Colchester, 5 April 2016

Just after midday on 5 April 1968 RAF pilot Alan Pollock, senior operational flight commander on No. 1 (Fighter) Squadron, flew Hawker Hunter FGA.9 jet XF442 through the span of Tower Bridge in London. The unauthorised action – which cost him his air force career – was part of a personal protest against the RAF's decision not to celebrate its 50th anniversary with a flypast over the capital.

PRINTS available from: my Jet Age gallery. 

While en route from RAF Tangmere in West Sussex to his squadron's home airfield at RAF West Raynham in Norfolk, Flt Lt Pollock flew into central London, circled the Houses of Parliament three times – carefully avoiding the 387 feet tall (118 metre) Millbank Tower – then headed down the River Thames at very low level.

He said afterwards that it was only as the "matronly structure" of the world's most famous bridge loomed ahead that the irresistible idea of going straight through the middle of it occurred to him.

As he approached he could see that the crossing traffic included a double decker bus. He kept as close as he dared to the upper walkways – which were not open to the public in those days – and for a heart-stopping moment thought the Hunter's tail fin was going to collide. Happily it did not, and he continued downriver and back to base.

When he landed he was arrested, and was retired from the RAF a few months later on medical grounds: denied a court martial at which he could have presented his case.

I liaised with Alan Pollock while making the picture. Initially I had placed his Hunter in the centre of the gap. He insisted however that it was much closer to the top.

He estimated his airspeed at 350 knots (403 mph, 591 feet per second, 180 m/sec), and got out a map of central London to calculate that it would have taken just seven seconds for the jet to travel through Tower Bridge from when the thought of doing it first struck him, as he approached London Bridge further upstream.

I imagine that if it happened tomorrow any number of smartphone videos would be online within minutes and some people would even manage 'selfies'. Then, however, if anybody did capture his escapade on any sort of film it has not emerged that I am aware of. I could not resist making a Flight Artworks version, showing the Hunter in scale with the bridge (and the bus), as if photographed at 1/4000 sec on a high resolution digital camera.

RE-MAKING HISTORY

The most complex aspect of making the picture was reconstructing Tower Bridge as it was in 1968. For one thing, its metalwork did not acquire its now-familiar red, white and blue colours until the Queen's Silver Jubilee in the 1970s. Various online sources, including the official Tower Bridge website, say that before then it was chocolate brown.

Tower Bridge in 1968. Photo courtesy of Aletha Huston

In fact on the outside it was grey. That is apparent from archive photographs – including this one supplied by an American relative of mine that was taken in 1968 – and was confirmed to me by historical paint consultant Patrick Baty, who worked on the most recent complete analysis and restoration of the paintwork.

Structurally the biggest difference by far is to the upper walkways. When the bridge was built in the 1890s these were intended for pedestrians to use when the bascules were raised as they were frequently then. But they were essentially a metal lattice open to the elements, rarely saw any legitimate use, and were closed off in 1910.

They stayed that way until 1982, when the visitor exhibit inside Tower Bridge was opened. They were then opened again to pedestrians, having had roofing, glazing and ornamental parapets added. I have rebuilt them as they appeared before the remodelling, when they also did not have the big crests that adorn their outward faces.

POLLUTION

Work in progress screenshots

An unpleasant environmental fact of early 20th Century architecture in London is that it was absolutely filthy – so black with pollution that I struggled to make the present pristine structure look revolting enough. In an odd contrast the pointed tops of the two towers, which are now clean stone, were painted white at the time and I have tried to portray that.

The finials were a later addition so I have removed them. And numerous other details have changed, such as the signal posts for river traffic.

Winding back the clock on The Photographer's Ephemeris gave me the direction and inclination of the sun at noon on the day in question. The Thames of course is noticeably tidal: I consulted the Port of London Authority on the state of the river at the time. The very helpful Port Hydrographer, John Pinder, hindcasted for me that there was an average low water at 1240 that day of 1.3m; at noon the tide was still ebbing, with a height of 1.5m.

Modern view (2016)

The weather was described by Pollock himself as "one of those rare perfect, 8/8 Gordon's, crystal, gin clear days when all the colours shout out brightly", with not a breath of wind and no clouds: call it artistic licence but I left in the little puffs of cloud that were around when I made my background photograph because they gave a sense of depth to the sky, and in fact the Met Office's archive suggests there was some scattered low cloud over west London.

I felt it needed this once all the City skyscrapers that now form the bridge's backdrop had been painted out. From the low angle viewpoint across the river there really would have been nothing much visible beyond the bridge apart from the Tower of London.

Finally, the London Transport Museum customer services assistant Katy Green kindly unearthed the bus timetables for that day. The red double-decker Pollock saw heading south over the bridge as he flashed above it would have been either a 78 or a 42, and probably a Routemaster. I opted for the 78, as a tribute to "the bus that jumped the bridge" in the previous decade. But that's another story.

So there you have it: the Tower Bridge Hawker Hunter incident.

Prints are available in various formats via the Jet Age gallery on the Flight Artworks website at www.flightartworks.com. Licensing enquiries are welcome. 

You can hear the whole story from Alan Pollock himself in a lengthy interview in the Imperial War Museum's collection: www.iwm.org.uk/collections/item/object/80027439

Some statistics:

• Tower Bridge is 800 ft (240 m) long overall with two towers 213 ft (65 m) high. The central span is 200 ft (61 m) between the towers, with a height from the road deck to the upper walkways of 141 ft (43 m). The width of the towers is 60 ft (18.3 m).
• The Hawker Hunter FGA.9 was 45 ft 11 in (14 m) long with a wingspan of 33 ft 8 in (10.3 m): one sixth the width of the gap between the towers.
• A London Transport Routemaster was 14 ft 4 in high (4.4 m).