On 21 October 2025, Teesworks notified the local media that bomb disposal experts had been called to one of its building sites after a suspected WW2 device was found.
Previous events
The recent find came only weeks after “historical ordnance” was uncovered at the under-construction Net Zero Teesside (NZT) plant. Two years prior to this, in August 2023, an “unexploded device” was found near the site of the former Redcar Blast Furnace. This is adjacent to the NZT plant, and is known as the “Foundry Zone”.
Unlike in previous similar episodes, Teesworks hasn’t confirmed the location of the latest find of what is known as unexploded ordnance (UXO).
Danger: unexploded bomb
There are two main UXO risks. The first is from unexploded enemy bombs, the second is from defence munitions.
Enemy coast ahead
Taking the bomb risk first, this dates back to several enemy raids that took place between 1941 and 1943. A diary of events recorded in nearby Warrenby details the attacks that took place. A map, prepared as part of the Environmental Statement for the proposed H2Teesside project, shows the Luftwaffe bombing target zone:
H2Teesside
The H2Teesside site boundary is outlined in red on the above map. This is the controversial “blue hydrogen” site, of which more later. As can be seen from the map, only a small portion of this site came within the bombing target zone
Target-rich environment
The German bombers weren’t aiming at the Redcar steelworks that most people are familiar with. That wasn’t completed until 1979. The bombers’ target was the Redcar Iron and Steelworks, operated by Dorman Long & Co from 1917 to 1967. It was broadly south east of the later steelworks. The historical records “identify significant bombing within the area”.
Net Zero Teesside (NZT)
H2Teesside’s immediate neighbour to the east will be NZT. NZT will consist of a gas-fired power station and a carbon capture plant. The outline of NZT can be seen in the map below. By comparing this map with the one above, you can see that much more of the NZT site falls within the area that was targeted by the Luftwaffe.
Long Acres
British Steel Corporation, who built the 1970s steelworks, didn’t level all of the land that they purchased. They’d had bigger plans, including a second blast furnace, but these were never realised. Much of the land to the east of the NZT site, now known by Teesworks as “Long Acres”, consists of slag heaps from the first steelworks. Some of these haven’t been disturbed since before the Second World War. The Long Acres area was the primary target of the bombers, which explains why neighbouring Warrenby took so many hits.
Which wire do I cut?
So, the further east you go within the former Redcar steelworks, the more likely you are to find unexploded bombs. However, it has to be stressed that none have been found since the Teesworks project started. A map produced by Zetica UXO confirms that the overall bomb risk is low.
Home-grown ordnance
The second UXO risk at Teesworks is from defence ordnance. The map below shows H2Teesside mapped over defensive features. These include an artillery gun battery and several minefields.
So why is UXO being found now?
This is probably due to increased activity, particularly on the NZT site. Balfour Beatty was awarded a groundwork contract in September, and work has commenced. There’s a lot of machinery onsite, as can be seen from this photo taken on 24 October:
Piling rigs
Two piling rigs can be seen at the left and centre of the photo. The excavations will be tens of metres in depth, and may have disturbed small-scale UXO.
H2Teesside
Work hasn’t commenced at the H2Teesside site. There’s still controversy over whether it will even be built. Energy Secretary Ed Miliband is due to make a decision regarding a possible go-ahead on 30 October. Teesworks is now in favour of building a data centre here, with an almost identical footprint to H2Teesside. Miliband has asked whether the data centre could be sited elsewhere. However, there aren’t many alternatives sites. If there were, they’d have snapped up by now.
Foundry Zone
Whichever project is finally selected, it will be built in the so-called “Foundry Zone”. But there’s a lot of work required here before any building commences. Teesworks has given the impression that the entire former Redcar steelworks site had been remediated. Here’s an example from 2023. But this is far from the case.
Further work is required
In April 2025, the South Tees Development Corporation (STDC) issued a £13.2mn tender for remediation work at the foundry. Teessiders might be wondering what happened to the £560mn that’s already been spent.
Redcar Blast Furnace
The contract winner will need to demolish the remains of Redcar Blast Furnace. This can be seen to the left of the photo below. Yes, it’s still there, three years after Teesworks claimed to have “successfully” demolished it. When the furnace has gone, they’ll have to remove millions of tonnes of demolition waste. This was dumped here after being hastily removed from the neighbouring NZT site. After this, the piling rigs will finally move in, and we’ll see what they unearth.
Long Acres
Meanwhile, over at Long Acres, there’s even more ground disturbance. Work has started on repairing the water main that leads from Coatham Marsh to the former steelworks. The focus on water main renewal may hint that Teesworks is preparing for a data centre. However, the site will need a water supply whatever is built. And the pipes are almost 50 years old.
Men at Work
This photo, taken on 25 September 2025, shows construction activity at Long Acres. The work includes excavation of a new trench to avoid an obsolete pipe bridge. The bridge can be seen to the top right of the photo. The new water main route can be seen in the foreground. It will skirt around the northern boundary of the NZT site, which can be seen in the far distance.
Gas network
There’s still a lot of earthmoving ahead. Contractors will need to connect NZT to the CATs natural gas network. The gas comes ashore from the North Sea at Coatham beach, just north of Coatham Marsh. The facility can be seen below:
Utilities
NZT will also need to dig a trench for its CO2 pipeline to the North Sea. Finally, there’ll need to be excavations for the remaining utilities; sewage, electricity supply, data cables and roads.
Digging for Britain
With over a century of industrial archaeology, and the potential for unearthing more UXO, you never know what will happen when you put spades in the ground at Teesworks.
Thanks to James Waterson for contributing to this article
