What Relay Engineering does

Relay Engineering Limited is a UK-based specialist engineering services contractor founded in 1989 and headquartered in Plymouth, operating as a wholly-owned subsidiary of Denholm Energy Services. The company delivers turnkey mechanical, electrical, structural, fabrication, NDT, calibration, compressed air, thermal/acoustic insulation, industrial rope access, and pre/post-weld heat treatment services to the defence, marine, and energy sectors. Its core technology stack includes well-equipped workshops with Rotoweld 3.0 automatic pipe spool welding robotics, water jet and plasma cutting systems (up to 150mm cut thickness), CNC bending, mobile calibration laboratories, and advanced NDT methods such as phased array, digital radiography, and SCAR. A second product line — AI-integrated CCTV, crane boom tip cameras, and mobile signal amplification systems — has been deployed on over 50 drilling rigs and 30+ offshore vessels.

The business model is project-based professional services plus hardware sales. Revenue streams comprise engineering services projects delivered to defence, marine, and energy clients; calibration/verification services through both permanent and mobile laboratories; and compressed air equipment sales, hire, and service via the Industrial Air Power brand (trade counters in Avonmouth and Bridgwater plus shop.airpower.co.uk). Pricing is custom and project-based with multi-year contract cadences; no public pricing tiers exist. Go-to-market is direct enterprise field sales supported by approved-supplier status with major UK defence contractors, and the company maintains a network of 12+ offices across the UK (Plymouth, Falmouth, Portsmouth, Avonmouth, Bridgwater, Aberdeen, Carnforth, Glasgow) and the Middle East (Bahrain as regional HQ, Abu Dhabi, Dubai, Dammam). The customer base is anchored by the Royal Navy, all major UK shipyards, and offshore oil & gas operators in the Gulf, with regulatory clearances (CONDO-approved, security-cleared personnel, ISO 9001/14001/45001, JOSCAR, IRATA, Cyber Essentials Plus, SSIP) functioning as both compliance requirements and barriers to entry.

Relay's recent strategic activity centres on the March 2025 acquisition of Mechanical On-Site Services (MOSS) from ICR Integrity via parent Denholm Energy Services, expanding on-site mechanical machining, leak sealing, and controlled bolting into its defence and energy service portfolio. The company operates as part of a broader Denholm Energy Services group that includes Denholm Environmental, Petrasco, Denholm Zholdas, and Denholm Yam, with Relay sub-brands spanning Relay Marine Services, Industrial Air Power, Denholm Engineering, Denholm Wellclad, Denholm KSW, and ATS.

Name

Relay Engineering

Legal name

Relay Engineering Limited

Website

https://relay-engineering.com

Company type

Private

Founded year

1989

Operating status

Operating

Headcount range

11–50 employees

Short description

Relay Engineering is a UK-based specialist engineering services contractor, wholly-owned by Denholm Energy Services, delivering turnkey mechanical, electrical, structural, fabrication, NDT, and calibration services to the defence, marine, and energy sectors across the UK and Middle East.

Ownership category

akta.pro rank

Headquarters

HQ city

Liverpool

HQ country

United Kingdom

HQ region

Europe

Offices12 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

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

Revenue model

1. Engineering Services Projects: Relay Engineering generates revenue through providing comprehensive engineering services including electrical, mechanical, and structural engineering across defence, marine, and energy sectors. Services are delivered as turnkey project solutions from initial design through to final delivery, spanning new builds, repair, and maintenance contracts.
2. Compressed Air Equipment Sales and Service: Trading as Industrial Air Power, the company sells, leases, and provides maintenance services for air compressors, dryers, filters, and air tools. Operates trade counters in Avonmouth and Bridgwater plus online shop (shop.airpower.co.uk). Provides both long and short-term hire on compressors, dryers and filters.
3. Calibration and Verification Services: Provides calibration and verification services through permanent certified laboratories and mobile field facilities for electrical test equipment, pressure, flow, temperature, gas, humidity, and weight measurement devices.

Pricing tiers

Go-to-market motion1 record

Distribution channels3 records

Marketing channels2 records

Core offering

Relay Engineering is a specialist engineering services provider delivering turnkey project solutions across the full engineering spectrum for the defence, marine and energy sectors. The company provides electrical, mechanical, structural, fabrication, NDT, calibration, compressed air, thermal insulation, industrial rope access, and heat treatment services from initial design through to final delivery, deploying CONDO-approved and security-cleared personnel to onshore, offshore and at-sea locations worldwide.

