Sir Thomas Peirson Frank

The discreet hero who saved London from flooding during the Blitz

Five years ago, in October 2014, a memorial plaque dedicated to Sir Thomas Peirson Frank was unveiled in Victoria Tower Gardens next to the Houses of Parliament. Until then, virtually no-one knew his name yet it was his vital work that literally saved London from drowning during the Blitz. He was one of that proud and modest generation who got on with what they had to do to protect the country, and then quietly returned to their civilian lives without talking about their achievements and in many cases families were unaware of what they had done.

At the time, his work and that of his team on permanent standby to protect London from flooding, was kept out of the public eyes for reasons of national security. This was partly to give nothing away to the enemy and partly so as not to undermine public morale by making known the very serious danger that significant areas of the capital were at risk from flooding by the Thames.

And yet, this quiet, unassuming but highly efficient engineer, who served with the Royal Engineers in WW1, was at the heart of efforts to keep London as safe as possible and to keep traffic moving throughout the intensive bombing during the War. In 1939 he was appointed the London County Council coordinating officer for Road Repairs and Public Utility Services, and was knighted in 1942 for his organisation of the city’s vital infrastructure, though his flood prevention work was carefully kept secret. He remained in charge until 1945.

On his appointment as President of the Institution of Civil Engineers in 1945 he was asked to give an account of his work in his Presidential Address, which was kindly passed on to me by his grandson, Martin Frank. Though overseeing repairs affecting services across London, he was specifically concerned with drainage, vital in a densely populated low lying area; with the Thames bridges, vulnerable to aerial attack and the construction of four temporary bridges should any become impassable; and a raft of flood defences. As early as July 1934 he was asked to help prepare a report on the parts of London most at risk from flooding. In a transcript of his report he explains “About 20 square miles of the County of London lie below the level of the highest recorded tides and about 10 square miles are below the level of ordinary spring tides.” After a serious flood in 1928 when much of central London was inundated, including sections of the Underground and the Blackwall and Rotherhithe tunnels, and fourteen people trapped in their basements were drowned, Peirson Frank was well aware of the problems that the city could face: the potential for far greater casualties and widespread disruption in the case of war was alarming.

The fact that his team was able to react so quickly after a breach in the Thames walls was down to his creation of four depots: Battersea Park; Southwark Park; Tunnel Avenue, Greenwich; and Pyrimont Wharf, on the Isle of Dogs. Each was manned 24 hours a day with a store of timber, tarpaulin and sandbags. They were in operation by August 24, 1940. To ensure the quickest response possible, a tug and barges loaded with sandbags were on permanent standby to carry out emergency repairs; which would have to be done as quickly as possible before high tide. Frank describes how on May 11, 1941 “the river wall at Bankside was breached, but by prompt action on the part of the depot staff, temporary protective measures were constructed before high tide which occurred about two and a half hours later.” When possible, their work was carried out at night to minimise the risk of observation by enemy spies.

The Underground tunnels passing beneath the Thames were also at risk, so the London Passenger Transport Board installed hydrophones to detect and locate unexploded bombs. They also installed floodgates to protect the rest of the system and those who sheltered in the stations during the Blitz. Precautions were taken at Blackwall and Rotherhithe road tunnels, both of which emerge on the south bank of the Thames below the high tide level. Each was fitted with a 22 ton flood gate.

In all, Peirson Frank’s teams were called to 122 bomb strikes on the river walls. Gustave Milne, Director of the Thames Discovery Programme, whose researchers have done so much to bring Sir Thomas Peirson Frank’s vital war contribution out from the shadows, explains that “Any one of those could have flooded the area behind the wall causing massive destruction and loss of life.” But it was only when he and his team noticed the many repairs in the river wall that they began to look for documentary evidence. And on searching through the London Metropolitan Archives they discovered logbooks, photographs and correspondance concerning the London County Council’s Thames Flood Prevention and Emergency Repair plans hidden or forgotten for seventy years. They were astonished by this unexpected find and by the sheer number of sites listed.

Frank’s repair to the wall in Victoria Tower Gardens can be clearly seen from across the Thames

One of the best known of Frank’s surviving repairs, for many have been completely rebuilt, is at Victoria Tower Gardens next to the House of Lords. It was struck by a large high explosive bomb on the night of April 16-17, 1941, thought to have been aimed at the Houses of Parliament. It blasted a nine-metre hole in the Thames wall, leaving a large part of Westminster exposed to flooding at the next high tide. But the team reacted quickly, filling in the breach at once with sandbags, then rubble and eventually in August, 1941, with shuttered concrete.

The repair in the wall of Victoria Tower Gardens shows how the blast extended well below the high tide mark

And you can still still the repair from both inside Victoria Tower Gardens, where there is additional strengthening to the parapet in the form of a buttress, and from the river side on the foreshore below, where broken pieces of granite from the original wall lie scattered among the stones in the mud.

