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The ADT offers hauling versatility

The ADT offers a highly versatile option for earthmoving applications and manufacturers are offering new and improved models with the latest low emission engines - Mike Woof writes The versatility and adaptability of the ADT has seen this type of machine become one of the most important types of equipment for the global off-highway machinery sector. The once popular motor scraper now sells in only limited numbers, even in the US, and has been replaced by the more versatile excavator and ADT combination o
May 20, 2014 Read time: 10 mins
Hydrema and Komatsu ADTs
ABOVE: Hydrema now uses Cummins power in both of its ADTs, the diminutive 712 and larger 722; BELOW: Komatsu has upgrade its HM300 ADT with a new Tier 4 Final diesel as well as other improvements
The ADT offers a highly versatile option for earthmoving applications and manufacturers are offering new and improved models with the latest low emission engines - Mike Woof writes

The versatility and adaptability of the ADT has seen this type of machine become one of the most important types of equipment for the global off-highway machinery sector. The once popular motor scraper now sells in only limited numbers, even in the US, and has been replaced by the more versatile excavator and ADT combination on most job sites around the world.

From sales of relatively low numbers of machines in the UK and Scandinavia where the machines originated, the ADT is now a key earthmoving tool worldwide. 178 Caterpillar and 359 Volvo CE dominate the market, with the combined sales of these two firms outselling all the other manufacturers put together. Both companies have long histories in this market segment, and with Volvo CE claiming to have built the first true articulated haul truck. However competition has increased over the decades and Caterpillar and Volvo CE now have a long list of rivals in the segment, with all the major firms having recently upgraded their designs to meet the latest US and European emissions requirements.

In the volume market, Caterpillar and Volvo CE’s main competition has come from 1240 Bell, 176 Case/Astra, 695 Doosan (previously 1239 Moxy), 257 John Deere, 2300 Komatsu and 1222 Terex, although in Latin America there is the Brazilian firm 1241 Randon and there are now some Chinese producers in the country’s home market also. However this situation has now changed.

Volvo CE’s acquisition of Terex’s truck business in Motherwell is a major development for the ADT sector, but was made for the rigid truck line. Some time ago Volvo CE revealed its interest in re-entering the rigid truck market following the sale of its share in the Euclid business to its then partner, 233 Hitachi. A tie-up to distribute the Italian 2740 Perlini rigid truck range in some territories followed, but any further agreements between the companies halted. However the purchase of the Terex truck range brings with it a five model line-up of rigid haulers with payloads from 32-91tonnes, the TR35, TR45, TR60, TR70 and TR100. The purchase also brings with it the three model Terex ADT range, comprising the TA250, TA300 and TA400, with capacities of 25, 28 and 38tonnes respectively.
Given that Volvo CE is already the world market leader in the ADT sector with its own range, there is a question as to what the firm will do with the Terex models it has now acquired. The rigid truck range is complementary and the addition of this is the primary reason for the purchase. What Volvo CE plans for the Terex ADT range is not immediately clear. These models may be incorporated into Volvo CE’s 5316 SDLG brand, the firm’s Chinese-made value brand for machines such as wheeled loaders and excavators, to target emergent markets. But it is worth noting that ADT sales are still comparatively small in many of the emergent territories and Volvo CE may opt instead to continue with the parts business for the Terex ADTs, while phasing out the range.

The pace of technological development has been rapid also and South African firm Bell Equipment is introducing its B25E and B30E ADTs to the North American market, with these models offering improved engine output and better travel speed over the models they replace. This increased travel speed helps boost productivity as the trucks can travel more quickly when unladen, further assisted by slight increases in load capacity as the B25E can carry 24tonnes and the B30E has a capacity of 28tonnes. The trucks are powered by 2796 Mercedes diesels rated at 210kW in the B25E and 240kW in the B30E, with the engines now driving through Allison transmissions. The Bell machines have long been noted for low fuel consumption and the engine and driveline upgrades have further improved this factor, aided by greater efficiency from the revised hydraulics.

Automatic traction control is offered due to the new inter-axle differential lock system. This detects when one axle loses traction and then modulates the power transmission to all six wheels so as to minimise tyre slip. Limited slip differentials are fitted in the axles and also engage automatically. Bell has upgraded its telematics system, which allows remote diagnostics checks as well as geofencing and will help with fleet management. The cab is upgraded with better vibration damping and a larger monitor giving a rear camera view as well as allowing the operator to monitor performance and carry out fault-finding.

To improve its ADTs, Caterpillar has installed new engines that deliver more power along with sophisticated transmission Controls that help optimise efficiency. To meet the needs of clients (and the availability of clean diesel fuel) in different territories, Caterpillar is offering the C-Series ADTs with engines that meet Tier 4 Final/Stage IV, Tier 3/Stage IIIA or Tier 2/Stage II emissions requirements. The 23.6tonne capacity 725C has a 4% increase in power to 234kW (as well as a 20% increase in torque) from its CAT C9.3 diesel, with a diesel-particulate filter and selective-catalytic-reduction system providing exhaust after-treatment to meet Tier 4-Final/Stage IV market requirements. Both the 730C, and 730C EJ ejector models have capacities of 28tonnes and are driven by CAT C13 diesels providing 30% more torque and nearly 16% more power at 274kW, again with diesel-particulate filters and selective-catalytic-reduction to meet Tier 4-Final/Stage IV needs.

