Malcolm Bates travels to Germany to see an an electric Sennebogen ‘Green Line’ materials handler with an on-board Hatz powerpack.
Funny, I’m thinking as my to see how the authorities in Berlin future. Then it was the most convenient airport of entry to get to the town of Grimma – a two hour drive down the Autobahn. Today? I’m heading off to Schöneiche near Potsdam to see how the authorities in Berlin dispose of the mixed waste from this dynamic, expanding city.
True, Berlin has always been a ‘destination city’ for tourists, but in previous decades the prime reasons for visiting were perhaps more bound-up in ‘history’. Today, Berlin is more about a bright future. In trade. As a centre of increasing political importance. Culture. And of course, tourism.
So with more and more visitors, there is an increasing need to ensure the city is kept clean and tidy. We might well take a look at the refuse and recycling collection operations in Berlin in a future issue, but for now, let’s have a look at how Berlin’s bulky household waste is disposed of. Once upon a time, like in most other large cities, waste was trucked out of the city and tipped in landfill.
Indeed, the clay pits at Schöneiche, that once supplied clay to nearby brickworks, saw a second life as a landfill site. Today? Aside from the obviously man-made grass slopes and occasional gas valve, there is little clue as to the current use. The materials recovery site is clean and tidy with trees, a smart office and truck weighbridge. It’s quite peaceful.
Appearances can be deceptive – I’ve arrived along with Florian Attenhauser, mar-keting manager at Sennebogen, during a quiet spell. We’ve come to visit site manager Dirk Theuser to see how two electricallypowered Sennebogen materials handlers have replaced the diesel materials handlers in the waste processing plant.
But by the time we find him, have an introductory discussion and get kitted-up with our regulation site safety gear, the number of articulated refuse bulkers and truck-trailer combinations with hooklift containers entering the site has increased dramatically.
The site handles some 180,000 tonnes of material annually from the outer districts of the city such as Ostprignitz-Ruppin, Rudersdorf, Prignitz, Bernau, Barnim and Maarkish Oderland. In total, greater Berlin now has a population of 3.4 million people.
A BREATH OF FRESH AIR
The organisation responsible for operating the site, MEAB mbH (short for Maarkische Entsorgungsanlagen Betriebsgesellschaft), naturally has to maintain a high standard of both site safety and operational efficiency. But a number of additional factors have made things more of a challenge.
Firstly, to reduce noise and dust pollution (and indeed unpleasant smells) impacting on local residents, the entire operation is undercover. But because dust is both a health hazard and a factor in limiting the life of any diesel-powered machine, the entire tipping floor and hoppers leading to the waste processing side of the operation, is undertaken in a negative pressurised environment.
“The plant has a throughput of 75,000 cubic metres of fresh air every hour,” Dirk Theuser informs me as I try to visualise how much that might be. I settle for ‘impressive’. The pressurisation has two key advantages, he tells me – firstly it reduces dust levels and prevents it escaping when the doors to the facility are opened. It also helps prevent the air temperature inside increasing to health warning levels during the shift.
“This part of Germany can get very warm in the summer months,” Dirk informs me. As I was about to find out, he’s not kidding. The temperature inside can soon reach 40 degrees and I’m sweating already!
But while a reduction in dust and the lowering of the air temperature clearly has benefits for both the humans working on site (some 20 in total), as well as the machines, it doesn’t resolve the issue of diesel exhaust pollution. While updating the trucks and hydraulic machinery obviously helps, it’s a fact that diesel-powered machinery is not designed to work inside a building all shift long.
And as the facility was located on the edge of a former landfill that is producing significant quantities of landfill gas, it made sense to explore the option of using electrically-powered waste handlers powered by electricity generated by a landfill gas-fuelled plant, thus ‘closing the circle’ by using recycling resources. Which is where the Sennebogen ‘Green Line’ materials handlers come into the story, right? Well, yes, except ...
CABLE-TIED?
