Dennis Eagle has unveiled a pre-production prototype of a totally new compact refuse collection vehicle (RCV) designed specifically to meet the demands in urban operations. It’s designed to reduce impact on other road users, pedestrians and cyclists, but without compromising on payload potential. How is that possible? Malcolm Bates investigates...
Colin Chapman, boss of Lotus and one of the most original thinkers of all time among automotive engineers had a fa
vourite saying: “Add lightness and simplify.” This helps explain why a Lotus could out-perform larger and more powerful competitors on both the road and the race track. True, the demands on a refuse collection vehicle (RCV) are just about as far away from those of a sportscar as is possible to imagine. Or are they?
The vehicles we specify to collect and transport domestic and trade waste and recyclables have grown to become some of the largest, heaviest and most expensive trucks to be seen on residential streets where people live – and in urban downtown areas, where they shop or work.
They have a considerable impact on the environment – and increasingly run the risk of ‘an impact’ of a more physical kind due to the pressures of ever-increasing traffic congestion. Driving a large truck in a crowded city street is a tough, stressful job – so we
should be reducing stress, not adding to it.
One solution to this problem would be to arrange collection rounds (routes) to be undertaken before the traffic starts to build-up – such as very early in the morning. But the noise created by a diesel vehicle using hydraulic binlifters would surely upset residents. So that option remains dependent on specifying a suitable battery electric-powered option like the PVI.
But using a smaller RCV capable of squeezing through gaps in the traffic and turning around in tight ‘hammerheads’ which would require a conventional RCV to reverse into position before starting work, could also speed-up the collection process and reduce stress as well. The problem? Until now, smaller RCVs were handicapped by equally small payloads, which results in a higher cost-per-tonne ratio; and are also arguably less efficient in air quality terms.
But now? There’s another option. Or at least there will be shortly because UK-based manufacturer Dennis Eagle has taken a leaf out of Colin Chapman’s book and ‘added lightness’ to produce a compact two-axle 16 tonne gross RCV that is capable of delivering an impressive payload potential of 8 tonnes. That’s around three tonnes more than a conventional 18 tonner. How has this been achieved?
I would like to say by ‘adding simplification’, but I’m not sure that does justice to the amount of design work that has resulted in what Dennis engineers like to call “an integral chassis-less construction.”
In fact, in strict automotive terms, the construction of this brand new and as yet un-named pre-production prototype isn’t ‘chassis-less’ or ‘integral’ in that it would still drive and function without being fitted with a body/hopper unit.
The term I would use to describe the clever structure that includes the power unit and running gear is a ‘spaceframe’. Rather than conventional steel channel sections braced with cross-members and outriggers, there is a stressed alloy steel structure that has been designed to achieve optimum strength with minimum weight.
LIGHT BUT STRONG
At the same time, a great deal of attention has been given to optimising the payload potential within the smallest overall dimensions. By saving weight, it’s been possible to reduce the size of the road wheels and tyres, giving a lower centre of gravity and making crew entry (and exit) to the already low-entry cab even better.
Less gross weight has also enabled the size (and yes, the weight as well) of the power unit to be reduced, which has created more space within that clever ‘frame’ structure. And this in turn has enabled ... well, it’s enabled the completed vehicle to turn much sharper thanks to a considerably tighter steering lock from the ‘narrow track’ front independent suspension system. Yes, independent suspension on an RCV. Why? Because it creates more space for the front wheels to turn sharper.
So let’s just have a quick recap. Instead of a massive four-axle 32 tonner, a conventional three-axle 26 tonner, or a two-axle vehicle with a gross weight of around 18 tonnes (depending on local regulations), here we have a compact 16 tonner with a payload potential of around 8 tonnes with a binlifter. And yet, it looks no larger than a current 10/12 gross weight machine.
Due to the nature of waste and recyclables collection operations, the compaction body/hopper unit – and the bin lifters – are pretty conventional, although Dennis Eagle engineers have developed a ‘tapered’ rear hopper profile to help reduce potential ‘swing-out’ damage on tight turns. Plus of course, smaller wheels and tyres have enabled the hopper load-over height to be reduced, while also enabling a high volume body/hopper design within any
given overall height. This might not sound like any big deal, but it could enable access to underground service areas in shopping malls that current full-size RCVs cannot reach.
BRINGING IT ALL TOGETHER
I’m still wondering how all these clever design features might come together and complement each other when I get the chance to find out for myself – I’m told I can take the completed vehicle for a short test run. True, it’s not possible to actually run the vehicle with a ‘live’ load today as, at the time of writing, Dennis Eagle didn’t want the completed vehicle to be seen in public.
But already I’m ‘getting’ the concept. A number of specialist truck designs have been produced over the years to compact overall dimensions, while aiming to provide a high payload for tough operations. Indeed, I own a ‘Freighter’ chassis manufactured by British manufacturer Shelvoke & Drewry (SD) that features a ‘narrow track’ chassis, a tight turning circle and small diameter road wheels and it was designed and built in 1922! But there’s not been an innovative vehicle like this designed specifically for urban opera
tions for several decades. Let’s fast forward to ‘the future’. This
new Dennis could actually be available within a couple of years – before 2020 in other words. The driver’s controls are much like those on a current-model Dennis ‘Elite-6’ – except the instrumentation and control systems are all to the next level.
This pre-production model features a low-entry crew cab giving accommodation for driver and three crew with a flat cab floor. It gives the driver cross-cab access to the nearside without having to exit into busy traffic.
The kerbside door can be either a conventional hinged door, or a ‘bus-type’ folding door and on production versions, ‘kneeling’ front air suspension could reduce the already low step height even further, as the vehicle comes to a stop.
Right, the control systems tell me I can now start the engine and ... That’s a surprise. On this diesel-powered development vehicle, the power unit is a Euro-6 Cummins. Surprisingly, it’s only a four-cylinder 4.5 litre capacity unit producing 220 hp, so it sounds rather different to what I was expecting. It’s not that it’s noisy, or ‘rough’ compared to a six-cylinder unit. Just different. But on production models? It looks as though both a ‘Zero Emissions’ all-electric version (with lithium-ion battery pack) and a CNG (compressed natural gas) version will be available to give operators a choice of fuel to suit local inner city zone regulations.
The transmission however is entirely familiar, in that it’s an Allison 6-speed automatic with simple push-button control on the dash. Handbrake (park brake) off and we’re away. The overall impression is one of responsiveness. Time to try out the tight steering lock. That is impressive.
I stop, then reverse into a side turning, before selecting ‘drive’ and flooring the throttle. Interestingly, the smaller road wheels don’t compromise stability, helped no doubt by the full air suspension, low centre of gravity and that rigid spaceframe.
The mix of ‘current’ and ‘the future’ is really interesting. There is nothing ‘revolutionary’ in this new design. But I’m thinking that’s probably a good thing. It would be too
much of a gamble to order a whole new fleet of revolutionary RCVs, only to find problems once they enter service. ‘Innovative’ then? Yes, without question. But does this innovative specification meet the brief for a faster, more nimble vehicle, capable of picking up a viable payload, while having a reduced impact on both other road users and residents in the area it serves?
Yes. Again, no question. But is such a specialised vehicle a viable economic proposition? How do you calculate the reduced impact on the environment? Although not in production yet – but it’s close – and although chassis prices haven’t been announced, initial trials suggest there’s another bonus to ‘Thinking Small’
Fuel usage, tyre wear and the impact such a vehicle might have on urban highways should all be much improved, judging by initial test results.