Component transfer goes electric
On Friday 16 February, a toroidal field coil was moved from the Assembly Hall to a storage place a few hundred metres away. Quite a routine operation at ITER, and yet this transfer was a world premiere. The trailer that transported the 350-tonne component was powered by a first-of-a-kind electrical unit specially developed by Dutch specialist Mammoet for ITER and global logistics provider DAHER.
For years, since ITER began handling massive components on site, transfer operations have depended on self-propelled modular trailers (SPMT) equipped with conventional diesel power pack units (PPU) pumping high-pressure oil into the trailer's hydraulic motors. Diesel motors are powerful and dependable but also noisy, and their exhaust鈥攁lthough filtered and evacuated when the SPMT is operating inside a building鈥攊s heavy with fumes and fine particles.
One of the main challenges for Mammoet in developing an all-electric version was to fit a powerful electrical motor and 1.5 tonnes of batteries into the existing power pack frame, so that no specific adaptation would be needed to connect it to the SPMT. "The e.PPU, as we call it, develops an equivalent power and much bigger torque than its diesel equivalent," explains Michel Bos, who oversaw the development of the system at Mammoet. The power pack's batteries deliver 320 kW of power, equivalent to 460 hp, and can handle two days of standard operation on site before requiring a charge. A five and a half hour connection to a 63A electrical outlet is sufficient to bring the batteries back to full capacity.
Another advantage of the electric motor is silence. At 60 dB the noise generated is equivalent to that of a washing machine. "And electricity is much cheaper than diesel fuel," adds Bos who is now dealing with "dozens of requests" to produce more e.PPUs.