Rail earns when it moves.
Measurement keeps it moving.
Rolling stock, depots and rail infrastructure depend on measurement that keeps working through vibration, washdown, ballast dust and weather. Gill capacitive level sensing, non-contact position feedback, oil debris monitoring and ultrasonic wind measurement are built for exactly that.
We aim to respond in one working day.
Availability is the number the whole railway is judged on
A train only earns when it is in service. When it stops unexpectedly, the cost quickly extends beyond the failed component.
Coolant and fuel levels fall. Gearboxes shed debris. Brake systems wear. Doors and mechanisms move thousands of times.
The earlier those changes can be detected, the more opportunity there is to act before they become a service-affecting failure.
But rail sensing has to survive the environment too: vibration, contamination, wash-down, temperature changes and long service intervals.
Gill sensing is designed to remove mechanical weak points and monitor developing conditions continuously.
Capacitive level sensing removes the float. Non-contact position sensing removes physical contact. WearDetect monitors ferrous debris in lubricating oil. Ultrasonic wind measurement provides airflow and wind data without moving sensing components.
Measurement becomes part of the availability strategy, not another potential failure point.
The measurements behind a unit that stays in service
Railway measurement happens across the vehicle, the depot and the infrastructure around it.
Level. Position. Wear. Wind. Airflow.
The challenge is making those measurements reliably in environments where vibration, contamination, restricted access and repeated movement are standard operating conditions.
Gill addresses that challenge by removing mechanical weak points wherever the application allows.
Capacitive sensing measures liquid without a float. Non-contact inductive sensing separates the sensor from the moving mechanism. WearDetect monitors ferrous debris in lubricating oil, identifying developing wear between inspections. Ultrasonic sensing measures wind and airflow without moving components.
The result is sensing specified around the realities of rail, from the vehicle and depot to tunnels and exposed infrastructure.
Inspection is a snapshot. Wear keeps happening.
Between one examination and the next, level and machinery condition can change. A failure can develop in the gap, which is why continuous measurement can provide information that a scheduled inspection cannot.
WearDetect: CANbus or Modbus RTU
The wash plant is part of the environment
High-pressure water, detergent and ballast dust are routine on a railway. Sensing equipment has to be specified for that environment rather than treated as though wash-down were an exceptional event.
IP67 | Non-contact | Solid-state
A tunnel has no natural ventilation
Airflow in an enclosed structure is a controlled quantity. The sensor measuring it has to operate through dirt, heat and piston effect over long service intervals.
WindSonic: no moving parts
The measurement has to remain provable
Where a measurement contributes to a safety case, maintenance decision or availability assessment, traceable calibration provides evidence that the instrument itself has been verified.
UKAS-accredited | ISO/IEC 17025:2017
Every service decision starts at a measurement point
A railway measures on the vehicle and along the route. Level in every tank. Wear inside every drive. Position on everything that moves. Air flow in the tunnel and wind on the exposed miles.
Coolant, fuel and hydraulic level
Level on a moving vehicle is measured in a tank that is shaking, sloshing and rarely level, which is the condition a float handles worst.
- LevelPro stainless steel, IP66 and IP68, 0-10 V or 4-20 mA, RS232 for configuration
- LevelLite lightweight aluminium, IP68, voltage or current output
- DD1615 level display local readout at the tank or in the cab
Traction gearbox and axle wear
Gearboxes and axle boxes give warning in the oil long before they give warning anywhere else, and that warning is the earliest one available.
- WearDetect fine and coarse ferrous debris, water presence and oil temperature
- WearDetect with Display the same sensor with an integrated readout
- Condition monitoring 0-10 V, 4-20 mA, CANbus or Modbus RTU output models
Brake wear and brake control
Brake pack wear is inspected on an interval, which means it is unknown for most of the time between inspections on a safety-related system.
- Blade25 25 mm linear or 90 degree angular, configurable range
- Blade60 60 mm linear for longer actuator travel
- Blade Dual Output single and dual channel where redundancy is required
Door position and interlocks
A door that will not prove takes the unit out of service, and the sensor proving it is cycled hundreds of times a day in weather and grit.
