The new APT 1500 R welding robot with its many new features and wide range of application is a significant leap in technology. This machine is based on many years of experience gained by Plasser & Theurer with flash-butt welding technology and on important demands made by the users. The development was driven, additionally, by the new European welding standard EN 14587-2.

The new APT 1500 R welding robot is already operating successfully in Austria and was presented in Salzburg at the 18th International Convention of the ÖVG (Austrian Society for Traffic and Transport Science) to the interested participants.

The new mobile fully automatic APT 1500 R welding robot made by Plasser & Theurer fulfils the higher requirements to be met by electric flash-butt welding and is setting new standards in respect of the technology used and the achievable welding quality.

These higher requirements consist of a greater geometric accuracy after welding, high breaking forces and fatigue strength. In compliance with EN 14587-2, it is also necessary to separate the application of welding current and clamping of the rail, and to shear off the upset metal in the direction of the pressure.

Main features of the newly developed welding robot. The welding robot performs an automated welding sequence without manual interaction, thus achieving a high reproducible welding quality. The closure weld or final weld is a firm feature of the newly developed welding robot because the rail pulling device with a tractive force of 1500 kN is integrated in the welding head. The rails to be welded are lifted automatically into the welding head, placed in position with the help of automatic height centring and running edge alignment and a special measuring system monitors the process continually. The welding gap between the rail ends is also produced automatically, if necessary by pulling the rails together. At the same time, all major welding parameters are recorded and stored. The optional use of pulsation welding achieves a high quality weld in less time and with shorter burn-off lengths. The welding current is transmitted to the underside of the rail head and to the upper side of the rail foot thus reducing the preparation work before grinding. The clamping jaws are designed so that it is no longer necessary to grind off the maker’s marks (rolling marks) on the rail web. Another special feature of the new welding robot is that it is the first in the world to use a supply of alternating current with a medium frequency of 1,000 Hz. The welding robot is powered by direct current which means that there is no other dependency on the impedance of the electric circuit. After rectification of the alternating voltage the high frequency produces a very low residual ripple of the electric welding voltage which has a very positive effect on the welding quality.

The new welding robot has been approved and certified in Germany and Austria in compliance with EN 14587-2.

The welding plant incorporates a non-contacting temperature measurement for accurate cooling of high-alloy rails and integrated air quenching for fast cooling of head-hardened rails.

Range of application of the APT 1500 R. The welding robot welds in-situ rails and rails laid in the track and can perform closure welds and final welds. Furthermore, it can also be used temporarily in stationary plants or for welding in rail depots.

Rail-mounted APT 1500 RA flash-butt welding machine. This four-axle machine is built in standard railway vehicle design. The fully automatic rail welding robot is mounted on a manipulator. The machine is equipped with hydraulic jacks to raise the machine on one side to relieve the rail being welded. The entire welding sequence is evaluated and documented in the machine.

Other models available are a road/rail-going lorry and a welding container.