Ain’t no mountain high enough
With the down run to Durban a success, Truck Test 2012 participants still had a lot more to look forward to. GAVIN MYERS rejoins the action with part two of his Truck Test 2012 report.
The days between May 19 and 22 were among the most hectic of the year so far for the FOCUS team, and no doubt for our support team too – Karen Smith and Lindsay Basset from Engen, Fritz Hellberg of Hellberg Transport Management and Adrian van Tonder from Barloworld Logistics.
After the exhausting activity of the day before – from being up and about long before dawn on a freezing Joburg winter morning, accompanying the 18 extra-heavy trucks every step of the way to Durban, and only retiring much later that evening – we were happy to have a day of relative calm on the Sunday.
Well, we weren’t exactly relaxing so much as writing articles and compiling photos to meet our deadlines for the June edition so we could bring you all the action from part one of our adventure. Nevertheless, it did provide us with a chance to recharge for the next two days.
Happily so too, because on Monday, May 21, the madness continued. Everyone was looking forward to the much-publicised parade, which was held at Dube Trade Port at King Shaka International Airport. The trucks were already in parc fermé at Dube, having arrived on the Saturday evening, and as the morning wore on the yard began to hum with activity.
Dunlop had kindly set up a comfortable marquee to host the drivers, co-drivers and everyone else involved for a delicious lunch and the announcement of the preliminary down run results. These were awaited with bated breath as everyone wanted to get some idea of how they fared. The results were also announced at the Road Freight Association (RFA) lunch in their tent shortly thereafter. For the overall results, turn to page 14. The full breakdown of results is available at focusontransport.co.za.
Following the announcement, the rigs pulled out of the yard and readied for their 15 minutes. Once all the RFA delegates had gathered, the trucks took off with a flurry of hooters and air horns. The procession could only be described as emotional, as the trucks completed two laps to the smiles and applause of the crowd, each gleaming rig catching the attention of the spectators. A particular favourite was DAF’s entrant – with its eye-catching branding, it was evident plenty of effort was put into the rig. It was a great experience for drivers and observers alike, and confirmed how enthusiastic everyone was about the test.
Not least of which was MAN CEO Bruce Dickson. “We’re very proud to have taken part, and worked hard to achieve the best economy from our vehicles in line with our motto of Consistently Efficient. The TGS 26.480 and TGS 26.440 that have taken part are exactly the same as a customer would buy, and we still hope to have done well with them,” said Dickson during his television interview with FOCUS editor Charleen Clarke.
Truck Test 2012 was set to come to an end the following day. Drivers and co-drivers were ready and roaring to begin their up run at an early 05:00, when the first truck was sent on its way back to the Anderson’s Transport depot in Alrode, Johannesburg. We were met on the busy KwaZulu-Natal highways outside a freezing Pietermaritzburg by an ER24 response vehicle that accompanied the trucks along some of the way.
The first stop of the journey was Engen Truck Stop Mooi River. This was followed by Engen Tugela and then Highway Junction in Harrismith, each stop compulsory, as they had been on the way down. Although it had been arranged prior to the test that the vehicles would not need to stop at weighbridges, it was made compulsory for each of the 18 trucks to stop at the Heidelberg weighbridge in order to confirm their mass before returning to Anderson’s.
At around 14:00, the first truck arrived at the Anderson’s yard. One by one, we tracked each vehicle using Ctrack’s mobile software as they got closer and closer to the end of their run. The final vehicle was home by 17:00.
Over the four days, it was amazing to see the camaraderie among all the truck drivers and manufacturers, despite everybody taking the test seriously. Sure, there were a few surprises in the results too and, being the first time anything of this magnitude was conducted, there were a couple of minor hiccups (which have already been ironed out), but Truck Test 2012 was nonetheless deemed an overwhelming success by all. And an experience that will not be forgotten for a long time. We must, of course, thank the fantastic participants – DAF, Hino, International, Iveco, MAN, Mercedes–Benz, Scania, TATA, UD and Volvo – and sponsors Aero truck; Afrit; Andersons Transport; Barloworld Logistics; Ctrack; DHL; Dunlop; Engen; ER24; HTM; N3 Toll Concession and Serco, for without them, that would not be the case.
Those fancy trailers
By the very nature of this test, which aimed to demonstrate different concepts rather than being a scientific test, it was not possible to draw conclusions as to the effectiveness of aerodynamics. The exceptions, of course, were the DHL rigs.
These had identical truck-tractors (Actros 2644s) but one was hitched to a conventional curtainsider, albeit with advanced aerodynamics, and the other to the worldwide DHL teardrop-design with otherwise similar aerodynamics. These two rigs carried identical but very light loads, and could therefore very nicely demonstrate the effectiveness of the teardrop trailer. Despite the curtainsider also having advanced aerodynamics, the teardrop outperformed its fuel consumption by 3,9 percent, a significant amount.
Barloworld claims a reduction of 35 percent in drag by the advanced aerodynamic aids it attached to its rig. In this venture, they were strongly supported by a CSIR division.
Reading between the lines
The last South African truck test was held in 2005 and attracted just six participants. This time around, we had 18 rigs taking part and generous sponsorship from Engen, Afrit, Serco Industries, the N3 Toll Concession, Digicore and Dunlop. Co-organiser FRITZ HELLBERG of Hellberg Transport Management reports
From the outset, it was stressed that this was not a competition but a demonstration of what 6×4 prime movers are capable of in different configurations over varying topography.
