Emerald Bridge Fibres: A short-haul submarine cable connecting Ireland and the United Kingdom
Emerald Bridge Fibres is a submarine telecommunications cable linking
Clonshaugh, Ireland, and
Holyhead, United Kingdom, across the Irish Sea. With a length of approximately 120 km, it is a relatively short cable designed to provide connectivity between these two important landing points. Owned by Zayo, Emerald Bridge Fibres has been listed as in service since 2012 according to GeoCables records.
What makes Emerald Bridge Fibres notable is the lack of publicly disclosed technical specifications, such as design capacity, fiber pair count, and supplier details. This absence of information limits the ability to fully characterize its technological capabilities. Additionally, live latency measurements suggest that the cable is part of a broader network infrastructure, where routing and terrestrial factors significantly influence end-to-end performance.
Quick facts
| Cable name | Emerald Bridge Fibres |
| Length | 120 km |
| Ready for service | 2012 (GeoCables database) |
| Owner | Zayo |
| Status | In service |
| Design capacity | Not disclosed |
| Fiber pairs | Not disclosed |
| Supplier | Not disclosed |
| Landing points | Clonshaugh (Ireland), Holyhead (United Kingdom) |
| Other cables at Holyhead | CeltixConnect-1 (CC-1) |
🗺 Show Emerald Bridge Fibres on the interactive cable map
Route
Emerald Bridge Fibres spans the Irish Sea, connecting Clonshaugh, located near Dublin, Ireland, to Holyhead, a port town in Wales, United Kingdom. This corridor is a key link for data exchange between Ireland and mainland Britain, supporting regional connectivity and international traffic. Holyhead is also a landing point for CeltixConnect-1, another submarine cable in the area, which provides redundancy options for traffic traversing this route.
Why it was built and what it carries
Emerald Bridge Fibres was likely built to enhance connectivity between Ireland and the United Kingdom, addressing the growing demand for high-speed data transmission in the region. Ireland has become a hub for data centers and technology companies, necessitating reliable and low-latency links to the UK and beyond. While the cable's exact design capacity and fiber count are not publicly disclosed, its role is presumed to be critical for regional data traffic, including enterprise communications, cloud services, and internet transit.
History: what can be established
GeoCables records indicate that Emerald Bridge Fibres was ready for service in 2012. No conflicting dates have been identified in industry sources, making this timeline uncontested. Zayo, the cable's owner, is a well-known provider of bandwidth infrastructure, including fiber networks and data center services. The cable's operational history appears stable, with no publicly reported outages or major upgrades.
Capacity and technology
The design capacity, fiber pair count, and supplier of Emerald Bridge Fibres have not been disclosed in public sources. Without operator documentation, it is impossible to attribute specific technological details to the cable. However, given the short distance of 120 km, it is reasonable to assume that the cable employs standard submarine optical transmission technology, potentially with a limited number of repeaters or none at all, depending on its design.
Latency: the physics
Theoretical one-way light propagation over the 120 km wet segment of Emerald Bridge Fibres is approximately 0.6 ms, with a round-trip time (RTT) floor of 1.2 ms. However, live measurements conducted via remote probes show significantly higher end-to-end latency:
- Clonshaugh to Holyhead: minimum 20.3 ms, average 54.1 ms (138 checks)
- Holyhead to Clonshaugh: minimum 21.2 ms, average 25.7 ms (24 checks)
These figures reflect the full internet path, including terrestrial network segments, routing inefficiencies, and terminal equipment delays. The discrepancy between theoretical and observed latency underscores the complexity of measuring submarine cable performance in real-world conditions.
Redundancy: what happens if it breaks
Holyhead is also a landing point for CeltixConnect-1 (CC-1), which provides an alternative route across the Irish Sea. In the event of a fault on Emerald Bridge Fibres, traffic can be rerouted via CC-1 or other cables serving the Ireland-UK corridor. Standard industry practices for cable repair include deploying specialized cable ships to locate and fix faults, which can take days to weeks depending on weather conditions and the nature of the damage.
Bottom line
- Emerald Bridge Fibres is a 120 km submarine cable connecting Clonshaugh, Ireland, and Holyhead, United Kingdom.
- Owned by Zayo and listed as in service since 2012.
- Technical specifications such as design capacity and fiber pairs are not publicly disclosed.
- Theoretical latency is low, but real-world measurements show higher end-to-end delays due to terrestrial factors.
- Redundancy is available via CeltixConnect-1 and other regional cables.