Undergrounds: Enamel transits rapidly underground


In Madrid, Munich, Paris, Berlin, Budapest, Washington, Singapore, Caracas, Milan… Enamel resists chemical, atmospheric and human agents; makes writing and sprays easy to clean away; offers bright, substantial colours, great for reproducing any pattern, slogan, map, sign system and information; recommended for décor…


If we were to plant flags bearing the ideal logo of the International Enamellers’ Institute in all the underground railway systems where vitreous enamelled panels and décor have recently been used, we would need a planetarium to do it. In fact, enamelled modules have been installed in Madrid, Munich, Paris, Berlin, Budapest, Washington, Singapore, Caracas, Milan…


There would be a much thicker scattering of flags if we were then to add one for each airport, railway station, hospital, ship, important public and private building… But let’s stick with the underground railways for now. And let’s start by looking at the great photographs of some of these installations.


The first impression you get as you look at the big passageways and waiting areas is one of sheer brilliance, of a subdued gleam, the luminous substance of the colours and the sense of cleanliness and hygiene that emanates from the enamelled surfaces large and small, as they reflect the lights. The next thing you notice is just how easily the enamelled elements blend in with the context, the other materials and décor in each case.


The endless potential for making modular use of colours and patterns and the slight signs of geometric grouting between flanking panels enliven these large spaces, lightening even the heaviest, most intrusive shapes. The photos show the striking, colourfully varied array of what can be done with looks and patterns, qualities that make enamel popular everywhere, but especially so in northern climes, where the sunlight is neither as strong nor as frequent as it is further south.


Silk screen printing can be used to reproduce images and symbols related to the cultures of north and south, west and east (look at the spectacular effects achieved in the Singapore underground), scientific images (as in the Museum station of the Munich underground, which depicts animal skeletons and ancient Greek vases); but also quite simply advertising images, geometric patterns, drawings and cartoons, all of them extremely up to date. This is shown to great effect by the photographs that record how “once again, the Paris Métro has chosen enamel for its make-up”: a fresco measuring thirteen metres long and 2.7 metres high, featuring a silk screen print that required four passages through the kilns, has been installed in the station at Réamur.


Silhouettes two metres tall depict young visitors to the museum and the library of the CNAM (National Conservatory of the Arts and Crafts) located near the station, which holds a rich heritage of works: the fresco is also an effective, attractive way of taking care of the need to provide information and signage, as it acts as an invitation to discover the treasures up on the surface. This continues past traditions, as enamel used to be used extensively in past centuries (and still is in some countries!) for road signs announcing local place-names and other information of various kinds. Using differences and nuances of colour, or by explicitly referring to services or whatever else is available in the vicinity of the individual stations, these illustrations can make the various stops easier to recognise at a glance, an obvious advantage for travellers.

Washington, D.C.

In the Washington DC subway, for example, little maps showing the entire route and all the stations have been reproduced on the columns, combining the useful with the decorative.
Enamel is also eminently suitable for the benches, seating, waste baskets, ashtrays, screens and other décor features usually found in underground railway stations, as enamel is an ideal material for places that are used by large crowds of humans in conditions that are not always ideal, as they are subject to sudden changes in climate and temperature, as well as to pollution both outdoors and indoors. But as well as resisting chemical agents and eccentric weather, enamel is also great at coping with human eccentricity: graffiti and spray writing whose artistic inspiration and content is often of questionable value have now unfortunately spread everywhere. Enamel makes it child’s play to wipe the slate clean of the creations of so many graphic vandals, using any ordinary detergent or solvent. In addition, enamelled sheeting can also be moulded and funnelled in various ways (for Milan’s Line 2, for examples, the designer duo Albini and Helg opted for diamond-tipped moulding for the panels, for the precise purpose of discouraging writing).


