A filigree steel tower illuminates Lake Geneva—and showcases what’s possible when precision rope technology enables architectural vision

THE CHALLENGE: Building a Working Lighthouse That’s Also an Architectural Statement

Imagine standing at the harbor entrance of one of Europe’s most prestigious sailing clubs, the Société Nautique de Genève, and being tasked with creating something that must:

• Function as an actual lighthouse guiding vessels on Lake Geneva
• House working facilities for regatta timekeepers during major sailing events
• Withstand extreme conditions including wind, water, and severe temperature swings
• Make an architectural statement worthy of Geneva’s sophisticated waterfront
• Achieve a slender, transparent profile without compromising structural integrity

The solution? A 21-meter steel and glass tower wrapped in 13,000 meters of Jakob stainless steel rope.

THE VISION: From Concept to Chrome-Steel Reality

In February 2023, Geneva-based BUREAU Architects (Daniel and Galliane Zamarbide, Carine Pimenta) received planning permission for an extraordinary structure: the “Ylliam” lighthouse. By October 2024, construction began. By spring 2025, it stood complete—a gleaming testament to Swiss precision and nautical heritage.

The architectural brief was clear but challenging:

• Create a functional lighthouse for navigation
• Incorporate fiber-optic connected office space for timekeepers
• Use materials that celebrate maritime tradition while embracing modern engineering
• Achieve structural stability with a filigree, transparent aesthetic

The answer lay in sophisticated rope technology.

THE JAKOB SOLUTION: Rope Structures That Bear the Load

Working with RUCH Metallbau (Altdorf) for metal construction, Jakob Rope Systems delivered the critical load-bearing rope structures that make the lighthouse’s slim profile possible.

The Technical Approach:

Horizontal Bracing System A circumferential curtain of pre-stressed stainless steel ropes provides horizontal bracing for the entire structure. Inspired by bridge construction engineering, these ropes efficiently distribute wind loads across the tower, allowing for the slender silhouette that defines Ylliam.

Materials Engineered for Marine Environment

• Chrome-nickel steel structure: Maximum corrosion resistance and dimensional stability
• 13,000 meters of open spiral strand rope (Ø 10mm): With Jakob Forte M16 turnbuckles and clevises
• 27 meters of circular wire strand rope (Ø 4mm): For specific tension applications
• 72 Forte M10 tension rod systems: Precision load distribution

The Engineering Challenge: Material Transitions Glass, steel, and concrete each respond differently to temperature changes. The structural connections at these interfaces required precise engineering to accommodate different thermal expansion coefficients while maintaining structural integrity under wind and climate stress.

Jakob’s preliminary dimensioning calculations and on-site rope adjustment and measurement ensured these critical transitions performed flawlessly.

BY THE NUMBERS: Ylliam Lighthouse Performance

• 21 meters of vertical structure with filigree profile
• 13,000+ meters of stainless steel rope providing horizontal stability
• 100% functional as working lighthouse and office facility
• Zero compromises between architectural vision and structural requirements
• Spring 2025 completion from October 2024 construction start

WHY THIS MATTERS FOR US ARCHITECTS AND ENGINEERS

Challenge: Structural Requirements vs. Aesthetic Vision

Traditional lighthouse construction prioritizes function over form, often resulting in utilitarian structures. Ylliam proves you don’t have to choose.

The Difference: Rope Technology as Load-Bearing Structure

Unlike conventional bracing that adds visual bulk, Jakob’s pre-stressed rope systems:

• Distribute loads efficiently without obstructing sight lines
• Maintain transparency while providing full structural integrity
• Weather marine environments with stainless steel corrosion resistance
• Enable precise adjustment on-site for optimal performance

From Engineering to Architecture

Bridge construction techniques, adapted for vertical structures, open new possibilities for waterfront architecture. When you can rely on rope systems for critical load-bearing functions, you’re free to pursue dramatically slimmer profiles and more transparent designs.

