contractor J&P-AVAX regularly having to encounter steep slopes
of sometimes 30 - 35˚ inclination.
Working safely in this tough environment was the most
important consideration for this contractor and why, on this
project, the company elected to rely only on Volvo CE’s rotating
pipelayer technology for all pipe handling duties. The company’s
fleet comprised 16 units – 10 PL3005D (51 t tipping capacity),
five PL4608 (80 t tipping capacity) and one PL4809D (90 t
tipping capacity, and up to 102 t with the optional, additional
counterweight). The additional counterweight is ideal when
working with a boom extension for tie-in operations or pipe
unloading and stacking. The smaller PL3005D features an extra
heavy, standard counterweight for added stability.
John Joannou, responsible for machine procurement at J&P-
AVAX, said at the time: “I was impressed by the machines’ excellent
stability. The 360˚ swing capability, cab comfort and the load
management system (LMS) is much appreciated on this hilly project.”
Unrivalled safety
Safety is at the forefront of Volvo’s rotating pipelayer design.
Lowering-in pipe on steep slopes, or even travel on steep
slopes, is not without its hazards. Gravity takes over, allowing
the pipe to swing downhill and increase weight to the rear,
which can be potentially dangerous. With Volvo’s unique,
360˚ upper structure swing capability, the boom can simply be
positioned uphill, thereby allowing the load to be kept ahead of
the machine, ensuring better stability and operational safety in
these demanding conditions. Boom pads fitted to the underside
of the boom will protect the pipes from damage, although it is
not uncommon for a contractor to apply additional padding to
help hold the pipe more steady and prevent swinging, thereby
minimising unnecessary concern for the operator who can then
focus on the task in hand.
The tendency for pipe to swing downhill on a slope naturally
puts extra strain onto machine components. To overcome this
problem Volvo pipelayers feature a heavy duty, hydro-mechanical
slew lock. This lock can be engaged at every 10˚ interval around
the slew ring, enabling the operator to lock the upper structure
at the most appropriate angle to combat pipe backswing while
at the same time resisting additional strain and wear on the
machine’s components. The steeper the slope, the more the
boom can be positioned towards the front of the machine. When
working on tie-ins, this slew lock feature enables the pipe to be
held steady during the start of the welding process.
Carlos Aiello, a pipelayer operator with French contractor
SPAC, appreciated the slew lock for other reasons, commenting:
“It is a very delicate operation doing tie-ins and this machine
is extremely stable and precise. I also like the machine’s upper
structure swing lock feature for pulling pipes under crossings.”
Improving further still its slope performance, the latest model
PL4809D brings a 70% improvement in tractive force enabling it
to climb a 30˚ slope with ease with a heavy load in the hook, in
addition to its ability to move with ease over rough terrain.
Precise load management
A further safety enhancing feature is the machine’s unique,
onboard LMS, which alerts the operator of the need to engage
the machine’s heavy-duty, hydro-mechanical slew lock on slopes
above 10˚ and is calibrated to work on all slopes up to 30˚.
Using sensors mounted on the boom and on the machine’s
upper structure, the LMS permanently monitors the slope
inclinations – fore/aft and lateral – boom angle, orientation and
load. Information is fed continuously to the operator, via both
Figure 2.
State-of-the-art, onboard LMS.
Figure 3.
Cameras enhance site safety.
Figure 4.
Lowering-in alongside both sidebooms and crawler
cranes on the Bunde-Etzel 48 in. pipeline in northern Germany.
100
World Pipelines
/
FEBRUARY 2016
