4NRJ

What 4NRJ does

4NRJ is a French private company (SARL, founded 2008, registered capital €400,000) specializing in the design, homologation, and supply of specialized equipment for railway catenary (overhead line) and signalling infrastructure. Headquartered in La Chaussée-Saint-Victor, near Blois, the company develops and commercializes voltage detectors for 750V–25KV networks, laser profilometry and self-centered laser rulers for contact wire wear and height/stagger measurement, long-life autonomous inclinometers for catenary support verticality monitoring, connected tension meters, insulating telescopic poles, hand stop signals, and intervention kits, several of which are protected by registered patents (P-FIX quick-connection system, Battery Anti-Ejection, LEVIATAN lifting hook). Hardware is paired with four companion mobile applications (4NRJ Codes, MESUREFC, RLAHD, USUREFC) and Bluetooth/LoRaWAN connectivity for field data capture and QR-code-based tool lifecycle traceability.

The company serves a narrow vertical of French railway infrastructure operators and their maintenance contractors, with SNCF and RATP as its two named anchor customers. 4NRJ holds 24+ SNCF homologations across its product portfolio and one RATP-specific certification, making regulatory certification the central pillar of its competitive position. Manufacturing is outsourced to selected industrial partners while 4NRJ retains design, prototyping, and quality control. Revenue is generated primarily through one-time B2B equipment sales via direct, consultative engagement, complemented by trade show presence (SIFER) and ongoing digital app distribution on Google Play. The company has no disclosed external funding, operates with 11-50 employees, and is described as 'human-sized' and founder/management-owned.

Name

4NRJ

Legal name

4NRJ SARL

Website

https://4nrj.com

Company type

Private

Founded year

2008

Operating status

Operating

Headcount range

11–50 employees

Short description

4NRJ designs and supplies specialized catenary maintenance, voltage detection, and measurement equipment for French railway operators, primarily SNCF and RATP, holding 24+ SNCF homologations and multiple patents across voltage detectors, laser rulers, and autonomous inclinometers.

Ownership category

akta.pro rank

Product category

Railway Infrastructure Equipment

NAICS

Instruments and Related Products Manufacturing for Measuring, Displaying, and Controlling Industrial Process Variables (334513), Instrument Manufacturing for Measuring and Testing Electricity and Electrical Signals (334515), Other Measuring and Controlling Device Manufacturing (334519), Navigational, Measuring, Electromedical, and Control Instruments Manufacturing (33451)

SIC

Railroad Equipment (3743), Measuring & Controlling Devices, Nec (3829), Industrial Instruments For Measurement, Display, And Control (3823), Instruments For Meas & Testing Of Electricity & Elec Signals (3825)

akta.pro primary industry

Rolling Stock Testing, Inspection & Certification (NDT, commissioning, compliance) (TLAKAIAM)

akta.pro secondary industries

Condition Monitoring & Predictive Maintenance Instrumentation (Vibration/ultrasound, oil analysis sensors, IIoT monitoring) (IMAGAFAG), Test & Measurement Equipment (Oscilloscopes, DAQ, signal analyzers, calibration benches) (IMAGAFAC)

Keywords

• Railway catenary maintenance
• Voltage detection equipment
• Overhead line measurement tools
• Railway signaling equipment
• Insulated telescopic poles

Headquarters

HQ city

La Chaussée-saint-victor

HQ country

France

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Technology or R&D, Operations, Marketing or Sales

Revenue model

1. Railway Infrastructure Equipment Sales: 4NRJ generates revenue primarily through the sale of specialized catenary maintenance tools, voltage detectors, measurement equipment, and monitoring systems to railway operators and maintenance companies. Products include voltage detectors (VAT series), laser measurement rulers, inclinometers, lifting equipment, and custom tool development. The company designs and manufactures specialized tools for catenary maintenance, signalisation, and railway track maintenance.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels5 records

Core offering

4NRJ designs, develops and distributes specialized tools and equipment for railway catenary (overhead line) infrastructure maintenance, including voltage detectors (750V to 25KV AC/DC), laser profilometry contact wire measurement systems, self-centered laser rulers, long-autonomy inclinometers for support pole monitoring, connected tension meters, insulating telescopic poles, hand stop signals, surveillance cameras and intervention kits. The company delivers turnkey solutions from specification and CAO/DAO design through prototyping, industrialization via manufacturing partners, installation and after-sales support to railway operators (SNCF, RATP) and maintenance contractors. Products are sold as one-time industrial equipment purchases and complemented by smartphone applications for digital data capture and tool traceability.