TECHNICAL SPECIFICATIONS

Location: North pier, Société Nautique de Genève, Cologny, Switzerland

Architects: BUREAU (Daniel and Galliane Zamarbide, Carine Pimenta), Geneva

Metal Construction: RUCH Metallbau, Altdorf

Rope Structures: Jakob Rope Systems

Timeline:

• Planning permission: February 2023
• Construction start: October 2024
• Completion: Spring 2025

Jakob Products:

• Open spiral strand rope Ø 10mm with Forte M16 turnbuckle and clevis (≈13,000m)
• Circular wire strand rope Ø 4mm (≈27m)
• 72 Forte M10 tension rod systems
• Suspension rope holders, 10mm
• Engineering services: preliminary dimensioning, on-site adjustment and measurement

Primary Materials:

• Chrome-nickel steel (structure)
• Stainless steel ropes (bracing)
• Glass (enclosure)
• Concrete (foundation)

DESIGNING FOR DEMANDING WATERFRONT CONDITIONS

Marine Environment Considerations:
Waterfront structures face unique challenges that landlocked buildings never encounter:

• Constant moisture exposure from lake spray and humidity
• Temperature fluctuations from water-cooled nights to sun-heated days
• Wind loading with no urban buildings to provide wind breaks
• UV exposure reflecting off water surfaces
• Visual expectations where structures are seen from all angles, including water

Jakob’s Stainless Steel Advantage:

• Marine-grade stainless steel components resist:
• Corrosion from moisture and salt
• UV degradation
• Temperature-induced expansion and contraction
• Cyclical stress from wind loading

The Forte series turnbuckles and clevises allow for precise tensioning adjustment, compensating for any material movement over time and maintaining optimal structural performance.

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BEYOND GENEVA: APPLICATIONS FOR WATERFRONT ARCHITECTURE

While Ylliam is a lighthouse, the engineering principles apply to diverse waterfront projects:

Marina Facilities

• Yacht club structures
• Harbormaster offices
• Observation towers
• Covered moorings

Waterfront Commercial

• Restaurants with water views
• Retail pavilions
• Event spaces
• Transit terminals

Recreational Infrastructure

• Fishing piers
• Observation platforms
• Beach facilities
• Waterfront parks

Any project requiring transparency, structural elegance, and marine-environment durability can benefit from this rope technology approach.

THE JAKOB DIFFERENCE: Why Waterfront Projects Choose Swiss Rope Systems

1. Marine-Grade Materials AISI 316 stainless steel as standard—the same grade specified for offshore marine applications. Not an upgrade, but the baseline.

2. Load-Bearing Rope Technology Unlike decorative cable systems, Jakob ropes are engineered as primary structural elements. This means architects can eliminate bulkier bracing systems without compromising safety.

3. Engineering Support Throughout From preliminary dimensioning through on-site adjustment, Jakob engineers are partners in the process, not just suppliers. For complex projects like Ylliam, this collaboration ensures the theoretical engineering translates perfectly to built reality.

4. Proven in Demanding Environments Decades of bridges, facades, and structures in harsh climates prove the durability. When your waterfront project has a 50+ year lifespan expectation, proven performance matters.

PLANNING A WATERFRONT OR LANDMARK PROJECT?

The engineering that makes Ylliam lighthouse possible—combining transparency, structural integrity, and marine-environment durability—is available for your next project.

Schedule a Technical Consultation

• Our engineering team will review your:
• Site conditions and environmental factors
• Structural requirements and load specifications
• Aesthetic vision and architectural intent
• Timeline and budget parameters

What You’ll Receive:

• Preliminary feasibility assessment
• Conceptual rope structure design
• Material specifications for your environment
• Estimated scope and timeline

Credits

• Building Owner: Société Nautique de Genève, Cologny
• Architecture: BUREAU (Daniel and Galliane Zamarbide, Carine Pimenta), Geneva
• Metal Construction: RUCH Metallbau, Altdorf
• Rope Technology: Jakob Rope Systems