ISABEL RUBIO ARROYO | Tungsteno

Son los mejores amigos del hombre, pero su lealtad va más allá de la simple compañía. Con un olfato que supera en miles de veces el del ser humano y una inteligencia y capacidad de entrenamiento fuera de lo común, los perros se han convertido en héroes modernos: son capaces de detectar fugas, identificar plagas, colaborar en diagnósticos médicos y realizar hazañas que han salvado vidas.

Perros detectores de fugas

Algunos perros han revolucionado la detección de fugas ocultas en redes subterráneas de agua potable. Suki, pionera en Latinoamérica, identifica pérdidas que de otro modo serían invisibles, incluso bajo asfalto o tierra. El proceso comienza con imágenes satelitales para señalar zonas críticas, y después el perro rastrea y marca con precisión el punto exacto gracias a su olfato, capaz de detectar cloro a gran profundidad. “Tras un acucioso entrenamiento ha recorrido 235 kilómetros, detectando 608 fugas con una tasa de respuesta positiva de un 96%, permitiendo recuperar agua equivalente al consumo anual de más de 10.000 personas”, explicó Franco Nicoletti, gerente de Distribución y Recolección de Aguas Andinas, al periódico EL PAÍS.

Suki, una perra entrenada en Chile para detectar fugas de agua ocultas bajo tierra. Crédito: CNN Chile.

También se han implementado programas de este tipo en países como Bélgica. Allí la empresa The Sniffers comenzó en 1991 a utilizar perros para detectar fugas en instalaciones químicas rurales y de difícil acceso. “Nuestros perros localizan fugas de gas, fugas de aceite, fugas en cables de alta tensión refrigerados por aceite y tomas ilegales con rapidez, precisión y eficiencia”, explica la empresa.

Canes rastreadores de plagas ocultas

Las termitas provocan daños importantes en edificios de todo el mundo. Existen perros entrenados para detectarlas. En los años 80, la Universidad Estatal de Ohio certificó equipos de beagles capaces de localizar colonias vivas de termitas, incluso cuando había tan solo ocho ejemplares en un trozo de madera. Estos canes también pueden detectar moho. Según la compañía Mold Solutions, son capaces de identificar esporas y micotoxinas con una sensibilidad entre 1.000 y 10.000 veces superior a la humana. De esta forma, agilizan las inspecciones, al localizar moho sin necesidad de métodos invasivos, lo que ahorra tiempo y costes.

Aliados en laboratorios

Los perros tienen un papel emergente como herramienta de detección precoz y cribado de enfermedades humanas, gracias a su capacidad olfativa para identificar compuestos orgánicos volátiles específicos asociados a diferentes patologías. Perros entrenados pueden discriminar entre muestras de individuos sanos y enfermos con patologías como diferentes tipos de cáncer (pulmón, próstata, mama, ovario, melanoma, osteosarcoma) o infecciones virales como la COVID-19.

Los investigadores entrenan a perros para detectar la COVID-19. Crédito: CBS New York.

En estudios controlados, la sensibilidad de los perros para detectar la COVID-19 ha oscilado entre el 81% y el 97%, mientras que la especificidad se ha situado entre el 91% y el 100%. Los investigadores señalan que estos resultados son comparables a los de pruebas diagnósticas convencionales, aunque varían según factores como el entrenamiento, el manejo de las muestras o la experiencia del perro. Su uso en hospitales aún es limitado por la falta de protocolos estandarizados y la necesidad de estudios más amplios.

Héroes de cuatro patas

Muchos perros han destacado a lo largo de la historia por su lealtad, valentía e inteligencia, al lograr hazañas que los han convertido en verdaderas leyendas. Laika, una perra callejera de Moscú, fue el primer ser vivo en orbitar la Tierra en 1957, un sacrificio que abrió el camino a la exploración espacial humana. Balto y Togo, perros de trineo siberianos, lideraron la “Gran Carrera de la Misericordia” en 1925, transportando un suero contra la difteria a Nome, en Alaska, y salvando numerosas vidas.

Laika fue una perra callejera de Moscú que pasó a la historia por ser el primer ser vivo en orbitar la Tierra. Crédito: Euronews

Entre los perros que también alcanzaron fama y reconocimiento por sus hazañas, está el sargento Stubby. Este bull terrier fue el perro militar más condecorado de la Primera Guerra Mundial, desempeñando labores de detección y rescate en las trincheras. También es recordado Barry, un San Bernardo que rescató a más de 40 personas en los Alpes suizos en el siglo XIX. Su cuerpo embalsamado se conserva en un museo de Berna como homenaje a su heroísmo. Estos ejemplos muestran cómo los perros han dejado una marca imborrable en la historia gracias a su valor y fidelidad.

Tungsteno es un laboratorio periodístico que explora la esencia de la innovación.

Sacyr has undertaken a pioneering study to assess the impact of exoskeletons in construction environments as part of the Thematic Lab project.

This initiative, led by Sacyr’s Innovation and Health & Safety departments, aims to promote projects that contribute to the prevention of occupational risks. This effort combines technology, health, and workplace safety, analyzing how these devices can reduce physical effort, enhance ergonomics, and reshape the execution of repetitive and demanding tasks.

Through a rigorous protocol of muscular, kinematic, and functional analysis, different exoskeleton models are compared to identify which is most effective for specific activities.

An exoskeleton is an external, flexible structure—based on springs or elastic bands—that functions as a wearable mechanical aid. In engineering, robotic or passive exoskeletons are used to enhance strength and endurance, both for heavy or repetitive work and for the rehabilitation of people with mobility challenges.

The two departments at Sacyr initiated a study to determine how the introduction of an exoskeleton affects the process of replacing railway sleepers.
The study took place in early October on a railway project being developed by Sacyr. Tests were conducted on various tasks, such as handling heavy components, replacing sleepers, and tamping—activities that combine both effort and repetition.

During the trials, workers were equipped with an exoskeleton and body sensors that measured muscle activity and motion dynamics. Their performance was analyzed both with and without the device to compare and monitor the same variables.

Two exoskeleton models providing lumbar support were tested in the experiment. The main difference between them was that one was flexible, while the other was rigid.
 

After the pilot test, participants evaluated the exoskeletons from multiple perspectives, including usability, impact on performance, and their overall comfort and experience during use.

The field data collected will be used to assess the potential effects on muscular effort during different tasks, with the goal of informing decisions regarding their implementation and impact on workers’ safety and health.

ISABEL RUBIO ARROYO | Tungsteno

Climate change is fuelling longer and drier fire seasons. According to NASA, heat waves are intensifying, rainfall is declining, and conditions are becoming more favourable for large-scale burns. Recent studies confirm that extreme wildfires are becoming more frequent: their occurrence rose 2.2-fold from 2003 to 2023. In this article, we explore how burned landscapes recover, not only environmentally, but also economically and socially.

