The restoration of Thiepval

At over 45 metres tall, Sir Edwin Lutyens’ Thiepval Memorial to the Missing of the Somme in northern France is the world’s largest Commonwealth memorial to the missing.

The Thiepval memorial at dawn (Photo: Candia Lutyens).

The Thiepval Memorial to the Missing of the Somme dominates the landscape of northern France for miles around. Cared for by the Commonwealth War Graves Commission (CWGC), it stands on the former battlefield of the Somme, overlooking the site of some of the heaviest fighting of the first world war. The memorial commemorates more than 72,000 men of the British and South African forces who died on the Somme and have no known grave, the majority killed in the Somme offensive of 1916.

Thiepval was designed by Sir Edwin Lutyens and unveiled by the Prince of Wales in 1932. Architectural historian Gavin Stamp described it as ‘arguably Lutyens’s finest and most intellectually distinguished executed creation and certainly one of the greatest works of 20th century British architecture anywhere’. It is a remarkably clever and extraordinarily complex structure of brick arches piled on arches of four sizes in total, each different in height but proportionally identical. The arches create 16 piers on which the names of the missing are inscribed on nearly 3,000 panels of Portland stone.

Open to the elements on all four sides on an exposed hillside, maintaining Thiepval has its challenges for the CWGC. This is exacerbated by some unfortunate construction details, commonplace in their day but problematic a century later. There are 21 flat roofs, for example, all originally covered with a thin bitumen coating and draining into a vast maze of internal downpipes.

The structure is a concrete frame faced with brick. Concerns were raised about the suitability of the brick choice even during construction. It was nearly all refaced in the 1950s, although unfortunately with a similarly poor selection. Eventually it was refaced again in the 1970s with the ‘Nori’ Accrington engineering brick from the UK which we see today.

The problem is partly that the walls were originally built without a cavity. Severe problems with water penetration were noted after the second world war (when the building was barely 20 years old). The 1950s restorations involved forming a cavity behind the bricks and inserting bronze wall ties. This was an ingenious idea, but the detailing has led to continuing water issues. The works in the 1970s tried to address this by using a denser brick, but again some of the fundamental design weaknesses were not fully corrected.

In 2014–2016 the CWGC carried out the first phase of a major renovation. Starting with the upper part of the memorial, it involved inserting steel ties to fix the brickwork back to the concrete frame, repointing and re-roofing. The commission installed a new drainage system with 1.5 kilometres of pipes, architectural lighting, and new flagpoles for the French flag and the Union flag, topped with replacement bronze crowns.

The first phase was completed in 2016 to coincide with the Battle of the Somme centenary event, where Thiepval formed the centrepiece of the international commemorations with a service attended by the Prince of Wales and the President of France.

The CWGC began the second phase of the restoration last year. The work continues to the central and lower part of the memorial, as well as resolving water ingress through the brick terrace into the cavernous basement below. Thiepval has been listed by the French authorities since the first phase (‘Monuments inscrits au titre des monuments historiques’). This allowed a significant amount of grant funding as a result, from La Direction Régionale des Affaires Culturelles (DRAC), La Région Hauts-de-France and Le Conseil Départemental de la Somme, all of whom have given technical approval alongside generous financial support.

A particular challenge with the project has been correcting the design and construction issues which have led to rainwater penetrating behind the brickwork in such a harsh, windy spot. The wall cavity created in the 1950s is of varying thickness, generally around 30mm thick but often diminishing to almost nothing. A foil bitumen layer was installed across the inner leaf at the time, but very few wall ties were inserted and these have deteriorated.

The restoration work has involved inserting approximately 1,500 new wall ties, which serve a dual function of wall tie and scaffold anchoring, drilled around 200mm into the inner leaf. The brickwork has all been repointed and several new details created to shed the water clear of the top of the Portland stone commemorative name panels. A century of rainwater passing through the stone has led to deterioration and issues of illegibility of the engraved names of the missing. Fifty-two very badly deteriorated, cracked or illegible panels are being replaced in Portland stone and engraved in the CWGC’s own headstone workshop in France.

Many names will now be removed from the panels. Bodies have been found and recovered across the Somme battlefield ever since the memorial was unveiled, and still are being. Many have been positively identified and buried in one of our nearby cemeteries. They are no longer ‘missing’, so their name comes off Thiepval as we try not to double commemorate.

Throughout much of the period of the restoration the memorial has been inaccessible but an interactive, digital multimedia exhibition has been set up using mobile wifi points. Called ‘In the Shadow of Thiepval’, it is free to visitors to the memorial, who can access it using a smart phone or tablet. It describes the project and provides historical and architectural information, while also telling the stories of the men commemorated on the memorial.

The contractor for the restoration works is Monument Group of Belgium. The conservation architects Bressers, who oversaw the works to Phase 1, have also been appointed for Phase 2. The work is due to finish this summer.

This article originally appeared in the Institute of Historic Building Conservation’s (IHBC’s) Context 171, published in March 2022. It was written by Jon Gedling, director of estates at the Commonwealth War Graves Commission.

--Institute of Historic Building Conservation