JSalisbury Posted August 11, 2013 Share Posted August 11, 2013 Hi,I attenended a major event a couple of times over the last few days. On two of the days they indicated the start of a race by letting off a "Cannon" this seemed to be a charge that had a bright flash and a retort so loud you could also feel it. The distance from the nearest members of the public was only about 10m, and the seperation was a close mesh nylon type fence. The audiance varied from adults to very young children. First time round they did not advise the people in the vincity what to expect. What is the permitted peak sound level for young children and what would have been best practice and so on?Thanks Link to comment Share on other sites More sharing options...
Ynot Posted August 11, 2013 Share Posted August 11, 2013 Sounds very much like some sort of maroon, but the recommendations for use and distance from punters depends entirely upon the make and type of effect in use. It seems unlikely that you will be able to find out what they were using after the event, but for some ideas you could look up some of the maroon data sheets on the LeMaitre site... Link to comment Share on other sites More sharing options...
JSalisbury Posted August 11, 2013 Author Share Posted August 11, 2013 Hi,I will take a look at the LeMaiter website but this had a chest thump as well as aloud bang.. so I wonder if it was some form of class 4 firework, as they had a profesional firework display later. Link to comment Share on other sites More sharing options...
Ynot Posted August 11, 2013 Share Posted August 11, 2013 One of Lincoln's favourite demos at his pyro safety courses is the range of theatrical maroons available. The small and medium are pretty loud on their own (in a suitable bomb tank) but the large and extra large etc can certainly and literally pack a punch..... Link to comment Share on other sites More sharing options...
Shez Posted August 11, 2013 Share Posted August 11, 2013 Whilst researching a couple of years ago, I found a maximum permissible peak level of 137dB. Unhelpful without more details of weighting etc I know. Whilst back at university, we wanted to use a maroon in a show - can't remember what or why. The powers that be expressed concern so we arranged to demo each of the sizes for them. This was arranged to take place in the grass quadrant in the middle of the main administration building. We worked our way up through the sizes. Within about three minutes, security staff from all over the campus had appeared... The presence of several Estates managers fortunately sent them away again. They decided that they were all too loud. Link to comment Share on other sites More sharing options...
mackerr Posted August 11, 2013 Share Posted August 11, 2013 Hi,I attenended a major event a couple of times over the last few days. On two of the days they indicated the start of a race by letting off a "Cannon" this seemed to be a charge that had a bright flash and a retort so loud you could also feel it. The distance from the nearest members of the public was only about 10m, and the seperation was a close mesh nylon type fence. The audiance varied from adults to very young children. First time round they did not advise the people in the vincity what to expect. What is the permitted peak sound level for young children and what would have been best practice and so on?Thanks I don't know what you do in the UK, but in the US this is the standard starter's cannon. It fires 10ga blanks and is very loud. This is the cannon that has started every sailing race I've attended or sailed in. Mac Link to comment Share on other sites More sharing options...
dbuckley Posted August 12, 2013 Share Posted August 12, 2013 Some years ago, as part of a re-enactment, I fired a Le Maitre outdoor maroon; I was in a van about 20m away, and had seriously underestimated just how loud this thing would be. All the other pyro was contextually appropriate, this thing was way OTT. Link to comment Share on other sites More sharing options...
alistermorton Posted August 12, 2013 Share Posted August 12, 2013 One of Lincoln's favourite demos at his pyro safety courses is the range of theatrical maroons available. The small and medium are pretty loud on their own (in a suitable bomb tank) but the large and extra large etc can certainly and literally pack a punch..... The oft repeated phrase "You're only supposed to blow the bloody doors off" springs to mind with the bigger sizes. Link to comment Share on other sites More sharing options...
kerry davies Posted August 12, 2013 Share Posted August 12, 2013 It would be impossible to be definitive but IMO, this should have been treated as a "display firework" since it was obviously not in a tank and the flash was as described. I would be minded to use the 25m for Cat3 and below mines as the HSG124 guidelines suggest. That does not mean that they were "wrong" in what they did, just my safety first attitude. The distances for Cat4 are in HSG123 I actually used a small theatrical maroon from a mock US Civil War cannon back in the day before guidance. The gaffa tape holding it in caught fire and a smoke ring shot the entire diagonal length of Cheltenham Town Hall. Never again! Link to comment Share on other sites More sharing options...
ImagineerTom Posted August 12, 2013 Share Posted August 12, 2013 Erm.... it could just have been an actual cannon. That would match the description of what happened/looked like/felt and they are surprisingly common objects with several hundred years of use. Link to comment Share on other sites More sharing options...
kerry davies Posted August 12, 2013 Share Posted August 12, 2013 Hmmm? (tm Ynot) Cannon which are capable of being fired with a bore of over two inches are firearms while those under two inch bores are regulated by shotgun laws. Re-enacters hold firearms/shotgun licences along with storage and carriage licences and generally use a minimum of 30 metres for blank firing safety zones. Checking with Le Maitre with the precise details, which we don't exactly know, seems optimal. Link to comment Share on other sites More sharing options...
Jivemaster Posted August 13, 2013 Share Posted August 13, 2013 Maroons exist in several loadings so until more is known about the specific device it's hard to define anything. Conventional sound meters are not used as the sound isn't a steady state it's a single pulse so all the A, B, C, etc weightings are not used either. Link to comment Share on other sites More sharing options...
Brian Posted August 13, 2013 Share Posted August 13, 2013 ...I found a maximum permissible peak level of 137dB.That's for employees. There is no 'official' limit for the public. Link to comment Share on other sites More sharing options...
JSalisbury Posted August 14, 2013 Author Share Posted August 14, 2013 Last time they used the flash bang thing a few years ago, they warned the crowd about 5 mins in advance how loud it would be and so if people wanted or needed to move away they could and did a count down and encouraging people to stick their fingers in their ears. The fence that time was a solid sectional steel panel fence, and out of curiosity I did look round the end of the fence and appeared to to be some kind of charge attached to a stand. This time there was none of the above and just the thin nylon mesh fence. I was not expecting it to be loud, and I did complain I had invited a friend to the event who thankfully didn't come who suffers very badly from Hyperacusis. If she had been been there I would have been very unhappy. It is also an event where there are a lot of small children and ironicly where they let the device off is a less croweded part and so tend to get children and infants on the fence line... There are also a lot of dogs and again I know of some that would have been quite upset by it. Link to comment Share on other sites More sharing options...
dbuckley Posted August 14, 2013 Share Posted August 14, 2013 Now you mention that, you've reminded me of a funny; at the above-mentioned re-enactment I was involved in, there was not far away a dog show, and when one of the cannons fired, a dog bolted, and a lady got a busted finger from the pull of the leash... Planning and preparation prevents... Link to comment Share on other sites More sharing options...
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