During the renovation of Masthamnens quay, a smooth and thorough hydrodemolition of the quay edges is required. Therefore, they have chosen to do the job with Conjet’s Robots 557 and 367.

Approximately 160m³ of damaged and old concrete is to be removed at the east continuation of the south-side harbor Stadsgårdskajen in Stockholm, Sweden.
The quay consists of a large beam that needs repair on the outside, inside as well as on the topside.

The main contractor is YIT Sweden AB who is using Waterjet Entreprenad AB to do the hydrodemolition. Waterjet Entreprenad AB is owned by Delete Sweden AB. A total of six persons are working on the site.

Two robots from Conjet are being used: the Robot 557 and 367, that are both part of the 7-series. The 557 robot, a diesel driven unit on tracks, will be used for top side hydrodemolition. The 557 robot is the latest addition to the 7-series robots from Conjet featuring a heavy duty Multi-Purpose Arm (MPA). The Robot 367 is a wheel based, electrically driven robot with the same type of MPA. It will be used for outside hydrodemolition utilizing the rigidly constructed arm and chassis.
“The robots are well suited for this type of work”, says André Jansson, worksite manager at Waterjet Entreprenad AB. “We cut around 120 -150 mm deep in a total area of 1100 m². We are currently doing 5-7 m² / high pressure hour.”

Waterjet are also giving the new user interface from Conjet a thorough run-trough. Read more in a separate description.

The hydrodemolition is powered by two Hammelmann high pressure pumps at 500kW producing ~260l/min. The Super Silenced model will work at ~69dB(A) (at 7 meters). A hand lance pump from Hammelmann is also used on the project.

Two barges are placed alongside the quay for the cleaning work that the hand lance is doing. The barges also serve as a collector of the debris from the robots work preventing the debris from falling into the water. The Environmental Directives are clear on the handling of debris as well as noise pollution. Safety is paramount on the worksite.

“Hydrodemolition is going better than expected. We are somewhat ahead of schedule” André Jansson continues. “The benefit with the project is its size and the fact that it is fairly straight forward hydrodemolition. The biggest challenge is to finish hydro before winter arrives for real. That is our biggest concern.”

There are quite a few jobs running on quays in the Stockholm area. Waterjet Entreprenad AB has been awarded two larger contracts in parking garages that will keep them occupied over the winter.