The Humber skyline around east Hull and Paull could have looked a lot different if some shocking plans had been carried out.

The Second World War continues to shock and surprise historians 75 years on and that is no different for local chronicler Mike Covell.

He has spent much of lockdown stepping up his research and has uncovered some amazing local tales – none more so than the potential fate of Saltend.

"Sometimes when researching local history you will often find that the local historical sources are far from local,” he said.

“In the past few years I have uncovered research on Hull all over the world, with criminal cases turning up in Australia, records of the Hull City Police in East Riding Archives, letters turning up in the National Library in London, and numerous files held in the National Archives.

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“It makes sense then, when researching, to think outside the box and look around at the other archive catalogues across the country, and sometimes, it turns up some fascinating finds.

“During the Covid pandemic, the National Archives made all its online files that had been digitised free for download.

There are also files that send a real chill down the spine, like mundane sounding “CAB 63/122.”

“The very basic reference number, which is a unique number that enables people to find the file, hides a very dark secret, for this file was the Government’s instructions to blow up Salt End, should an enemy invasion take place during WWII!”

Files showing how Saltend could have been blown up during the Second World War
Files showing how Saltend could have been blown up during the Second World War

Here is the story about how Saltend very nearly disappeared from the Humber.

The file’s full name is “CAB63 Contingency plans to destroy oil and petrol stocks if invaded; account of an air raid on oil instillations at Salt End, Hull, with plan.”

It is 79 pages long and, for many years after the war, the file was classified and closed to the public.

The file outlines plans to ensure the enemy, under no circumstances, must take into its ownership the oil, spirits, petroleum, or other materials from processing plants.

Within the briefing document are several papers stamped “Secret,” and it is in these it lists several objectives, with one being “To deny oil supplies to the enemy in the event of a successful landing in this country.”

There is a list of large processing plants around the country, and among them is Saltend. The same list features several other sites around the Humber.

The first step of the plan would have seen see the Army stationed in or in close proximity to the refineries listed.

When the call came the army would immediately begin their task of putting out all of the refineries by puncturing storage facilities, pipelines, and tanks.

Watch: what residents think of living in the shadow of Saltend

When these were leaking out they would use anti-tank flame throwers to ignite the petroleum and then wait for the fire to spread to other tanks. Tests showed that many of these fires had spread quickly and resulted in the tanks exploding.

The second step was a back-up in case the first step failed and this involved a designated “demolition” team, either as part of the army detachment, or operating separately.

This group would enter the refinery and places charges on the tanks, pipes, and other vital structural assets. The demolition team would then trigger their charges and blow up the refinery.

The third and final step, which was also the last resort, would be to call in the Royal Air Force, who would carry out large scale bombing of the site.

The RAF had orders to fly in low and destroy as much of the site as they could in one sweep.

The plan was met with opposition at first, as many companies were worried about the financial costs of losing not just the fuel, but the processing facilities.

But large companies soon came on board and joined the effort.

A view of Saltend
A view of Saltend

Many of the refineries around the Humber Region had already been ring-fenced with a series of pillboxes, trenches, and other defences to thwart a potential invasion.

The Humber was also home to several AA gun batteries on the northern and southern side of the estuary.

At the end of the file is six page briefing document that covers the air raid that took place on Saltend on July 1, 1940.

A tank was on fire and the Hull City Fire Brigade were notified. At that time the site already had its own Fire Party and they too rushed to the scene to combat the fire.

Petrol was still spilling out of the damaged tank but the men carried on working despite being in close proximity to the tanks which were getting hotter and hotter.

As darkness began to fall the fire was still partially raging and there were concerns this could attract other enemy bombers so the roof of the tank was removed, and foam was poured in over what was left of the flames.

During the entire period of the fire, the air raid sirens were going off, the anti-aircraft guns were firing, but none of the workers took shelter and all continued to fight the fire.

A second bomb was dropped near the Haven Jetty, but this only left a crater in the river bank.

A number of military inspectors visited the site to see how much damage had been done and what could be learnt from it.

Thankfully the invasion never happened, and Saltend still stands today.