If we want to takea look that goes deeper than the surfaces, involving a technical discussion with people who have already used enamelled sheeting materials, qualities that are less visible but no less important come to the fore: these materials generate no toxic emissions in case of fire, they are fast to assemble and allow access to the underlying structures and technical plant; they need practically no maintenance at all and ar easy to clean, very often only requiring a damp rag or a jet of water or steam. All advantages that more than make up (and do so very quickly) for any greater initial outlay compared to other materials or claddings.

Last but not least is a value of enamel in underground railways that may appear to be abstract, but is still worth considering. If we allow the effect of the frantic rhythm of our lives, overcrowding during peak hours and the obligation to share words, noises and smells to be compounded by the deterioration of the spaces where we wait and transit, then the life of habitual travellers can grow even bleaker. A feeling of freshness and light, of cleanliness, full, restful colours, useful drawings and positive scenes can certainly help underground railways to become a better experience, so also improve our lives. It may be an abstract value, but it has significant repercussions, both personally and, as a result, socially and economically.

Tunnel covering with vitreous enamel steel panels

The tragic fires in the Monte Blanc pass (between France and Italy) and in the Tauer tunnel in Austria and in the Gottard tunnel in Switzerland have brought home the issue of road tunnel safety.

In those countries more attentive to safety issues such as Great Britain and France, the USA, the Far East and Oceania, the preferred tunnel wall covering system is one that uses vitreous enamelled steel panels. A comparison of various covering materials (aluminium, fibre-concrete, cis varnishing, vitreous enamel) shows that this last clearly leads over all other systems.

Regulatory standards consider vitreous enamel as being one of the most suitable products for road tunnel refacing. As these enamelled panels ensure long life, assembly ease and reduced maintenance needs.

Thick steel enamelled panels ensure:

:: Improved and uniform illumination at lower costs because they are photo-reflective;
:: Energy savings in gallery ventilation;
:: Effective control against the water that leaks from the walls;
:: The possibility of printing of architectural motives or signs to indicate emergency exits or assistance points directly onto the panels (silk screen or transfer)
:: Easy integration with cable ducts and technical services
:: Greater cleaning ease of the vitreous surface (graffiti can also be cleaned away with solvents)
:: Resistance to pressure and depression caused by traffic
:: Greater acoustic comfort

Sound deadening barriers

Such barriers are increasingly frequently applied along road and motorways in view of recent legislative trends, which are increasingly focused on making road travel more pleasant for the traveller and increasingly environmental friendly.
Both new and renovated infrastructures incorporate sound deadening devices.

There is a choice of the classic sound deadening stave which is assembled between double steel t-shaped elements or the tunnel


Vitreous enamel panels are highly versatile in architectural applications: they can be used both in new building works (ventilated façades, façade buffering, façade covering) and in the renovation and modernization of existing buildings. Vitreous enamel coverings offer the architect a wealth of aesthetic and functional scope. The façade or the portion of the building concerned may be designed according to the plastic effect required or according to the fixture of the panels to the existing structure. These panels can be used to replace walls, partitions, the doors of technical compartments, false ceilings and perforated panelling for any conditioning or ventilation systems that may be required.

The panel thereby becomes a new applicative element in each new project, as it may be adapted to the specific building requirements and needs. Although the tendency is that of standardizing the composition of the faces, there is unlimited scope for the production of elements of particular shapes, calendared pieces, or boxed or elliptical section pieces. The panels used in architecture must be produced with the greatest care in all production stages; the appearance of the panel must be free of any kind of defect. Last but not least is that designers for the surface quality, Its brilliance and the infinitive chromatic potential that it offers particularly appreciate the material.

The modern transfer printing techniques available today provide the possibility of writing, drawing or decorating the panel itself, with a host of graphic options and to the highest level of photografic resolution.

Thanks to its high level of mechanical resistance vitreous enamel and the features already cited above it is the ideal material use for in public settings characterized by a fast and consistent flow of people, in which accidents such as minor collisions or vandalism are common and which would damage any other material permanently; and important areas in which easy stain removal is essential, in the case of graffiti or the outbreak of fire. Making it particularly suited to use in public areas dedicated to public transport, airports, underground stations, railway stations. Another important advantage of the material is that it is highly versatile and can be adapted as necessary.

