MERMEC
MERMEC is an Italian supplier of railway diagnostics, signalling, and asset management technology, headquartered in Monopoli, Puglia, and operating through subsidiaries in around 20 countries.
Founded in 1970 as an agricultural equipment workshop, the company moved into railway maintenance and diagnostics in the 1990s under the Pertosa family, who remain its controlling owners through the Angelo Holding group.
Core products for wheel and axle monitoring
MERMEC’s wheel and axle portfolio centres on wayside and onboard measurement systems rather than a single product line.
Its hot box and wheel detector systems monitor axle, wheel, and brake temperatures at train speeds up to 500 km/h, flagging overheating before it leads to derailment or bearing failure.
Wheel profile measurement is handled by non-contact laser and camera systems that capture flange height, flange thickness, tread taper, wheel diameter, and related geometric parameters in real time as trains pass.
A separate wheel surface defects system uses high-definition cameras and dedicated illumination to detect tread defects such as shelling, spalling, and flat spots during normal operation.
These systems are typically bundled into multi-function safety gates, installed at fixed points such as tunnel approaches or high-capacity junctions, combining wheel and brake inspection with load, gauge, and bearing-temperature checks in a single installation.
Market position
MERMEC positions its measurement portfolio as covering more than 60 distinct diagnostic systems across track, catenary, signalling, and rolling stock, with wheel and axle monitoring forming one part of that broader offer.
Customers span conventional, high-speed, and heavy-haul operators, with wayside inspection portals supplied to national infrastructure managers across Europe and beyond.
The wheel and axle business sits within a wider group that has expanded significantly into signalling in recent years, a shift that has pushed group headcount well above the typical profile of a specialist wheel-monitoring supplier, though MERMEC has continued to operate as an independent, family-controlled group rather than a subsidiary of a listed or private-equity-owned parent.
Current activity
In 2026, MERMEC’s ownership structure is in transition: according to Italian financial press, Angelo Holding has agreed to sell MERMEC’s railway diagnostics, data analysis, and signalling activities to Siemens Mobility, a deal announced in May 2026 and expected to close by the end of the year.
Neither party has disclosed the financial terms; unofficial reports have put the value at around EUR 1 billion. The businesses included in the deal employ around 1,700 people and generated revenue of approximately EUR 430 million in fiscal year 2025 — a figure specific to the divested assets, not Angelo Holding’s total group revenue.
The reported transaction covers the diagnostics business — including wheel and axle monitoring systems — while MERMEC’s AngelStar signalling joint venture and Mont Saint Michel, together with the latter’s subsidiaries Compagnie des Signaux and MER MEC Deutschland, were reported to be excluded from the sale.
At the time of writing, the deal had not yet closed, and MERMEC continued to operate as an independently controlled group.
MERMEC has also remained active in European rail research, participating in the Europe’s Rail joint undertaking’s work on standardising infrastructure and rolling stock condition-monitoring data across national networks.