The advanced transmission controls modulate clutch engagement pressures in the CAT 6F/1R powershift transmission to optimise shifting and also allow faster acceleration. The revised engine compression brake in the 730C variants is said to provide more retardation on downhill ramps while the 725C now has a more efficient four mode fluid retarder. The C-Series trucks benefit from wet-disc-clutch locks in the axle differentials as well as the inter-axle differential, which help boost traction in poor terrain. Other upgrades to the C-series haulers include improved cabs with greater visibility and better serviceability as well as a revised dump body design that reduces carry-back, made from Brinell HB450 wear-resistant steel.
Doosan Construction says that its Tier 4/Stage IV Final ADTs offer considerable fuel savings, as well as productivity gains. The advanced machine diagnostics package has shown that under test, the DA40 can achieve a fuel consumption of 17litres/hour, which is said to compare well against competing models for efficiency. The firm claims that the cost/tonne for the DA40 and DA30 compares very favourably against rival machines in similar size classes. The basic structural design of the trucks remains and the DA30 and DA40 retain the articulation hinge located behind the turning ring, which the company claims provides a better weight distribution to the front axle, even at maximum articulation. The machines also retain the novel free-swinging rear tandem bogie, which is said to offer equal distribution of weight to the rear wheels. The rear drive design gives better rough terrrain performance as it can more closely follow undulating ground than a live axle system and also allows for more even tyre wear than the live axles used by most other ADT manufacturers. The DA40’s productivity is aided by its high top speed of 58km/h, its increased body capacity of 24.4m³, and the 40tonne payload (an increase of 15% from the payload over the earlier Mt41).

The 2415 Hydrema ADT range is for smaller machines and the firm has revised its 912 model, switching from 299 Perkins power to a 196 Cummins Tier 4 Interim/Stage IIIB diesel. The QSB4.5L engine Hydrema has selected delivers 105kW, an increase of 8% while also delivering 20% more torque, at 620Nm. But in spite of the increased output, Hydrema says that the fuel consumption is similar to that of the earlier machine. The engine is located under a new cover that lifts clear of the chassis to provide easy access for maintenance. The trucks also have a redesigned air conditioning system, with the condenser moved to the front of the cab for improved airflow. The 912 has increased ground clearance but a lower overall height, making it easy to manoeuvre on-site. A 6.7litre Cummins diesel rated at 201kW and driving through a ZF6WG210 transmission is used in the 922, with its 20tonne capacity and which features a rear bogie drive similar in concept to that used in the much larger Doosan ADTs.
255 JCB says that its two small ADTs, the 714 and 718, are highly versatile and suit duties in a range of earthmoving operations. High manoeuvrability is said to allow for good positioning to load and unload and the trucks can be used with a variety of loading machines. The durable rear body design and high power outputs are said to compare well against rival trucks in their respective size classes. The JCB 714 and 718 both feature an Electronic Monitoring System (EMS), which monitors machine performance. Another feature for both trucks is the ability to select two- or four-wheel drive while the machines have limited slip differentials as standard to improve traction. The trucks have top speeds of 41.5 and 39.4km/h and are powered by diesel delivering 160 and 173kW respectively.

Komatsu has several upgrades to its 28tonne capacity HM300 ADT, with the installation of a new Tier 4 Final compliant diesel as well as a number of other improvements. The new SAA6D125E-7 diesel delivers 242kW as well as fuel savings over the earlier engine, while the truck has the Komatsu Traction Control System (K-TCS), offering optimum traction in soft ground conditions. The system automatically applies the inter-axle differential lock and can also apply the brakes in the event of tyre slip, so as to regain traction. The automatic retarder allows the operator to select the optimum operating speed on downhill travel and fully loaded hauls, eliminating acceleration generated by the grade of the slope.

Another important feature is the upgraded KOMTRAX remote monitoring system, which provides the user with remote access to machine data through the internet or through a special app for a smartphone. This also provides information on fuel levels, operating hours, location and maintenance alerts, as well as monitoring diesel exhaust fluid levels, ambient air temperatures and pressures.

The HM300 weighs in at 53.5tonnes laden and is performance matched for loading by excavators weighing from 30-60tonnes. In addition, the HM300 cab has also been revised and offers improved visibility and comfort.

Volvo CE is keen to retain its strong position in the ADT market with upgrades to its G-Series machines. Top of the six model range is the A40G FS articulated hauler, which is powered by a turbocharged six-cylinder Volvo diesel that meets the Tier 4 Final emissions regulations. The Volvo drivetrain and inline dropbox is designed for high ground clearance and the truck has an automatic traction control (ATC) as well as differential locks as standard to provide traction on difficult ground. The ATC system switches between drive combinations of 6x6 and 6x4 to ensure lower fuel consumption or provide maximum traction. If required the differentials can be locked and all six wheels will rotate at the same speed to maximise traction in the worst conditions. A novel feature of the A40G FS is full hydraulic suspension on all wheels, which helps boost productivity and makes the truck more comfortable to drive at speed.

The G-Series models can be equipped with Volvo’s onboard weighing system, which allows for precise machine productivity monitoring, helping to optimise payload and minimise wear, tyre damage and high fuel consumption. On FS models, the system uses full suspension pressure sensors to monitor weight, relaying information to load software integrated into the machine’s electronics. Indicator lights tell the truck driver, as well as the operator of the loading unit, the load placed in the dump body. As with other Volvo CE machines, the G-Series comes with the firm’s CareTrack telematics technology and other improvements include a new high visibility cab.

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