Transformers & Rectifiers (I) Limited

What Transformers & Rectifiers (I) Limited does

Transformers & Rectifiers (I) Limited (T&R) is a UK-based, privately-held specialist manufacturer founded in 1951 and headquartered in Guildford, Surrey. The company designs, manufactures, installs, and maintains bespoke power transformers and transformer rectifier units, offering what it describes as one of the widest product ranges globally: liquid-filled power transformers (up to 10 MVA, 36 kV), traction transformer rectifiers (up to 6.5 MW), industrial transformer rectifiers, voltage regulating transformers (under its proprietary Brentford brand), voltage stabilising transformers, shore-to-ship power supplies, earthing and auxiliary transformers, dry type transformers (using DuPont NOMEX insulation), cast resin transformers, and signaling transformers with integrated low-voltage stabilisers. All units are custom-engineered and produced in-house at the Guildford facility, with rigorous testing including BS EN 50327/50329-compliant KEMA-certified short-circuit testing.

T&R serves safety-critical and infrastructure customers across rail (Network Rail, London Underground, Transport for London, MTR Hong Kong, MRT Jakarta), electricity networks (National Grid, EDF, Hydro Quebec, Bahamas Power and Light), marine and naval dockyards, defence (BAE Systems), glass manufacturing, steel (TATA Steel), and broader industrial sectors. Its revenue is generated primarily through one-time, quote-based sales of bespoke engineered equipment under multi-year contracts, supplemented by after-sales maintenance and spare-parts services. The company holds ISO 9001, ISO 14001, and ISO 45001 certifications and operates a B2B enterprise sales motion combining direct field sales, regional distributors in Asia-Pacific, and active participation in global trade shows (Asia Pacific Rail, Power Transmission & Distribution Technology Expo, Floating Offshore Wind).

The business model rests on regulatory approvals (T&R is the sole UK-approved supplier of 25 kV signaling transformers with stabilisers and is approved by Network Rail, TfL, and London Underground), proprietary IP (the Brentford linear voltage regulator), and decades-long customer relationships in rail and utilities. A wholly-owned sister company, T&R Test Equipment Ltd., provides complementary high-voltage test sets and is co-marketed at industry events. The company is independent with no disclosed PE/VC backing and is led by Managing Director Neil McFadden with a management team of seven directors covering technical, sales, operations, finance, contracts, and service.

Name

Transformers & Rectifiers (I) Limited

Legal name

Transformers and Rectifiers

Website

https://transformers.co.uk

Company type

Private

Founded year

1951

Operating status

Operating

Headcount range

101–250 employees

Short description

Transformers & Rectifiers (I) Limited is a UK-based, privately-held specialist manufacturer (founded 1951) designing and producing bespoke power transformers and transformer rectifiers for rail, utilities, marine, defence, and industrial customers globally, with in-house design, manufacturing, and KEMA-certified testing at its Guildford facility.

Ownership category

akta.pro rank

Product category

Power Transformer Manufacturing

NAICS

Power, Distribution, and Specialty Transformer Manufacturing (335311)

SIC

Power, Distribution & Specialty Transformers (3612), Electronic Coils, Transformers & Other Inductors (3677)

akta.pro primary industry

Transformers (Power, Distribution, Instrument, Specialty) (IMAGAAAA)

akta.pro secondary industries

Power Transformers, Reactors & Auxiliary Power Systems (EUADACAJ), Reactive Power & Power Quality Equipment (Capacitor Banks, Reactors, STATCOM/SVC, Harmonic Filters) (IMAGAAAG)

Keywords

• Power transformers manufacturing
• Transformer rectifier units
• Traction power equipment
• Voltage regulating transformers
• Shore to ship power supply

Headquarters

HQ city

Guildford

HQ country

United Kingdom

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

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

Revenue model

1. Custom Transformer Sales: Design, manufacture, and sale of bespoke transformers and transformer rectifier units tailored to customer specifications. Products include power transformers (up to 7500kVA, 36kV), traction transformer rectifiers (up to 6.5MW), voltage regulating/stabilising transformers, dry type transformers, cast resin transformers, and specialised shore-to-ship power supplies. One-time equipment sales with project-based revenue.
2. After-sales and Maintenance Services: Ongoing after-sales support, maintenance services, and spare parts for installed equipment. Part of ISO 9001 commitment to delivering highest quality incorporating ongoing after-sales and maintenance services.

Pricing tiers

Go-to-market motion3 records

Distribution channels4 records

Marketing channels6 records

Core offering

Transformers & Rectifiers designs, manufactures, installs, and maintains bespoke power transformers and transformer rectifier units, including liquid-filled, cast resin, and dry-type transformers (up to 10MVA/36kV), traction transformer rectifiers (up to 6.5MW), shore-to-ship power supplies, earthing and auxiliary transformers, and proprietary Brentford voltage-regulating/stabilising units. All products are custom-engineered to customer specifications and fully tested in-house at the Guildford, Surrey facility for global rail, marine/naval, electricity utility, glass, steel, and industrial customers.

