UXO Risk in Sheffield

UXO City Guide

Home Office Bombing Statistics for Sheffield

Record of German Ordnance dropped on the County Borough of Sheffield

High Explosive Bombs (All types)

1,121

Parachute Mines

25

Oil Bombs

0

Phosphorus Bombs

0

Fire Pots

0

Pilotless Aircraft (V-1)

0

Long-range Rocket Bombs (V-2)

0

Weapons Total

1,146

Area Acreage

39,586

Number of items per 1,000 acres

28.9

Why was Sheffield targeted and bombed in WWII?

The outbreak of WWII placed Sheffield as a valuable target for the Luftwaffe as a military industrial hub of northern England. Sheffield’s industrial works were primarily centred on Steel and Armaments, which was immensely important to the UK’s war effort.

The Hadfield Steel works was, at the outbreak of the war, the only place within the UK capable of producing 18-inch armour piercing shells¹. The city’s English Steel Corporation Vickers churned out Rolls Royce Merlin engines used to power Spitfire aircraft, and throughout the war – Sheffield’s steel works produced 872 Matilda Tanks, 515 Churchill tanks and over 116,000 tank components².

Luftwaffe target photography of Sheffield.

Home Office Bombing Statistics for Sheffield

Home Office bombing statistics indicate that 1,146 items of ordnance were recorded to have been dropped on the County Borough of Sheffield over the course of the war. This included an estimated 1,121 High explosives bombs and 25 parachute mines, resulting in a bomb density of almost 28.9 items of ordnance per 1,000 acres.

Bomb damage in Sheffield’s retail district.

Sheffield city centre after bombs fell – December 13, 1940.

Major bombing raids in Sheffield

Following a Royal Air Force (RAF) raid on Berlin on 25th August 1940, Hitler personally influenced a change in Luftwaffe bombing tactics. The Luftwaffe moved away from bombing RAF Stations, Military Camps and Naval Bases, and instead sought reprisal with the indiscriminate bombing of civilian areas to affect the UK’s morale.

Sheffield was bombed in 16 separate raids, the most significant of these was on the nights of 12th/ 13th and 15th / 16th December 1940, which together were codenamed Operation Crucible.

At 7pm on the 12th December, the air sirens began and across 9 hours – approximately 300 German bombers raided the city and an estimated 350 tons of high explosive bombs were dropped on the city.

While key factories and railway lines were identified as key target areas, in fact – the city centre and residential suburbs suffered the worst of the bombing³.

The Marples Hotel in Fitzalan Square received a direct hit and in total 70 civilians were killed, the District Gas Company sustained a massive explosion after one bomb pierced a holding tank and reportedly every building on Angel Street was either destroyed, damaged or burnt⁴.

Raging fires took hold of the city centre and shopping districts while high explosive bombs fell indiscriminately across the whole city, in industrial areas and residential suburbs.

Additionally, areas such as the Moor, King Street, Broomhill and Neepsend were also left devastated by the bombing raids⁵.

A map of recorded bomb strikes throughout Sheffield.

Mapping showing where HE bombs fell in Sheffield.

The Luftwaffe bombers returned on 15th December, once again targeting Sheffield’s industrial north-east with incendiary bombs and flairs. Many heavy steel factories, such as Hadfield’s, Brown and Baileys sustained direct hits, but none were severe enough to significantly hamper production⁶.

Throughout this raid, the Attercliffe area suffered the worst of the bombing and subsequent fires and damage. Throughout these raids, it is reported almost 700 civilians were killed, approximately 82,000 houses out of 150,000 were damaged and numerous landmarks were badly damaged or destroyed. While Sheffield was bombed on many more occasions, none would prove as destructive as the raids in December 1940⁷.

1948 aerial photography of Sheffield City Centre, showing areas of cleared land and ruined structures from bomb damage.

Sheffield city centre in flames following a bombing raid.

Does UXO still pose a risk to construction projects in Sheffield?

The primary potential risk from UXO in Sheffield is from items of German air-delivered ordnance which failed to function as designed. Approximately 10% of munitions deployed during WWII failed to detonate, and whilst efforts were made during, and after the war to locate and make UXBs safe, not all items were discovered. This is evidenced by the regular, on-going discoveries of UXO during construction-related intrusive ground works across the UK – not just in Sheffield.

Occasionally items of British explosive ordnance are also encountered – often associated with WWII defensive measures or Home Guard operations. However, some areas of the city may entail a greater level of risk, given the extent of munitions development and storage within the city and its factories.

I am about to start a project in Sheffield, what should I do?

Developers and ground workers should consider this potential before intrusive works are planned, through either a Preliminary UXO Risk Assessment or Detailed UXO Risk Assessment. This is the first stage in our UXO risk mitigation strategy and should be undertaken as early in a project lifecycle as possible in accordance with CIRIA C681 guidelines.

It is important that where a viable risk is identified, it is effectively and appropriately mitigated to reduce the risk to as low as reasonably practicable (ALARP). However, it is equally important that UXO risk mitigation measures are not implemented when they are not needed.

While there is certainly potential to encounter UXO during construction projects in Sheffield, it does not mean that UXO will pose a risk to all projects. Just because a site is located in Sheffield does not mean there is automatically a ‘high’ risk of encountering UXO. It really does depend on the specific location of the site being developed.

A well-researched UXO Risk Assessment will take into account location specific factors – was the actual site footprint affected by bombing, what damage was sustained, what was the site used for, how much would it have been accessed, what were the ground conditions present etc.

It should also consider what has happened post-war – how much development has occurred, to what depths have excavations taken place and so on. This will allow an assessment of the likelihood that UXO could have fallen on site, gone unnoticed and potentially still remain in situ.

Recent UXO discoveries in Sheffield

Below are some articles highlighting some UXO incidents and discoveries that have been reported in national and local press:

In July 2023, an unexploded WWII bomb was found in the Meadowhall retail park in Sheffield: https://www.bbc.co.uk/news/uk-england-south-yorkshire-66168437

In October 2022, police shut off Calder Park in Wakefield after an unexploded bomb was found in wetland: https://www.examinerlive.co.uk/news/west-yorkshire-news/drama-police-shut-calder-park-25158589

In December 2020, a suspected WWII bomb was found in a residential garden in Sheffield: https://www.yorkshirepost.co.uk/news/crime/bomb-disposal-unit-called-after-suspected-ww2-explosive-is-found-in-sheffield-garden-3054803

In May 2020, a glass grenade dating back to WWII was dug up in a residential garden in Sheffield: https://www.examinerlive.co.uk/news/local-news/sheffield-mums-shock-after-digging-18299926

In October 2016, several streets in Sheffield were closed after an unexploded bomb was found during building work: https://www.bbc.co.uk/news/uk-england-south-yorkshire-37539801