Decades for forests to 'breathe' again

The recovery of forests after a fire depends on several factors, including the intensity of the blaze, the type of ecosystem, how frequently fires occur, and the degree of human intervention. Vegetation usually returns gradually. Satellite-based analyses show that within the first five years, only about a third of what was lost reappears; after ten years, nearly half; and after thirteen years, just over half. In other words, while landscapes begin to regenerate quickly, it can take decades for a forest to regain its previous maturity. In some cases, full recovery may stretch beyond 40 years.

To speed up the recovery process, researchers recommend a range of techniques, such as covering the soil with mulch to protect it and help it retain moisture, planting fast-growing plant species to reduce erosion, installing physical barriers such as logs or straw mats on slopes, and introducing beneficial microorganisms that enhance soil fertility and structure.

 Flames advance, destroying vegetation in a forest area. Credit: Unsplash

Mobile factories to speed up housing reconstruction

In 2025, large wildfires struck Spain, Portugal, France, Canada, the United States, Cyprus and Colombia, destroying homes and forcing mass evacuations. After such disasters, rebuilding quickly and affordably becomes a top priority. While authorities often provide financial aid and subsidies for the reconstruction of affected areas, some experts offer technical advice to ensure that newly rebuilt homes act as "firebreaks". The focus is on incorporating fire-resistant materials and systems that reduce future risk.

New initiatives are also emerging to accelerate recovery. One, led by ABB Robotics and Cosmic Buildings, deploys mobile robotic microfactories to assemble modular homes directly in affected areas. "With AI-driven robotics and digital design, we are cutting build times by up to 70% and reducing costs by 30%, with near zero waste," explains Marc Segura, president of ABB Robotics.

Mobile robotic microfactories that build modular houses after fires. Credit: ABB Robotics

In addition to destroying homes, forest fires have a major economic impact that spans multiple sectors and can last for decades. The economic impact of wildfires across Europe amounts to several billion euros per year. These fires particularly affect sectors such as agriculture, livestock, tourism and forestry.

When health is threatened by wildfires

Wildfires endanger the health of millions of people. They often cause death, burns, smoke inhalation and displacement. Exposure to smoke raises the risk of respiratory problems, such as asthma and infections, increases hospitalisations, and contributes to cardiovascular disease. It can also worsen pre-existing conditions and have long-lasting impacts on physical and mental health.

Wildfires also take a heavy toll on mental well-being. They can trigger anxiety, depression, insomnia, and post-traumatic stress disorder (PTSD) in adults and children alike. Research shows that children are particularly vulnerable. The loss of housing, forced displacement, and traumatic experiences can leave lasting psychological scars, hinder academic performance, and cause stress-related physical symptoms.

To mitigate these impacts, experts recommend providing a combination of medical care and psychological support. Detecting anxiety or PTSD in children and ensuring that older adults continue their treatments are crucial. Several studies also highlight the importance of strengthening social assistance through financial and housing support, as well as encouraging activities that relieve stress and foster resilience to aid full recovery.

· — —
Tungsten is a journalistic laboratory that explores the essence of innovation.

Ana Aurora Grande Barriga

Management Systems 
Quality, Environment and Energy

The new Sustainable Mobility Law marks a turning point, recognizing mobility for the first time as an accessible and inclusive right. For the first time, mobility is recognized as a citizen’s right, accessible and inclusive.

It also boosts state funding for urban transportation, accelerates the digitalization of our transport systems, and sets a clear goal: achieving climate neutrality in the transportation sector.

Its pillars include:

•    Clean and healthy mobility: Transportation accounts for 29% of Spain's greenhouse gas emissions. The law demands significant progress in decarbonizing the transportation sector and achieving climate neutrality.
•    Digitalization and innovation: The Integrated Mobility Data Space (EDIM) will be created to centralize mobility information and drive innovation.
•    Increased investment: Almost €10 billion in European funding will be available to support mobility projects.
•    Mobility as a right: The law prioritizes protecting state funding for urban transport, ensuring everyone has access to mobility options.

What does it mean for companies like Sacyr?

The bill mandates that workplaces with over 200 employees, or 100 per shift, must implement a Sustainable Mobility to Work Plan (SMWP). This SMWP, developed in collaboration with employee representatives, must prioritize active transportation (walking, cycling), public transit, carpooling and low-emission vehicles.

It also contemplates the possibility of appointing a mobility manager to coordinate these efforts. 

A monitoring report is required every two years, and non-compliance could result in fines of up to €6,000.
Furthermore, transport hubs and toll roads must meet energy efficiency standards, including:

•    Certification in environmental and energy management systems (ISO 14001/50001)
•    Carbon Footprint Assessment
•    Using energy from renewable sources and securing guarantees of origin for renewable energy.

What are we doing?

Sacyr’s Quality, Environment and Energy Department has already launched initiatives that align with the law's objectives. We provide bicycle and electric scooter parking, electric vehicle charging stations, hybrid and electric vehicles for staff and encourage public transport use through Sacyr Flex, our transit pass program. We also actively promote and encourage carpooling, which benefits the environment and economically incentivizes drivers through Energy Savings Certificates (ESCs) approved by the Spanish Government.

Flexible work arrangements, efficient driving training in our environmental best practices manual, and the use collaborative work tools that minimize commuting between worksites are also integral to our operations.

We also maintain a fleet of electric and hybrid vehicles (powered by cleaner fuels like LPG), which also generate ESCs for the company. We prioritize train travel over air travel for business trips, reducing our carbon footprint. And we are incorporating biofuels, which can reduce net CO2 emissions by up to 90% compared to traditional fuels.

Looking Ahead: New Opportunities

This law not only sets requirements, but also inspires innovation. It opens doors for pilot projects in mobility digitalization and encourages public-private partnerships to develop automated vehicles.

In construction, it promotes sustainable infrastructure like transport terminals, bike lanes, and energy-efficient buildings. It also champions rail transport through the creation of new rail freight corridors.

The law also encourages intermodal connections between bicycles and public transportation in concession areas and promotes rapid electric vehicle charging on highways.

Finally, subsidies are planned for companies developing SMWPs, helping them stay competitive while advancing sustainability.
In short, this law bill challenges us all to actively participate in creating a better future. At Sacyr, we’re prepared to lead the way toward cleaner, smarter, and more people-centric mobility.
 

¿Qué estamos haciendo?