Pieces of the original wall still lie scattered on the foreshore

Peirson Frank’s grandson, Martin Frank, born after his grandfather’s death said that the War, being a taboo subject for so many of that generation, the family knew nothing about his secret work until they were approached by the BBC in 2013. The producers of Coast wanted to include a section on how Frank saved London from flooding, and shortly afterwards Gustave Milne got in touch and told them of his discoveries. They already knew about his involvement with the widening of Putney Bridge, the new bridge at Wandsworth in 1940; and the demolition and construction of the new Waterloo Bridge in 1942, where you can see his name inscribed with others at the north end of the bridge. But they knew nothing of his vital flood prevention work.

The names of politicians, architects and engineers, including that of Sir Thomas Peirson Frank carved on Waterloo Bridge
Waterloo Bridge

Having made his discoveries, Gustave Milne felt strongly that Peirson Frank’s heroic work for the protection of London from flooding should be remembered, and it was at his suggestion that a plaque in his memory be fixed to his repair of the Thames wall in Victoria Tower Gardens. It was installed on October 29th, 2014 by the then Westminster City Mayor, Audrey Lewis. Grouped around her were several of Peirson Frank’s descendants, Gustav Milne, representatives from the Institution of Civil Engineers, the Greater London Authority, and the University College Institute of Archeology, together with the Thames Discovery Team, supported by the Museum of London, all of whom had played a part in uncovering and sharing the vital work of Sir Thomas Peirson Frank. Now the story of the exceptional service he gave to our country in the Second World War will live on.

Plaque commemorating Sir Thomas Peirson Frank centred on his wartime repair in Victoria Tower Gardens, still good after all these years
Plaque fixed to the wall of Sir Thomas Peirson Frank’s repair in Victoria Tower Gardens

For further information see:

The Thames Discovery Programme
For more on the temporary wartime bridges see the fascinating A London Inheritance site, whose author has many historical pictures taken by his father from 1946 to 1954.
Cover image of Sir Thomas Peirson Frank by kind permission of his grandson, Martin Frank.

The Thames Barrier

A masterpiece of British engineering and design protecting London since 1982

In 1972 Londoners were asked “If London flooded tomorrow, would you know what to do?” Well most of us didn’t. We were aware of the Thames and its tides of course but hadn’t given the possibility of flooding much thought. Not so the government, they were clearly worried and began a series of measures to raise public awareness. There were a number of public service broadcasts, articles in the press, and notices delivered to thousands of residents in low lying areas close to the river. Living near the Royal Hospital, Chelsea at the time, we received an A5 sized notice warning us about possible flooding from the sewers. Not a happy prospect. There were instructions on one side and ‘HELP’ written in big red letters on the other, which we were supposed to stick on, or wave out of an upstairs window. Luckily we never had need of it and ten years later the Thames Barrier had been completed and London protected for years to come.

Always on the alert, and taking into account information from satellites, weather ships, oil rigs and coastal stations, the Environment Agency can forecast potential danger of flooding up to thirty-six hours in advance. When computer calculations based on a combination of high spring tides, expected tidal surges, low atmospheric pressure and strong winds indicate a risk of flooding, the team at the Thames Barrier are ready to set the flood defences in motion. However, the final decision to close the barrier rests with the Thames Barrier Duty Controller.

At the time of writing the most recent closures have been on Sunday September 30 and Monday, October 1st, 2019. The Barrier has now been closed 186 times since it first came into operational service in 1982. Since its first test in November of that year, this masterpiece of British design and engineering has been operational, ready to be put into a defensive position to protect 125 square kilometres of central London from flooding. It stretches 520 metres across the Thames at Woolwich and its shining, hooded piers are a striking feature of the landscape.

A feature of the landscape: the shining hooded piers of the Thames Barrier

London has been flooded throughout its history both as a result of rising sea levels and the progressive tilting of South East England. The problem was exacerbated by the gradual embankment of the Thames in the second half of the nineteenth century, which channelled the river into an ever smaller space, so raising its level in central London.

The severe 1953 flood that struck coastal areas along the North Sea and particularly Canvey Island where fifty-nine people were drowned and 13,000 evacuated from their homes, and an earlier flood that had struck the heart of London itself in 1928, drowning fourteen people and making thousands homeless, began to concentrate minds on devising proper flood defences for the capital.

In 1954 Hansard reports that the Waverley Committee set up by Parliament, proposed that: “As an alternative to raising the banks”, which would have been likely to obscure stretches of the river from view, “the possibility and cost of erecting a structure across the Thames, which could be closed in a surge should be urgently investigated.”

However, it was not until a further review, conducted by Sir Hermann Bondi in 1967, taking the project forward, that any action took place. The site for the barrier was then fixed at Woolwich, from New Charlton across to Silvertown as part of an overall plan which included the raising of the river banks further downstream. Then a design had to be chosen.

