Two years, one 7-tonne lattice boom crane and a 2-cylinder Deutz that runs again
A Sennebogen apprentice has spent two years stripping and rebuilding a 1959 S803 duty cycle crane, down to remanufacturing imperial bearing seats for axles that started life under US Army trucks.
A machine with a long working life behind it
Patrick Niemeier, a fourth-year agricultural and construction machinery mechatronics apprentice at Sennebogen in Straubing, took on the complete restoration of an S803 duty cycle crane built in 1959. The lattice boom crawler weighs around 7,000 kg and lifts up to one tonne. After decades in service its technical condition was poor – which, by his own account, was exactly what made the job interesting.
Stripped to the frame
“We dismantled the machine from the ground up,” Niemeier said. The work began with the outer panels, then the engine and gearbox, and finally full disassembly of the upper structure and undercarriage. Every component was inspected, then cleaned, repaired or repainted. Bearings, bolts and bushes were renewed to take up the considerable tolerances that had accumulated over the machine’s life.
The axles caused the most trouble. They originally came from US military trucks of the Second World War, so nothing was metric. “All the bearings and oil seals are in inches. We had to build and rebuild many parts ourselves – such as new bearing seats or adapted diameters – to make everything tight and functional again,” he explained.
The two-cylinder Deutz engine proved more rewarding. All the parts were tracked down, and the engine now runs properly again. As Niemeier put it, the technology is simple enough that you can still genuinely work on it.
“It was great to see how a functioning duty cycle crane is created from many individual parts. This project showed me how important perseverance and precision are – and how much fun technology can be.”
— Patrick Niemeier, apprentice, Sennebogen
Tested and running
After two years of work with fellow apprentices and trainers, the S803 has been successfully tested and is running as it should. For a manufacturer whose current duty cycle crane range tops out at 300 tonnes, a one-tonne machine from 1959 is a reminder of where the product line started – and, for the apprentices involved, a rather more instructive training exercise than a workshop bench.
Projects of this kind put an apprentice through the whole machine rather than a single system: structural repair, hydraulics, drivetrain, bearings and paint, plus the fabrication work needed when a replacement part simply does not exist. Niemeier carried the restoration alongside his regular training, supported by fellow apprentices and instructors at the Straubing plant.
Source: Sennebogen — Photos: Sennebogen