Desde la Dirección de Calidad, Medio Ambiente y Energía de Sacyr, ya hemos puesto en marcha varias iniciativas que nos acercan a los objetivos de la ley. Contamos con aparcamientos para bicicletas y patinetes eléctricos, puntos de recarga para vehículos eléctricos, flota de vehículos eléctricos e híbridos para los trabajadores, y fomentamos el uso del transporte público a través de Sacyr Flex, nuestro programa para adquirir tarjetas de transporte. También promovemos y sensibilizamos al personal sobre el coche compartido, que además genera beneficios económicos para los conductores, gracias a los Certificados de Ahorro Energético (CAE) aprobados por e Gobierno de España. 

La flexibilidad horaria, la formación en conducción eficiente en nuestro manual de buenas prácticas ambientales y el fomento de herramientas informáticas de trabajo colaborativo que reducen los desplazamientos entre centros de trabajo son otras medidas que ya forman parte de nuestro día a día.

Además, disponemos de una flota de vehículos eléctricos y coches híbridos (con combustibles menos contaminantes, como el GLP), que también genera CAE’s con beneficios económicos para la empresa. Priorizamos los traslados de trabajo en tren, en sustitución del avión, que es más contaminante. También estamos incorporando el uso de biocombustibles (que puede reducir hasta un 90% de las emisiones netas de CO2 en comparación con el combustible de origen mineral).

Mirando hacia el futuro: oportunidades que se abren

La ley no solo exige, también inspira. Abre la puerta a proyectos piloto de innovación y digitalización en movilidad, fomenta la colaboración público-privada para el desarrollo de vehículos automatizados. 

En el ámbito de la construcción, promueve infraestructuras sostenibles como terminales de transporte, carriles bici y edificios energéticamente eficientes. Además, fomenta el transporte ferroviario, con el desarrollo de nuevas autopistas ferroviarias, para el transporte de mercancías y de personas.  En el área concesional, se impulsa la intermodalidad entre bicicleta y transporte público, y la recarga eléctrica rápida en autopistas. 

Además, se prevén subvenciones para empresas que desarrollen sus PMST, lo que representa una oportunidad para seguir avanzando sin perder competitividad.

En definitiva, este proyecto de ley nos reta a ser parte activa del cambio. En Sacyr, estamos preparados para liderar el camino hacia una movilidad más limpia, inteligente y humana.

Industrialization brings factory-style processes into the construction sector, enhancing productivity and introducing a high degree of automation. It encompasses research and innovation in mechanizing and assembling components in a factory setting, applying these techniques to prefabricate various elements like bathrooms, facades, and technical partitions.

This approach is faster and more sustainable, minimizing waste and requiring fewer energy resources, while also simplifying maintenance.

Bathrooms and facades are among the first elements to undergo this industrialization, according to Mónica Silva Laiz, Head of Building at Sacyr Engineering and Infrastructure Engineering department in Spain.

"Industrialised construction is here to stay, and we are today one of the pioneering companies in carrying out this transformation. It is a new way of conceiving construction," explains Mónica Silva.

Sacyr is implementing industrialization as a key component in projects across Chile, the United Kingdom, Spain, and Italy.

In Chile, we operate a factory assembling prefabricated bathrooms for three hospitals: Sótero del Río, Cordillera, and Buine Paine.

The construction of the Milan Hospital in Italy also incorporates industrialized bathrooms and facade sections.

In Spain, we've employed these factory processes at the 12 de Octubre Hospital, installing prefabricated GRC (glass fiber reinforced concrete on a metal frame) facades, among other elements. These methods are also being implemented in residential developments across several Spanish regions.

At the New Velindre Cancer Center in Cardiff (Wales, UK), we're constructing prefabricated facades using light steel frames with external finishes in wood and copper sheets, incorporating windows and glazing. The facade modules are manufactured in Spain and shipped to the UK for on-site assembly.

Furthermore, through the Valdesc project, we're exploring a novel industrialized construction system for facade envelopes using recycled materials, ensuring high rates of circularity and decarbonization. This system will enhance thermal efficiency and simplify component dismantling, combining efficiency, productivity, and safety. 
 

The project, funded by the Science and Innovation Missions Programme (CDTI), is being carried out by a consortium led by SisTem and with the participation of Sacyr Conservation, Alsa, Vodafone, Anteral and Grupo Infonorte. With a budget of four million euros, it was launched in October 2024 and will last until December 2025.

A safer, more connected and smarter road

Iconica's objective is clear: to transform road infrastructure into active components of mobility.

To this end, the consortium is working on solutions that:

•    Improve road safety through smart and predictive technologies.
•    Facilitate real-time communication between vehicles and infrastructure over 5G networks.
•    Integrate elements such as intelligent beacons, capable of transmitting alerts or even modifying the use of lanes depending on traffic.
•    Increase the protection of vulnerable users, such as roadside workers, through their geolocation and communication to digital navigation platforms.

The role of Sacyr Conservation

Within the Iconica project, Sacyr Maintenance leads two key lines of research. On the one hand, it develops IoT geopositioning devices to signal temporary or mobile works, which will be integrated into the STEP (Safer Transport for Europe Platform) platform.

Secondly, it investigates flexible beacons, which allow additional lanes to be opened or closed remotely, based on traffic prediction algorithms that use data from the infrastructure and the connected vehicles themselves.

"We already have a prototype of beacons installed in a project in Huelva to study their resistance to the passage of heavy vehicles and the effects of heat, rain and dust," explains Álex Otero, innovation project manager at Sacyr Engineering and Infrastructures.

Iconica is integrated into Vodafone's STEP mobility platform, which centralizes data and informs drivers about incidents on the road, such as workers, objects on the side of the road or stationary machinery.

The data and incidents collected are communicated to STEP and also shared with DGT 3.0 (Spanish Traffic Authority), which makes it possible for applications such as Google Maps, Waze or Here to alert drivers of possible risks on their route.

Another of Sacyr Conservation's lines of work focuses on traffic modelling and prediction. The behavior of traffic on the A-3 is currently being analyzed with the aim of planning works, causing as few disruptions as possible to users and anticipating traffic jams.

"The most important thing for Sacyr Conservation is to improve safety and protect people who work on the road, geolocate them and alert drivers in real time," adds Álex Otero.

Patricia Muñoz Pequeño
Sustainability Manager
Strategy, Innovation and Sustainability Division

In hindsight, sustainability reporting has undergone significant changes in recent years. Gone are the days when companies like Sacyr, with unwavering commitment and sensitivity to these issues, voluntarily provide information relevant to their ESG strategies and performance using internationally recognised frameworks, with GRI at the forefront.

With the adoption of the Non-Financial Reporting Directive (NRFD) in 2014, and its Spanish transposition in Law 11/2018, sustainability reporting became a legal obligation and, since that time, the importance of these reports has only grown.  

In 2023, with the goal of defining a clear framework for sustainability reporting that would ensure the quality of the information published, data comparability, and the consistency of the information shared by companies, the European Union approved a new Corporate Sustainability Reporting Directive (CSRD) with common reporting standards known as the European Sustainability Reporting Standards (ESRS).

