On 6 August 2018, the collision of a liquefied petroleum gas (LPG) road tanker with an articulated lorry carrying flammable solvents and a car transporter resulted in a huge explosion on the A14 motorway within Borgo Panigale, a neighbourhood of Bologna, Italy. It was a case of boiling-liquid expanding-vapour explosion (BLEVE), where nearly all the road tanker cargo combusted in a matter of seconds upon release, generating a tremendous amount of thermal radiation. The accident killed two people, injured 145 and caused significant damage to the surrounding commercial and residential area. One span of the viaduct where it happened collapsed and a gash opened in the motorway.[1][2]
 Collapsed viaduct after the explosion with charred remains of the tanker pressure vessel | |
   | |
| Native name | Esplosione di Borgo Panigale |
|---|---|
| Date | 6 August 2018 |
| Time |
|
| Location | A14 autostrada (motorway) within the Borgo Panigale neighbourhood of Bologna, Italy |
| Coordinates | 44°30′55.05″N 11°16′48.85″E / 44.5152917°N 11.2802361°E |
| Type | LPG road tanker boiling-liquid expanding-vapour explosion (BLEVE) |
| Cause | Vehicle collision |
| Deaths | 2 |
| Non-fatal injuries | 145 |
Vehicle collision
editThe collision involved a liquefied petroleum gas (LPG) road tanker, another articulated lorry carrying flammable solvents and a car transporter. It took place on the northbound carriageway of the ramo Casalecchio (Casalecchio branch) of the A14 motorway, which connects the A1 motorway to the A14 main route, within Borgo Panigale, a neighbourhood of Bologna, Italy.[1][3] The stretch of motorway where the accident occurred crosses a densely populated area in the outskirts of Bologna and is flanked on both sides by the Tangenziale di Bologna, or Bologna ring road. Luckily, many businesses were closed due to the summer holidays.[1]
The collision was caused by the road tanker, which rear-ended a near-stationary lorry laden with class-3 flammable solvents in intermediate bulk containers (IBC). Pushed from behind by the impact, the second lorry rear-ended the car transporter directly in front.[4] The crash occurred at 1:44 pm.[5] The cause of the collision is unknown. Cameras captured the tanker heading straight into the preceding vehicle, which possibly eliminates the hypothesis of mechanical failure, because steering and brakes would have needed to fail at the same time. Later it emerged that the driver was not in contravention to applicable rest regulations and speed limit. The tanker pressure vessel was also mechanically sound.[6] The amount of LPG in the tanker was estimated at 23[5] or 25 tonnes.[1]
Initial fire and BLEVE
editThe cargo of the rear-ended lorry ignited immediately, which resulted in a large pool fire engulfing the affected vehicles.[3][4][7] The source of ignition was either engine or exhaust hot surfaces or mechanical sparks.[5] By chance, police units were on the spot at the time of the accident and diverted traffic away, both on the motorway and the adjacent urban roads.[7]
The pressure vessel of the LPG tanker did not breach as a direct consequence of the crash. However, it was surrounded by flames from the pool fire. The vessel was not fire-proofed nor did it have a relief valve. Neither arrangement is required by Italian regulations or in the international ADR agreement. Seven minutes and 20 seconds after the collision, the tank failed due to loss of mechanical properties caused by external heating. This resulted in a massive BLEVE.[3][5] Fire services did not have sufficient time to reach the location before the explosion. The fireball diameter was estimated at more than 170 metres (560 ft) and its height above ground at 130 metres (430 ft). Its duration was around 8 seconds.
This BLEVE is notable because it caused the collapse of the span of viaduct on which it happened. Computer simulations have assessed a blast overpressure of about 500 kPa at short distances from the source, in fact a value sufficient to cause the failure of a road bridge like the one involved in the accident.[8]
Aftermath
editGiven the tremendous thermal radiation, people within a radius of 100 metres (330 ft) from the exploded road tanker would have died or received major injuries. The explosion sent fragments hundreds of meters away[7] and shattered windows up to 500 metres (1,600 ft) away.[9] Buildings were damaged as far as 200 metres (660 ft) away.[1] A nearby car dealer lot caught fire and all the cars on sale were destroyed as a consequence.[7] A second car dealer on-sale stock was also affected.[10][11] Fires were extinguished two hours after the explosion.[11]
The road tanker driver died on the spot upon the first collision.[3] A second victim died on 14 August.[7] Thirteen among those hospitalized were policemen (11 carabinieri and two from the Polizia Stradale, or the Italian highway patrol). Prime minister Giuseppe Conte visited the injured at the Ospedale Maggiore in Bologna, where most of the wounded had been hospitalized, and the burn unit in Cesena. The other burn victims had been transported to the Parma burn unit.[4]
References
edit- ^ a b c d e Vanzini, Vasco (7 February 2019). "Il BLEVE del Borgo" [The BLEVE of Borgo] (PDF). Lavori Pubblici (in Italian). Archived (PDF) from the original on 4 February 2024. Retrieved 4 February 2024.
