The Cat Certified Rebuild program sees a pipelayer rebuild with first-ever engine emission upgrade

Normally, pipelayers are found wherever water, gas or oil pipes need to be laid. Where most of the construction machines of this type are being used to build pipelines, there are also a few working on moving the conveyor belts at open pit mines. This is the case in Garzweiler, Germany, where one of Europe's largest power producers, RWE Power, produces approximately 40 million tonnes of lignite from an area that measures 66 square kilometres.

A 70-tonne Caterpillar pipelayer 589 has been moving conveyor belts every day since 1994. It also helps when conveyor belts need to be replaced. This allows the machine to play out its greatest advantage; due to its heavy counterweight, the Cat 589 can transport heavy loads on its side, in addition it is an all-terrain vehicle. Over the years, it has racked up almost 15,000 hours, and it  was beginning to show. While the pipelayer certainly deserved a break from its unfailing service, the people from RWE Power simply could not manage without it. With no new machine available in this weight category, the Cat 589 had become irreplaceable. In order to get the pipelayer back in shape, RWE Power and Zeppelin's Cologne branch decided to have it rebuilt, creating a second life for this valuable machine while keeping non-renewable resources in circulation and significantly reducing engine emissions. Not only would the machine life be extended, but it would be cleaner and more efficient, an important environmental benefit.

Good past experiences with rebuild

But what exactly is done when a machine is rebuilt? In short, its technology is updated to the latest state of the art. First, it is disassembled completely, reworked, rebuilt from scratch, and then assembled again. Thus, the customer receives a machine that is practically as good as new with the related warranty, and he can use it for many more years. The cost of a rebuild is significantly lower, varying from 55 to 70 percent of the transaction price of a new machine.

"RWE Power already had a good experience with the rebuild of a Cat scraper in 2006, and so we did not have to convince them of the advantages. Since then, the scraper has been doing its work in its customary reliable way. And that is exactly what we expect from the rebuild of the pipelayer," says Dietmar Steiger, a salesman from Zeppelin.

The complete disassembly of the pipelayer at the Zeppelin work shop took four months. All the parts - including engine, radiator, transmission and axles - where taken apart, inspected and repaired by service technicians. All the components of this construction machine were rebuilt exactly to the strict requirements Caterpillar has set for its rebuild program. This also applied to the various bearing locations on the base frame, boom and chassis. For this purpose, the bearings were drilled or welded out and machined to the specified dimensions.

"By the time the machine had been assembled again, all key technology innovations had been integrated which have meanwhile been added to the series production," explains Dieter Richter, Zeppelin shop administrator. Zeppelin service manager Klaus Pick adds, "A very special challenge was the rebuild of the engine from mechanical to electronic control, which also required changing the radiator." "Such a rebuild of a pipelayer, including the engine, was a first not only for Zeppelin, but also for Cat. It has never been done before," reports Thomas Daniels, Zeppelin service manager for the Cologne region.

The rebuild also included the operator station. The cab was replaced by a new, more comfortable cab that was specifically built for this machine type, and equipped with special lighting and an auxiliary heating system according to RWE specifications. Finally, components, panels and frame were sandblasted and repainted so that the machine's outside also shines again.

14,500 parts replaced in four months

In total, 17 Zeppelin employees from the shop, transmission department, welding, chain press and cylinder, parts store and office were working on this project. They were in constant communication with the customer. Wolfgang Krichel, shop manager, and Günter Plonczynski, mining infrastructure manager, both from RWE Power, compliment, "Cooperation with Zeppelin worked really well and was very constructive." In order to meet the tight deadlines, Cologne service manager Klaus Pick, shop manager Jürgen Krawinkel, and salesman Dietmar Steiger coordinated the work to make sure that the large job was completed step by step. In total, 14,500 parts were replaced.

When all work was completed, the machine was taken back to the open pit mine in mid-March 2008. Thanks to the rebuild, it will be able to move conveyor belts there for another 15 years, and it will continue to be an indispensable help when replacing conveyor belts. If necessary, for 1,000 hours a year day in, day out. 

About the Cat Certified Rebuild program

The Cat Certified Rebuild program is a factory developed, complete machine rebuild process, which includes critical engineering updates ensuring the machine features all the latest technology. The cost of a rebuild is significantly lower varying from 55 to 70 percent of the transaction price of a new machine. Yet the machine has a like-new warranty. The rebuild is performed by Cat dealers to Cat specifications.

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