Hilary Burke reports from Lodge Farm in Lincolnshire, where contractor KWR Plant’s Senneboggen 718 is being put to work on reducing the height of a shelterbelt of crack willow.

LODGE Farm, between the small hamlets of Stubton and Brandon, lies a few miles south-west of Newark-on-Trent. The most economically efficient use of the level, well-drained land – as it happens, just inside Lincolnshire – is for arable crop production. With the grain harvesting season in full swing, the morning of 12th August saw one of the agricultural holding’s largest wheatfields still awaiting the attentions of the combine harvester.

It was, however, not the only harvesting operation booked in that day for Lodge Farm. KWR Plant were due to reduce the height of the crack willow shelterbelt that grew between the big wheatfield’s well-made access track and the substantial drainage channel that kept the soil in good heart. Ensuring the considerable amount of cut material was safely deposited in the timber zone to await chipping – well clear of the track and wheatfield and out of the watercourse – was the first objective of the exercise.

Forestry Journal: The Vosch grapple saw is a lightweight attachment that combines precision cutting with viable timber production. Kevin Russell takes his time and works the head through the dense foliage of the willows to prune the first tree and clear a line of sight for subsequent operations.The Vosch grapple saw is a lightweight attachment that combines precision cutting with viable timber production. Kevin Russell takes his time and works the head through the dense foliage of the willows to prune the first tree and clear a line of sight for subsequent operations.

Owner Kevin Russell and KWR’s contract manager, Alec Pearson, had agreed to set themselves another challenge. A two-hour window of harvesting operations would demonstrate to invited visitors exactly what KWR Plant’s Sennebogen 718 could deliver in terms of dealing with rideside, trackside or roadside overgrowing trees. Machines had been inspected and engines and hydraulic systems warmed up as the clock ticked down to the scheduled start of operations.

At precisely 10 am Kevin Russell set off southbound from Lodge Farm’s yard in the Sennebogen 718 along the track to the mid-point of the shelterbelt of willows. Machine operator Rimvydas Miseikis followed in the Ponsse harvester. Rim, as he is known by the KWR Plant team, would lead back towards Lodge Farm clearing regeneration and sucker growth between the big willow boles with the Bracke C16 silviculture/biomass harvesting head.

Kevin would follow in the Sennebogen 718, employing the Vosch grapple saw to section the spreading crowns of the willows. With the crop of cereals still awaiting harvest, Henry Hillsden in the Fendt tractor had been obliged to turn the UFKES Greentec chipper unit at the far end of the track and would draw up behind the two harvesting machines when operations commenced.

German manufacturer Sennebogen has been producing lifting and handling equipment in Bavaria since 1952. Crawler and duty cycle cranes from 30–300 T lifting capacity form one of the company’s most successful machinery ranges. Custom design and fabrication of heavy lifting equipment for dockside use is another of Sennebogen’s speciality services.

Forestry Journal: The Sennebogen 718 forms an extremely stable work platform. Powerful upper carriage slewing combined with the precise positioning systems of the Vosch grapple saw ensures cut material is under control at all times. Once on the ground, longer material can be reduced and manipulated into the produce zone.The Sennebogen 718 forms an extremely stable work platform. Powerful upper carriage slewing combined with the precise positioning systems of the Vosch grapple saw ensures cut material is under control at all times. Once on the ground, longer material can be reduced and manipulated into the produce zone.

In the company’s material-handling range the 8100/1130/8160 crawler or rail-mounted models see regular use loading and unloading timber vessels in the port. In the mill yard the four-wheeled Mobile 723/730/735, with all-wheel steering and powerful boom configuration, are extremely adept at unloading trucks and supplying the mill infeed. The Sennebogen 718 has been developed from the smallest of the range and is now fulfilling an extremely specialised role in the German manufacturer’s fleet.

Fuelwood harvesting for chipwood production is a relatively new sector for Sennebogen and the design engineers were committed to developing a machine that was a truly efficient all-rounder for biomass contractors. One of the most promising spheres of operation was to allow dead, dangerous or problem trees to be sectioned at height. On roadsides, beside waterways, near railways or in the built environment timber could be quickly and safely lowered to await the attentions of the chipper. The quick interchange of attachments makes the 718 a multifunctional carrier; being rapidly converted, for example, to load woodchips or round timber.

Forestry Journal: With a quarter of an hour remaining of the two-hour time slot, Kevin Russell dismantles the crown of the willow nearest Lodge Farm’s yard. A fairly stiff breeze had sprung up and was not assisting the lowering of the sections into the designated timber zone. Nevertheless, even with the Sennebogen’s K13T crane at full extension the Vosch grapple saw has complete control of the sizeable limbs.With a quarter of an hour remaining of the two-hour time slot, Kevin Russell dismantles the crown of the willow nearest Lodge Farm’s yard. A fairly stiff breeze had sprung up and was not assisting the lowering of the sections into the designated timber zone. Nevertheless, even with the Sennebogen’s K13T crane at full extension the Vosch grapple saw has complete control of the sizeable limbs.

A newly developed crane, the K13T, has increased the working range of the 718 and has also reduced the machine weight to 21.4 T. Nevertheless, at full 13 m extension it still has a lifting moment of 1.7 Nm. An inner boom of 6.5 m and an outer boom of 4.2 m – with a 2.05 m extension – has given the crane an operating action suitable for efficient timber harvesting at the stump with one of the smaller harvesting heads. Managing tree-planting schemes commonly associated with infrastructure projects is just one of the tasks ideally suited to the Sennebogen 718.

