From the sensor to the ship: electronic systems for an increasingly connected vessel

There are companies that enter the marine sector by adapting technologies developed elsewhere, and companies that, over time, build part of their identity around the needs of the vessel: EsiWelma belongs to the latter category. Based in Serra Riccò (GE), it designs and manufactures electronics for civil, industrial, military and marine applications, handling everything from defining specifications to design, from circuit board production to testing and after-sales support.

At sea, vibrations, the salty atmosphere, continuous operation, confined spaces and regulatory requirements transform every component into a link in a larger system. It is not enough for a sensor to measure accurately or for a control unit to execute logic correctly: they must communicate, be diagnosable and provide information that is comprehensible to those operating the system. It is here that electronics cease to be mere equipment and become part of the ship’s architecture.

Design, manufacture, maintain

What sets EsiWelma apart is precisely its ability to combine two disciplines that are often kept separate: product engineering and a manufacturing culture. The company manufactures its own equipment, as well as OEM and private-label systems, but also works to customer specifications, right down to the production of circuit boards, prototypes and pre-series runs.

‘We manufacture to their designs and specifications, but where necessary we can also produce our own products based on their specifications,’ explains Alessandro Repetto, Sales Manager at EsiWelma. The product portfolio ranges from gas detection to static power conversion, from UPS systems to battery chargers and frequency converters, from automation to HVAC systems, right through to electronics for fuel distribution. A broad yet coherent diversification: transforming a required function into industrialisable hardware and software that is well-documented, testable and supported.

Navim Group: electronics takes to the seas

Since 2019, EsiWelma has been part of the Navim Group, a Genoa-based company specialising in equipment and systems for passenger and merchant ships, military vessels, offshore installations and large yachts. Joining the group has provided the company with a natural context in which to further expand its maritime work.

‘EsiWelma is the group’s electronics arm,’ summarises Repetto. The statement is succinct, yet it accurately describes the role: when a mechanical or electromechanical system requires sensors, power supplies, control logic, alarms or interfaces, the project can draw on the existing catalogue or develop a bespoke solution. In a modern ship, the distinction between mechanics and electronics is becoming increasingly blurred: what really matters is the behaviour of the system as a whole, its ability to communicate with other systems and to provide useful information to the crew. The value therefore lies not in the individual component, but in its integration.

Detecting a gas means managing a safety chain

The Sensigas range illustrates this point very clearly. The UR21 detectors can operate as stand-alone devices, with a 4-20 mA output to control panels, PLCs or existing safety systems; with an optional board, they can also feature relay outputs. The UR41 family, on the other hand, is designed for a local network connected to the UCE40 control unit. The latter can manage up to 99 peripheral devices, including sensors, relay modules, displays and alarm devices, with configurable thresholds and the ability to control external equipment.

This is the difference between simply ‘detecting’ an abnormal concentration and organising a response: detecting, interpreting, signalling, and, if necessary, activating ventilation, solenoid valves or other safety functions, whilst transferring the information to higher levels of supervision.

This is where the user experience comes into play, taking on concrete significance on board. The operator must be able to tell within seconds whether they are looking at a pre-alarm, an alarm or a fault; they must be able to identify the affected point and understand the system’s status without turning every event into a ‘treasure hunt’ amongst control panels and wiring.

A clear interface, consistent diagnostics and a clear hierarchy of information are just as much a part of safety as the sensor itself. On-board automation – if the term is freed from the mere image of lights and blinds controlled by a touchscreen – begins precisely here: with the ship’s ability to know what is happening within its own spaces and to communicate this effectively to those in charge.

Sensigas Smart: modularity and connectivity

The most recent development is Sensigas Smart, developed in 2025 and launched on the market at the end of the year. The platform adopts a modular architecture on a DIN rail: the master unit, sensor modules, inputs and relays can be combined according to the required configuration. CAN Bus, Ethernet and serial connections allow functions to be distributed and enable communication with supervision and SCADA systems; diagnostics become an integral part of the system.

Above all, the way the system is conceived has changed: no longer a monolithic control centre to which everything is connected, but a modular, expandable platform that is easier to integrate into the ship’s overall framework. For the designer, this means being able to tailor the architecture to the vessel’s actual requirements; for those who will use and maintain it, it means having more organised information and a more transparent structure.

MED and ATEX: technology must demonstrate where it can operate

In the maritime sector, innovation alone is not enough. Equipment intended for use in potentially explosive atmospheres must comply with ATEX requirements (ATEX 2014/34/EU), whilst for specific marine applications, MED certification (MED 3.54) comes into play. The Sensigas range includes certified versions for these applications, featuring different enclosures and degrees of protection; some models operate within an extended temperature range from -40 to +70 °C: these are not minor details.

In an engine room, near fuel lines or on LNG-powered vessels, the enclosure, sensing element, electronics, cabling and alarm logic all form part of the same system. Navalimpianti, a company within the Navim Group, proposes systems in its projects for leading international shipyards that feature sensors distributed across critical areas and control panels managing electronics, alarms and interfaces, which can be integrated with other safety systems. The speed with which a local measurement is transformed into a coordinated response is a key part of the project.

A field of expertise that goes beyond the individual product

However, it would be inaccurate to reduce EsiWelma solely to gas detection. The company’s mission also encompasses activities in power and signal electronics, automation, the manufacture and repair of circuit boards, and fuel distribution systems for specialist civil and military applications. Among its references are units of the Italian Navy and design and maintenance work on the electronic control and safety systems of the TAPIRO and TRIGA RC1 research nuclear reactors at ENEA Casaccia: a field very different from that of ships, but united by the need for fail-safe design, rigorous documentation and operational continuity. It is perhaps this common thread that ties such diverse experiences together.

Contemporary electronics are moving away from isolated components and increasingly towards interconnections: between sensor and control centre, machine and supervision, alarm and intervention, designer and user. On board, where every cubic metre contains functions that must coexist and communicate with one another, this culture of integration becomes a tangible advantage. After all, the best technology is that which is simply there without constantly demanding attention.