But misgivings and opposition to this new regulation soon arose from the private sector; first, due to the technical complexity and breadth of its requirements and the difficulty of implementing them, highlighting the need for further clarification in certain areas, as well as greater flexibility in their application. 

Secondly, the smaller companies affected expressed doubts about their capacity to comply with this new regulation using their own resources and the potential damage that would be caused by the additional costs required for this purpose. 

The foregoing is paired with a deeper reflection on the part of the European Union; in a complex international environment facing major global changes, ensuring the autonomy, competitiveness, and resilience of the European economy without abandoning the sustainability commitments it has made, has become more crucial than ever.  

This has prompted the EU to redefine its roadmap, while keeping its ambition intact, as demonstrated by i) the strategy of the Green Industrial Deal, designed to strengthen the competitiveness of European industry while accelerating decarbonisation, and ii) the Omnibus Package, the main objective of which is to reduce the administrative burden on companies when reviewing various sustainability regulations, without renouncing the principles of the European Green Deal. 

From a reporting perspective, the Omnibus Package affects CSRD requirements as follows: 

-    Simplification of standards, reducing the number of requirements and providing greater technical clarity in their application. These texts are expected to be available in Q4 of 2025. 
-    Two-year postponement of entry into force for companies, allowing more time to adapt. 
-    Redefinition of application thresholds, excluding listed SMEs and modifying the ranges for the rest. 
-    Maintenance of limited assurance, eliminating the possibility of reasonable assurance in the future.  

In short, 2025 marks a turning point in this area, reflecting the European Union’s commitment to moving toward a more sustainable economy without jeopardising business competitiveness.  

We are in Palencia, in the works of the high speed section of 20.7km Palencia Norte - Amusco, belonging to the Palencia-Aguilar de Campoo HSR line.

Here we have developed a Krainer type retaining wall with disused concrete sleepers from the old Palencia railroad line. Do you want to know how?

Jorge, Rebeca and Luis tell us about the challenges involved in creating the Krainer wall with reused concrete sleepers instead of traditional wooden logs and the positive impact we generated. The main function of this innovative structure is to stabilize slopes and mitigate erosion problems.

Rewatch other Circular Transformation installments.

The materials passport is a unique digital document that gathers detailed information on each material used in a project, including its description, quality certifications, technical specifications, and geographical origin. This tool makes it possible to calculate the carbon footprint and optimize resource management throughout the entire life cycle of the product.

The pilot was carried out at the prefabricated bathroom factory in Jumilla (Murcia), in collaboration with the startup Cuatro Digital and suppliers such as Pladur and Canteras y Hormigones. The primary aim was to establish a blockchain-based methodology to guarantee the traceability of materials used in modular bathroom production.

“This system collects key information on every material, allowing us to measure its environmental impact and generate precise traceability reports,” explains Patricia Díaz, Innovation Business Partner with Sacyr Engineering and Infrastructure.

The bathrooms produced with this methodology were supplied to the NODE housing development in Carabanchel (Madrid). Thanks to this solution, it has been possible to:

• Connect the different stakeholders across the value chain during the industrialized construction process.
• Ensure efficient management of resources.
• Advance toward more sustainable operations through a secure platform that provides insights into material lifespan and reuse potential.

Recognized by Madrid City Council

The development of this pilot was made possible thanks to an award from Madrid City Council, granted in the first edition of the “Blockchain and Advanced Technologies Projects” competition. In this call, Cuatro Digital, presented by Sacyr, was selected as the winner.

These awards seek to recognize and support startups and professionals that stand out for proposing innovative solutions based on disruptive technologies.

Next steps: scaling up and regulatory alignment

Following the success of the pilot, we are now focused on scaling the model to other projects and construction processes. This work aligns with the European regulatory framework, which in the coming years will require detailed information on the materials used in all buildings within the European Union.

“We are working to scale up this solution and get ahead of upcoming European regulatory requirements,” concludes Patricia Díaz.

ISABEL RUBIO ARROYO | Tungsteno

Before any woman in the United States earned an engineering degree, Emily Warren Roebling was already leading the construction of the Brooklyn Bridge. After the death of her father-in-law and the illness of her husband, she stepped in to take charge of the project, becoming the first female field engineer and overseeing every detail of its completion. Her life and legacy secured her place as a key figure in the history of engineering.

The tragedy that led her to lead the Brooklyn Bridge project

Warren was born in 1843 in Cold Spring, New York, into an upper-middle-class family. She attended the Georgetown Visitation Convent, a prestigious girls-only school, where she studied mathematics and science despite prevailing beliefs that higher education was unnecessary for women. Later in life, at the age of 56, she earned a women’s law course certificate from New York University and won a $50 prize for her essay "A Wife's Disabilities," in which she criticised the legal restrictions on women's financial independence.

Warren met Washington Roebling, a young officer, while visiting her brother at an army camp during the Civil War. They fell in love and soon married. In 1867, before construction of the Brooklyn Bridge began, the coupled travelled to Europe on a belated honeymoon to research technical innovations for the project that her father-in-law, John A. Roebling, had designed. There they studied the use of caissons—pressurised watertight chambers used to build underwater foundations for bridges—as well as other advanced bridge-building techniques.

Tragedy propelled Emily Warren Roebling to the forefront of engineering. In 1869, her father-in-law died of tetanus after an accident on the construction site. Her husband, Washington Roebling, assumed the role of chief engineer, but became gravely ill. Exposed to the dangers of the newly introduced pneumatic caissons used to construct the bridge’s foundations, he developed severe decompression sickness and was confined to bed.

Warren took the lead in building the Brooklyn Bridge. Credit: Intrigued Mind

From self-taught engineer to women's rights activist

With Washington unable to work, Warren assumed a crucial role: she managed her husband's communications, studied his plans, copied his specifications, and relayed instructions to assistant engineers. Washington described her as his "wisest counsellor" and "a woman of infinite tact." She visited the construction site daily, attended board meetings, and oversaw the project, all the while carefully concealing the extent of her involvement in order to protect her husband's reputation. Along the way, she learned about material strength, stress analysis, cable construction and the mathematics of the catenary curve.

Shortly before the bridge's inauguration, she drove a carriage across it to test its vibrations, carrying a rooster as a symbol of victory. On 24 May 1883, she became the first person to cross the Brooklyn Bridge in a carriage during its official opening, and later that day she hosted a reception at her home for US President Chester A. Arthur.

After the bridge’s completion, she travelled alone to Europe, where she met Queen Victoria in London and attended the coronation of Tsar Nicholas II in Moscow. Upon her return, she gave lectures about her experiences in Russia for the Federation of Women's Clubs, becoming increasingly active in the fight for gender equality. She toured the country, speaking in defence of women's suffrage and social services for the poor, and urged women to study law.

