The wheel load checkpoint measures the dynamic vertical wheel force as the train passes and calculates the static load figures.

The benefits.

• Detects overloaded vehicles or those whose load has shifted.
• Prevents derailments due to incorrect loading.
• Detects serious wheel damage.
• Early diagnosis of wheel damage allows appropriate wheelset maintenance to be undertaken.
• Wheels in good condition cause less damage to the infrastructure and reduce noise and vibration emissions.
• Detects technical problems on bogies and vehicles.
• Automatically measures the weight of vehicles using certified wheel load checkpoints (employed as certified track scales).

The technology.

• Rail deformation measured using strain gauges.
• Dynamic vertical wheel force calculated from the signal.
• Dynamic wheel force measuring range = 0–50 t.
• Measurement accuracy of vehicle and train weight < 2%.

The facts.

• Developed in-house by SBB.
• 33 systems: at border entry points, in marshalling yards, on main traffic routes.
• 40 million axle measurements per year; 1,500 alerts per year.

The fire detection system measures the smallest concentrations of typical combustion gases (CO and CO₂) and, if an incident occurs, prevents trains from proceeding into critical areas or entering tunnels.

The benefits.

• Detects fires in the early stages.
• Protects critical areas of track and long tunnels.

The technology.

• Measures the smallest concentrations of characteristic combustion gases using highly sensitive gas analysers based on infrared absorption spectroscopy.
• Consists of two combined measuring stations at least 300 m apart in a tunnel on the approach to the structure requiring protection.
• Provides evidence within 20 seconds of a train passing through.
• Estimates thermal power based on concentration change, velocity and tunnel cross-section.

The facts.

• Developed in-house by SBB.
• 24 systems in approach tunnels to critical tunnels or on sections of track.
• < 10 fire alerts/year.

The hot box and locked brakes detection system monitors the temperatures of rail vehicles’ axle box bearings and brakes at normal line speed.

The benefits.

• Detects damage to axle box bearings.
• Identifies defective brake mechanisms.
• Prevents wheel and brake disc failures.
• Prevents damage to rolling stock.
• Prevents derailments and fires.

The technology.

• Uses infrared detectors to measure the temperature of the axle box bearing, wheel rim and brake discs.
• Uses special infrared optics to record the measuring range.
• Uses rail contacts to assign the measurements taken to individual axles.

The facts.

• 99 systems, mainly on main traffic routes.
• On average, one system every 30 kilometres of track.
• 100 hot box alerts per year (overheated axle box bearings).
• 2,000 locked brake alerts per year.

The out-of-profile and antenna detection system checks, at normal line speed, whether rail vehicles are complying with the clearance profile and detects objects which may be close to the contact line.

The benefits.

• Detects whether the profile has been exceeded as a result of incorrectly loaded or defective vehicles.
• Prevents collisions with railway infrastructure and with passing trains.
• Prevents fires and material damage caused by touching the contact wire.

The technology.

• Measures the train's profile with a laser scanner and compares it with the target profile.
• Reconstructs and displays the train as a 3D model so as to help to asses whether an alert should be issued.
• Records on camera instances of the clearance gauge being exceeded.

The facts.

• 12 systems on freight traffic routes.
• 1,200 vehicle alarms per year due to profile violations.
• 20 vehicle alerts per year caused by truck aerials.

The natural hazard alarm system detects rockfalls, rockslides, landslides, debris flows, avalanches and snow slips near the tracks.

The benefits.

• Prevents derailments and collisions with rocks, earth or snow on the track
• Increases the safety and availability of the SBB rail network.
• Issues trend alerts to inform SBB geologists about activity in the protective netting.

The technology.

• Autonomously functioning sensors built into the safety nets transmit by radio their measurement readings for acceleration, position change and netting deformation.
• Transmits information via self-organising repeater networks and a base station.
• Redundant transmission from the base station to the network via fixed network or mobile LTE or GSM.

The facts.

• 27 systems, mainly on the Gotthard corridor.
• Over 1,800 sensors installed.
• Over 80 nets monitored over a total distance of 10 km.
• Detects serious occurrences in the Gurtnellen (Gotthard route) and Flamatt (Bern–Fribourg–Lausanne route) area.

