Thunderbolt Sirens

People who live near me no doubt know what these are, even if they don't know them by name. I am talking about the old skool Air Raid / Civil Defense / Tornado sirens that are used during storms and tested the first Saturday of every month in this area. These sirens, made by Federal Signal, were pretty common between the time they came out in 1952, until they ended production in 1990. There were three major models, the 1000, the 1000T, and the 1003. Now, they seem to be a dying breed, and there is a good chance that they will eventually go extinct given that parts are no longer made for them.

The 1000 is a single tone, the 1000T two tone, and the 1003 is a two tone that allows individual tones to be played.

These sirens, specifically the 1000T, has the most glorious siren tone known to man. Hearing one of these babies leaves you little doubt that the world will be coming to an end soon. If my city was under nuclear attack, I wouldn't want to be warned any other way. Hell, using these things for tornadoes seems to be an insult to them.





The reason I am writing this is that they are thinning out. The siren closest to my house thankfully still is a 1000T*, but who knows how long it will be there. Given that parts are no longer made, it seems like if it dies it would be replaced with a newer model, probably the 2001 series (which are being made and seem to be quite common in the surrounding area). These new sirens have some advantages, but they just don't have the tone.

Even going back quite a few years, I always thought "our sirens sound better". The sirens in surrounding areas have been the newer variety, which generate a laughingly annoying high pitched shrill sound. I would not even acknowledge a coming nuclear holocaust via these things.

The way most of these sirens work is they have a decent sized air compressor (hence a "supercharged siren") that feeds a "chopper". The chopper is two concentric cylinders, one fixed, one moving, with a row of holes in both. As the moving cylinder spins, the holes alternatively line up and are blocked. Air from the compressor is forced through the holes when they are open, and blocked when they are not. The speed of rotation of the chopper determines the frequency. The Thunderbolt design uses 3 motors. One for the air compressor, one for the chopper, and one to rotate the horn. The air compressor is the fairly large box halfway up the pole. The frequency can be adjusted, and because of the separate air compressor somewhat independently of the output. This is in contrast to non supercharged designs, where lowering the frequency might reduce output (because the pressure is reduced as well). Sirens in a given area will not generally match up unless someone went out of their way to tune them. This just adds to their character, in my opinion.

There are a couple of factors in the secret to the sound of the 1000T. Perhaps the biggest is the fact that the 1000T is dual tone. It is a minor third in Just Intonation, certainly not a cheery pair of notes. Also, these sirens seem to be a fair amount lower in frequency than most newer designs. This significantly limits the shrillness, and to me, gives them far more authority. Another thing is the horn design. It is a long, slender exponential horn. Apparently, the throat of the horn is overloaded, distorting the base waveform which gives the sirens the brassiness they are known for. Annoyingly, you would almost think that most of this could be implemented in the modern sirens.

The newer models are a few DB louder, but I'll bet they can't be heard as well inside a building due to the higher frequency. Some might argue that the annoyingness of the newer models increases the chance people will react to them. I say that the erie tone of the Thunderbolts is much better; the new sirens might have a higher chance of being noticed, but the Thunderbolts have a higher chance of being noted. The newer models are supposed to be better on maintenance, which is why they are used. However, I see no reason that the improvements made to the newer models can't be made to the Thunderbolts. Alas, this was attempted in the 80s, and didn't sell.

Well, I think I have made my point. The Thunderbolt sirens are in fact glorious, and hopefully will be around for at least a little longer.

*I believe, it could be a 1003 but I have never heard separate tones from it. These were generally used as a separate signal for volenteer fire depts, which we do not have here in the city.

Why Led Zeppelin Need to do at Least One More Tour

To those I consider friends, it's no secret that Led Zeppelin are one of my favorite bands ever, certainly in the top five, and probably in the top two or three (my favorites do change over time and with my mood). And let's be frank, right now they are probably in the number one spot. I also think they are one of the greatest bands ever, regardless of anyone's personal taste for them. Whether you like them or not, you are a fool if you say they are not excellent at what they do. Actually, taking that into account, they probably are in my number one spot for both best band and greatest band. Some of the other artists I like are solo, like Jimi Hendrix, and while his band was certainly great, as a whole I think Zeppelin were better.

I strongly believe that Zeppelin should do at least one more major tour. Why? Well, the obvious is what I just stated, I love them and would kill to see them live. But it goes deeper than that. They broke up 2 years before I was born, and have performed minimal times since. As such, I have had virtually no chance of seeing them live, ever. If I had tons of money AND was lucky enough to win the ticket lottery, yes, I had a remotely minute chance of seeing them in 2007. I would like them to perform one last time, so that a new generation can enjoy their music in a live setting. But, the biggest reason is their age. They ain't exactly young, and won't be around forever. They could still do a tour at the present time. Yes, John Bonham is dead, and that is tragic. And yes, I suppose it isn't "really Zeppelin" without him. Filling his shoes is a challenge. But frankly, his son has shown himself to be a capable substitute, and it would be a great tribute to his father to take his place. And it isn't like John died a fighting cancer or anything, he literally drank himself to death. But the point is, three of the four original members are still around, and going strong. Jimi Hendrix's band? All three of the original members dead. Only one member of his second lineup (Band of Gypsys) survives at the moment. All fairly recent if memory serves. Robert and JPJ, on the other hand, have both been touring, and Jimmy wants to. JPJ and Jimmy both want to reunite the remaining members, but Robert is being difficult. I can see his side, but see mine.

The concert they did in 2007 was awesome. Yeah, they weren't as good as the old days, but they still rocked. FAR better than some others of their age (cough cough The Who) and better than many current bands. Robert's voice ain't half bad considering. He can't quite hit all those high notes anymore, but really he sounded pretty good. Jimmy frankly sounds 100 times better than he did in the early 80s before he got clean.

Jimmy is the brains behind the group, and my favorite member. I would honestly settle for him touring with a Robert Plant sound-alike playing old Zeppelin tunes. If JPJ is in on it, even better. I'd really like to see Robert get off his damn high horse, but that doesn't look like it is gonna happen.