Last week was exciting…if you’re into pulling people out of wrecked cars. That is exactly what a few teams of firefighters from around the world were doing, organized as a competition, but in reality a live forum to exchange experiences and techniques. If you are ever involved in a serious car accident (MVA, RTA, or whatever denomination it has in your country!), these are the people that will pull you out. I took some photos and videos, these are a few from my Flickr album, the videos will come in a couple of days – enjoy (or not!).

Hampshire Fire & Rescue Service working on the extrication of a victim.

The tools of the trade – hydraulic jaws of life, as they are known, powered by portable pumps, they put on tons of pressure when cutting or spreading.

An upside down car with a side obstacle, this one was pretty tough, but well handled by the Bridgend South Wales Fire & Rescue team.

Royal Berkshire Fire & Rescue about to extricate a victim with a longboard. They completed the first task in the assigned 20 minutes, but could not get the second casualty out in time. Even though, a pretty impressive show.

Not quite sure where this team was from, but they got a very tough one, with a completely overturned vehicle.

Update: As I finished writing this, I noticed the competition results are out – here they are:

Overall

1st Hampshire F&RS, England
2nd Royal Berkshire, England
3rd Bridgend South Wales F&RS, Wales

Complex Class

1st West Yorksire F&RS, England
2nd Central Scotland F&RS, Scotland
3rd Bombers De La Generalitat, Spain

Standard Class

1st Hampshire F&RS, England
1st Royal Berkshire, England
3rd Crecsent Link, Northern Ireland

Rapid Class

1st Hampshire F&RS, England
2nd Central Scotland F&RS, Scotland
3rd Royal Berkshire, England

Best Team Captain

1st Bridgend South Wales F&RS, Wales
2nd Royal Berkshire, England
3rd Crecsent Link, Northern Ireland

Best Medic

1st Hampshire F&RS, England
2nd Royal Berkshire, England
3rd Consorcio Provincial Toledo, Spain

Best Technical

1st Hampshire F&RS, England
2nd Central Scotland F&RS, Scotland
3rd Royal Berkshire, England

Congratulations to all!

For the last week, a chocolate factory on a neighbor town has been burning down to the ground. After the first 24 hours, it seemed like the fire was under control, but nobody mentioned the hundreds of tons of highly caloric substances that were stored in the basement, under the factory floor, which was as large in surface as the factory itself. There was a single access ramp to this basement, which became blocked due to the initial fire’s debris, and so a wall breach was required. When this was done, the gulp of fresh air caused the latent fire below to erupt violently, completely burning the factory to a mass of twisted metal, and by radiation, the office building next to it.

The sad part is that the scene reminisces of ground zero at the World Trace Center after the terrorist attack of 9/11/2001. Here is a picture that shows part of the structure, click here to go to the full set on Flickr.

It took us a week to get the fire under control, which is the state you see in these photos. Fatty products, such as oils and cocoa butter, used in the production of chocolate as we buy it in stores, is not necessarily extremely flammable, but holds a huge amount of calories, which when set off are very difficult to control.

Today is a sad day for firefighters – six years ago, 343 brave men gave their lives to save thousands of others in the terrorist attack on the World Trace Center in Manhattan, New York. Never forget. Enough said.

They are usually forgotten, as they tend to see a lot less action than non-airport bound firefighters, but boy, do they have cool equipment to play with! Airport fire departments have some very tight performance parameters, basically, because when a huge piece of aluminium, titanium, passengers and fuel crashes and ignites on or near a runway, every second counts. That’s the reason this 40-ton baby accelerates from 0 to 80 Km/h (50mph) in around 25 seconds. In proportion to weight, this is faster than a 1997 McLaren F1, which hits 100 Km/h (60mph) in 3.3 seconds! And this is what it looks like:

The Rosenbauer Panther 8×8 MA5 airport and rescue firefighting vehicle. Sporting a 1000 hp engine (yes, that is not a typo), it carries 12.5 tons of water, 1.5 tons of foam liquid, and up to 1 ton of NP powder. Full specs here. Up to three monitors (two mounted at the front, one top) give it a range from 25 meters up to 85 meters, all controlled from the cabin with joysticks and cameras. At 11 bars of pressure, the top monitor can empty the water tank in two minutes. The cabin controls look like something out of Star Wars:

Note the complex MFD control system for the hydraulics – so much for turning a wheel and having water come out a hose, right? While I did part-time work at Southend Airport, I was able to ride and operate a much smaller, much simpler, but equally fun Carmichael truck. Will post a pic when I find it and scan it (film rolls back then, the only thing digital in cameras was your finger).

You probably have seen the video on YouTube about a molten Fonera, apparently due to overheating, which shows the plastic case completely deformed. Gizmodo (also in spanish) and other sites are also reporting on this. As usual, Fon has censored the post on their forums that broke the story, but alas, thanks to their partners at Google, here is a cached version. Even Martin Varsavsky seems worried about this. It seems the damage is obviously from heat, but could it have come from the Fonera itself?

I, and others, have our doubts about wether this video is a fake stunt, or a true story. It is true that the Fonera overheats, much more than would be expected from a consumer-electronics product, but to the point of causing physical damage to the plastic case?

The heat problem

Heat in electronics mostly comes from dropping voltage by converting current into it, in our case, the voltage regulator in the Fonera drops 5V to 3.3V at 500mA, resulting in the dissipation of 850mW. That’s right, we are dumping 850mW right into the atmosphere in the form of heat. This brings the operating conditions very close to the maximum ratings for this regulator, which has a maximum rated thermal resistance of 90ºC/W, my calculations put the operating conditions at 88ºC/W. Additionally, the wireless section of the Fonera is also converting a lot of energy into heat.

