The department of Drôme is located in the Auvergne-Rhône-Alpes region and is an area featuring many “greenways”, including a trail that starts in Montélimar and continues for over 60 km to be explored by bike, on horseback or on foot.
A new section now being added will also connect the small village of La Batie Rolland to the other existing trails, increasing the total length of this bike path which is one of the most interesting in all of France.
A trench to assure the long life of the bike trail
The new section is being laid with a special pavement that not only guarantees an excellent surface for bike riding, but also features a type of asphalt that retains the natural color of the aggregate.
The path, however, requires protection from the effects of the roots of the dense vegetation flourishing at its sides in many sections. Because the roots grow constantly, they pose a threat to the long term integrity of the surface, a significant problem that impacts the durability of the new bike path. A solution was found by digging a trench 90 cm deep and 15 cm wide for an initial section of 3 km on each side (for a total of 6 km).
The trench is being lined with a special anti-vegetative sheet that prevents the roots from penetrating the trench, forcing them to run parallel to the trench or else grow in the opposite direction. And because they do not cross the path, they avoid causing the pavement to lift, a condition that could make cycling difficult and dangerous.
Although it may seem easy an easy task, digging the trench presents several challenges because the quantity of roots already under the edges of the trail as well as the different-sized stones meant that the attachment used would have to be sufficiently strong and durable to guarantee the desired productivity and precision.
François Gilles, owner of GTPSE, the contractor for the job, pinpointed the solution by choosing the Simex CHD 120B chain trencher -- a version for machines fitted with booms -- which the contractor had ordered from area manager Nicolas Mariatte of our dealer CIMAX TP based in Colombier-Saugnieu. The chain trencher was coupled to a Komatsu PW 118 MR wheel excavator weighing 12 metric tons.
Productivity and reliability, a Simex hallmark
The Simex CHD 120B chain trencher stands out from the many models on the market for its impressive structural strength and the use of chains constructed with materials assuring a high resistance to wear. GTPSE chose the attachment with a chain including hoe blades and teeth to exploit the hydraulic power of the attachment and that of the excavator (pressure 130 l/m, flow rate 240 bar).
These features greatly benefited productivity: by making the most of the weight and stability of the excavator, the CHD 120B managed to perform problem-free trenching, tackling knotty roots and splitting large stones for the entire 6 km without giving the slightest sign of difficulty.
While on the job, the CHD 120B also excelled for the efficiency of the discharge screw which was united to the trench clearing device to keep the trench clean, all to the advantage of the productivity and rapid execution of the project.
Despite the difficult conditions of the terrain, the excavator advanced at an average of about 200 meters/hour, productivity that fully satisfied the contractor’s technicians. The technicians also emphasized how the ability of the attachment to push down to a depth of 1200 mm offered an advantage from an application standpoint, both on the bike path site (where the CHD had to arrive at an inferior depth than the maximum) and in future applications.