While releasing a new machine for the European and North American equipment markets requires skilled engineering in developing engines to meet the latest emission regulations, when releasing machines for the Middle East, Africa and Asia, manufacturers have to focus on toughness, with machines expected to perform in harsh conditions – often with minimal maintenance.
For Doosan, that means ensuring that its machines can work in the full range of conditions, from 0 degrees up to 60. And rather than simply printing a label on the tin and expecting the machine to work, the Korean equipment maker is fully prepared to test product prototypes in advance of their market launches to ensure they’re rugged enough, and – if necessary – make modifications prior to release.
Doosan’s new DL range of wheel loaders will replace the current popular Mega series. Two models – the DL250A and DL420A will be on display at the company’s stand at Intermat Middle East this month.
Following on from the launch of new wheel loaders for the European markets, the DL series has been adapted with Tier 2 engines, for the Middle East fuel grades, and a number of technical improvements to cater for the harsh conditions.
Releasing its DL series of wheel loaders some months after the launch of the European version of Doosan’s new wheel leaders, there are a number of improvements that have been made, similar with many of their machines released into the Middle East including the DX series excavators.
The need to adapt their machines for the work conditions of the Middle East and Africa guides Doosan, in a process where extra reinforcing of the undercarriage and arms and minimisation of electronics are but a few of the changes.
A system called ‘Finite Element Analysis’ is used by Doosan to ensure an extended lifetime for main structures such as the chassis and lift arm, which are subjected to intensive laboratory testing and analysis to increase reliability.
One top of that, their machines undergo a rigorous field testing process before finally being released, with engineers pouring over the field data to see if any additional modifications are needed.
For field testing the DL420A, Doosan looked to Saudi Arabia, for while the Kingdom is one of the most important market for Doosan globally, more importantly it’s also home to some of the harshest and most operating conditions in the Middle East, and in the world.
Situated in the south-east of Saudi Arabia, near the borders with Oman and the UAE, lies Shaybah, an important site for Saudi Aramco and its extraction operations in the Empty Quarter (Rub’ al Khali.)
While the Empty Quarter may be home to extensive hydrocarbon wealth, in machinery circles the name Shaybah is a by-word for atrocious operating conditions.
The area is site of extensive road building, but with ambient temperatures reaching 60 degrees or higher, only the toughest machines can work without breaking down.
The demands made on equipment are enormous, making Shaybah the logical location for testing a prototype.
With the machine operating long hours, a team of Doosan engineers was able to scrutinise data, and measure the machine’s performance, looking in particular at the cooling system.
The engineers were then able to perform modifications – or ameliorations – locally, and continue with the testing to test the performance.
Any modifications are then incorporated into the factory production and standardised, in time for the machine launch.
For the DL420A, this meant that engineers were able to fine-tune its coolant system, with the changes incorporated into the factory production in Korea.
Earlier this year, PMV was fortunate enough to drive the test version of the new machine in Al Khobar, Eastern Province, the headquarters for Doosan’s Saudi dealer, Saudi Diesel Equipment Co. Temperatures in Al Khobar don’t ordinarily reach 60 degrees in the summer – but by the time we reached the test patch at 6am the mercury was already pushing past forty.
Following on from Doosan’s popular Mega series of wheel loaders, the DL420A has a number of major improvements, both for operator comfort and for mechanical reliability.
The cabin has benefitted from a redesign, and has a strengthened air conditioning system, with four AC outlets blowing cool air directly onto the driver. The AC system incorporates a double filter, ideal for dusty or polluted working environments, and Doosan is promising a climate controlled environment similar to a passenger car.
The operator’s job is also made easier with improved power steering, including a load sensing system with a flow amplifier and priority valve. The 11 litre engine provides plenty of grunt, and the machine automatically dips into first gear to prioritise the power for the hydraulic arms and bucket when it is being operated.
The ‘lift arm raise kick-out’ and ‘return to dig’ functions should also be welcomed. Activated by the joystick, the function brings the bucket up to horizontal, or brings the face down to dig.
The bucket itself is a high-capacity 3.9m³, with a range of attachments available. Both the lower and side panels of the bucket have been reinforced with additional steel plates. Dump height is also improved, to 4.3 metres at the maximum height, or 3 metres when the arms are at maximum reach (45 degree angle).
On a technical level, there are a number of features that make the DL420A well-suited to the Middle East, where heat dust and sand are major considerations in the operating environment.
The three-stage air filter has a cyclone pre cleaner, which uses centrifugal force to eliminate dust, and the cooling compartment is separated from the engine compartment to prevent warm and dusty air from entering, and allows better control of air intake.
With axle technology from the German OEM manufacturer ZF, the axles are equipped with a new breather system intended to proven clogging from dust and sand. Both the front and rear axles are fitted with limited slip differentials, which allows for maximum traction and easy driving over soft ground, including sand.
And the brake piping has been integrated into the axle housing, protecting it from shocks when driving over rough terrain. The overall result is increased durability of the axle and reduced wear on the brake discs.
Technicians have an easier time, with improved access to the engine bay for maintenance. Behind the reinforced steel radiator grille, the radiator fan is reversible, designed to make cleaning of the cooler easier when the machine is operating in dusty environments.
Verdict
Doosan’s Mega series of wheel loaders has been a popular range in the Middle East, so there’s no doubt that there is a lot riding on the DL series. The DL420A driven by PMV combines the best of both worlds: rugged build quality and tough components, with ease of operation and a comfortable cabin for operators.
The robust AC system and comfortable cabin should mean that operators are more alert and productive, and the engine too should be capable of putting in the long hours. Likewise, Doosan’s approach to machine development should also inspire confidence.
A willingness to put their machine through its paces in one of the toughest environments in the world means that there will be no secrets or problems to be ironed out after the release date – and buyers can be pretty sure that a machine that can handle Shaybah –the hottest part of Saudi Arabia – will be right at home in the Middle East.
Specifications:
Engine: DE12TIS, 11 litre, 6 cylinder Tier II
Gross power max: 210 kW (282 hp) @ 2100rpm
Gearbox: ZF 4 WG 260 (three operating modes)
Max torque: 1275Nm @ 1200rpm
Breakout force: 197 kN (20t)
Bucket: 3.9m³ (standard)
Operating weight (max): 22,170kg
Max overall length: 9030mm
Cooling: 3-stage air filter with Turbo 3 cyclone dust separator
