Introduction Signalling Solutions is the UK's sole channel for signalling products previously supplied by ALSTOM Transport Information Solutions. This section includes information covering the range of products sold directly for the UK rail network. If you require any additional information including a copy of the product price list then click info@signallingsolutions.com HW Point Machine The Type HW electrically operated, non-trailable, point machine is a well established product, extensively used on railways in the UK and world-wide. Its robust and high integrity design features include full locking and detection facilities and provide for ease of accessibility to all parts and speed of operational maintenance.       Equally suitable for left or right hand layouts the HW will operate single or double ended points, double slips or movable switch diamonds, regardless of variations in switch fitting or weight of rail. High Voltage Impulse Track Circuits (HVITC) The track circuit is a fundamental component of the fail-safe system on railway networks as its main function is to detect, whatever the conditions, a train on a track. This function is carried out by ALSTOM's High Voltage Impulse Track Circuit on more than thirty major railways in the world. Solid State Interlocking (SSI) ALSTOM Solid State Interlocking (SSI) is a proven electronic signalling system used on all types of railways throughout the world.  The modular format of SSI ensures an optimisation of ease of design, installation and maintenance for a wide range of system applications.  SSI provides high levels of safety and availability and allows comprehensive diagnostics, such as self monitoring, which report failures quickly and accurately to maintenance staff. ATP -Automatic Train Protection ALSTOM Automatic Train Protection (ATP) equipment is a safety system that supervises: Train speed against permitted train and line speeds Braking on the approach to speed restrictions, signals at danger and buffer stops ALSTOM ATP provides information, warns if braking is required and, if necessary, intervenes by making a full service brake application.     The system will make an emergency brake application and bring the train to a stand if it detects the train has passed a signal at danger without authority. ALSTOM ATP will also make an emergency brake application if the train rolls away. Signalling Solutions is able to supply both trackside and trainborne ATP equipment.   SO Hydraulic Supplementary Drives The ALSTOM SO system is a range of hydraulic actuators, which provide positive point blade movement proportional to their position in the turnout.      The system includes both back drives and swing nose frog drives (originally developed for the Italian market), to meet the requirement for various lengths of turnout, including high speed.