On a recent visit to Tullamore, Liam Keilthy was struck by the side view of a multi-storey carpark nearing completion to the rear of a new shopping centre on property across the river from the Bridge Hotel. On investigation it turned out to be a lightweight ‘space frame’ steel structure, which he describes as the first use of this technology in Ireland and a potentially exciting development.
Passers-by are struck by the open and light design with excellent penetration of daylight and naturally ventilated areas. The three-level carpark was erected on a prepared site in less than eight weeks and cost less than EUR5,000 per space. This compares to a ten month-plus construction period for concrete car park structures and costs of EUR10,000+ per space. On this basis the system appears to have a lot to offer.
The concept is to prefabricate the structure off site and erect it on site in a very short timeframe using factory trained teams of erectors. The galvanised and powder coated members are precision engineered and fabricated prior to shipment. The structure goes up smoothly with little noise or site disruption.
Internally the car park is brightly lit and well signed with light boxes suspended from the ceiling recesses. The ramps are gentle and wide – easy for both pedestrians and vehicles to navigate. The decks are well finished in what appear to be integrated steel and concrete panels. The walking surface has good slip resistance.
The vertical members are all lightweight ‘I’ beams causing minimal disruption to sightlines. This is critical in a structure that uses structural columns positioned within the parking area. In most concrete structures these columns tend to be massive and lead to a reduced sense of personal security and pose navigation hazards for vehicles. In this structure, they are about 150 mm square and are totally unobtrusive.
The internal grid is very generous at 7.5 m x 5.0 m. This allows for three parking spaces between each pair of columns. The lightweight columns permit each parking space to be ‘future proof’ at 2.5 m wide by 5.0 m deep. This compares to the standard 2.4 m x 4.8 m used in most modern facilities.
Because of the design and structure this system is effectively de-mountable. It could be used as an interim parking solution on busy sites where the long-term strategic plans envisage major new facilities but where timing may be uncertain, for example hospitals, airports, factory complexes or universities.
A hospital that needs staff parking but cannot justify the investment in a high spec building nor commit long term to a permanent location for a multi-storey car park should find this a very attractive proposition. Local councils could consider this system for local car parks where charges are going to be kept low and commercial returns are not a major consideration.
To say that the costs per space of this system are very low compared to traditional systems and structures may be to compare apples with oranges. The typical ‘space frame’ carpark built using systems reminiscent of childhood ‘mecano’ sets increases in cost if for example:
a high specification brick or stone cladding is added
passenger lifts or fireproof stairwells are included
the lobbies and stairs have tiled floors and plastered walls
As the saying goes, ‘horses for courses’. This system has a definite place in the parking business and can resolve some significant issues for owners of restricted sites.
There are other technologies available for carparks including:
stacking systems where one car is raised above another to double the capacity
moving pallet systems where eleven cars can be fitted into a space occupied by six by means of an additional deck
large-scale automatic ‘warehousing’ systems where robotic lifts take cars from ground level and store them in bins for later retrieval.
In Paris some apartment blocks are meeting their parking requirements by tunnelling a vertical shaft into the court-yard, installing a cylindrical silo and closing over the opening with a garden. Cars drive onto a plate, the driver locks up, and leaves and the car is dropped down and slotted into a bin beneath the plaza. The whole unit is controlled by a computer and smart cards.
The new lightweight systems, through the combination of low cost and short erection time, will enable many existing surface car parks to be expanded in an economical and efficient way. The stacking systems and moving pallets are already in use here. Engineers and architects may find it useful to include these concepts in their portfolio of parking solutions.