Headroom, not capacity, was the constraint on a Prague city-centre underground car park
Czech UNIC dealer KMB has supplied a UNIC-506 spider crane for the construction of a multi-storey underground car park in central Prague, where extremely low ceiling heights ruled out conventional cranes from the outset.
Working beneath existing structures
The project involved building underground garages on a busy city-centre plot. The combination of confined working areas, narrow access routes and lifts that had to be carried out beneath existing structures left very little room for a machine to stand up in, let alone slew a load.
Headroom was the deciding factor. KMB selected the UNIC-506, a compact crawler crane intended for exactly this kind of low-clearance work, and moved it into the underground space to operate directly beneath the finished soffit.
2,200kg loads in a confined bay
Despite the small footprint, the URW-506 handled loads of approximately 2,200kg through the works, placing them with the accuracy the sequence demanded. Its outrigger configuration could be adapted to the asymmetric set-up positions available, which is often the limiting factor in a car park structure where columns and ramps break up the floor plate.
Responsive controls allowed lifting close to walls, ceilings and structural elements — a routine requirement underground, where the margin between the load, the crane and the permanent works can be measured in centimetres rather than metres.
Avoiding structural work to suit the crane
The wider point for the contractor was what did not have to happen. The job was completed without bringing in larger machinery and without modifying the structure to accommodate it, which kept the programme intact and avoided a temporary works exercise that would have added both cost and risk.
KMB is the official UNIC Cranes Europe dealer for the Czech Republic and Slovakia, and has built a portfolio of confined-space lifting that runs from high-rise glazing in Prague to industrial installation work. The company supplied the crane and supported the customer through the underground phase of the build.
Dense urban sites like Prague city centre place a premium on equipment that minimises disruption at street level, and an underground lift carried out by a machine that can be tracked in through a normal access ramp does not require road closures or crane pads.
The UNIC-506 has since been superseded in the UNIC range by the URW-546, though the model retains a strong reputation for confined and low-headroom work of this type.
Source: Unic — Photos: Unic