Bomb found at Paris St. Denis

[Nick Beale]

Many of you will have seen on the news this past week that trains in and out of Paris Gare du Nord were halted when an unexploded bomb was unearthed on the tracks about 3 km from that station.

It was late made safe and widely reported as weighing 500 kg but, metric units aside, every report seems to have assumed it was an Allied weapon based on the fact that the the RAF and USAAF dropped a lot of bombs on French transport links (and the probability that few journalists even know the Luftwaffe bombed targets round Paris in June 1940 and again in August 1944). Has anyone seen confirmation of the bomb's origins?

[Bombphoon]

Hard to tell from the scale in the photos, but it's an RAF GP 500lb or 1000lb HE bomb. News suggests it's from one of the raids in April 1944 that heavily targeted the Gare de Nord railway station.

[Chris Going]

There are thirteen areas round Paris where any major development is attended by significantly ‘above backround risk’ for EROW/UXO discovery. While in 2025 some GAF ordnance slumbers on, desiderata from Paula and small scale Luftwaffe efforts in August 1944, by far the majority of air dropped UXO/EROW is of US and UK origin. It’s less the Gare du Nord, Bomphoon, but the skeins of trackways N of the Gare du Nord, towards St Denis.

Some years ago I prepared an overview of the Paris area which involved trawling through contemporary reconnaissance imagery, armourers manifests, fusing, and so on, and made some visually impressive ‘peril maps’. I am currently comparing these with records of actual finds.

While the generally accepted worry is bashing into a bomb hull and provoking a ‘high order’ detonation, the risk from failed time-delay fuzed ordnance, especially with transport networks, is not negligible. Failed time delay fuzed ordnance is getting more prone to exploding spontaneously (one or two a year in Europe, in Germany and Austria). Certain types of piling and basement digging during the redevelopment process aren’t helping.

Best

Chris G

[Nick Beale]

Originally Posted by Chris Going

It’s less the Gare du Nord, Bomphoon, but the skeins of trackways N of the Gare du Nord, towards St Denis … the risk from failed time-delay fuzed ordnance, especially with transport networks, is not negligible.
Chris G

And to think of the number of times I must have passed over that on the Eurostar over the last 30 years …

[Chris Going]

Hi Nick,

...as you and I know the risk comes comes not so much in trundling past in a train as energetically digging about in the ground without adequate preparation when there’s significant ‘above background’ risk. There is a world of difference between embarking on a planned programme of EROW/UXO prospection, and making safe prior to development (or redevelopment), than making a chance discovery during invasive works and having to mount an emergency response.

Reading between the lines of the local newspapers, it’s often hard to see if UXO discoveries on construction sites are planned or by chance. The most recent event at St Denis seems to have been associated with bridge construction work. There was one nearby in 2019, again during construction works.

Best

Chris G