s e t - u p variances.
So where are the benefits with Nomatch?
The first benefit is realized in safety. Nomatch is i m m u n e to those sources of energy t h a t would have no problem igniting an electric m a t c h - head: induced c u r r e n t s from lightning, radio transmitters, stadium lighting switch gear, a n d transformers; stray c u r r e n t s from ground loops; friction from pulling on wires, impact from dropping shells; a n d electrostatics both in the form of induction from large fields on sheet plastic (or other sources) a n d conduction from electrostatic discharge of a charged body into the leg wires of an e-match. This first benefit grants peace of mind during storage, transpor- tation, a n d handling of assembled devices. If the front is to be fired with a Nomatch starter designed to take fire from an electric m a t c h (ES-24), the entire front c a n be set up as inert until it is armed with the insertion of the elec- tric m a t c h into the rubber coupler on the starter. The same is t r u e for non-electric h a n d fired fronts using the Nomatch fused starter (FS-24). The front is only armed a n d ready to go after the starter is assembled last.
The next benefit realized with using Nomatch is the labor a n d time savings during field set-up. A crew c a n set up a n d interconnect a Nomatch front in about half the time it takes to do the interconnections using wire on an all-electric m a t c h front. Nomatch interconnections are plug & play "no-brainers". No worry about high re- sistance poor wire connections, nor complex series/parallel resistance balancing calcula- tions on complex field layout patterns. No need for ohmmeter trouble tracing. Simply walk the line after set-up to make sure all connections are tight.
The next benefit is t h a t the entire front can be fired with one electric match-fired shock tube starter (ES-24) with a single cue on an ordinary firing panel. However, it is recommend t h a t two e-match starters be used; one on each end of the front, as cheap i n s u r a n c e against any missed or loose connections. On extra long fronts, a few electric match-fired starters are tee inserted into the line a n d equally spaced along the front. This is done to synchronize timing on fronts longer t h a n 2000 feet. The largest front reported to date by Disney World, h a s been 6,000 feet with fireworks every 10 feet, and using only 6 electric match-fired starters. It performed flawless. The shock t u b e signal takes 0.8 seconds to go a mile in one direction which is 5,280 feet. On t h e Disney front, a CD box was u s e d to fire the 6 electric m a t c h e s due to the high resistance of 6,000 feet of series wiring even though there were only 6 electric matches. T h u s for Disney, there were actually 5 fronts going at the same instant (e-match at each end, 4 in between). Therefore, the entire front fired in less t h a n 0.2 seconds, hardly an eye blink. Another benefit is t h a t the Nomatch system is waterproof after set-up in dry conditions. As- sembly m u s t never be done in the rain. Here, I m e a n the interconnections at tees a n d rubber couplers are waterproof should it rain after set- up is complete. The API a n d starter aluminum t u b e connections to shock t u b e are not water- proof. The API's are protected after placement into the fireworks devices, a n d these devices are normally covered with foil or plastic in the threat of rain. The starters m u s t be protected from rain by placing a small plastic bag over the starter assembly. The bag is t h e n gathered closed a n d taped against t h e shock tube. A stick is placed in the ground, a n d the assembly with plastic bag is taped to the stick s u c h t h a t the opening end of the bag faces down at the ground. This way, water cannot r u n down the shock t u b e a n d into the end of the bag, even if it is closed with tape. With Nomatch, there's no worry about u n i n s u l a t e d wire connections lay- ing in a puddle after a rain storm passes, thereby presenting a short circuit failure or ground c u r r e n t loops.
And there you have it! A full description of the Nomatch method of fronts a n d its benefits. A fi- nal note: think flights a n d salvos of shells; they work j u s t as well. WO