From the forty-one plans considered, it was engineer (Reginald) Charles Draper, working with Rendel, Palmer and Tritton, who came up with the chosen solution. It was a revolutionary idea inspired by a simple gas cock in his home. He was photographed in 1981 by Gordon Gahan, overlooking the as yet incomplete barrier, proudly holding a gas ball valve like the one that had given him the idea: a poignant image as Charles Draper sadly died before the work was finished.

(Reginald) Charles Draper © Gorden Gahan

There followed ten years of modelling, testing, refinement of the design, and actual construction; longer than planned as it was the first project of its kind. There were also funding problems and a number of serious industrial disputes. The Thames Barrier finally became fully operational in November 1982 when it rose for the first time, and was officially opened by the Queen in May, 1984.

Towards the end of its construction, intrigued by reports of its innovative design, we took our young sons to see how the work was getting on. Not easy. There were no signposts. But armed with an A to Z map we got quite close and luckily spotted a workman in a hut on a nearby building site. Clearly we were not the first to have been on this trail as he produced a photocopy of a rough map with directions to a viewpoint at the top of some metal stairs. Breathtaking. The barrier really was as impressive as it had been made out to be.

These days you can see the barrier from the Thames Barrier Park, in Silvertown north of the river; the Thames Barrier Information Centre, near Woolwich, on the south side; or from a boat passing though the barrier itself. It was this last view that really brought home to me the massive achievement of all those involved with the building of London’s most important defensive structure.

Approaching the barrier from upstream, its distinctive gleaming metal-hooded piers seem to rise up through the water like dragon’s teeth warriors each with a cyclopesian eye. The closer you come, the more impressive they are.

Approaching the Thames Barrier from upstream
Reflections of the river in the round window at the top of one of the piers

The six main steel gates are D-shaped. When set in the defence position their rounded surfaces face downstream and their flat surfaces upstream. Known as rising sector gates they normally lie flat at rest in concrete sills on the river bed, allowing free movement of shipping and normal tidal flow. Operated by a hydraulics system in the towers they can be held in four positions: rest, defence, underspill and maintenance. When the barrier is used or tested, the gates are moved into place shortly after low tide to hold back the flow of the river on the upstream side and to stem the incoming tide downstream.

The Barrier fully open with gates at rest on the river bed
The Barrier fully closed with the gates in the defence position

A strong tidal surge will build up considerably more water on the seaward side so that when the tide begins to flow out the gates are gradually moved into the underspill position, allowing a carefully controlled flow upstream so as not to create a rush of water. The gates can only be lowered into their resting position once the levels on each side are the same. They can also be raised and held above the water to allow access for maintenance. In addition, there are four non-navigable gates set close to the river banks.

Two of the gates in the underspill position allowing water from the seaward side to flow upstream underneath
Controlled flow of water flowing upstream from beneath the gates in the underspill position

The decision to close the barrier is made by the Duty Controller after assessing reports from a team of flood forecasters. Taking into account the flow into the tidal Thames at Teddington, the predicted tide levels and weather conditions that can affect the height of a tidal surge, forecasters can predict the likely risk up to thirty-six hours in advance. The control room is staffed at all times. If necessary, the barrier will be closed roughly four hours before the peak of an incoming surge. Each steel gate takes ten to fifteen minutes to close, and the whole barrier an hour and a half.

Flood forecaster Alan with the Thames Barrier in the background

Flood forecaster Alan, who also runs the barrier’s Twitter feed explains that though they run monthly test closures they’ve “never had to close between May and August to protect London against a high tide since the Thames Barrier became operational in 1982. It doesn’t mean that we’re not on the lookout though.”

This year’s annual test closure was due to take place on September 29th but had to be cancelled after particularly high tides meant that the barrier had to be closed twice in three days for real, to protect London from flooding.

Workboat PROWLER moored with another craft at pier 8.

As mentioned earlier, the barrier has been closed to protect London 186 times but the exceptionally high number of fifty closures in the 2013-14 flood season caused real concern. Doubts were raised that the barrier would be able to protect the capital beyond its originally estimated lifespan of fifty to sixty years. However after a study, Dick Tappin, a member of the original team who created the barrier, wrote in 2014 that “The Thames Barrier remains fit for purpose” and provided it is properly maintained, “it will remain so to at least 2070.” This was backed up by a government study revised in 2016 saying that the Thames Estuary defences, “which include the Thames Barrier and 350 kilometres of flood walls and embankments, smaller barriers, pumping stations and flood gates” will continue to protect London throughout the century. We are fortunate that the marvel of modern engineering that is the Thames Barrier will be with us for a while yet.

Approaching the Thames Barrier from the footpath near Greenwich

For the main source of my article, with understandable, technical information and explanatory diagrams, click on the: Thames Barrier and follow @AlanBarrierEA for up-to-date info. An internet search will reveal many striking images of all kinds of ships passing through the barrier including some by Photographer Rob Powell on http://onthethames.net