Product overview

4NRJ is a railway infrastructure company specializing in innovative catenary maintenance, signaling, and rail track tools. The product portfolio centers around specialized measurement equipment including the CLINALERT inclinometer systems for support verticality monitoring, MESUREFC laser profilometry for contact wire thickness measurement, RLAHD and REGLIGHT laser rulers for height/offset measurements, and CTS connected tension meters. The offering includes comprehensive voltage detection equipment (750V to 25KV AC/DC), insulating telescopic poles (PI46, PI56, PIVAT), surveillance cameras (VIGICAT), safety signals (SAMNG, SAMRA), and intervention kits (KIC). Supporting products include hydraulic equipment, lifting hooks, hoists, site lighting, bird protection systems, and specialized storage solutions. Digital integration is achieved through mobile applications (4NRJ Codes, MESUREFC, RLAHD, USUREFC) downloadable from Google Play Store for Android/iOS, with Bluetooth connectivity for select devices. The company also provides custom solutions for specific client requirements.

Differentiator

Problem solved

Functional benefit

Brands

• 4NRJ Codes: Application for managing equipment and professional tooling with QR code traceability solution.
• MESUREFC
• RLAHD
• USUREFC

Products and services

• CLINALERTMINI (Mini Inclinometer) Plug & Play autonomous inclinometer with 15+ years battery autonomy installed from ground using an insulating catenary pole; provides continuous angular offset measurement of catenary support posts for verticality monitoring with LoRaWAN connectivity and SMS/email alerts.
• MESUREFC (Laser Profilometry Contact Wire Measurement) Laser profilometry system for measuring catenary contact wire thickness from the ground without work engines; records measurement data via a smartphone application with 6-hour continuous measurement autonomy and +/- 0.05 mm accuracy for wires under 12mm diameter. Holds SNCF approval N° DEO 19369.
• RLAHD (Self-Centered Laser Ruler) Self-centered laser ruler using a Leica laser camera for precise height and offset (stagger) measurement of the catenary contact wire versus rail axis; features a rolling system, RLAHD smartphone application connectivity and +/- 2mm height accuracy. Holds SNCF approval N°: DPI EO 15093.
• REGLIGHT (Light Laser Ruler) Light laser ruler for measuring catenary contact wire height and stagger; connected device with self-centering and integration with the RLAHD free application. Holds SNCF approval N°: MTP EO 17036.
• CTS (Connected Tension Meter Ensemble) Connected tension meter measuring mechanical tension of cables and catenary contact wires from the ground; Bluetooth 4.0-enabled with free smartphone application, measuring range 100-3000 daN and utilizing the patented P-FIX connection. Holds SNCF approval N°: DEO 19370.
• VAT DCC 1500V (Bi-Impedance Voltage Detector) Voltage detector for 1500V and 750V DC power lines with bi-impedance system for nominal voltage discrimination to avoid false positive detection during maintenance activities; operates from -25°C to +55°C. Holds SNCF approvals N°: DPI EO 12139 (1500V) and N°: DPI EO 13230 (750V).
• KIT VAT 15KV AC Voltage detector kit for 15KV 16.66Hz AC power lines featuring P-FIX quick connection to SNCF poles, auto-test function, and permanent threshold control. Holds SNCF approval N°: DEO 20178.
• KIT VAT 25KV AC Voltage detector kit for 25KV AC power lines with unipolar voltage measurement via electrical field, featuring instant LED and sound alerts. Holds SNCF approval N°: MTP EO 14070 (also referenced as AGT 25 449 for the VAT 25KV G2 AC variant).
• PI46 (Insulating Telescopic Pole 4.60M) Insulating telescopic pole extending to 4.60M for catenary work, featuring taper lock system, anti-rotation design, and foam tube compliant with IEC 60855-1 standard.
• PI56 (Insulating Telescopic Pole 5.60M) Insulating telescopic pole extending to 5.60M for catenary operations, with a 3.8kg mass weight and IEC 60855-1 compliant foam tube.
• VIGICAT (Catenary Support Surveillance Camera) 4G surveillance camera with 355° horizontal / 95° vertical rotating lens controllable via smartphone through the UBox application; solar-powered with motion detection up to 10m, night vision up to 20m, IP66 rated for outdoor railway environments.
• SAMNG (New Generation Hand Stop Signal) New generation hand stop signal for worksite safety featuring LED lights, powerful magnet system, waterproof housing, and folding reflective flap visible up to 105 km/h winds. Holds SNCF approval N°: 7.391.0313.
• SAMRA (360° Hand Stop Signal) 360-degree hand stop signal with 8 LEDs arranged for complete visibility, designed for construction site safety before intervention; supplied for Paris metro (RATP) operations.
• KIC (Catenary Intervention Kit) Comprehensive catenary intervention kit for quick ground-level operations including pruning saw, cable cutting pliers, and grip pliers with dedicated P-FIX connection. Holds SNCF approval N°: MTP EO 18128.
• CLINALERT (Standard Inclinometer) Standard Plug & Play inclinometer with 10+ years autonomy for continuous angular offset measurement of catenary supports; installed from ground using insulating catenary pole.
• MDFLECHE (Sag Measurement Tool) Sag measurement tool for catenary contact wires using a rotating laser with magnetic reference system; data recorded in application history with theoretical accuracy of ±4mm at 30m.
• USUREFC (Contact Wire Wear Indicator) Visual wear indicator for catenary contact wires allowing monitoring from ground level; triggers at predefined thresholds (8.8mm for 107mm², 9.8mm for 150mm² contact wires) and managed via the USUREFC mobile application.
• BLOKCLR2 (CLR Immobilization Device) Earthing immobilization device securing poles with strap between rails without shunting; winner of the 2018 SNCF worksite safety award (Victoire de la Sécurité).
• All-in-One 4NRJ Mobile Application Unified mobile application announced for March 2026, combining the digital ecosystem previously distributed across 4NRJ Codes (QR code tool traceability), MESUREFC (contact wire measurement), RLAHD (height/stagger measurement) and USUREFC (wear indicator management).

