Super soakers: firefighting apparatus in the GCC
Greg Whitaker explores the kit that's being used to tackle GCC blazes
If you have ever been fortunate enough to spend Thursday night watching the traffic amble along Dubai Marina’s beachfront road, the chances are you’ll have seen some fine and rare vehicles.
Gold-painted Hummers, spangly Bentleys, and orange Lamborghinis all gingerly crawl over the speed humps in a grand procession. Porsches are so commonplace that to see a fender-bender between them is not unheard of.
There are so many ‘look-at-me’ cars that it almost becomes boring. However, there is still one vehicle guaranteed to make everybody sit up and take notice. Painted yellow and red, and making a noise louder than even the most bass-heavy sound system, is the Civil Defence’s Mercedes Actros fire engine.
As it tears through, with cars shuffling to one side to let it pass, everyone on the street will stare at it. This is partly because emergency response vehicles hold a fascination even for those with no interest in machinery – and partly because something nearby is probably on fire.
But where do these vehicles come from? The running chassis are supplied by the usual vehicle manufacturers, but in this case, the bodies themselves are custom built in the Emirates by local firm, Bristol Fire Engineering.
The vehicles – referred to in the firefighting trade as ‘apparatus’ – are shipped everywhere across the Gulf, and as you might expect, each appliance is built to bespoke specifications that vary according to the requirements of the municipality in question.
However, there is one thing that all Middle Eastern fire trucks have in common: the ability to keep cool even when stationary, and in the most severe temperatures. This, according to Bristol Fire Engineering’s engineering manager, Saad El-khayyat, is due to their uprated cooling systems.
“Because of the extreme heat, the dynamics of these vehicles must be different” he said.
“We have to build trucks with a substantially larger cooling systems than you might expect,” El-khayyat added.
The best base vehicle for severe-duty use in the desert will not necessarily be the one that is fastest when racing across a city centre. But this is no matter, according to El-khayyat, as a wide range of truck chassis are suitable for building upon.
“The selection is largely made by the client, but we try to guide them in the direction of the most suitable vehicle for their specific applications,” he explained.
Of course, it isn’t just public bodies that require fire apparatus in the Middle East. Those operating within the oil and gas sector also represent important clients for Bristol Fire. According to El-khayyat, these machines tend to have higher discharge capacities compared to those ordered by local authorities.
The primary pump is usually larger, and the discharge guns – known as ‘monitors’ – typically sport wider bores to quench fires before they turn into environmental disasters.
Bristol Fire sources most of its hardware from US-based firm Williams Fire; a firm that specialises in the design and manufacture of devices that are equipped to deal with industrial blazes.
One of the special monitors produced by Williams Fire is the ‘flex nozzle’ package. Manufactured for use with dry chemicals on fires involving gas, alcohol, or pressurised fluid, this nozzle is said to deliver 13kg per second of dry chemical, which the maker – using typical American hyperbole – describes as a ‘shock-and-awe’ method to deal with three-dimensional and toxic blazes.
Another key difference between modern equipment and older-generation machines is the quantity of on-board electronics.
As with so much kit in the machinery world, banks of valves and levers are being surpassed by electromechanical controls, operated by panels of buttons and push-switches. Electronically-governed pressure control was a rarity twenty years ago, whereas today, it is found on the majority of apparatus.
Firms such as US-based Class1 make a range of pressure governors that are coded into the vehicle’s CAN network.
These systems monitor engine RPM and other pertinent data directly from a unit’s ECU, allowing the governor to react very quickly to any changes in pump pressure as the firefighters connect and disconnect various hoses on the apparatus’ valves.
The top model in the range is able to take a variety of metrics into account, such as oil pressure, cooling system temperature, and how long the pump has been running.
The ability to tap into a vehicle’s network controllers certainly has its merits, but technology is never used for the sake of it on these machines. The Williams’ Hot Shot II Foam System combines older, balanced pressure technology with modern, hydrostatic drive systems.
These were developed to handle sheer-thinning or ‘thixotropic’ concentrates in use for industrial fires today. On this system, a small amount of concentrate is always being circulated through the foam manifold and returned to the suction side of the foam pump. This keeps the concentrates from congealing, and ensures that foam is immediately available should a discharge be opened.
The hydrostatic drive system runs directly from a power take off on the chassis. Doing it this way allows it to be engaged at any engine RPM, whereas systems that run directly from the pressure governor require the engine to be run to idle. As the concentrate pump operates independently of the water pump, the fire crew has the option of tackling the blaze on more than one front.
Of course, today’s fire trucks are more than just mobile pumps. Many are designed to act as search-and-rescue machines. Most people will be familiar with the ‘jaws of life’ – hydraulically powered pincers that can cut through a vehicle’s windscreen pillars – but one development that not everyone will have seen is the replacement of the traditional fireman’s ladders with aerial work platforms (AWPs).
Finland-based manufacturer Bronto Skylift produces a boom especially for the fire truck market. Being articulated means that the lift can reach into areas inaccessible to straight arms, and with a total length of 112m, the product is currently the largest of its type on the market.
The platform itself can be used to carry firefighting hoses, and even at maximum height, the maker claims that it can deliver 3,800 litres of water per minute. The platform also boasts a safe working load of 500kg.
This is just the start of the innovation currently taking place within the firefighting sector. So, the next time you see a truck screeching towards an emergency, bear in mind the technology that’s keeping you safe.
When it comes to fighting fires on desert oilfields, one of the major obstacles that firefighters must overcome is the dearth of surrounding water hydrants. To this end, a special type of apparatus is required to carry water: the tanker.
Unlike conventional water bowsers, tankers are fitted with on-board pumping systems. However, the power offered by these pumps in isolation is often insufficient to fight fires. Instead, they are attached to fire engines, which draw the water into their tenders.
In some areas, tenders are also used to pump water during floods. In this scenario, heavier-duty pumps can be installed. In turn, fast-drain valves are usually fitted to the sides and rears of tankers. This allows the emergency services to empty thousands of gallons of water into a tanker in just a few seconds.