In Singapore, the country’s civil defence force has launched a radical line of new-age fire trucks, to replace the conventional box shape. Designed for narrow urban streets, the vehicles look more like a rugged SUV than a traditional truck. But what does this unique redesign tell us about forthcoming changes for the wider emergency-vehicle industry? This article investigates.
Singapore’s cutting-edge re-model of the traditional fire-truck design still has enough space to fit five people and a completely integrated compressed air foam pump system. So, does this launch mark the end of the conventional fire truck for the rest of the world? Probably not. But it does show that emergency vehicles can break conventions and still be fully functional.
City streets are getting slimmer – much to the dismay of emergency-vehicle drivers. Anyone who lives in a city has witnessed large fire engines struggling to squeeze through traffic on narrow streets, potentially losing valuable seconds in a high-stake callout. Singapore’s redesign has been developed to solve this problem.
Back in 2014, firefighters called for wider roads to be built in San Francisco, California. The government publicly opposed this, arguing for narrower, safer streets. While this may seem counterintuitive, they argued that wider urban streets encourage faster driving and lead to deadlier collisions.
Interestingly, research backs up this argument. A study by civil engineer Dewan Karim on intersections in Toronto and Tokyo found that lower crash rates were linked to lanes measuring 10–10.5ft in width, compared with 12ft-wide lanes.
Narrower roads get the thumbs up from the government, leaving vehicle manufacturers reconsidering emergency-vehicle design. After all, a fire truck normally measures between 7 and 9ft wide, which on a 10ft-wide road, leaves little room for error. What’s more, it isn’t just road width that is causing issues. Higher volumes of traffic and excessive on-road parking can also cause problems for emergency vehicles when navigating domestic roads.
As shown in Singapore, emergency-vehicle manufacturers are redesigning vehicles to meet modern demand – not only to streamline the size of vehicles but also to improve manoeuvring and agility.
To achieve this, chassis designers in the emergency-vehicle sector are turning to custom parts suppliers to help them produce more compact and agile emergency vehicles than ever before, with no compromise to functionality and ergonomics.
Of course, in this highly regulated industry, a complete redesign of an emergency vehicle cannot happen overnight. One subtle change to the vehicle chassis or steering system could have huge implications to a vehicle’s performance, if not carefully considered and validated.
As vehicle manufacturers take on new design projects with challenging space-saving specifications, mass-produced vehicle parts won’t suffice. Instead, chassis designers should work closely with bespoke steering parts suppliers that can design, manufacture and test parts specifically for the emergency-vehicle project.
Manufacturers of new or niche vehicle concepts will also depend on lower-volume orders of parts, which may not meet the minimum order volumes of some large well-known part suppliers. Pailton Engineering, a specialist manufacturer of steering systems, has a low-volume cell specifically for orders like these.
New-age emergency vehicle concepts, like the Singapore example, may address the problems associated with narrow streets, but as with any new design concept, access to flexible design options will make or break any ambitious project. When sourcing parts, choose experts that already have a good track record working with non-standard specifications and offer complete design flexibility.
Urbanisation is producing additional challenges, aside from narrower roads. Flooding is ever more evident in urban areas, as a result of less water being able to infiltrate impermeable surfaces, such as concrete. The big flooding problem is only going to get worse, as climate change makes extreme rainfall more common, and emergency vehicles will need to contend with these changes.
The traditional parts that have been commonplace in emergency vehicles for decades will need to adapt in response to the changing environment. Increased moisture increases the chance of internal corrosion to steering parts, as well as contamination and lubrication leakage.
For one Pailton Engineering customer, the design and development engineers were challenged with producing a next-generation bevel box that could endure high levels of operation in high-moisture conditions. Also known as a mitre box, the integral part transmits torque in the steering system, across two steering shafts at a 90-degree angle.
The engineers endeavoured to redesign the bevel box for their customer, to ultimately keep water out, and lubrication in, even in extremely cold and wet environments.
The team made strategic design upgrades of this steering component; including a unique lubrication that would enable operation in temperatures as low as -40 degrees Celsius. Additionally, they added a new housing to the design in a bid to improve sealing capabilities.
With new design additions in place, they validated their design options with a bespoke 56-week-long testing programme. During this time, the test bevel boxes endured a sustained period of submersion, salt and grit exposure and extremely low temperatures, all while the bevel boxes were in continuous operation.
‘We set up a bespoke, brand new test station at Pailton Engineering, to make sure our latest bevel box design was fit for purpose,’ explained Emma Cygan, design and development engineer at Pailton Engineering. ‘This involved submerging the generation three bevel box in saltwater for extensive periods of dynamic testing and evaluation. The bevel boxes were subjected to dynamic submersion and low temperatures.
‘Quite frankly, we have abused these bevel boxes. We wanted to see if the sealing design features, such as the serration cover and outer full cover, could endure this continual operation, salt and grit exposure and incredibly low temperatures, all while keeping water out of the component. We knew if the bevel box could handle this, then enduring real-world extremes would be easy.’
Fifty-six weeks was a long time to wait to see if the part had lived up to claims. When the nail-biting day finally arrived, the engineers were thrilled to find that even after the intense moisture and grit exposure, no trace of water had entered the vital component. While the bevel boxes externally showed evidence of the conditions they had faced, the internal characteristics of the bevel box were pristine – no sign of corrosion, moisture or contamination.
To complement this, Pailton Engineering also sent the bevel box to external testing facilities. Here, the bevel box was found to meet ASTM B117, an internationally recognised standard of salt testing. It also was shown to conform with ingress protection codes IP66 and IP67.
IP66 enclosures can protect against powerful water jets while IP67 are able to protect against immersion up to 1m. For emergency vehicles on route to urban destinations, this design upgrade could make all the difference. While fire trucks aren’t wading through a meter of water regularly, increasing floods could make this a more regular occurrence.
Furthermore, it is the lower-level, long-term exposure to moisture that can render some steering parts unsound. Over time, corrosion and lubrication leakages can gradually worsen, resulting in very stiff steering and high torque characteristics. In these cases, operators face downtime to replace the problematic steering parts, such as the bevel box. Unfortunately, that’s one less fire truck available for emergency call-outs for a problem that could have been avoided.
In relation to the aforementioned Singapore new-concept vehicle, some fire-truck design engineers may not see the need for an entire design overhaul as demonstrated in this radical example. Yet, as shown with the bevel-box case, small changes can reap huge benefits in helping fire trucks respond to the changing environment.
For emergency-vehicle design engineers in need of flexible design options, it’s time to look further afield than standard catalogue parts. The level of ingress protection celebrated by Pailton Engineering’s engineers was a result of customer-specific in-depth analysis and thorough trials, which many multinational steering parts suppliers do not offer. Urbanisation, climate change and flood rates aren’t slowing down. Expert design will be the only way to tackle the issues faced by emergency vehicles.
For more information, go to www.pailton.com