- Blade25 non-contact, unlimited mechanical life, IP67
- Blade360 full 360 degree rotary, IP67, RS485
- Blade Dual Output a redundant second channel from one sensor
Pantograph and suspension travel
Pantograph height and secondary suspension travel move continuously under load at line speed, in the weather, for the whole diagram.
- Blade60 60 mm linear or 90 degree angular, fully configurable
- Blade360 360 degree rotary for a pivot measurement
- BladeCom configuration travel, switch points and output limits set before fitting
Overhead line and clearance
Overhead line equipment is judged on position and on the weather acting against it, and both measurements sit out in the open for decades.
- WindObserver 70 precision 2-axis, stainless steel 316, IP66
- MaxiMet GMX501 multi-parameter station for a fixed installation
- Blade360 360 degree rotary position for lineside mechanisms
Tunnel ventilation and air flow
Ventilation and smoke control in an enclosed structure are governed by measured air flow, in an environment that ruins moving parts.
- WindSonic 2-axis ultrasonic, no moving parts, 4-20 mA options
- Tunnel monitoring the application page for ventilation and air flow
- AN0044 WindSonic single channel tunnel mode, 4-20 mA
Depot and maintenance shed
The depot decides what comes off the unit and when, and that decision is better made from a debris trend than from mileage run.
- WearDetect with Display integrated readout for a walk-round check
- WearDetect CANbus and Modbus RTU into a fleet system
- Labcal calibration independent UKAS-accredited calibration, Lab 0625
Trackside weather measurement
Speed restrictions, de-icing and possession planning are weather decisions, and the number that counts is the one measured at the location.
- MaxiMet GMX551 wind, temperature, humidity, pressure, solar and rainfall in one unit
- MetConnect separable sensors with Pt100 and analogue inputs
- TruMet PW100 infrared optical rain gauge, no moving parts
Platform and passenger environment
Wind on an exposed platform and conditions under a canopy affect passenger comfort and, at the extreme, whether the station keeps operating.
- WindSonic 60 0 to 60 m/s, 0 to 360 degrees with no dead band
- MaxiMet GMX240 compact station with rainfall measurement
- Heat stress monitoring WBGT measurement where crowding and heat combine
- WindUltra compact heated 2-axis sensor, 270 g, IP69k for washed-down and exposed positions
Signalling and lineside equipment
Lineside cabinets and mechanisms are visited rarely and expected to work always, which puts the burden on the sensor rather than the inspection.
- Blade360 full 360 degree rotary, IP67
- Blade25 25 mm travel with PWM, RS232 and RS485 options
- LevelSlick FEP coated, for the liquids that defeat other sensors
Level crossings and road interface
A crossing is a mechanism at the boundary between two networks, and both its position and the weather around it have to be known.
- Blade360 360 degree rotary for barrier position
- MaxiMet GMX600 station with optical rainfall measurement
- WindSonic lightweight 2-axis ultrasonic wind measurement
Embankment, drainage and flooding
Earthworks fail after rain, and the useful measurement is rainfall at the location plus level in the drainage that is supposed to carry it away.
- TruMet PW100 0 to 200 mm/hr, 5 per cent accuracy, 0.1 mm resolution
- LevelSlick FEP coated for conductive liquids with particles
- LevelPro robust stainless steel level sensing, IP66 and IP68
Wind on bridges and exposed routes
Exposed structures carry wind limits for empty stock and high-sided vehicles, and the limit is only defensible if it is measured at the structure.
- WindObserver 75 0 to 75 m/s, stainless steel 316, heated
- Bridge wind measurement the application page for bridges
- WindObserver 90 0 to 90 m/s for the most exposed sites
Depot fluid and lubricant storage
Bulk tanks at a depot are checked by dipping them, which is the job that gets skipped on the night it matters.
- LevelPro stainless steel, IP66 and IP68, current or voltage output
- LevelSlick FEP coated for viscous, particulate and corrosive liquids
- Custom level sensing built to the tank and the liquid
Calibration and the safety case
Where a measurement supports a safety case, a performance regime or a contractual availability claim, it needs traceable calibration behind it.