The Brooklyn Bridge was the longest suspension bridge in the world when it opened on 24 May 1883. Credit: Jf Szekely / Wikimedia Commons

An "everlasting monument" to sacrifice

In 2024, an average of 103,051 vehicles, 28,845 pedestrians and 5,504 cyclists crossed the Brooklyn Bridge every day. This infrastructure has become a living legacy of Warren's vision, effort and determination. "Wife, mother, lecturer, student, world traveller and clubwoman, this multi-faceted Victorian woman was a pioneering example of independence," says the American Society of Civil Engineers (ASCE).

As New York Congressman Abram Hewitt said during the opening ceremony, the bridge represents "an everlasting monument" to Warren's dedication and personal sacrifice. "The name of Emily Warren Roebling will...be inseparably associated with all that is admirable in human nature and all that is wonderful in the constructive world of art," he said.

Tungsten is a journalistic laboratory that explores the essence of innovation.

At Sacyr Agua, we’re pushing the boundaries of sustainability and innovation by detecting and removing microplastics in our wastewater treatment plants (WWTP). By joining forces with Captoplastic, we are working together to make this possible.  

Although microplastic pollution (plastic particles smaller than 5 mm) occurs throughout the whole water cycle, reducing them in the treated water leaving our WWTP is a significant step in protecting the environment.

These plants are designed to remove organic matter and conventional pollutants from wastewater, but they do not normally include specific processes to deal with the wide variety of microplastics that reach them. 

“As well as becoming their preferred partner for projects in Spain, this partnership also allows us to use Captoplastic’s technology and references exclusively in markets such as Australia, Peru and Colombia,” says Eduardo Campos, Managing Director of Sacyr Agua.

An agreement built on innovation

The collaboration with Captoplastic began following a successful pilot project at the Yecla WWTP (Murcia), managed by Sacyr Agua, as part of our open innovation programme, Sacyr iChallenges. 

It was there that we discovered Captoplastic’s pioneering solution, which continuously detects and removes microplastics. This fits perfectly with our commitment to sustainability and our drive to bring advanced technologies into our business.

Pilot project success

To test and validate the technology, Captoplastic moved a demonstration pilot plant from the Cantoblanco campus of the Autonomous University of Madrid to the Yecla WWTP, where the trials were carried out.

Beforehand, a detailed study of the microplastics present in the different stages of the plant was completed, both in the water line and the sludge line. Several types of microplastics were identified, including polypropylene (PP), polyethylene (PE), polycaprolactone (PCL), poly(ethyl acrylate) (PEA), acrylic, polytetrafluoroethylene (PTFE) and polyurethane (PU). 

These microplastics were found in different forms, such as pellets, fibres and fragments, with the highest concentration in the sludge line.

The results of this first pilot trial were very positive, showing a 76% reduction in the initial concentration of microplastics. This proves the effectiveness of the solution and its potential to be scaled up.

Captoplastic Technology

Captoplastic is a Madrid-based small business dedicated to developing innovative solutions for detecting and removing microplastics. Established in 2020, the company has been recognised as a Knowledge-Based Company and works with strategic partners such as the Universidad Autónoma de Madrid and the BeAble Innvierte Kets Fund.

Its technology uses an agglomeration technique, adding an inorganic agent to the water stream so that it binds with microplastics and forms larger aggregates that can then be removed. 

Thanks to the magnetic properties of the agent, the aggregates can be easily separated and removed from the water stream. The process can handle large volumes of water efficiently. The captured microplastics can be recycled, making this a zero-waste technology that is environmentally friendly throughout its entire cycle.

ISABEL RUBIO ARROYO | Tungsteno

The lost city of Atlantis has captured the collective imagination for centuries. According to ancient myths and tales, this enigmatic land vanished mysteriously beneath the waves. Despite the fascination it generates and the countless theories and searches for its supposed underwater ruins, science has found no conclusive evidence of its actual existence. However, history does offer us real examples of cities that have truly been claimed by the sea.

A window into the Bronze Age under the sea

In 1967, British oceanographer Nicholas C. Flemming discovered the remains of an ancient city under the sea, near the island of Elafonisos in southern Greece. The site was identified as Pavlopetri, a settlement that is thought to date back to the Bronze Age. The following year, a team from the University of Cambridge organised an expedition to study the site. Around 5,000 years old, Pavlopetri is one of the oldest known submerged cities, with streets, buildings and tombs still preserved beneath the sea.

The prehistoric city covered 90,000 square metres and featured a complex water management system—with canals and drains, as well as a cemetery. “This neglected place in prehistoric times had occurred to be a thriving port with intense social stratification, and a lifestyle that made the Head of Investigation John Henderson to talk about the Greek Pompeii,” note the authors of a 2016 study. Several studies suggest that the city may have been submerged around 1000 BCE. Three theories attempt to explain how this happened: one suggests a gradual rise in the sea level, another a sinking of the land, and a third that a combination of earthquake and tsunami caused the city’s disappearance.

Digital reconstruction of Pavlopetri. Credit: University of Nottingham

Temples, jewels and sunken ships

In the year 2000, underwater archaeologist Franck Goddio discovered the ancient city of Thonis-Heracleion, located seven kilometres off the Egyptian coast in the Nile Delta. Founded in all likelihood in the 8th century BCE, this port city served for centuries as the main gateway to Egypt for ships arriving from the Greek world, and it was renowned for its commercial and religious significance.

The city suffered several natural disasters, and it is believed that an earthquake eventually caused it to sink beneath the sea. The European Institute for Underwater Archaeology has studied the submerged site and uncovered more than 60 shipwrecks near its ruins, reflecting the area’s intense marine activity. During excavations in 2023, researchers discovered the remains of a sanctuary dedicated to the Greek goddess Aphrodite, as well as a temple to the god Amun. They also found gold jewellery, silver artefacts, ceramics, and bronzes imported from Greece. Well-preserved wooden structures were also found, as well as ritual and funerary items, such as silver libation dishes (used for offerings poured in honour of a deity) and alabaster vessels for perfumes and ointments.

Heracleion, the ancient Egyptian port city that collapsed beneath the sea.

The "wickedest" city of the New World

Port Royal, in Jamaica, was once the most important commercial center in the New World. The town, “commonly referred to as "the wickedest city on earth", conjures images of marauding pirates, daring naval conquests, looting, riches, destruction and devastation,” according to the United Nations Educational, Scientific and Cultural Organization (UNESCO).

It began as a strategic cay used for cleaning and refitting ships when the Spanish arrived in the 16th century. Following the English conquest in 1655, it quickly developed into a fortified city and flourished as the principal commercial and naval port of the English Caribbean. Its economy thrived on the slave trade, sugar, and privateering—and it gained notoriety as a lawless paradise of alcohol, money, and sex, where one in four buildings was reportedly either a bar or a brothel.