- ^ Bosotti, Filippo (21 December 2021). C-ITS e trasporto di merci pericolose su strada: possibili ambiti di applicazione [C-ITS and Dangerous Goods Road Transportation: Possible Scope of Application] (PDF) (Masters dissertation) (in Italian). Milano, Italy: Politecnico di Milano. p. 38. hdl:10589/183404. Archived (PDF) from the original on 4 February 2024. Retrieved 4 February 2024.
- ^ a b c d Information Concerning an Event Occurred During Carriage of Dangerous Goods According to 1.8.5 (PDF) (Report). Working Party on the Transport of Dangerous Goods of the Economic Commission for Europe Inland Transport Committee. 1 November 2018. Archived (PDF) from the original on 6 June 2021. Retrieved 5 February 2024.
- ^ a b c "Incidente Bologna, inferno sul raccordo A1-A14: esplode un tir, crolla un ponte" [Bologna Incident, Inferno on the A1–A14 Connection: An Articulated Lorry Explodes, a Bridge Collapses]. Il Sole 24 Ore (in Italian). 6 August 2018. Archived from the original on 22 September 2020. Retrieved 4 February 2024.
- ^ a b c d Cocchi, Giovanni (19–24 June 2022). The Bologna LPG BLEVE (PDF). 28th International Colloquium on the Dynamics of Explosions and Reactive Systems (ICDERS). Paper 197. Archived from the original (PDF) on 6 February 2024. Retrieved 6 February 2024.
- ^ Caprino, Maurizio (14 August 2018). "Incidente di Bologna, autista e cisterna erano ok. Ma i problemi dell'autotrasporto restano" [Bologna Incident, Driver and Tanker Were OK. But Road Transportation Issues Have Not Gone Away]. Il Sole 24 Ore. Strade sicure blog (in Italian). Archived from the original on 6 September 2018. Retrieved 4 February 2024.
- ^ a b c d e "Traffic Accident Caused Major Explosion in Bologna". Riskope. 15 August 2018. Archived from the original on 1 October 2018. Retrieved 4 February 2024.
- ^ Li, Jingde; Hao, Hong (January 2021). "Numerical Simulation of Medium to Large Scale BLEVE and the Prediction of BLEVE's Blast Wave in Obstructed Environment". Process Safety and Environmental Protection. 145: 94–109. doi:10.1016/j.psep.2020.07.038. eISSN 1744-3598. ISSN 0957-5820. S2CID 224899295.
- ^ Report of the Informal Working Group on the Reduction of the Risk of a BLEVE (PDF) (Report). Working Party on the Transport of Dangerous Goods of the Economic Commission for Europe Inland Transport Committee. 18 February 2019. Archived (PDF) from the original on 9 June 2021. Retrieved 5 February 2024.
- ^ "Bologna, cisterna tampona un Tir: pomeriggio di fuoco sulla A14" [Bologna, Tanker Rear-ends an Articulated Lorry: Afternoon of Fire on the A14]. Corpo Nazionale dei Vigili del Fuoco (in Italian). 7 August 2018. Archived from the original on 3 August 2021. Retrieved 5 February 2024.
- ^ a b Bologna, un tir esplode in autostrada: il videoracconto [Bologna, an Articulated Lorry Explodes on the Motorway: The Video Story] (Online video) (in Italian). La Repubblica. 7 August 2018. Retrieved 5 February 2024 – via YouTube.
Further reading
editEyssette, R.; Heymes, F.; Birk, A.M. (25 February 2021). "Ground Loading from BLEVE Through Small Scale Experiments: Experiments and Results" (PDF). Process Safety and Environmental Protection. 148: 1098–1109. doi:10.1016/j.psep.2021.02.031. eISSN 1744-3598. ISSN 0957-5820. S2CID 233949365.