- Labcal UKAS-accredited, Lab 0625, ISO/IEC 17025:2017
- Air velocity calibration anemometers, Pitot tubes and thermal probes
- Pressure and temperature gauges, transducers, thermometers and data loggers
Find your rail application
Explore the measurement challenges across the vehicle and the infrastructure, from coolant level and gearbox wear to door position, tunnel ventilation and trackside conditions.
Coolant and Fuel Level
Continuous level with no float
Coolant, fuel and hydraulic level on a vehicle that is never still and rarely level. Capacitive sensing has no moving part, is fully sealed and is factory calibrated to the tank.
Engineering: Capacitive level sensing, stainless steel, IP66 and IP68, 0-10 V or 4-20 mA, RS232 for configuration.
Axle and Gearbox Wear
The overhaul decision, made on evidence
Traction gearboxes and axle boxes shed ferrous debris long before they fail. Capturing and counting it in real time turns a mileage-based overhaul into a condition-based one.
Engineering: Oil debris sensing, fine and coarse ferrous debris, water and oil temperature.
Brake and Door Position
Proved, not assumed
Brake pack wear and door position are safety-related measurements checked on an interval and assumed in between. A non-contact sensor makes both continuous and reportable.
Engineering: Non-contact inductive position sensing, configurable range, IP67.
Pantograph and Suspension
Travel measured without a wear item
Pantograph height and secondary suspension travel are continuous measurements on parts that move for the whole diagram, in weather, at line speed.
Engineering: 25 mm and 60 mm linear travel, 360 degree rotary, analogue and digital outputs.
Tunnel Ventilation and Air Flow
Air flow in an enclosed structure
Ventilation and smoke control in a tunnel are governed by measured air flow. The sensor sits in dust, heat and piston effect for years, so it cannot have anything to seize.
Engineering: 2-axis ultrasonic wind measurement, single channel tunnel mode, 4-20 mA.
Depot and Trackside Conditions
The conditions behind the decision
Wind on exposed structures, rainfall on embankments and drainage, and temperature at the depot all feed operational decisions and the record that follows them.
Engineering: Compact weather stations, optical rainfall, precision 2-axis wind measurement.
insight
Why oil debris monitoring changes a rolling stock overhaul plan
Rolling stock maintenance is planned on mileage, because mileage is the number everyone has. It is a reasonable proxy and a poor predictor: two units on the same diagram wear differently depending on load, gradient, driving and how the last repair went.
Oil debris measurement changes the basis of the decision. WearDetect is fitted as a smart sump-plug replacement or in a bypass circuit, uses a magnet to capture ferrous wear particles suspended in the oil, and reports how much fine and how much coarse debris has been captured. A rising coarse count is a traction gearbox telling you it is failing while it is still a gearbox.
It also reports water presence, with a datasheet minimum of around 10 per cent free water, and oil temperature, which covers two of the other common ways an oil-lubricated drive gets damaged.
The same logic runs through level and position. A coolant level that arrives over CAN stops being an inspection task, and a brake wear measurement that is continuous stops being a guess between exams.
Rail technologies
Products engineered for rolling stock and the infrastructure it runs on, spanning capacitive level sensing, non-contact position feedback, oil debris monitoring, ultrasonic wind measurement and independent calibration across Gill.
Rolling stock
Level sensing
Capacitive liquid level sensors
Coolant, fuel, hydraulic and water level with no float to jam, including a FEP-coated variant for the liquids that defeat everything else.
WearDetect
Oil debris sensor
Fitted as a smart sump-plug replacement or in a bypass circuit, it captures ferrous wear particles and reports how much fine and coarse debris has been caught.
Blade position sensors
Non-contact inductive position sensing
Brake, door, pantograph and suspension feedback from a sealed sensor measuring across a gap to a passive activator, so there is nothing to wear.
DD1615 Level Display
Local readout for the level sensors
Where the level has to be readable at the tank or in the cab rather than only in the data system.