Old map of Port Royal. Credit: The Gentleman’s Magazine / Wikimedia Commons

Excavations have revealed that beyond its many taverns, Port Royal also featured workshops, homes, and warehouses. The city stood out for its wealth and its prominence as a key center of trade and piracy in the Caribbean. In 1692, a devastating earthquake caused two-thirds of the city to sink into the sea. Subsequent fires and hurricanes thwarted any attempts at full recovery. Although Port Royal persisted as a British naval base and secondary port, it never regained its former status as a thriving hub of commerce and piracy. Today, it survives as a small fishing village in Jamaica.

In early 2024, the Community of Madrid approved the Cognitive Hospital project, a comprehensive management platform for hospital infrastructure. 
The project is based at the Hospital del Henares (Madrid) and is being developed by a consortium led by Sacyr, with participation from companies like Sener, Cuatro Digital, Aptica, Fracttal, and Open Ingenius. It is a three-year project with a €6.1 million budget, funded by the Community of Madrid through the European Regional Development Fund (ERDF).

As a result of this project, the hospital will benefit from continuous connectivity, sensors measuring air quality with virus-capturing nanofibers, devices improving energy efficiency, virtual reality technologies simulating evacuations, geolocation of equipment, and modules measuring the hospital's overall environmental impact.

After a year of work, Sacyr has developed the core of the cognitive platform. This platform will connect all existing management software systems at the Hospital del Henares, alongside the innovative solutions, technologies, and sensors developed and implemented within the project.

The platform developed by Sacyr integrates all innovative elements of the Cognitive Hospital project by creating an intelligent software platform that facilitates the digitalization of the hospital. This improves the experience for both patients and staff while promoting the sustainability of the facility's operations.

This is creating a smart hospital capable of autonomously managing its operations more efficiently, using real-time data generated during the infrastructure's operation.

"The new software platform is already operational and already receiving data from systems currently in place at the Hospital del Henares, as well as from the new sensors, LiDAR systems, and other devices being installed," explains Alba Rocío Pérez, Innovation Manager with Sacyr's Strategy, Innovation and Sustainability Department.

During the project's first year, the partners conducted an in-depth study of the hospital's physical and digital structure, using the Smart Readiness Indicator (SRI) methodology to objectively assess the building's "intelligence" level. This helped identify potential improvements and address deficiencies more efficiently than current methods allow.


 

Furthermore, Sacyr has advanced the implementation of a space management system using LiDAR technology. Its primary function is to identify and prevent overcrowding or queuing in customer service areas. "We aim to enhance patient comfort and reduce waiting times through innovative data collection," Alba Rocío explains.

Through the creation of a point cloud with LiDAR technology, Sacyr has also successfully obtained a BIM (Building Information Modeling) model of the hospital building. Thanks to the technology developed within the Cognitive Platform and the BIM model, a digital twin of the Hospital del Henares has been created, providing updated information on the building, systems, and equipment.

Sacyr Engineering contributed to the project in its first year by streamlining the BIM model. This allows for more efficient work with the building model, both during the construction and maintenance phases.

The second year will focus on completing a comprehensive analysis of the hospital, including impacts related to the use and maintenance of its facilities (consumption, waste generation, and maintenance activities).

PTEC Award

The Cognitive Hospital project recently received the Spanish Construction Technology Platform (PTEC) Award for the Best R&D&I Project in the construction sector.

They say words are carried on the wind. Perhaps that’s why we created the “Strategic Plan: Carrying the Word” communication series, in which Sacyr professionals explain the main concepts of our new strategic cycle in their own words.

The terms chosen are Rating, Water, AI, Transport, Sustainability, P3, Security, Diversity, X3, and Social.

Over the course of 10 months, we travelled to 10 locations with 10 different teams in order to determine the ambitions and ideas that will guide our strategy in the coming years.

Since the launch of our Strategic Plan in May 2024, we have continued to grow and consolidate our position as a leader in the development of greenfield infrastructure transport, social and water projects. 

We will discuss the journey of the “Strategic Plan: Carrying the Word” throughout Sacyr.

Rating

Our investment team is working to obtain an investment-grade rating. This goal will consolidate our global growth as a concessionaire, allowing us to accelerate our development in international markets.

Water 

We provide our experience, technology, and innovation in end-to-end water cycle management to ensure water quality and access. In early 2025, we secured our first major concession contract in this strategic cycle with the wastewater treatment, reuse, and subsequent sale project in Antofagasta (Chile).

AI

Because technology is crucial to achieving our strategic objectives, our ICT team works to ensure the optimisation and automation of processes, while predictive analysis allows our professionals to focus on more strategic tasks.

Transport

We “teleport” to the recently opened Belfast Transport Hub for the first international chapter of our “Strategic Plan: Carrying the Word”. By developing transport infrastructure, we drive connectivity, improving the links between people and communities.

Sustainability

Colombia’s Canal del Dique demonstrates our work toward a better world. Ensuring our projects have a positive impact on the surrounding communities is the foundation of the 24-27 Sustainable Sacyr Route, which is based on four pillars: the planet, people, prosperity, and governance.

P3

Public-Private partnerships (P3 or PPP) are essential to the advancement of society. Infrastructure development through P3 projects facilitates their maintenance, operation, and improvement under optimal conditions. Chile is one of our main concession markets.

Safety

In every project we undertake, we implement strict health and safety protocols that allow us to meet our objectives while protecting our teams. Our preventive culture and the commitment of our senior and middle managers are the driving forces that help us minimise accidents and increase safety training. 

Diversity

We will only achieve the ambitious goal of becoming the world’s largest greenfield infrastructure developer by 2033 with diverse and inclusive teams. Our Diversity, Equity, and Inclusion Policy and Plan guide us in our commitment to gender, functional, cultural, demographic, generational, experiential, and cognitive diversity and establish concrete objectives, measures, and indicators through 2027. 

X3

In this strategic cycle, we will triple the invested equity and our P3 asset valuation. Translated into figures, we aim to achieve an invested equity total of 4.5 to 5 billion euros and an asset value of between 9 and 10 billion euros. Italy is one of our most important concession markets, where we will continue to grow in the coming years through the SIS consortium.  

Social

The Sacyr Foundation serves as a conduit for the positive impact of our professionals. More than 1,000 employees participate in volunteer programmes related to the Sacyr Foundation’s primary focus areas: early childhood development, environment, inclusion, emergencies, disabilities, and healthcare.

Luis Esteban
Director Arquitectura en Sacyr Ingeniería e Infraestructuras

Se cumplen 15 años de la rehabilitación del Palacio Velázquez del Parque del Retiro (Madrid) por parte de Sacyr, en la que tuve la suerte de formar parte del equipo como jefe de obra. 