Quantifiable outcome

• 15+ years battery autonomy for CLINALERTMINI inclinometer, eliminating maintenance intervention
• +3 more outcomes

Named customers2 records

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration5 records

Feature7 records

Partnerships

Three partnerships are on record, tiered core and minor.

• SNCFcoreStrategic or Co-development PartnerMajor French national railway operator and primary customer. 4NRJ holds multiple product homologations from SNCF for voltage detectors, measurement tools, and safety equipment. Products are designed and certified for use on SNCF catenary and signalling infrastructure. Collaborative relationship in product specification and certification.
• RATPcoreStrategic or Co-development PartnerParis public transport operator (Régie Autonome des Transports Parisiens). 4NRJ supplies specialized equipment including SAMRA 360° hand stop signal for Paris metro operations. Products carry RATP-specific certifications and configurations.
• Industrial Manufacturing PartnersminorImplementation/ SI/ Consulting PartnerSelected manufacturing partners responsible for product industrialization. Partners chosen based on domain expertise and ability to meet project constraints including dimensional, functional, and regulatory requirements. 4NRJ maintains design control and quality oversight while partners handle production.

Scale indicators2 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Geismar: Geismar is a French-headquartered manufacturer of railway maintenance equipment for track, catenary, and overhead line work. It is the closest direct peer to 4NRJ, competing across catenary tools, measurement devices, and track maintenance equipment sold to operators including SNCF.
• Cembre: Cembre is an Italian manufacturer of electrical connectors, cable accessories, and tools including railway-specific tooling for catenary and signaling maintenance. Comparable to 4NRJ as a Europe-wide supplier of certified railway tools and installation equipment.
• Sécheron Hasler: Sécheron (part of Sécheron Hasler Group) supplies DC power equipment, electrical safety devices, and catenary-related products to rail operators. It overlaps with 4NRJ's voltage detection and catenary electrification tooling, especially for tram and metro networks.
• Mors Smitt: Mors Smitt manufactures railway signaling, safety, and electrical measurement equipment. It is comparable to 4NRJ in serving rail operators with certified safety and voltage-detection devices, and competes in adjacent railway electrification niches.
• Caténair: Caténair is a French specialist in catenary installation and maintenance services and tooling for railway overhead lines. It is a direct peer to 4NRJ with comparable product scope in catenary measurement and intervention equipment for SNCF and adjacent rail operators.

Broad incumbents

• Pandrol: Pandrol is a global rail infrastructure equipment supplier specializing in rail fastening systems, track components, and electrification hardware. Comparable to 4NRJ as a supplier of specialized railway infrastructure tools, though Pandrol operates at much greater scale and geographic reach.
• Huber+Suhner (Railway division): Huber+Suhner supplies connectivity and electrical solutions including for railway electrification and overhead line systems. Comparable to 4NRJ in components used in rail catenary systems, though as a much larger incumbent serving global customers.
• Schunk Transit Systems: Schunk Group's transit systems business (formerly Schunk Transit Systems, now part of Carbo System) supplies carbon strips, catenary components, and overhead line equipment to rail networks globally. Comparable to 4NRJ in the catenary/wear-indicator space but operating at much broader scale as an incumbent.

Others

• Trenitalia / RFI internal tooling (as adjacent ecosystem): RFI (Rete Ferroviaria Italiana) is the Italian rail infrastructure manager that procures catenary maintenance and inspection tooling comparable to 4NRJ's products. While not a competing vendor, RFI's procurement specifications and homologation requirements serve as a benchmark for the type of organization 4NRJ would need to certify with to expand beyond France.

Emerging players

• Furrer+Frey: Furrer+Frey is a Swiss railway electrification specialist focused on overhead contact line design and components. While more design-focused than 4NRJ, it competes in the same catenary ecosystem and supplies tools/components to European rail operators.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/Innovationcatenaire4NRJ
• LinkedInlinkedin.com/company/4nrj

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about 4NRJ