Differentiator

Problem solved

Functional benefit

Products and services

• Electrical Engineering Electrical engineering services including power generation equipment, pumps, marine electrical systems, hazardous area systems, cable management systems, switchboards and control panels, fire and gas systems, CCTV and crane camera systems for marine, defence and energy clients.
• Mechanical Engineering Mechanical engineering services for marine, defence and energy platforms including ship refit and repair, submarine maintenance, and infrastructure upgrades.
• Fabrication Welding, machining and fabrication services using modern well-equipped workshops including Rotoweld 3.0 automatic pipe spool welding robot, water jet and plasma cutting, CNC bending machines, and small pressure vessel manufacturing.
• Thermal & Acoustic Insulation Thermal and acoustic insulation services for marine vessels and industrial applications, delivered across UK and Middle East operations.
• Calibration & Verification Calibration and verification services through permanent certified laboratories and mobile field facilities for electrical test equipment, pressure, flow, temperature, gas, humidity and weight measurement devices.
• NDT Services Non-destructive testing services including phased array ultrasonic testing, Computerized Radiography (CR), Digital Radiography (DR), and Small Controlled Area Radiography (SCAR) for detecting flaws in complex industrial environments.
• Compressed Air (Industrial Air Power) Sales, leasing, hire, installation and maintenance of air compressors, dryers, filters and air tools, trading as Industrial Air Power with trade counters in Avonmouth and Bridgwater and an online shop at shop.airpower.co.uk.
• Mechanical On-Site Services (MOSS) On-site mechanical engineering services including precision machining, leak sealing, controlled bolting and flange management, delivered to client sites globally through the acquired MOSS Mechanical On-Site Services brand.
• Industrial Rope Access IRATA operating member delivering industrial rope access services for inspection, maintenance and installation in hard-to-reach locations across marine, oil & gas, and industrial sites.
• Pre/Post Weld Heat Treatment Pre and post weld heat treatment services delivered across UK and Saudi Arabian operations for industrial and marine applications.
• Architectural, Outfitting & HVAC Works Architectural outfitting, insulation, deck coating and marine HVAC services delivered through Relay Marine Services LLC in Dubai for maritime clients.
• AI-integrated CCTV & Crane Camera Systems AI-integrated CCTV camera systems and crane boom tip cameras for real-time safety monitoring, incident detection, and access control on marine, oil & gas and drilling rig environments; over 50 drilling rigs in the Middle East and over 30 offshore rigs and vessels with mobile signal amplification systems installed.

Quantifiable outcome

• Over 50 drilling rigs in the Middle East equipped with Relay's CCTV and crane boom tip camera systems
• +1 more outcomes

Named customers3 records

Segments4 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability2 records

Feature5 records

Partnerships

One partnership is on record.

• ICR IntegrityminorOthers · 31 March 2025Denholm Energy Services, through its Relay Engineering subsidiary, acquired Mechanical On-Site Services (MOSS) from ICR Integrity in Glasgow. The transaction aims to strengthen DES's capabilities in the defence and energy sectors and foster growth for MOSS. ICR Integrity sold its MOSS subsidiary as part of this transaction.

Scale indicators6 records

Recent moves5 records

Expansion highlights5 records

Direct peers

• Babcock International Group: Largest UK naval support services contractor delivering through-life engineering, refit and sustainment to the Royal Navy. Directly comparable as a UK-headquartered engineering services provider supporting Royal Navy dockyards and complex naval platforms alongside Relay.
• James Fisher and Sons: UK-listed marine services provider offering ship-to-ship transfer, subsea, defence and offshore engineering. Comparable in serving the Royal Navy, UK shipyards and Middle East offshore operators with mechanical, electrical and NDT-style support services.
• A&P Group: UK ship repair, conversion and marine services operator with yards including Falmouth, where Relay also operates. Overlapping marine engineering services, naval and commercial vessel refit scope and UK shipyard customer footprint make it a direct operational peer.
• Haskoning: Royal HaskoningDHV provides marine, coastal and offshore engineering consulting and project delivery globally. Comparable for marine engineering services, electrical/power distribution scope and Middle East offshore exposure.
• Royal IHC: Dutch marine technology and services provider focused on dredging, offshore and mining vessels with electrical, automation and shipbuilding services. Comparable for marine electrical engineering, switchboards, power distribution and shipyard customer overlap.
• Briggs Marine: UK marine and offshore services contractor working with defence, ports and energy clients. Similar service mix (mechanical, electrical, inspection) and reliance on UK and Middle East marine customers makes it a comparable peer.

Broad incumbents

• BAE Systems: UK prime contractor operating major naval shipyards (Glasgow, Portsmouth, Devonport, Filton) and the broader defence portfolio. Comparable because BAE both competes for and subcontracts scope to Relay across the same Royal Navy and shipyard customer set.
• Thales UK: UK arm of Thales delivering defence electronics, sonar and maritime systems plus through-life support to the Royal Navy. Comparable as a Royal Navy and UK shipyard engineering services incumbent with security-cleared workforce.
• Wärtsilä: Global marine technology and services group providing ship power, electrical and automation systems plus lifecycle services. Comparable as a marine electrical engineering, switchboard, automation and after-market services peer operating at much larger scale.
• Sembcorp Marine: Major global offshore and marine engineering group providing rig new-builds, repairs and offshore platform services. Comparable for offshore/marine mechanical, fabrication and electrical scope for the same Middle East drilling rig customers.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Facebookfacebook.com/100068448714377
• LinkedInlinkedin.com/company/relay-engineering-limited

Revenue estimate

Valuation estimate

Number of profiles

Subsidiaries9 records

Funding overview

Funding rounds

Investors

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

M&A1 record

Investments

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

Frequently asked questions about Relay Engineering