Volvo pipelayers are designed and purpose-built to achieve high lifting standards and maximise productivity, which increases safe operation in aggressive and demanding environments like Australia.
Turning against the sideboom/pipelayer tradition, two Volvo pipelayer models currently available from CJD are both developed around the EC460C crawler excavator, and can provide a 360degrees swing capability. This swing capability allows for infinite pipe handling and placement possibilities, enabling the ability to pick up pipe at any angle irrespective of the position of the undercarriage and ease of machine repositioning and directional change. When working on slopes, the swing enables the boom to always be positioned uphill, optimising stability.
The PL4608 pipelayer, with an operating weight of 57,475 kg, has a maximum tipping capacity of 80,000 kg, while the PL4611 pipelayer weighs in at 68,140 kg, and has a tipping capacity of 110,000 kg. Where operational safety is concerned, the management of such a heavy load potential is facilitated by a load management system.
An onboard computer monitors the boom angle, machine orientation and inclination utilising boom and base machine-mounted sensors.
The computer uses this information to compute and display actual loads and related working loads in real time. This information, provided to the operator on a monitor in the cab, allows full control of the load to be maintained, whether on level ground or on a slope. Externally, the load condition is transmitted via light bars mounted on both sides of the boom tip, with lights moving between green to red depending on the load. This serves the linesman who can see instantly if any machine is being overloaded, directing other machines on the line to take up the load. The lights are equally visible to other operators on the line and other personnel on the ground.
Tipping: the issue
With machine tipping an issue on pipeline sites, CJD said that machine stability was a prerequisite in the design of these models. For example, the PL4608 features a hydraulically variable gauge undercarriage. Fully retracted, the overall machine width is 3.15 m, to facilitate machine transportation, expanding to 3.65 m to provide a wide working stance and excellent stability on site. With the undercarriage retracted, the machine is at an acceptable width for road transportation.
The PL4611 features a bigger, fixed-width undercarriage, providing an almost square working platform. The longer booms fitted to these machines are mounted inside the track frame and close to the machine’s centre line, further enhancing overall machine stability and facilitating their ability to manage heavier loads. The asymmetric, open design of the boom provides a clear view to the work area. The length of the boom – 9.14 m on the PL4608, 11.6 m on the PL4611, compared with 6.1 m and 8.5 m on conventional sideboom pipelayers – provides for a longer reach and hook height, so depending on ground conditions, where there may be a risk of sidewall collapse, the machines can sit back from the trench.
In addition, the larger undercarriage on the PL4611 does not hamper transportation, the machine can raise itself from the ground and use its pipelayer boom to lift off its side track frame assemblies and load these onto a flatbed trailer.
Machine stability is the key factor in avoiding machine tipping as from an environmental perspective, a machine that tips will spill fuel and oil and where soil contamination is involved there can be high penalties imposed and a costly clean-up bill for the contractor. High ground clearance enables work on rugged terrain while their excellent, overall stability and traction, and the choice of single, double or triple grouser track shoes ensures they can work in any underfoot conditions – dry, sandy, rocky, muddy and even on up to 35 degree grade slopes.
Onsite efficiency
Wide gauge and track shoe widths reduce ground pressure and soil disturbance while providing a greater ability to work in softer underfoot conditions. The ability to lay pipe off both sides of the machines can allow for a narrower right-of-way, saving time, material, and landscape. This ability to swing is also a benefit at bending stations as the pipe can be picked up and swung to the bending machine while the machine’s footprint does not change. Conventional sidebooms need to turn on their tracks and this destroys the ground.
The entire disassembly process for transportation of the two pipelayers can be achieved in one hour. As the boom on both models does not have to be removed for transportation, this further speeds up the process.
Standard safety features include an anti-two-block device, with auto kick-out at full lift to prevent the winch blocks from coming into contact. A flag block that pivots 5 degrees to left and right enables load self-centering, and a mechanical, upper structure swing lock is useful when moving on a slope with pipe, or in applications such as pipe welding where the pipe needs to be held in position.
Volvo Pipelayers exceed global design and safety requirements for pipelayers as well as cranes; most significant are OSHA regulations, ASME B30.14, ASME B30.5, ISO8813, and DIN 15018 and 15019.
Flexibility on the spread
Given the heavy lift capability of these machines, allied to their 360 degree swing function, the pipelayers can also have a role to play in other applications outside pipelaying where a heavy lift capability is required. They can also be converted back to standard excavators with standard digging equipment, a process than can be achieved in less than a working day with two technicians. This was an important consideration in the development of these machines in order to ensure maximum machine utilisation and, consequently, the best return on the customer’s investment when sold on.
On a pipeline site, this pipelayer/excavator conversion capability provides a degree of flexibility across the pipelaying process that has not previously been achievable. For digging the trench and preparing the pipe bed, the machine can be used as an excavator. For stringing, it can be used as a pipelayer or an excavator, fitted with a vacuum shoe. For pipe bending and welding it can be used as a pipelayer or an excavator. For lowering in and tie-ins, it can be used as a pipelayer and for backfilling, used as an excavator. According to CJD, there could be substantial cost savings coming from reducing the total number of machines required onsite, plus, savings on machine transportation costs.
Maintaining value
On pipeline sites, often in remote locations in Australia, back-up support is essential in terms of parts and maintenance. To assist with keeping its equipment up and running, Volvo offers the CareTrack telematics machine tracking system as standard on its larger machines, and this is set to include the pipelayer products.
CareTrack has been developed to work with the machine’s own diagnostics and combines two independent systems – GPS and mobile phone, or data via satellite, depending on availability in certain regions. These systems are co-ordinated in CareTrack and only two items need to be installed in the machine: a small computer with an integrated GPS receiver and modem plus antenna. The CareTrack system can then be accessed on a password-protected website, which provides the following information:
* The location of the machine, which provides theft protection as well as enabling service and refuelling to be coordinated;
* The rate of fuel consumption and when it’s time for the next service;
* Reports on how the machine is being used, as well as the machine’s service history and service reminders.
Where dusty conditions prevail in Australia, machines can be fitted with options such as micro-mesh screens to limit ingress of dirt into the engine and side compartments and an oil bath pre-cleaner for the air intake filter.