Product overview

Transformers & Rectifiers Ltd. is a specialist British manufacturer offering bespoke power transformers and transformer rectifier units. The company provides one of the widest ranges of transformer products globally, including: Power Transformers (liquid filled up to 10MVA), Traction Transformer and Rectifier Units (up to 4.25MW), Industrial Transformer Rectifier Units, Voltage Regulating Transformers (Brentford Regulator brand with IP rights), Voltage Stabilising Transformers, Shore to Ship Power Supply systems, Earthing and Auxiliary Transformers, Dry Type Transformers using NOMEX insulation, Signalling Transformers and Voltage Stabilisers, Railway Sub Station Transformers, and Cast Resin Transformers. The product portfolio serves critical infrastructure sectors including rail (traction power, signalling), marine (shore-to-ship power), electricity networks (utilities, distribution), glass manufacturing, and steel production. Products are designed, manufactured, and tested in-house at the Guildford, Surrey facility, with each unit custom-engineered to customer specifications. The company also maintains legacy product lines for Southern Transformer Products, Gresham Transformers Ltd, and Partridge Transformers Ltd.

Differentiator

Problem solved

Functional benefit

Brands

• Brentford: Linear voltage regulator design owned by Transformers & Rectifiers Ltd., sought after worldwide for excellent engineering standards.

Products and services

• Traction Transformer and Rectifier Units Traction transformer rectifiers up to 4.25MW including uncontrolled diode rectifiers for traction, crane and dockyard power supplies, and controlled thyristor rectifiers for metal finishing, water treatment, refining, and heating. Designed for railway and heavy industrial customers; the only UK manufacturer designing and producing traction rectifier units under one roof.
• Power Transformers Liquid-filled power transformers incorporating Mineral Oil, Midel 7131, or Silicone fluid. HV/HV units range up to 10MVA at 36kV; HV/LV units range up to 7.5MVA at 36kV. Available as free air breathing or hermetically sealed designs.
• Industrial Transformer Rectifier Units Industrial transformer rectifiers designed to dissipate generated heat using natural air, forced air, water-forced, or oil-immersion cooling methods.
• Voltage Regulating Transformers (Brentford Regulator) Variable ratio transformers (the proprietary 'Brentford' carbon-roller linear voltage regulator design, IP-owned by T&R) providing variable output from fixed input voltage, ranging from few kVA to few thousand kVA. Single and three phase options with Mineral Oil, Midel 7131, or air-cooled configurations.
• Voltage Stabilising Transformers Voltage stabilisers supplying reliable and constant voltage to variable networks. Manufactured as one component for lower kVA ratings, or as part of transformer packages up to 10MVA. Designed for operation in diverse climates from icy Russia to Caribbean heat.
• Shore to Ship Power Supply Power supply equipment fed from 6.6kV or 11kV 60Hz input, providing constant 450V output to naval dockyards worldwide. Equipped with voltage monitoring relay for stable voltage supply to submarines and fleet support vessels.
• Earthing and Auxiliary Transformers Transformers providing a neutral point for unearthed systems and facilities to limit line-to-earth fault currents. Supplied to National Grid, London Underground, and various wind farm and distribution networks.
• Dry Type Transformers Dry-type non-encapsulated transformers using DuPont NOMEX aramid paper insulation (which neither melts nor supports combustion and is self-extinguishing), engineered for applications where liquid-filled transformers are not viable.
• Signalling Transformers and Voltage Stabilisers Voltage stabilising transformer units supplying constant voltage signalling supply to the traction industry. T&R is the only approved supplier to the UK railway industry for 25kV single phase signalling transformers combined with low voltage stabilisers.
• Railway Sub Station Auxiliary and Isolation Transformers Auxiliary and isolation transformers manufactured as approved supplier to Network Rail Ltd, London Underground, and Transport for London (TfL), in accordance with each client's relevant standards.
• Cast Resin Transformers Cast resin transformers for rectifier, converter, traction, and distribution applications with throughput capacities up to 5 MVA and highest system voltages up to 24 kV.
• Southern and Partridge Transformers (Legacy Brand) Legacy product lines maintained for customers of acquired brands (Southern Transformer Products, Gresham Transformers Ltd, Partridge Transformers Ltd) for which T&R holds original designs and specifications.
• After-Sales and Maintenance Services Ongoing after-sales support, maintenance services, and spare parts for installed transformer and rectifier equipment, part of T&R's ISO 9001 commitment to delivering highest quality across the equipment lifecycle.

Quantifiable outcome

• Products have been operating continuously since before the moon landing and remain in operation today
• +4 more outcomes

Named customers23 records

Segments7 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Nine partnerships are on record, tiered core, strategic and minor.