Infrastructure
WindSonic
Lightweight 2-axis ultrasonic anemometer
For tunnel air flow, platforms and lineside masts, where having no moving parts matters more than a specification sheet.
WindObserver
Precision 2-axis ultrasonic anemometer
The stainless steel open-head range for bridges, viaducts and the most exposed miles, where the wind limit has to be defensible.
MaxiMet
All-in-one weather station, no moving parts
One unit, one cable, one output string for trackside, depot and station conditions, including optical rainfall for drainage and earthworks.
WindUltra
Compact heated 2-axis ultrasonic anemometer
The smallest sensor in the range, for platform canopies, lineside cabinets and washed-down depot positions where size, weight and power are the constraint rather than absolute accuracy.
UKAS-accredited calibration for six measurement parameters
Labcal is an independent UKAS-accredited calibration laboratory, Lab 0625, operating to ISO/IEC 17025:2017. It provides calibration across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity, all under one roof.
For rail that includes anemometers, Pitot tubes and thermal probes used on ventilation and trackside monitoring, alongside pressure gauges and transducers, thermometers, temperature and humidity probes and data loggers. Labcal supports equipment from Gill and other manufacturers, which matters on a network where instruments arrived with different projects and different contractors.
01 · Gas and air flow
Gas meters · Mass flow controllers · Dispensing systems · Low-flow laboratory to higher-flow industrial
02 · Air velocity
Anemometers · Pitot tubes · Thermal probes
03 · Liquid flow
Flow meters and sensors · Process control equipment · Water used for the accredited capability
04 · Pressure
Gauges · Transducers · Manometers · Transmitters
05 · Temperature
Thermometers · Probes · Thermocouples · Data loggers
06 · Humidity
Hygrometers · Probes · Transmitters
The measurement has to reach the train management system and the depot
A sensor on a unit is only worth fitting if its output arrives where someone acts on it, whether that is the train management system, the cab display or the fleet system in the depot office.
Gill supports environmental monitoring, industrial sensing, embedded electronics and systems integration, so rolling stock builders, operators and infrastructure managers can bring measurement into existing vehicle networks, SCADA and asset management systems.
Whether the requirement is CAN on the vehicle, Modbus into a tunnel ventilation system, a 4-20 mA channel into an existing controller, or a configurable sensor embedded into an OEM build using the Blade developer tools, engineers can support integration from specification through commissioning.
Outputs and options
- CAN & RS232 : Train management and vehicle networks
- Modbus & RS485 : Tunnel ventilation, SCADA and lineside
- 4-20 mA & 0-10 V : Analogue channels on existing controllers
- BladeCom : Travel, switch points and output limits set before fitting
Why rail operators specify Gill
Gill level sensors keep measuring at -40°C, and WearDetect counts ferrous wear debris in traction gearbox oil. Designed and manufactured in Lymington, Gill technology is specified in 150+ countries.
Nothing in contact, nothing to wear
Blade position sensors measure across a gap to a passive activator, so the mechanical life is effectively unlimited and there is no wear-related drift on a door cycled hundreds of times a day.
Sealed for the wash plant
IP67 non-contact sensing and fully sealed capacitive level electronics survive high pressure water, detergent and ballast dust as routine rather than as an exception.
Level measured without a float
Capacitive sensing gives continuous level in a tank that is shaking and rarely level, factory calibrated to the installation.
Wear caught while it is still wear
WearDetect distinguishes fine from coarse ferrous debris in real time, so a traction gearbox becomes a planned change rather than a failure in service.
Built for decades outdoors
WindObserver is stainless steel 316 and IP66, operating from -55 to +70 degrees C with heating, which is what a lineside installation actually asks for.
Evidence when it is asked for
Independent UKAS-accredited calibration across six parameters, for equipment from any manufacturer, keeps a mixed estate on one traceable schedule.
Rail application notes
2 application pages and 2 numbered application notes for this sector. The pages describe the measurement problem and the instruments that answer it; the numbered notes are the original engineering documents, each with its PDF.
