Background History

Modern concrete technology traces its history back to the middle of the 19th century with the discovery of Portland cement and the art of using steel rods to reinforce concrete. In the early days, exclusively fixed forms were used – but the construction became complicated and expensive when it came to the erection of tall structures. The idea gradually emerged of using a low form – about 3 to 5 feet high – and making it slide upwards at such a rate that the concrete would have time to harden sufficiently not to flow out beneath the form.

The form was raised by means of screw jacks, which climbed up vertical rods and were completely manual in operation. One man could look after up to 5-7 jacks of this type. On major works 20-30 men per shift could be required – just to carry out the lifting operation.

The first experiments with a hydraulic slipform jack was performed 1943. The lifting equipment consists of a number hydraulic jacks, connected to an oil pressure pump. The pump is calculated to serve up to 75 jacks and can be controlled and operated by a single person.
Patent registered to Erik von Heidenstam and Emrik Lindman, AB Byggförbättring, 1944.

The invention of the jack was soon followed by the elaboration of a series of other ancillaries, such as a universal yoke and steel form, which can quickly be assembled and dismantled. This fully mechanised and fully automatic slipform technique became known as “the Concretor-Prometo System” or “the Swedish Slipform Method”.

The first residential building in the world, a seven-storey building in Västertorp, Stockholm, Sweden, was built using slipform technology.

Our slipform technology has been used in the construction of a large number of hydropower plants in Sweden. Examples are: Forsmo, Grundfors, Lasele, Ligga, Långbjörn, Näverede, Porsi, Stensele, Stenungsund, Stornorrfors, Umluspen and Vargfors. The picture shows slipforming of the arch dam at Vargfors, Sweden, 1958.

Over the years, the company’s technology has been used to build hundreds of water towers around the world.

During the early 1960s, our method for the construction of mushroom-shaped water towers was developed. In step one, the shaft is slipformed, then the water reservoir is cast on the ground. In a final step, the reservoir is lifted – with our equipment for heavy lifting – and anchored to the top of the shaft.

The first picture shows a water tower in Tyler, Texas, US. The other shows several water towers in Kuwait city. (During the project, a total of 31 water towers were built at various locations in Kuwait.)

A block of residential buildings (a total of 1302 apartments) was built using our expertise and technology.

Slipforming of observation tower “Kaknästornet”, Stockholm, Sweden
Height 155 metres.

Slipforming of columns and piers for the approach viaducts, the cable anchors and bridge pylons. Raising and lowering of formwork for cross beams on the bridge piers.

Slipforming of pillars for Ölandsbron, Sweden, as well as raising/lowering the formwork of the bridge deck.

Hydraulic technology for raising the slipform and heavy lifting of the work platform for the SkyPod.
Total height 553 m, slipformed up to level 446 m. The CN-Tower held the record for the world’s tallest free-standing structure for 32 years, from 1975 until 2007, when it was surpassed by the Burj Khalifa.
Read more here!

Slipforming of the gravity structure. At the time, the world’s largest of its type (440,000 tons). 1950 nos slipform jacks were used.
Total height 237 m, slipformed up to level 160 m.

Our technology for launching bridges was developed in the early 80s and became a big success. A new type of wire climbing jack (T15 Strand jack) was used to pull the superstructure of the bridge to the other side.

During the mid-90s, the company develops its method for serial production of concrete structures. Gantry slipform has been used in previous projects, but now the method is refined and the first generation of our skidding system “The CCV-system” is launched. The system was initially used for construction of caissons for ports and land reclamations.

Slipforming of shaft with simultaneous lifting of tower crane. The outer walls are tapered and leaning inwards at the same time.
Our heavy lifting technology was also used to lift the tower head and antenna.

Total height 435m, slipformed to level 320m. Construction of the shaft started January 1999. Lifting of antenna was completed in 2006.

The longest combined motorway/railway bridge in the world, and the world’s ninth longest suspension bridge, with highest pylons in the world (322m).
Slipforming of 4 pylons up to level 208m.

Our Heavy Duty Slipform System is developed to be extra rigid and at the same time very time efficient for repeated dismantling and re-assembly works.
This system allows for large cast-in items, as the distance between yokes are up to 3,5m, instead of more common 1,5-2m distance. The heavy duty yokes, with clearance of 1100mm for horizontal installation of rebar, provides a very efficient and convenient workplace for concrete and reinforcement workers.
The Heavy Duty Slipform set-up uses our strongest slipform jack, the R72 (22-ton jack) which can be positioned almost anywhere due to a very strong upper deck structure which supports the complete slipform. Instead of having to position one (or two) jack(s) at each yoke position, as with traditional slipform set-up.