UXO risk in Chelmsford

Why was Chelmsford targeted and bombed in WWII?

During WWII, Chelmsford was one of the most important manufacturing hubs in Essex, and was home to a number of significant factories for the Allied war effort. It was often a reserve objective for German bombers that had missed their London targets, as well as an easy target for lone ’tip and run’ raiders.

A number of factories were directly identified by the Luftwaffe, and appeared on reconnaissance maps and images. One such facility was the Marconi Wireless Telegraph Co. Ltd, presented in the following photo dating from October 1941.

Chelmsford was also situated on the General Headquarters Hardened Stop Line. This line of pillboxes, gun emplacements and strongpoints was designed to hold back an anticipated German Invasion, and provide a rallying point for defending troops. Whilst the line was never used to repel an invasion, many of the pillboxes and emplacements can still be seen to this day.

Home Office Bombing Statistics for Chelmsford

Details obtained from the official Home Office bombing statistics, indicates the quantity and type of bombs that fell on the Metropolitan Borough of Chelmsford during WWII (excluding incendiary bombs). A total of 320 recorded bombs were recorded, equating to 67.1 items of ordnance per 1,000 acres.

Primary Bombing Targets

Chelmsford housed two main bombing targets for German bombers:

• Hoffmann’s Factory: This factory produced ball bearings essential for wartime production, including joints bearings and machinery used in thousands of applications – including military vehicles, tanks and aircraft.
• Marconi’s Radio Factory: Known for its pioneering telegraphic communications research and production. Marconi was the centre for military radio production, making man-portable, vehicle and aircraft radios – as well as components for all manner of communications equipment. It also managed several shadow factories across the country producing Marconi equipment under licence.

Major WWII bombing incidents in Chelmsford

One of the worst conventional raids in Chelmsford took place in May 1941, when the Marconi works was attacked. Three 500kg and two 250kg bombs, including several delayed action bombs, were dropped in an accurate raid on the factory. The bombing raid destroyed much of the machine and paint shops, and a row of houses nearby. A number of men trapped in the burning paint shop were killed but the worst incident in Chelmsford was sadly yet to come.

On the 19th December 1944, a German V-2 rocket struck close to the Hoffmann works. The rocket exploded near Hoffmann’s C Factory’s Cage & Assembly Department, devastating the area. The incident caused the town’s greatest loss of life from a single wartime event, with 39 fatalities. Several dwellings in Henry Road were completely destroyed, and many nearby streets suffered damage.

To record bombing over the city, Chelmsford produced a bomb map (see below), which documented the location, type and date of each incident. These are supplemented by bomb damage records, which provide more detailed accounts of the incidents, the resultant damage and any measures taken to remediate the situation.

Both the Hoffmann and Marconi works also maintained their own bomb damage maps and files which provide more a more detailed insight into incidents. The city is also covered by Ministry of Home Security bomb census mapping and tracings, which highlights the precise location, size and details of the bombs which fell during each recorded incident (see example below).

Thankfully, a number of landmarks in the city survived the bombing, including Chelmsford’s magnificent Gothic cathedral; dating back 800 years, as well as the 18th-century Shire Hall and the Stone Bridge (dating to 1784) which also endured the war.