• T&R Test Equipment Ltd.coreStrategic or Co-development PartnerSister company exhibiting together at Power Transmission & Distribution Technology Expo 2026 and other industry events. T&R Test Equipment provides high-voltage test sets and relay testing solutions. Together the organisations provide expertise spanning power conversion, transformer manufacture, testing, commissioning, maintenance, and electrical network support.
• University of Nottingham Faculty of EngineeringcoreStrategic or Co-development PartnerInnovate UK Knowledge Transfer Partnership (KTP) collaboration focused on design, development, and testing of bi-directional power converters for modern electrical networks. Project led by Dr Al Watson and Dr Rishad Ahmed with KTP Associate Amir Ostadrahimi. Enables transition towards greener, more flexible power networks.
• MRT JakartastrategicStrategic or Co-development PartnerJakarta Mass Rapid Transit - discussions on how T&R's proven traction transformer and rectifier systems can support Indonesia's growing rail transport infrastructure.
• PLN DistributionstrategicStrategic or Co-development PartnerIndonesian state electricity distribution company - discussions on power solutions for Indonesia's growing power networks and infrastructure investments.
• Kum Shing GroupstrategicStrategic or Co-development PartnerHong Kong engineering and infrastructure company - discussions on future collaboration opportunities in power network upgrades and substation modernisation. T&R Test Equipment conducted technical presentations and training sessions for Hong Kong distributors.
• Beijing Electrification Engineering Co., LtdcoreStrategic or Co-development PartnerPart of China Railway Electrification Bureau Group - manufacturing 25 traction transformer rectifier units for Hong Kong MTR Corporation Phase 1, with Phase 2 successfully secured. Long-term partnership for rail electrification projects.
• British Ukrainian AidminorOthersCharitable partnership for supporting Ukraine's energy infrastructure maintenance and repair. T&R Group contributed equipment package alongside T&R Test Equipment Ltd.
• University of Nottingham PEMC InstitutestrategicStrategic or Co-development PartnerPower Electronics, Machines and Control Research Institute - team visit to discuss innovation, future technologies, and opportunities for collaboration in power engineering research.
• Guildford CollegeminorOthersApprentice program in conjunction with Guildford College for developing talent from within. Helps attract and develop right talent bringing new and innovative ideas.

Scale indicators5 records

Recent moves6 records

Expansion highlights7 records

Direct peers

• Hitachi Energy: Hitachi Energy (formerly ABB Power Grids) is the world's leading power and traction transformer manufacturer, directly comparable to T&R across traction transformer rectifiers, signalling power supplies, and bespoke power conversion products serving rail, utilities, and industrial customers globally.
• Hammond Power Solutions: Hammond Power Solutions is a North American specialist manufacturer of dry-type, cast-resin, and custom-engineered transformers serving industrial, renewable, and utility customers - a closely comparable peer by product range, custom-engineered go-to-market, and end-market mix.
• Winder Power: Winder Power is a UK-based specialist manufacturer of distribution, power, and rectifier transformers with bespoke engineering capability - a direct UK peer competing in the same industrial, rail, and utility niches that T&R serves.
• CG Power and Industrial Solutions: CG Power manufactures power and distribution transformers, including traction and industrial rectifiers, serving rail, utilities, and industrial customers globally - a closely comparable manufacturing peer with similar product breadth and international footprint to T&R.
• Virginia Transformer Corp: Virginia Transformer is a US-based custom-engineered power transformer manufacturer serving utility, industrial, and renewable customers with bespoke units up to large MVA ratings; closely comparable in custom-engineering capability and traction/specialty industrial segments to T&R.

Broad incumbents

• Siemens Energy: Siemens Energy is a global conglomerate manufacturing power transformers, grid technology, and rail electrification equipment including shore-to-ship and traction converter solutions, overlapping with T&R's full product portfolio but as part of a much broader energy portfolio.
• Schneider Electric: Schneider Electric manufactures a wide range of power, distribution, and specialty transformers as part of its broader electrical equipment portfolio, competing with T&R in utility and industrial applications while serving a vastly larger global customer base.
• GE Vernova: GE Vernova (formerly GE Industrial Solutions / GE Power) manufactures large power transformers and grid equipment for utilities and renewables; overlaps with T&R's power transformer and earthing/auxiliary product lines but operates at meaningfully larger scale and broader scope.
• Eaton: Eaton manufactures dry-type and cast-resin transformers as part of its electrical Americas and Europe portfolios, comparable to T&R's dry-type and cast-resin transformer offerings; however Eaton is much broader spanning power management rather than specialising in bespoke traction/rail products.

Emerging players

• Cavotec: Cavotec is a specialist in shore-to-ship power connection systems and port electrification equipment - directly comparable to T&R's Shore-to-Ship Power Supply product line and naval dockyard customers. Serves as a focused peer in T&R's marine and naval vertical.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks1 record

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/transformers-and-rectifiers-ltd

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Subsidiaries1 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 Transformers & Rectifiers (I) Limited