DESIGN AND MANUFACTURE OF NEW THAMES LIGHTHOUSES

The Port of London Authority (PLA) is responsible for maintaining safe navigation on one of the UK's busiest inland waterways. As part of its ongoing infrastructure programme, structural inspections revealed that three existing lattice tower lighthouses — at Crossness, Coldharbour and Margaretness — had reached the end of their serviceable life.

These historically significant structures, installed initially by Trinity House in the early 20th century, were in deteriorating condition. To ensure continued safe navigation along this stretch of the Thames, CU Phosco was appointed via competitive tender to design and install replacement solutions that would meet heritage sensitivities and modern safety standards.

CU Phosco proposed and delivered three 8m lightweight mid-hinge columns, each supporting a free-issue solar-powered beacon. The red-painted columns retain the original structures' traditional appearance and focal height, ensuring continuity for mariners and minimal visual disruption.

Each column is equipped with a mid-hinge mechanism, allowing the beacon to be lowered for maintenance without the need to work at height — significantly improving operational safety and reducing ongoing maintenance risks.

Access to each location was particularly challenging, with the sites positioned along narrow towpaths. CU Phosco used specialist-tracked cranes and MEWPs to ensure a safe and efficient installation, carefully dismantling and removing the original towers in sections.

Installing the new mid-hinge columns has significantly improved safety by eliminating the need to work at height. Maintenance efficiency has also been enhanced, as the beacon units can now be serviced from ground level, helping to reduce both downtime and long-term operational costs.

Notably, the design of the columns preserves the visual heritage of the original structures by matching their height and distinctive red finish, maintaining the familiar skyline for mariners. By safely decommissioning the ageing lattice towers, CU Phosco has removed a potential structural risk and replaced it with a durable, modern alternative that aligns with the Port of London Authority's long-term infrastructure goals.