"Dragging equipment detection" uses a stop plate to determine whether vehicle parts such as screw couplings, brake hoses or fuel filler caps are dangling down with the potential to cause damage to systems such as ETCS balises.

The benefits.

• Detects objects dangling down from vehicles, e.g. screw couplings or brake hoses.
• Protects the Eurobalises on the tracks, thus increasing availability.

The technology.

• Acceleration sensors positioned in the track record the mechanical impacts on the stop plates.
• Rail contacts for recording trains and identifying individual axles.
• Impacts recorded on camera.

The facts.

• Approx. 60 screw couplings, approx. 25 brake hoses and approx. 5 miscellaneous parts are detected per year.
• 34 systems at 18 locations, mainly on freight routes and at border entry points.

In order to prevent disruption to the overhead line caused by excessive upward lift forces exerted by locomotives, the pantograph lift measurement system measures the current collector's contact pressure – depending on the locomotive's speed. 

The benefits.

• The automated lift measuring points are used to monitor the upward contact pressure exerted by the pantographs. This can reduce the extent of any damage to overhead contact lines caused by pantographs.
• It allows those traction units which exert increased pantograph pressure to be identified. 

The technology.

• The degree to which the contact line is lifted is measured as the train passes by.
• An optical system is employed because of the 15kV high voltage environment. With an optical rotary encoder, the perforated disc is rotated by the movement of the contact wire, generating pulses via the fibre optic cable. The measuring system analyses the red-green optical fibre pulses to measure the lift.

The facts.

• 6 measuring systems are installed at 2 locations.
• The system measures trains passing at speeds of 125km/h.

Non-contact RFID readers at the edge of the track identify the vehicle number as the train passes, enabling seamless tracking of vehicles. SBB makes the measurement data available to the railway undertakings so that they can, for example, improve their vehicle maintenance planning.

The benefits.

• Being able to identify specific carriages allows measurement data to be assigned to each vehicle. 
• Digitalisation of the data and real-time analysis of the measurement readings enable early detection and warning of damage to specific axles. This assists maintenance based on a component's actual condition and helps to increase quality and improve rolling stock availability.

The technology.

The passive RFID transponders attached to the vehicles are read by RFID readers as trains pass at speeds of up to 180km/h. A rail contact is used in conjunction with the RFID reader so that any defects can be localised to specific axles.

Central data processing and network-wide availability of the measurement readings.

The reader has a 65° wide angle antenna and uses the UHF RF unit with a bandwidth of 865-868 MHz, with optimal connectivity via PoE+.

The facts.

• 123 installations are distributed throughout the SBB network.
• The systems record around 11,000 trains each day.
• 50% of the vehicles recorded are fitted with tags.

The Visual inspection system captures images of the entire train composition from every perspective as trains pass by at line speed.

The benefits.

• The condition of a vehicle can be checked while it is working normally.
• Monitoring of wearing parts.
• Tracking vehicle damage.

The technology.

• High-performance cameras with high light sensitivity, short exposure times and high frame rates.
• Powerful illumination in the invisible infrared range.
• High-performance IT infrastructure for image transmission and storage.

The facts.

The pilot system is installed at a location where approx. 170 trains pass each day at speeds of up to 140 km/h.

Track scales are used to weigh freight wagons for accounting purposes and to ensure compliance with maximum values. Conventional track scales are costly to maintain and, when used, involve much time and effort spent on manual shunting. That is why they are being continuously replaced at appropriate locations by certified wheel load checkpoints. This allows the weighing procedure to be automated and considerably shortened.

The benefits.

• Weighing of rail vehicles.
• Automated weighing process without manual involvement.
• Online access to weighing reports.

The technology.

• Rail deformation measured using strain gauges.
• Dynamic vertical wheel force calculated from the signal.
• Dynamic wheel force measuring range = 0–50 t.
• Measurement accuracy of vehicle and train weight: <2%.

The facts.

• Around 37 non-automated static weighbridges and dynamic track scales in freight stations.
• 4 certified wheel load checkpoint systems in marshalling yards with online access to measurement records.
• Measurements taken at speeds of between 5 and 40 km/h.