Los trabajos incluyeron la ejecución de una nueva cubierta y la restauración integral del espacio interior. Un trabajo desafiante ya que el edificio cuenta con Nivel 1 de protección con grado singular y está catalogado, dado su valor histórico y artístico.

Fue la primera obra de Sacyr en el emblemático pulmón verde de la ciudad de Madrid y un orgullo para la compañía participar en la restauración del Patrimonio Nacional. 

Imagen del interior recogida de la cuenta oficial del Palacio de Velázquez.

El Palacio de Velázquez fue inaugurado en 1883 como pabellón temporal para la Exposición Nacional de Minería, Artes Metalúrgicas, Cerámica, Cristalería y Aguas Minerales, que se celebró en Madrid ese año, durante el reinado de Alfonso XII.  

Su arquitecto Ricardo Velázquez Bosco le dió nombre al edificio y siguió para su proyecto el modelo que Joseph Paxton había establecido al proyectar el Crystal Palace de Londres. El diseño organiza una arquitectura amplia, cubierta con bóvedas de estructura de hierro, donde el cristal se usa para dotar de iluminación natural a los grandes espacios interiores.

Acabada la exposición el edificio, lejos de demolerse, paso a destinarse a Museo de Ultramar.  Hasta la actualidad donde pertenece al Ministerio de Cultura, quien lo dedica a sala de exposiciones temporales del Museo Nacional Centro de Arte Reina Sofía.

Pese a la antigüedad del edificio, tiene un curioso y actual nexo de unión con la arquitectura contemporánea. Las columnas de fundición, que pueden ser una de las más singulares características del edificio, podrían considerarse como los primeros ejemplos de construcción industrializada porque se fabricaron en taller.  Siendo por tanto una de las primeras semillas de la prefabricación e industrialización, que después de tantos años, se retoma en la actualidad con mucha fuerza.  

  


En este contexto de la construcción del Palacio Velázquez, es relevante indicar que la producción y exportación de hierro había crecido enormemente en España a partir de 1875, y con ello surgieron en Madrid las primeras fábricas de hierro (fundido y colado), desde las cuales se suministró al proyecto.

Todo ello permitió que las columnas de hierro pudieran ser elegidas por catálogo y llegaran a la obra completamente terminadas, solo esperando a ser colocadas. 

El éxito de este edificio le supuso al arquitecto Velázquez el encargo de otros edificios importantes como la Escuela de Ingenieros de Minas y el Palacio de Cristal del parque del Retiro, donde continuó usando soluciones de estructuras metálicas de hierro fundido con el empleo añadido de grandes lucernarios.

Earlier this year, we launched the "Circular Transformation" series to highlight initiatives that aim to promote circularity, directly from the people leading the charge.

We're prioritizing the use of sustainable materials, preventing waste generation, and increasing reuse and recycling to create new forms of value.

Now that we're halfway through the campaign and the year, we're taking the opportunity to compile the initiatives from the series that we've published monthly. Our performance in Circular Economy has allowed us to reuse, recycle, and recover more than 23 million tons of waste since the beginning of 2020.

Here are the initiatives from the Circular Transformation series!

Treatment of the water used in the tunnel excavation at the Port of A Coruña

Tunnel and gallery excavation requires water for the machinery to drill through rock. To reuse this water, we've installed two treatment plants at the expansion project of the access to the Outer Port of A Coruña (Spain), which we are developing for Adif.

After treatment, we discharge it into natural flows, reservoirs, or the sea, where it can be used for industrial purposes.
 

A brine collector that extends the life of materials in the Llobregat Basin

We have renovated the facility with a new brine collector of 8.7km and 184 liters per second capacity. During the project, we recovered polyethylene pipes from the bypasses of the work and pavement milling so that the city council of Sallent (Barcelona) can use it in future works.

With these initiatives, we improve environmental protection, modernize infrastructures, regenerate water, and improve mining activities.

Reused Materials at the La Llagosta Logistics Terminal

We are developing the construction of the La Llagosta (Barcelona) international logistics terminal for Adif to turn it into a strategic logistics hub on the Mediterranean corridor.

The project stands out for the reuse of asphalt pavement, ballast, and concrete debris, which allows for a positive environmental impact and cost savings by reducing the consumption of new materials.

Circular Initiatives in Madrid Construction Projects

We manage sacks, recycle plasterboard, and reuse pallets. These are some of the initiatives we are carrying out in Madrid to minimize the environmental impact of our construction projects.

Zero Waste Certification for Our Hospitals in Chile

Our best practices have allowed us to obtain the Zero Waste distinction in the Sótero del Río, Provincia de Cordillera, and Buin Paine hospitals.

Obtaining this certification reflects the full alignment of the projects in Chile with Sacyr's Zero Waste Plan, which seeks to achieve 80% of waste reused, recycled, and recovered annually.
 

Circular economy as an economic model to fight climate change

Prioritizing materials with recycled content, working with local suppliers, and properly managing the waste we generate are key factors in reducing emissions.

Through this approach, we have managed to reuse, recycle, and recover 92% of the waste generated in Sacyr's activities in 2024.

The Zero Waste Plan is the vehicle for achieving our circular economy goals and guides our steps in this area. With the impetus of the plan, we have avoided the emission of 10,000 tons of CO2eq since 2020 and expect to reduce 15,000 tons of CO2eq by 2030.

Until the end of the year, we will continue to showcase Sacyr's circular economy projects. Follow us closely on our social networks and don't miss the upcoming content of Circular Transformation.

The new Sótero del Río Hospital (Santiago de Chile, Chile) is bound to be one of the largest healthcare facilities in Latin America, and also one of the most sustainable. This project, developed by Sacyr Engineering and Infrastructure, has obtained the Zero Waste certificate, and is now conducting a novel pilot to introduce a hybrid boom truck fueled by green hydrogen into its fleet. 

The aim is to improve the efficiency and reduce emissions produced by diesel trucks by implementing a hybrid green hydrogen injection system into the combustion chamber.

The new dual combustion system has been designed in Italy specifically for this vehicle model, as it is the first time it has been implemented in a boom truck. The installation of this kit was carried out by AndesH2, a company that has experience in Colombia and Chile. 

"This innovative project arose from the urgent need to reduce the emissions generated by the equipment used on site. Considering that, in the long term, we must focus on progressively forming and shifting a fleet of heavy equipment with zero emissions, including hopper trucks, backhoes, trucks with lifting equipment, among others," explains Rodrigo Fernández, Construction Manager at Sacyr's Metro L7 in Chile.