Operating Theatres

Hospital Guzzardi-
Vittoria RAGUSA

Vitreous enamel in the operating theatre

Durability, maximum hygiene, easy assembly and integration with technological installations, together with a wide range of colours that favour recovery: these are the advantages offered by vitreous enamel panels for operating theatres and hospital interiors.

Hospital S. Camillo-
Forlani ROME

There are many sound reasons for stating that vitreous enamel is the ideal material for lining operating theatres and other spaces in hospitals and health service locations in general.
Topping the list are the well-established qualities that derive from its vitreous nature and range from its hardness to its porosity free impervious nature which offers a guarantee of hygiene.
Along with its resistance to abrasion is so important because it ensures that there are no bacteria, cracks and interstices that could then be used by germs and moulds to take hold and proliferate. This high degree of hygiene is particularly important in hospital environments, where frequent use has to be made of sometimes very strong detergents and solvents for fast cleaning, decontaminating and disinfecting operations that would have any other material on its knees in short shrift – but not so vitreous enamel.

Hospital S. Camillo-
Forlani ROME

The characteristics of the panels themselves also offer some interesting advantages: their boxed, doubled edges facilitate assembly and attachment to the frame of the substructure, using bayonet/T-square attachments fixed to the edges. In addition, an ultra slimline joint can be formed between pairs of panels, which is then filled with a special sealant that stops any impurities from collecting in the space. As these panels have no horizontal joints, they are ideal for housings for all of systems necessary for making an operating theatre functional: medical gases, windows for passing surgical instruments and waste, diaphanoscopes and sterilisation equipment, as well as the power and air conditioning circuits. Meanwhile, cavities inside the panelling can house all the concealed plant systems, enabling everything to be maintained properly and easily: from time to time, all you have to do is remove those panels that are necessary to uncover the section of the plant systems that you need to check.

The extensive colour range in which vitreous enamel panels can be specified is another factor worth serious consideration, when designing health service interiors in general: this is because colour is an element whose importance is gaining increasing recognition. The psychological impact of colour, not only on the people who work in such structures, but above all on the patients. It is they who need to be surrounded by a restful, relaxing environment capable of inspiring them with the positive sensations that will help them have a better experience from their stay in hospital and aid faster recovery.

Enamel coating – Functional Characteristics
Vitreous enamel coatings applied to steel panels intended for architecture EN 14431
Steel substrate EN 10209
CleanabilityVitreous enamel can be easily cleaned. Generally a damp sponge is all it takes to wipe away any traces of dirt.NF A 92-032
HygieneDoes not allow bacteria to proliferate. The high degree of hygiene is particularly important in hospital environments.Bacteriological study undertaken by the Modena Hospital Institutes
Resistance to temperature risesEnamelled surfaces do not alter in any way when subjected to sudden temperature rises, even when it is significantISO 2747
Resistance to fireIncombustibleISO 1182
Chemical resistancePropertiesReferences
Resistance to acidsAcids at room temperature do not attack enamelled surfaces. This is a very important point in hospitals where frequent use has to be made of sometimes very strong detergents and solvents for fast cleaning, decontaminating and disinfecting operations.
Hydrofluoric acid shall not be used on vitreous enamelled surfaces.
EN 14483-1
Resistance to normal detergents (pH> 7)Liquid and cream detergents do not scratch or alter enamelISO 4533
EN ISO 4535
UNI 8026
Resistance to organic solventsEnamel is immune to attack from alcohol, trichloroethylene, acetone etc.N. A.
Mechanical resistancePropertiesReferences
AdherenceThe enamel coating must adhere to the steel supportEN 10209 annex D
UNI 8883
Hardness 5 -7 Mohs ScaleThe enamel coating is hard and is not chipped easilyEN 101
Scratch resistanceVitreous enamel is not scratched easilyEN ISO 15695
Resistance to fireIncombustibleISO 1182


%d bloggers like this: