Demag quality in the spotlight

21 November 2017


Terex invited hundreds of crane buyers and dozens of journalists to its Zweibr├╝cken facility to present its latest city crane, and to demonstrate the technical excellence of its Demag brand. Will North joined the tour.

While the star of the show was the new AC 45 City Crane, the day long tour and presentation was about the Demag brand as much as any single crane.

The day opened with a tour of the company’s all terrain plant in Wallerscheid. Here, Terex builds roughly one crane a day; across town in Dinglerstraße, it builds one of the big CC crawlers a week.

The company has focused on developing the lean techniques used at the plant. Where once only complex components like hydraulic parts were ordered using a just-in-time supply chain, now even the supply of steel plate follows the system. A ‘pull’ system is used: as material flows through the production in one direction, information flows in the opposite direction. As a crane approaches the paint shop, the signal for a new delivery of steel plate is sent to the start of the line.

At the same time as it has refined the supply of information from the production line, Terex has further modernised how it designs cranes. Until recently, the routing of hydraulic systems was worked out manually, on the prototype.

As pieces were bent to fit, their measurements were recorded. Now, with improved modelling, Terex plans this routing in the same CAD system used to design the rest of the crane, paying close attention to how workers will access the crane during assembly.

Terex values the input of its workers in how the line works. One very noticeable example during the tour was the direction the cranes face as they move through the plant. Until recently, carriers moved into final assembly forwards. However, one of the workers responsible for bringing finished booms over from the boom assembly line pointed out that this meant that every boom had to be turned around to be fitted to the carrier. Now, the carriers reverse along the line.

The cost of quality Quality always costs. If it isn’t paid for in advance, it will often be paid for later, either in lost opportunities, or in making right what has gone wrong.

At this event, Terex CEO John Garrison and Terex Cranes president Steve Filipov were frank about the issues the company had faced with some products.

The Challenger line, Filipov said, had been a challenge. The company had received a series of complaints from customers, and had committed to fixing them all.

Neither Filipov or Garrison would detail the costs of fixing these issues, or number of machines affected, but they pointed to the company’s results from last year: in Q3 of 2016, the company had set aside an extra $15m for warranty expenses. While Kevin Bradley had told analysts at the time this was ‘fairly broad-based’, a substantial chunk appears to have gone to fixing the Challengers.

In all, Filipov said, the company identified 97 issues with the crane. It offered customers the chance to have a new crane available while theirs was fixed, and set aside a space in the Zweibrücken line for repairs.

Bright blue and yellow future

Repairing mistakes is only one part of the company’s strategy. Equally important is making a commitment to the future, and celebrating past successes.

Key to this approach has been the Demag brand. Terex has now fully embraced the Demag name, which its customers had always been resistant to giving up. As a brand in its own right, it represents the premium end of the company’s product line; the company references the concept of ‘Demag technology inside’ for its US-built Terex cranes, to highlight technologies that add value to these cranes.

The focus on Demag, coming as Terex sold off parts of the company, lead many to think that the German crane business would itself soon be sold. Garrison addressed this directly in his presentation, saying, “The cranes business is not for sale. This is a business we are going to invest in.”

The next generation

The AC 45 City is one of the first fruits of this ‘new Demag’. The crane builds on the success of the AC 40 City, of which Terex has sold more than a thousand units.

Terex said the new three-axle unit ‘redefines compactness’ in the 45t lifting capacity class with a total length of only 8.68m, a width of 2.55m and an overall height of just 3.16m. Its height can be reduced to less than 3m when space is at a premium, as is the case indoors.

The crane features a larger cabin, which has been redesigned to reduce vibration and noise for the driver.

With the base section of its fully hydraulic 31.2m main boom also particularly compact with a length of 7.8m, the AC 45 City is able to work in buildings with a relatively low clearance while still keeping its boom at a steep angle.

A 1.3m-long runner is available for loads of up to 25t or with the threes heave hook block, which allows for six-part reeving. Offsettable main boom extensions of 7.1m or 13m increase system length to 44.2m.

For owners of the previous AC 40 City, the new crane can use their old main boom extension.

Like all Terex’s new cranes, the AC 45 City comes with the IC-1 Plus control system. Unusually, the crane’s variable load moment limiter can calculate capacity from infinite outrigger positions. This will be a particular advantage when setting the crane up in compact positions.

In addition, the Demag AC 45 City comes with features such as an axle load indicator, a hook height indicator, cruise control, and cameras for load, hook and hoist monitoring and for backing up. Remote radio control and storage boxes are included as well.

The crane will undergo further testing over the next six months, and is expected to be in serial production by the summer of 2018.

On the tour, Terex unveiled the first prototype as part of dramatic showcase in a hangar at Zweibrücken’s small local airport; the carrier for the second prototype was being assembled as we toured the factory.

The AC 45 City was not the only crane on display during the tour. In the hangar alongside the city crane was six axle, 300t, AC 300-6. This crane offers an 80m boom, able to lift 15t when fully extended, compared to 9t on its predecessor. Unusually for cranes in this class, a luffing jib is available.

On show outside the hangar were an upgraded AC 100-4 and the AC 55-3. The four-axle now has improved capacity in key areas, and standardised counterweight pieces.

On the three axle crane, Demag’s designers focused on keeping the crane compact, with no need for additional transport. They also paid close attention to reducing risks of corrosion and wear.