Secret plans of unsung World War II hero who saved London from drowning revealed

By Ben Miller | 30 October 2014

Hero who secretly saved London from wartime catastrophe honoured near sites of Luftwaffe bombings

A photo of an old book with black ink notes on it
An unpublished log book recording incidents threatening London's flood defences during World War II. The hero behind the unit dealing with them has been honoured© London Metropolitan Archive
An engineer credited with saving London from drowning on 121 occasions, thwarting the Luftwaffe’s destructive raids with a secret rapid response unit which repaired roads and public services during World War II, has been honoured after archaeologists revealed his astonishing heroics.

Peirson Frank was a civil engineer who would become the President of the Institution of Civil Engineers. Contemplating the catastrophic consequences of a wartime flood defence breach, he identified vulnerable places – including low-lying sites such as the Underground, where Londoners would shelter during the Blitz – and introduced secondary flood defences, as well as depots staffed by the Thames Flood Prevention Emergency Repairs unit.

An image of a painting of a man in a suit in profile
Sir Thomas Peirson Frank© Institution of Civil Engineers
New research has uncovered his full plans and the extensive repair work carried out in secret by a team intent on causing no alarm to the public.

“It was down to the ingenuity of this engineer that parts of our capital, including the main infrastructure network that supported it, survived the Blitz without being submerged,” says Geoff French, the current President of the Institution.

“Needless to say the consequences could have been devastating.

“While historic engineering greats like Brunel are frequently revered and well established in the engineering ‘hall of fame’, others like Sir Thomas Peirson Frank have remained unsung heroes.

“It is a truly fascinating story.”

A plaque honouring Frank has been created in Victoria Tower Gardens, next to the Houses of Parliament and along a riverwall where the deep, in-filled scars of the Blitz evidence the remarkable achievements of the defence unit.

A photo of a black and white photo in a scrapbook with black ink writing beneath it
A bomb strike on a river wall at Westminster© London Metropolitan Archive
Gustav Milne, of the Thames Discovery archaeological programme, calls the efforts of Frank's team “herculean”.

“Last winter illustrated the danger posed by floods,” he says.

“It’s a real credit to our community team that they were able to unravel this forgotten story, since all news of their efforts was deliberately supressed at the time.”

Martin Frank is Sir Thomas’s grandson. “The demands at the time for secrecy meant that this work was never widely recognised,” he points out.

“It is fitting, even after all these years, that we will have this plaque to remind future generations how close we came to catastrophe and how much we owe to Sir Peirson and his team.”

Who is Sir Thomas Peirson Frank?

Sir Thomas Peirson Frank (1891-1951) was London County Council’s Chief Engineer from 1930.

A photo of a wall by a river with holes caused by bomb damage visible
Damage to the riverwall near Frank's plaque© Thames Discovery Programme
Originally from North Yorkshire, during his nine years as Chief Engineer in London he directed improvements including main drainage and sewage installations, housing estate developments, the widening of Putney Bridge, as well as the building of new bridges at Wandsworth, Chelsea and Waterloo.

During the war he was appointed Co-ordinating Officer for Road Repairs and Public Utility Services for the London area, and directed the repair services that enabled London to carry on in spite of the severest air raids.

In recognition of his work he was knighted in 1942. His Knighthood recognised his work keeping London moving during the war but did not deliberately highlight his work protecting London’s flood defences for security reasons.

He was elected president of the Institution of Civil Engineers for the November 1945 to November 1946 session.

How did Frank save London?

With war becoming a reality, Frank started to make preparations to protect the Thames from flooding and potentially destroying large areas of London.

A photo of a man in a high visibility jacket carrying out archaeological surveying by a river
Researchers surveying the riverwall© Thames Discovery Programme
He commissioned a survey of London’s most vulnerable riverside sites, grading them from I (the worst) to III, and a programme of temporary works was put into place to provide a secondary line of flood defence in the worst areas.

With the onset of war, Frank established four depots to store sandbags, timbers and tarpaulins, so that the most vulnerable areas could be reached quickly following an incident.

These depots at Battersea, Southwark, Millwall and Greenwich were staffed with new rapid-response teams, called the Thames Flood Prevention Emergency Repairs unit, or TF.

Between 1940-5 the river wall was hit 121 times, with 84 incidents from 1940 to May 1941 (the Blitz) and a further 37 incidents up to 24 March 1945.

The teams were called into action to repair the river wall and subsequently not one of the hits resulted in a major flood.

Without the initial preparation, and the ongoing work of Frank and his team, these air attacks would have seriously breached the Thames defences and flooded large areas of the low-lying city.

Why is his story untold?

During the war, the work that Frank and his team undertook protecting the capital’s flood defences was never made public or reported in the news, being conducted in secret so as not to alert the Luftwaffe to the soft target posed by the river defences, and to contain public alarm concerning the danger of flooding.

What new research has exposed his story?

The Thames Discovery Programme, a project hosted by MOLA, recently undertook research for their Riverpedia Project, supported by University College London.

Researching unpublished reports in the London Metropolitan Archives, the team exposed the number and severity of the incidents and the actions that Peirson Frank and his team carried out to avert catastrophe.

In tandem with the study of the contemporary documents, community archaeologists from the Thames Discovery Programme also conducted fieldwork on the foreshore, surveying the present-day riverwall and recording the physical evidence of repairs.

Although extensive re-facing of the waterfront has taken place over the last 70 years, several examples of brick or shuttered concrete repairs from the 1940s can still be correlated with the incidents recorded in the unpublished log books.

How were London’s flood defences compromised?

Between 1940-5 the Luftwaffe’s intensive bombing struck the river wall 121 times. There were 84 incidents from 1940 to May 1941 (the Blitz), and a further 37 incidents up to 24 March 1945, covering the period of the Little Blitz and the V1 and V2 rocket attacks.

The devastation to the city during this period was immense and it is very likely that destruction of the flood defences would have had catastrophic consequences for low-lying London.

There were several incidents in the most vulnerable areas, such as the Isle of Dogs, Greenwich, Bermondsey and Southwark.

There was also a bombstrike at Westminster, close to the breach that fatally flooded in 1928. On this site, the parapet repaired in the summer of 1941 still survives in Victoria Embankment Gardens.

The deep in-filled bomb scar on the river wall itself can be seen from the foreshore, or indeed from across the river on the Albert Embankment, when the tide is out.

How has Frank been honoured?

At 2pm on October 29 2014, a plaque was unveiled next to the Houses of Parliament, in Victoria Tower Gardens.

The plaque is sited, appropriately, on the landward side of the surviving riverwall repair, which, according to the log book entry, had been blown apart on March 16 1941.

It was unveiled by the City of Westminster Lord Mayor Audrey Lewis, in front of representatives from the Institution of Civil Engineers - the organisation which funded the plaque - the Greater London Authority (the successor body to the LCC), the Museum of London Archaeology’s Thames Discovery Programme team and from the UCL Institute of Archaeology.

The proud descendants of Sir Thomas also took part in the ceremony.

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The work of Robert Dell, Signal Engineer of London Underground should also be considered. He was responsible for the protection of the London Underground lines running under the Thames by the installation of hydrophones in the Thames. These used triangulation to determine how close unexploded bombs that may have had time delay fuses were to the tunnels. This allowed the flood gates to be opened and the train service resume if the bombs were far enough away.
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