"Our main purpose is to evaluate the technical and economic feasibility of the gradual conversion of Sacyr's current fleet to low-emission equipment, thus ensuring compliance with more rigorous environmental standards and actively contributing to the sustainability of the sector," Rodrigo says.
"Our goal is to evaluate the benefits of introducing synthetic fuels such as green hydrogen," explains Etienne Valdés, R+D with Sacyr Chile's Innovation Department.

The project consists of the implementation of a dual combustion system designed in Italy specifically for the truck model. The installation of this kit was carried out by AndesH2, a company that has experience in Colombia and Chile implementing these modifications and being the first time that it has been carried out on a boom truck.

This process is called dualization or blending of green hydrogen to improve fuel efficiency. The installed kit is connected to the hydrogen tanks and injects the appropriate hydrogen percentages into the engine.
 

Preliminary first tests have already been carried out using 4 kg of hydrogen for a week in a controlled setting closed to traffic.

"It takes less hydrogen than diesel to reach the same energy efficiency in the engine. The engine is modified to inject 15% hydrogen on average into the fuel. This improves efficiency and reduces the use of diesel, so the engine is more efficient, and produces fewer emissions," explains Etienne.

The use of this fuel poses further challenges. "We have to create a safety plan with this equipment, and, as a second step, homologate the truck for use on public roads. Currently, we are managing an experimental permit certificate through the Ministry of Transport and Telecommunications, explains the expert.

ISABEL RUBIO ARROYO | Tungsteno

St. Peter's Basilica is not only the spiritual heart of Catholicism, but also a monument that encompasses centuries of art, architecture and mystery. From its origins in the time of Constantine to its underground nooks and passageways, this monumental temple continues to fascinate millions of faithful and visitors every year. Here are some of the most surprising and lesser-known facts about the world’s largest Christian church.

The history behind St. Peter's Basilica

The St. Peter's Basilica that we know today was not the first church to occupy this site. In the 4th century, Emperor Constantine commissioned a church to be built here, which stood for over a thousand years. However, it was not until 1506 that Pope Julius II decided to replace it with a new, monumental construction in tribute to the Apostle Peter, who is believed to have been buried on that very hill in the Vatican. Construction took almost 120 years and involved the participation of prominent Italian architects and artists such as Donato Bramante, Michelangelo and Raphael. While Bramante took inspiration from the Roman Pantheon for his initial design, Michelangelo was responsible for the iconic dome.

The imposing interior of St. Peter's Basilica. Credit: Fabbrica di San Pietro / St. Peter's Basilica

The largest Christian church in the world

This monumental work embodies the splendour of the Vatican. At 136.5 metres high, its dome is the tallest in the world. The interior covers more than 15,000 square metres and its total area extends to about 2.3 hectares. Recognised as a UNESCO World Heritage Site in 1984, it is considered the largest Christian church in the world.

View of the interior of the dome of St. Peter's Basilica. Credit: Fabbrica di San Pietro / St. Peter's Basilica

Saints welcome the faithful in the iconic St. Peter's Square

In front of the basilica, St. Peter's Square can host thousands of people. According to the Vatican's official website, Vatican News, more than 100,000 people attended Pope Leo XIV’s first greeting from the square. Designed by Gian Lorenzo Bernini, the square features an elliptical colonnade arranged in 284 columns in four rows, which symbolise the embrace of the Church. At its centre stands an Egyptian obelisk, flanked by two fountains. The square is adorned with statues of saints who welcome visitors and, according to the Vatican, represent the union between the heavenly and earthly churches.

St. Peter's Square and its iconic colonnade. Credit: Fabbrica di San Pietro / St. Peter's Basilica

The popes who rest beneath St. Peter's Basilica

Throughout history, St. Peter's Basilica has inspired numerous legends about hidden passageways and secret chambers beneath its structure. Beyond the myth, the truth is that there are several real underground spaces, such as the Vatican Grottoes and the Necropolis, which house ancient papal tombs. Although Pope Francis has chosen the Basilica of Saint Mary Major as his burial place, the remains of 91 popes lie beneath Saint Peter's. These papal tombs are located alongside those of members of royalty and nobility. Notable pontiffs buried here include emblematic figures such as Pius X and John Paul II. For archaeologists, this collection of tombs is a historical treasure of incalculable value.

The Vatican Necropolis. Credit: Fabbrica di San Pietro / St. Peter's Basilica

The Vatican's secret passageway

Very close to this monumental complex is the Corridor of Borgo, also known as the Passetto de Borgo, a fortified corridor connecting Vatican City with Castel Sant'Angelo. Although it doesn’t pass directly under the basilica, it forms part of the Vatican's defensive system and was constructed as an escape route for popes during times of crisis. The corridor’s most famous episode occurred during the Sack of Rome in 1527, when Pope Clement VII managed to escape through it and took refuge in the castle. According to Rome's Department of Major Events, Sports, Tourism and Fashion, “the Pope was saved by the skin of his teeth, running through the narrow corridor, while the courtiers and nobles who accompanied him protected him with a dark cloak to prevent his white robe from becoming an easy target.” Today, some sections of the Passetto can be visited on guided tours from Castel Sant'Angelo, revealing one of the most strategic and lesser-known corners of Vatican history.

View of the Passetto di Borgo from Castel Sant'Angelo in Rome. Credit: Rome's Department of Major Events, Sports, Tourism and Fashion

Tungsten is a journalistic laboratory that explores the essence of innovation.

In this installment of the Circular Transformation series, Paula Honrado and Gonzalo Vicente, from the Environment, Quality and Energy Department, explain the concept of the circular economy as a model to keep natural resources within the production cycle.

Prioritizing materials with recycled content, working with local suppliers, and properly managing the waste we generate are key factors in reducing emissions.

In 2024, over 92% of the waste generated from Sacyr’s activities has been reused, recycled, or recovered. Since 2020, we have avoided emitting nearly 10,000 tons of CO2 and have recovered more than 23 million units of waste.

In the May edition of the "Circular Transformation" series, we travel to Chile to meet the teams from Sacyr Engineering and Infrastructure who have achieved the Zero Waste certification for the Sótero del Río, Provincia de Cordillera, and Buin Paine hospitals.

This certification, promoted by the European Union, OECD, and United Nations Environment Programme, is obtained through an external audit that verifies that between 90% and 100% of the waste generated on-site is recovered or repurposed. By valorizing waste, the need for landfill disposal is avoided, along with the environmental impact associated with transportation.

This certification encourages us to continue excelling in waste management by converting waste into raw materials and reintegrating them into the value chain. It is also directly aligned with Sacyr’s Zero Waste Plan objectives, which aim to “achieve 80% annual reuse, recycling, and recovery of waste.” The next step is to carry out external audits with AENOR at the three hospitals.

In 2024, Sacyr was the first company in Chile to obtain the AENOR Zero Waste certification for the hospital project at Sótero del Río, having recovered 165,181 tons of waste — over 93% of the total generated.