Trailer mounted underbridge unit
By Maria Hadlow27 June 2011
Not all trailer platforms conform to the small and lightweight pattern although in its genre Terex Hydra Platforms HP 32 and HP 35 underbridge inspection units are just that.
With a three-axle configuration and 680kg (1500lb) tongue weight the machines are designed to be well balanced and are easily towed to the jobsite by 1t pick-up trucks. They are self-contained units, which are fully functional on their own, so the tow vehicle can drop them off and leave the site to handle other tasks. At less than one-half the cost of truck-mounted platforms, the machines offer an economically way to carry out bridge inspection, maintenance, restoration and utility work.
The units come standard in two platform lengths: the 9.8m (32ft) HP32; and the 10.7m (35ft) HP35. Both models have 454kg (1000-lb) platform capacity, enough for up to three workers plus tools. While standard at 9.8 and 10.7 m (32 and 35 ft), platform lengths can be customized to fit customer and jobsite requirements. The models can also be equipped with a special 3.8m (12.5 ft) long by 1.2m (4ft) wide bridge worker platform designed specifically for the removal of overhang brackets.
Dual hydraulic outriggers ensure stabile platform operation and can be mounted on either side of the trailer for left- or ride-side platform deployment. Powered by an on-board 13.4kW (18hp) gas engine with auto-idle, the self-erecting platform deploys in five minutes and requires only a single lane closure to operate. A hydraulically powered front drive wheel controls trailer movement on the bridge deck.
Both the HP32 and HP35 models are equipped the Tower Separation System, which can provide a 2.3m extension, the system includes hydraulically adjustable cross-linking arms and a level walkway with rails connecting the trailer to the vertical tower. The crossover has a vertical rise of up to 1.5m (5ft) to clear obstacles on the bridge deck without needing to retract the platform.
The platform rotates 180˚ and can be lowered to 5.5m (18ft) a voice-activated communication system connects workers on the platform to personnel at the main control of the trailer, enabling efficient trailer movement without leaving the platform. An auxiliary hydraulic pump and motor system enables the platform to be retracted to transport position should an issue arise with the main hydraulics.