The measurements

After I finished my tests, I got a comment from Pobletewireless, regarding his own measurements of the heat problem, which are shown in very cool thermographs (no pun intended!) – much nicer than my rather rudimentary method.

I measured the temperature of the Fonera using a thermocouple connected to a Fluke 123 Scopemeter via an 80TK thermocouple module. The thermocouple was placed in between the heatsink and RF shield, the case closed, and the Fonera powered, as can be seen in this picture:

After 10 minutes operating normally, the temperature had risen to an average of 72ºC, with a peak of 80ºC.

The second batch of measurements were performed drilling four small holes to allow the thermocouple into the casing, the locations are shown in the following picture:

Maximum temperature at one corner was 43ºC. Next, an attempt was made to melt the white lid of the Fonera, by exposing it to a high temperature airflow from a paint-stripping gun, and at the same time, applying slight pressure from below. The thermocouple was used to measure at which point the plastic became maleable, and deformation started. At around 100ºC, the plastic was soft enough that a solid object could change its shape – this is in line with ABS plastic thermal properties, which state a deflection temperature around 100ºC, depending on specific material composition.

As the deflection point test resulted as expected, the lid was then exposed to an airflow at 280ºC for two minutes. The result of this exposure is shown in the pictures below:

It’s obvious that some deformation has taken place, with discoloration and charring on the point where heat was directly applied. However, the front side of the lid had mostly retained its shape.

Conclusions

The Fonera does indeed run very hot, much hotter than it should, if anything, for the good of the internal parts. Electronic components are sensitive to heat, with maximum ratings given by each manufacturer in terms of storage and operating conditions. The higher the temperature, the lower the service life of any given component. Some are affected more than others, most notably, electrolytic capacitors have a high sensitivity to heat, as it can evaporate the electrolyte quicker, causing it to fail. The capacitors in the Fonera are made by Taicon, a taiwanese manufacturer, and are max-rated for 105ºC. From the datasheet [PDF], at this temperature, the capacitor will fail after some 2000 hours, around 83 days. Following Arrhenius’ Law, and since the area around the capacitors was found to be at around 52ºC, their expected life would be 7800 hours, or about 325 days – what a coincidence, almost a full year, after which your warranty has expired. Comparing the Fonera to a Meraki Mini, one realises that there is a serious design flaw, as apart from the Mini having a switched-mode regulator, the wireless section shares exactly the same design as the Fonera. The temperature measured outside the casing of the wireless section indicates that the junction temperature of the components inside has to be ridiculously high. So, one conclusion is that the Foneras will eventually fail due to overheating, and it will probably happen sooner than later.

On the deformation / melting video – in my opinion, it’s not real. At least, it couldn’t have happened without the Fonera reaching temperatures around the whole casing that would have caused some components to blow up (for example, the capacitors). The Fonera could not have undergone such an extreme temperature, and still function as shown on the video. The temperature gradient between the heatsink and one corner of the case is almost 2:1, thus, to reach a deformation temperature of say 200ºC at the corner, the heatsink must have been running at 400ºC! A final bit of evidence – the sticker. If you look closely at the video, the sticker on the bottom of the Fonera looks almost unscathed. Here is a picture of what it looks like after applying a 250ºC airflow for 30 seconds, which causes the plastic to deform:

Obviously, a more prolongued exposure would have damaged it even more. In all honesty, I would love to get more details from the guy who made the video, as it stands right now, I’d call it a hoax.

This Christmas, we should be receiving a gift we have been waiting for over 20 years. Our volunteer Fire Department started with a 4-wheel-drive and a cart-mounted 100 gallon water tank, and has since progressed to become the proud owners of two large all-terrain pumpers and one 4-wheel-drive with a small tank & pump for fast response. For the last seven years, we have been housed in a small portion of the basement of the town’s sports hall, sharing the space with many other organizations and groups, including the Police depot. It was simple, very dusty, no showers, toilets, changing or sleeping facilities, and barely space to sit around and be comfortable during a tour.

Before

These are some pictures of what the old house looked like.

The entrance. Bombers in Catalan can be translated as ‘pumpers’, from the word ‘bomba’ which means pump. As a matter of fact, the French call themselves Pompiers, so it ties in. Nothing to do with bombs, believe me!

This is the “control room”. Yeah, stop laughing. It looks real ugly now, as we have not really used the place much in the last two months, as construction work all around it have made it unbearably dusty.

Truck 202 and the 4-wheel, sleeping in a cold, humid and ugly place. The will soon have a much more comfortable stay.

Our mini-museum, showing some glass beer and perfume bottles, recovered from a house fire a few years ago. The heat was intense enough to deform the bottles into the shape you see, but not intense enough to turn them into glass blobs. Underneath are some very old nozzles.

More photos here.

The new firehouse

Here are some pictures of the construction work going on. It is still rough and unfinished, but it definitely has a shape now. All should be done by Christmas, when we will move in and provide the finishing touches.

Truck 202′s new sleeping quarters. In this space we could actually fit two trucks, it’s really amazing that after so many years, we are getting so much room!

This is the view from where the kitchen will be, towards the entrance, on the left. The Flickr photo has some comment notes. The doors on the left lead to the sleeping quarters and changing rooms & showers. We will keep the high ceiling, it makes the place look roomier.

This is a reverse look, towards the kitchen, which will go against the wall at the back.

In all, we are really happy that finally, after many years of only asking for a decent place to stay during tours, in return for our time spent fighting fires, rescuing cats, horses (don’t ask!) and other animals from the most unlikely places, pumping out water during floods, rescuing people and delivering food during heavy snowfalls, we will get a very decent firehouse.