Internal transport system of large-sized concrete elements


Kerkstra simplifies production processes and increases productivity with intra logistic transport system

The company Kerkstra produces, among other things, TT slabs and large-sized façade panels at its plant in Trenton, near Detroit, USA. During production, the early morning demolding of the precast concrete elements was an organizational and logistical challenge, as the transport to the storage area was done by truck. For this purpose, individual truck semitrailers were parked in the hall and then loaded one by one. Afterwards, each trailer was driven individually to the storage area and unloaded there by means of a rubber-tired gantry crane – also called MI-Jack.


WECKENMANN was given the task of developing a proposal for a truck-independent transport system that would meet the following requirements:

  • Maximum transport weight of 56 to

  • Transport of façade and TT panels of any length

  • Transport of the façade elements, both horizontally and vertically

  • Power supply via battery

  • Weather- and winter proof version

  • Operation by one person

  • Lowest possible overall height

  • Use of transport racks that allow loading or parking independent of the vehicle


The result of the planning and engineering project has been in successful operation since spring 2020 and consists in detail of two track-bound low-floor vehicles, each with a powerful battery on board.

Depending on the length of the element to be transported, individual transport racks are set up either individually or in pairs on the track system along the production tables one behind the other. Pluggable end plates are available for vertical transport of the façades.

Transport of the TT panel
Transport of façade elements

25 transports per day thanks to battery with high capacity

The operator moves the two vehicles either synchronously or reversibly in single operation under the respective transport rack, lifts it and moves the complete unit to an area outside the hall where either the TT slab or a transport rack loaded with wall panels is taken over by the gantry crane. For safety reasons, the distance between the two carriages is continuously monitored in synchronous travel operation to prevent the load from slipping, if one carriage fails.

Both carriages are operated via an industrial radio remote control, which allows the operator to see the travel range in front in the direction of travel in order to prevent possible collisions. In addition, each vehicle is equipped with safety bars at the front sides, which stop the vehicle in case of an emergency.

The battery capacity got reasonable reserves and easily allows 25 transports with a total distance of approx. 5 km per day without additional charging. The track in the outside area is long enough to park loaded transport racks there without having to wait for the gantry crane. This results in separate timing between the tasks of the gantry crane and the demolding crew, who has to clear the casting beds as quickly as possible in the morning.

TT slab taken over by the gantry crane

The vehicles are appropriately equipped for the weather conditions in North America and have an attachable snow plough, should it be necessary to clear snow from the track in winter.


With this investment, Kerkstra has significantly improved and simplified its production processes. Waiting times during demolding have been reduced and overall productivity has increased.

You can find our product brochure as e-book here.