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Tiago Charaf de Castro Quintão

General Manager of Forestry Operations at JSL


A case study

Among the various variables that affect the cellulose production process, the raw material used stands out, as wood represents the highest cost in production, it is estimated that more than 40% of the total cost is related to it. This is why technological investments are being directed towards minimizing these costs.

Among the various costs of wood is the logistical cost, for these logs to be transported to the industry and subsequently used for the production of cellulose. Aiming to reduce these costs, the entire logistics chain is moving in the search for efficiency, both customers (pulp and paper manufacturers) and transporters, who are looking for technologies that can differentiate them from the competition.

And, for efficiency, we can consider the most varied initiatives, one of which is most relevant being the proper optimization of the loading box of forestry transport implements (semi-trailers), which consists of transporting the largest volume of product possible in a single trip. It is common to see vehicles transporting wood logs on the highways, normally of the twin-train type (vehicles with up to 7 axles, with 2 trainsets and limitation of Total Gross Combined Weight) of 57 tons) and tritrem (vehicles with up to 9 axles, with 3 compositions and limitation of Total Gross Combined Weight of 74 tons).

Ordinance 268, of March 2022, approved by the National Traffic Secretariat, approves vehicles and combinations of cargo vehicles, as well as their weight and dimensions limits, depending on the size and compatibility of the roads. While the logistics chain seeks off-road transport options, using internal and private roads, where, with due investment in the size and structure of the roads, vehicles with greater length, height and width can be used. We have seen recent experiences with the use of vehicles known as pentatrem and hexatrem (vehicles with 15 axles or more, with 5 and 6 trainsets and no limitation on Total Gross Combined Weight). These are certainly options that significantly reduce the cost of transportation, but they present several operational limitations, including the location of the forests in relation to the factory, relief of the areas and maintenance and conservation of roads.

As the restrictions are great, most cellulose plants in Brazil still receive wood by conventional means of transport, using the country's roads, urban and rural highways. The challenge for transport companies to meet customer demand is, together with car manufacturers, to develop equipment that presents the appropriate ratio between the lowest weight (tare) possible, preserving the robustness and quality of the materials to be used in the manufacture of the equipment.

To provide a better example, I bring the experience that we, at JSL, as a logistics operator, have had over the last decade. For this demonstration, we will use as a reference the tritrem equipment for transporting logs, equipment made up of a mechanical tractor horse, 6 by 4 coupled to a set with three compositions, which has a total of 9 axles, a total length of up to 29.90 meters and total gross loaded weight of up to 74 tons. In the quest to increase the free load box for transporting logs, year after year, work is being carried out to study the components and materials used in the manufacture of implements, and the results are shown in the highlighted graph.

Still in 2010, there was equipment known today as “super heavy”, entirely made of conventional carbon steel, which had as its main characteristic robustness and ability to withstand severe operations. Starting in 2013, the market introduced the possibility of using low-alloy, high-strength steel in the equipment manufacturing process, which is up to 15% lighter than conventional carbon steel. The mix between carbon steel and Domex steel brought an immediate gain of more than 1 ton free to transport wood in the cargo box.

In 2014, in addition to increasing the share of special steel in the manufacture of equipment, the use of other components not used by the segment was introduced, namely the inclusion of pneumatic suspension, replacing mechanical suspension, chassis lowering, replacement from conventional iron wheels to aluminum wheels and, finally, the inclusion of Single running (reduction from 4 sets of wheels and tires per axle to 2 sets of wheels and tires per axle) with a change in tire tread width of 295 millimeters to 385 millimeters. This entire initiative brought a substantial gain of 4.9 free tons of wood in the cargo box compared to the super heavy equipment from 2010, an increase of 10.6%.

With the gains came the consequences of a large number of breakdowns and reduced availability, especially in regions of the country with greater operational severity, which forced the transporter and assembler to rethink the project. From 2016 onwards, already 2 years after the introduction of "extra light", it was necessary to reinforce the equipment structure and, in some regions, resume the use of double wheels.

From 2018 to 2020, with a great history of main maintenance interventions and mechanical availability, we arrived at the mix optimal use of components. This allowed us, throughout the entire period of migration from extra heavy to extra light, to capture a total cargo box gain of approximately 3.2 tons of wood, which represents a total increase of 7%.

Among the various lessons learned throughout the decade of development, we can highlight the main points, which are: project regionalization (each region of the country requires specific care when sizing the implement); suitability of the tire used depending on the coating used on unpaved roads; review of maintenance processes and the qualification and specialized training of maintenance labor, mainly with regard to the care of pneumatic suspension and welding of special steel alloys.

The chain's challenge is to continue seeking evolution, with regulatory initiatives for the use of larger equipment on highways. It is also necessary to continue the development of alternative components and materials that bring greater competitiveness to the sector, with a consequent reduction in costs and the number of vehicles on the highways, which positively impacts society.

In addition to the sizing of implements, in recent years, we have worked on several other initiatives, mainly focused on the use of technology to gain efficiency with better physical use of the fleet, cost optimization and, mainly, safety, which brings us greater sustainability for the business.