Participants were free to enter trailer and load configurations of their own choosing. The result was a field of 11 6×4 truck-tractors pulling interlink combinations, and six 6×4 truck-tractors hitched to tridem semi-trailers. Three rigs were entered by transport operators as opposed to manufacturers to show what aerodynamics can do (see sidebar story).
To be measured was payload, trip time and fuel consumption over pre-determined sections of the N3 and N2 from Alrode to Ballito, to give an overall productivity rating. On the down run this route was divided into Alrode to Harrismith (fairly flat), Harrismith to Tugela (very steep down Van Reenen’s Pass), Tugela to Cato Ridge (undulating with a steep climb to Mooi River and a drop to Cato Ridge) and Cato Ridge to Ballito (again fairly flat). The up-run was started at Dube Trade Port at King Shaka International Airport, the first section being to Mooi River (first flat then a long climb to Mooi River at 1 500 metres above sea level), Mooi River to Tugela (long downhill, then undulating), Tugela to Harrismith (steep climb up Van Reenen’s Pass) and finally Harrismith to Alrode (mostly flat).
All rigs were put through their paces with HTM’s TransSolve vehicle simulation package before the run began to see whether the vehicles performed as well in theory as in practice. Productivity is calculated using the payload in tonnes multiplied by km/h divided by l/100 km formula – which has proven to be a very reliable means of playing off speed against fuel consumption.
Of the rigs featuring interlinks, five were conventional curtainsiders, two were flat decks, one was a side-tipper and three were curtainsiders with advanced aerodynamics. The tridem trailer rigs consisted of four curtainsiders or reefers, and two flat decks.
It is very interesting and significant that the productivities of the tridems more or less matched those of the interlink rigs, with the exception of the MAN 26.480 and the DAF XF105, which were higher. Also significant is that the tridems generally had no problem beating the theoretical productivities generated by TransSolve whereas, of the interlinks, only the DAF managed to equal it despite the same algorithms being used throughout. This would indicate that tridem rigs have a dynamic advantage over interlinks, which we haven’t been able to put our finger on.
The above means that bigger is not necessarily better as our legislation stands at the moment, mainly because our 56-tonne gross combination mass (GCM) limit does not allow full axle capacity and bridge formula utilisation. This fact must be considered when purchasing vehicles for operations where a payload is carried in only one direction. In this scenario, the payload advantage of an interlink combination is negated by the additional tare mass of the interlink on the empty leg of the journey.
The more powerful vehicles like the Scania R620 and the Mercedes-Benz Actros 2658 would enjoy the biggest advantage over lesser-powered vehicles for the same GCM over those sections of the routes that have the longest or steepest climbs – Tugela to Cato Ridge on the down run, and Dube to Mooi River and Tugela to Harrismith on the up run. Taking the total travel times and the total litres of fuel used over these sections reveals that the most powerful vehicle (Scania R620) took 6:44 and 311,5 litres of fuel to cover these sections, while the least powerful of the interlink rigs (Volvo FH 440) took 7:31 and 297,3 litres. So, for a gain of 47 minutes the Scania used 14,2 litres more in fuel.
This is a misleading conclusion, however, since the Volvo took only 13 minutes longer for the entire trip but used 15 litres more fuel. Incidentally, the Scania R620 was the only Euro-4 vehicle in the test, but ran without AdBlue, which reduces the noxious exhaust gases – which means Scania has been able to significantly reduce the part-load fuel consumption of it Euro-4 engines.
The route was broken up into sections that represent different types of topography. How this topography affects speed and fuel consumption is best illustrated by the following extract from the results of one vehicle that took part in the test:
Clearly, the best average fuel consumption was achieved in the Harrismith to Alrode section, even slightly better than in the opposite direction. This is because Harrismith’s altitude is about 100 metres higher than Alrode’s. The section from Dube to Mooi River steadily climbs from sea level to 1 500 metres above at Mooi River over a distance of some 150 km, which explains the high fuel consumption over this section. Similar performance patterns were repeated by all the rigs.
Load and drag
The shape of the load being carried, or for that matter the shape of the trailer, plays a significant part in vehicle performance. The smoother the shape, the lower the drag, the better the trip time and the lower the fuel consumption. In other words, a well-tarped load of uneven shape will produce significantly less drag than a load with lots of protrusions.
Frontal area also plays a big part and in this context it is amazing to see how many rigs run on our roads with huge wind deflectors on the cab but a low trailer behind them; drag is created unnecessarily by the increased frontal area.
This test was conducted with the vehicles laden in both directions but in practice many runs involve an empty leg. This improves fuel consumption but virtually halves productivity as the empty leg has to be paid for by the laden leg.
The significance of productivity and simulation
The elements of the productivity formula are payload, average speed and fuel consumption – with the objective of increasing the former two and decreasing the latter. In this context, the vehicle manufacturing industry has played a huge part but transport operations also have their share of responsibility.
The simulation of operations before venturing into them has not yet been generally accepted in the South African transport sector. Some progressive transport companies have adopted this route and will not venture into a contract without first theoretically evaluating its profitability potential. In other words, a process of zero-based costing is followed rather than winning a contract on the basis of undercutting the opposition.
With Truck Test 2012, we wanted to get as many vehicle manufacturers involved as possible. As such, we allowed each company to enter a rig of their choice – provided it had a 6×4 prime mover. Looking forward, we will conduct truck tests on an annual basis, but the prime movers will alter from year to year so that the test will continue to provide useful information to a wide variety of industries. As such, future tests will be run on an even more scientifically-comparable basis. They may attract fewer entries – but we believe this is the right way to go.