There was one more local ‘issue’ that Dirk Theuser and his team had to overcome. “We were told by our insurance company that all the machines that we had working inside the facility had to be driven outside at the end of each shift and parked offsite. They could not be left inside overnight.”
This made it difficult – impractical in fact – to use electrically-powered machines with a retractable cable reel. And as there are no battery-electric machines available on the market to either a suitable duty level or with enough battery power to last a whole shift, it was time for ‘Plan B’.
“This is when we looked at the possibility of using an electric materials handler with an auxiliary diesel powerpack,” Dirk explained.
So how does that work? Luckily, Florian Attenhauser from Sennebogen was on hand to explain. “Materials handlers with an auxiliary diesel powerpack are exactly the same as our fully-electric machines, except the rear balance weight is replaced with a demountable module containing a 30 kW Hatz diesel engine.
This unit powers the hydraulic system when the main electrical supply connection is uncoupled,” he explains. As it only produces around 50 percent power of the electric motor, it isn’t designed to enable the machine to work outside. And it’s not a diesel-electric transmission like that used on the Cat D7E crawler/dozer.
Its purpose is to enable the machine to be driven under its own power to different locations on site, retaining basic lift/rotate boom functions. When fitted, the rear-mounted cable reel is deleted.
Florian Attenhauser reports a growing interest in all-electric machines, but notes that some operators have concerns that a machine only able to operate on the end of an umbilical electric cable has operational limitations. “The provision of the Hatz powerpack overcomes any such concerns over mobility,” he suggests.
A FURTHER OPTION
But now there is another option. True, this has not been specified by MEAB – where two Sennebogen electrically-powered materials handlers (a 12 metre boom Model 821 and a 10 metre boom Model 818) are now the main frontline machines.
Both feature the on-board Hatz powerpack with self-contained battery start and fuel tank module. But in Rotterdam, Sennebogen has supplied Green Line materials handlers with a stand-alone heavy-duty skidmounted powerpack to enable the machines to load (or unload) ships on the quayside, well away from any fixed electrical connection.
When required, the powerpack is moved to another location so the machine can continue working. Already, I’m wondering if the powerpack could be mounted on a trailer and towed behind the machine? I must ask a Sennebogen product designer about that.
That MEAB has now replaced the diesel Hitachi 360s, used previously, with the two electric Sennebogens is no reflection on Hitachi – the units have been reassigned to other duties. But significantly, after putting the first Sennebogen materials handler (the 821E) into service in 2015, the improvement in air quality and driver comfort were such that a second electric machine (the 818E) was delivered in 2016.
So far, the 821E has clocked-up 3500 hours, while the 818E has reached 2000 hours. Both feature the Sennebogen ‘Max-Cab’ with a hydraulic lift of 2.7 metres, giving a driver eye-line of up to 4 metres above ground level. Problems? Nothing serious. The high operating temperatures have resulted in an upgrade to the cab air-con system and added cooling and insulation to the electrical control cabinets – upgrades that have now been added to production machines.
THE BOTTOM LINE
The waste handling market is developing rapidly. Electric machines using power generated by landfill gas are now a reality, not a dream. At first glance, the use of a diesel powerpack seems like a backward step, but it does increase mobility and thus machine utilisation.
There are however two more strands to this story – this year marks the 60th anniversary of Sennebogen, so it’s an ideal time to take stock of what is on offer from the ‘Green Line’ range. Remember, the ‘heritage’ of a brand helps fashion its
future. So with the third generation of the Sennebogen family now playing a part, ‘the future’ looks very interesting. Expect to see a strengthening of the dealer network and brand image – and perhaps a new ‘whole life’ contract service package.
On a more practical level? Remember, Sennebogen is one of very few manufacturers able to supply both diesel and electric power, together with a combination of wheeled or tracked undercarriage, or fixed podium-mounted – materials handlers. So whichever way the waste handling market goes, there should be ‘a green machine’ capable of doing the job. In more ways than one.
