Lecture 8 Flashcards
The Birmingham Pub Bombings 1974 timeline
Timeline:
20:11 🡪 Code worded warning sent to Birmingham Post newspaper
20:17 🡪 Detonation in Mulberry Bush
20:27 🡪 Detonation in Tavern in the Town
21:15 🡪 Third bomb discovered
The Birmingham Pub Bombings 1974 fatalities
During the PIRA campaign in 1974 two bombs were detonated in Birmingham city centre
- Mulberry Bush 🡪 10 fatalities
- The Tavern in the Town 🡪 11 fatalities
- Third unexploded bomb in Barclays bank
- IRA would send a coded message to a major outlet ahead of time to give people a warning to evacuate the area to reduce harm to people
- In this case there wasn’t time for people to evacuate
What is a soft target?
Non military target, targeting normal everyday people
Facts of the Birmingham Pub Bombings 1974
- The first major attack on a ‘soft target’ in UK mainland
- This led to an explosion of anti-Irish xenophobic sentiment
(Ostracism, arson attacks, airport staff refusing to process Ireland-bound flights) - Wave of revenge attacks by loyalist terrorist groups in NI (mostly random shootings)
- IRA initially denied responsibility
- Immediate demand for the arrest of the perpetrators
- Home Secretary introduced the first Prevention of Terrorism Act
(Seven days detention and deportation to Ireland (N. or Rep.) for suspected terrorists)
Arrests of the Birmingham Pub Bombings 1974
Immediate arrests and non-forensic evidence
- Six men detained after taking a train from Birmingham to Heysham (Lancashire coast) about to board a ship to Northern Ireland
- The men were friends of James McDade (IRA bomber who had died in an explosion on 14th November)
- They agreed to undergo forensic testing to ‘rule them out’ of the bombing
What is frangex?
- Mixed explosive
- Type of gelignite found in quarries in Republic of Ireland
What were the Frangex bombs composed of in the Birmingham incident?
- 20-50% colloidon cotton (nitrocellulose dissolved in alcohol/ether) mixed with nitroglycerin
- 30-40% saltpetre (KNO3)
- < 15% wood pulp stabilizer (same role as diatomaceous earth)
How was the composition/construction of the bombs determined in the Birmingham Pub Bombings 1974?
- The unexploded ‘Barclays bomb’ was key in determining the composition/construction
- They are easily identified without taggants
- Each bomb was approximately 15 kg which caused a huge amount of damage
- As they found the bomb they knew they were looking for the presence of nitroglycerin on the suspects
What is colloidon cotton?
- Nitrocellulose dissolved in alcohol/ether mixed with nitroglycerin
- Nitrocellulose is easier to set off and nitroglycerine is more powerful explosive
What is the purpose of wood pulp stabilizer in frangex?
Wood acts as internal sacrificial barrier - the same as the diatomaceous earth in dynamite
What modern analytical technique could be used to detect the presence of nitroglycerin?
- GC-TEA as it looks specifically for nitro-containing compounds
- It is very sensitive so it can look for trace amounts
What can HPLC be used for?
It can be used to separate the components
How does the Griess test?
- This is a specific chemical test to look for NO2 ions which are generated from explosive materials that contain nitro groups
- The Griess reagent contains two components: sulfonamide + sulfuric acid + something else
- Sulfonamide reacts in the presence of some acid (usually sulfuric acid) and that reacts with the nitride ions. Specifically, to create the N2+. These subsequently react with other reagents and form a compound which gives a clear pink colour.
- Gives us a clear colour change which can be performed on site
- This method was used heavily, particularly for nitroglycerine
What test did the forensic analysts use in the Birmingham bombing?
The Griess test
What is the Griess test is usually paired with?
The Griess test was often paired with thin layer chromatography test for nitroglycerin (very low tech)