The machine is in a class of its own, however, on crown-reduction or dismantling duties. The hydraulically elevating E270 Maxcab gives the operator a precise perspective on the work in hand. An hour after the commencement of operations, Kevin Russell had behind him well over a score of clean high-pollarded willow stems. Rim, in the Ponsse harvester, was getting ahead with the undergrowth clearance and could spend a little time with the Bracke C16 head cleaning the lower growth from the remaining stems.

Forestry Journal: (L–R): Tom Morton, Henry Hillsden, Kate Russell, Rimvydas Miseikis, Kevin Russell, Alec Pearson.(L–R): Tom Morton, Henry Hillsden, Kate Russell, Rimvydas Miseikis, Kevin Russell, Alec Pearson.

Henry Hillsden, nevertheless, was not keeping pace. In fact, he had run down the drum in the Greentec chipper and stowed the loader. The simple fact was that the 25 m³ capacity Greentec chip-trailer was by now brimming over with fresh biomass-grade willow chips. The Ponsse and Sennebogen would need to travel back towards Lodge Farm and turn onto the wheatfield’s headland to allow Henry passage.

On constrained worksites there are always going to be interruptions. Alec Pearson had called for work to be halted a couple of times while visitors were shepherded through the exclusion zone to watch operations from the optimal viewpoint. The holdup incurred for delivering the chips to the yard at Lodge Farm took little longer; around 20 seconds or so to shift the loader clear and then tip the woodchips into the waiting road trailer.

With the Valtra/Greentec combination turned and soon on its way south again, the harvesters could back down and resume work. Bracke Forest AB’s C16 biomass harvesting and accumulator head is of a unique design. A heavy rotating disc with fixed teeth is common for timber cutting in the US and Canada. Combining a lighter spinning disc with a 3/4-inch self-tensioning harvester cutting chain was an innovation that was far more suitable for the lighter and more nimble cut-to-length machinery commonly operating in Europe.

Forestry Journal: In most circumstances, chipping the harvested timber and branchwood is not as time critical as the harvesting operations – especially if infrastructure closures leave limited windows of operation. With time to spare in the trial, the two harvesters were able to move aside to allow Henry Hillsden to unload the chip bin into a waiting skip. Henry was soon turned and back onto site for a second load.In most circumstances, chipping the harvested timber and branchwood is not as time critical as the harvesting operations – especially if infrastructure closures leave limited windows of operation. With time to spare in the trial, the two harvesters were able to move aside to allow Henry Hillsden to unload the chip bin into a waiting skip. Henry was soon turned and back onto site for a second load.

Van Osch Construction and Forestry BV is a Dutch machinery manufacturer, now based in Emmerich just across the German border. The design of the Vosch grapple saw again gave priority to weight reduction – in this case to increase the performance parameters when working at height. Much consideration, however, was given to the attachment’s rotating system. Accurate manipulation of the grapple saw was essential when working in and around the crowns; a firmly controlled grasp was needed to safely lower cut sections to the ground.

Sennebogen engineers had pursued a similar line of reasoning when developing the 718. While weight reduction was desirable, precise and perfectly controlled slewing of the upper section was of paramount importance for pruning and crown-dismantling operations. The provision of an oversize slewing ring would increase the power and sensitivity of the operation, with a slight decrease in slewing speed. Kevin Russell was able to put the Sennebogen/Vosch combination to the test with the northernmost willow in the shelterbelt.

With 20 minutes of the window of operations remaining, Henry Hillsden had another 25 m³ of chips in the Greentec tipping trailer. Kevin had a short discussion with his contracts manager, Alec, over the airwaves before moving onto the headland to allow Henry to access the Lodge Farm yard. With a quarter of an hour left, Kevin moved back to deal with the last crack willow.

Stark against the clear sky behind, the open-grown willow showed its true size. A steady, but gusty, westerly breeze had generated over the Lincolnshire plain. Kevin removed a substantial branch that hung over the wheatfield, raised it to the vertical position with the foliage streaming, and then turned it over to deposit it into the ‘timber zone’. After that it was plain sailing and machinery and operatives were clear of the working site with a good few minutes to spare.

Forestry Journal: Bracke Forest’s C16 Silviculture and Biomass Harvesting head employs a unique patented cutting system. A 3/4-inch self-tensioning sawchain fitted to the outside of a 795mm disc has enhanced cutting speed and durability without the large increase in attachment weight normally associated with tooth-fitted disc-cutting systems.Bracke Forest’s C16 Silviculture and Biomass Harvesting head employs a unique patented cutting system. A 3/4-inch self-tensioning sawchain fitted to the outside of a 795mm disc has enhanced cutting speed and durability without the large increase in attachment weight normally associated with tooth-fitted disc-cutting systems.

Kevin was able to relax for a while and extol the virtues of the Sennebogen 718: “The safety features on this machine are brilliant. We can put up a virtual wall by coding in slew and height restrictions on the processor. As we often deal with dangerous trees, we have opted for Lexan Margard polycarbonate protective screening and overcab caging. To operate the KWR Plant machinery, myself and all my operators need to be safe in the knowledge that the kit we use gives us the best protection available.”