Rail measurement questions, from the tank to the tunnel
Capacitive level sensors for coolant, fuel, hydraulic and water measurement; non-contact inductive position sensors for brake, door, pantograph and suspension feedback; oil debris sensing for traction gearboxes and axle boxes; and ultrasonic wind sensors and compact weather stations for tunnel ventilation, exposed structures and trackside conditions.
Because a float is a moving part in a tank that spends its life shaking. Capacitive sensing has no moving part, the electronics are fully sealed and solid state, and the sensor is factory calibrated to the installation.
LevelPro is the general-purpose choice in corrosion-resistant stainless steel, rated IP66 and IP68, with 0-10 V or 4-20 mA output and RS232 for configuration. The 4-20 mA output needs a 250 Ohm load resistor across the output.
Because a contacting sensor on a mechanism cycled hundreds of times a day is a consumable. The Blade sensors measure across a gap between a sealed body and a passive activator, so the mechanical life is effectively unlimited and there is no wear-related change in output.
They are rated IP67 and sealed for temporary immersion (1 m for 30 min), which is what lets the same part work in a door mechanism, a brake actuator and an underframe position.
Blade25 measures 25 mm of linear travel or 90 degrees of angular movement, and Blade60 measures 60 mm or 90 degrees, both fully configurable within that maximum. Blade360 measures a full 360 degrees of rotary movement.
Configurable range does not mean unlimited range, so the maximum travel per product is the number to design to.
It measures the wear itself. WearDetect captures ferrous particles suspended in the oil with a magnet and reports how much fine and how much coarse debris has been captured, so a failing gearbox is visible while it is still a gearbox.
It also reports water presence, with a datasheet minimum of around 10 per cent free water, and oil temperature.
Either as a smart sump-plug replacement or in an oil bypass circuit, with a wide range of fittings available and a separate electronics enclosure for mounting flexibility. It suits oils, fuels and coolants.
Output models are 0-10 V, 4-20 mA, CANbus or Modbus RTU, so it can feed a train management system or a depot system directly.
No. It detects ferrous debris, so it complements laboratory oil analysis and vibration monitoring rather than replacing them. What it adds is that the measurement is continuous and on the vehicle, so the trend is visible between samples.
WindSonic. It is 2-axis ultrasonic with no moving parts, so there is nothing to seize in dust, heat and piston effect, and it offers a single channel tunnel mode with a 4-20 mA output that drops straight into a ventilation control system. AN0044 covers that configuration.
For an exposed lineside or bridge installation, the stainless steel WindObserver range is the precision option.
WindObserver. It is stainless steel 316, IP66, operating from -55 to +70 degrees C with heating, measuring 0 to 75 m/s on the WindObserver 75 and 0 to 90 m/s on the WindObserver 90, with 0 to 360 degrees of direction and no dead band.
Accuracy is 2 per cent on wind speed and 2 degrees on direction at 12 m/s, which is what makes a speed restriction defensible afterwards.
Because leaf litter, ballast dust and debris block it, and a blocked gauge reports a dry cutting during the rain that is actually loading the earthworks. TruMet PW100 is an infrared optical gauge with no moving parts, measuring 0 to 200 mm/hr with 5 per cent accuracy and 0.1 mm resolution.
It outputs one pulse per 0.1 mm, replicating a tipping bucket, so it drops into an existing logger.
Yes. Labcal, Gill Group’s independent UKAS-accredited calibration laboratory (Lab 0625), operates to ISO/IEC 17025:2017 and calibrates equipment from any manufacturer across gas and air flow, air velocity, liquid flow, pressure, temperature and humidity.
Yes. The Blade range is designed for OEM integration, with a technical manual, a developers guide and the BladeCom tool for setting write protection, travel set points, switch points, output limits and dropout level, with a live graph display.
The sensor also reports health-check diagnostics, including sensor fault, activator in range and approximate temperature, which supports condition monitoring of the installation itself.
Speak to our team
Tell us what you need to measure, where and under what conditions. We’ll help you work out the appropriate approach.
We aim to respond in one working day.