City Boy Mobile Crane Flexes its Muscles

Space is at a premium in the city, so there’s no place to build but up. Navigating bulky construction equipment around narrow streets can be a real challenge. Dutch company Spierings Mobile Cranes helps builders "lift to the max," with its innovative, compact, self-erecting mobile tower cranes. Their newest addition, the SK487-AT3 City Boy, is the industry's first mobile tower crane with a plug-in hybrid electric drive system. A John Deere PowerTech PSS 6.8L Final Tier 4/Stage IV industrial engine helps keep it moving and lifting.

Two in one

Spierings' self-erecting mobile tower cranes are a unique design. They have all the features of a mobile telescopic crane and of a conventional static tower crane, combined into one machine — with wheels.

Spierings' mobile cranes make quick and easy work out of heavy lifting. The revolutionary mobile cranes can be set up, operated, and disassembled by a single person in just 15 minutes. The all-terrain chassis, designed and manufactured by Spierings, provides driving comfort and stability. The company's range of mobile cranes can lift up to 18 metric tons at a horizontal working radius up to 60 meters. All units can be operated both from the cab and from the ground.

Changing the industry with Hybrid Electric Drive Systems

The SK487-AT3 City Boy uses a hybrid electric drive system and can be driven either in full-electric, hybrid, or diesel mode — which is ideal in areas with strict emissions standards.

The hybrid electric drive system combines a drivetrain with a 370-kW (495-hp) electric motor, a generator powered by a 224-kW (300-hp) PSS 6.8L industrial diesel engine, and a lithium-ion battery pack. On-site, the hybrid electric drive system can be plugged into the power grid to operate the mobile crane and charge the battery. The John Deere engine — in combination with the generator — can be used in case of insufficient on-site capacity and to charge the battery while driving.

City Boy's compact size and three steered axels make it ideal for maneuvering in narrow city streets. Yet this mobile tower crane still offers a hook height of 30.2 meters with a horizontal jib and 55.45 meters with a 45-degree luffed jib. The unit can lift up to 7,000 kilograms without additional ballast blocks. With 90-degree rotation and variable height adjustments, the cab functions as a truck cab, a crane cab, and elevator.

Ramping up for the future

Spierings uses John Deere PowerTech E 4.5L Tier 3/Stage III A constant-speed industrial engines to power the hydraulics on its other mobile cranes. For City Boy and the crawler crane, they wanted a more powerful model for the industrial engine’s dual role.

Long-time supplier NPS Diesel B.V., John Deere engine distributor for the Benelux, provided integration and testing support, as always.

"We've used John Deere engines for over 10 years; we know the technology well, not in the least thanks to NPS Diesel. They have proven a consistently committed supplier," says Ivo Kolman, managing director of Spierings Mobile Cranes.

We’ve used John Deere engines for over 10 years; we know the technology well, not in the least thanks to NPS Diesel.

Ivo Kolman
managing director of Spierings Mobile Cranes