14 minute read
Explosi ves
EXPLOSIVES
E.W. DEAN, SENIOR OFFICER HUMBERSIDE COUNTY COUNCIL
Advertisement
Defini tion
A mechanical or chemical arrangement by means of which a predetermined and reasonably controled amount of work may be carried out using the force applied by the rapid expension of gases.
The two distinctive types of chemical explosive are known as deflagrating and detonating.
A deflagrating explosive such as gunpowder (black powder) and nitro compound are known as low explOSives giving fast burning with low pressures and need to be confined in an enclosed space in order to be effective, i.e. a gun breech and barrel or tightly packed in a drilled hole as in quarrYing,
A detonating explosive such as dynamite, gelignite, nitro glycerine and many other types of modern blasting explosives do not always require Such confinement to give rapid decomposition and extreme pressures.
A mechanical explosive Would be compressed air or steam both of which are regularly used in circumstances where a strictly effort is required, such as d1scharging naval torpedoes, catapulting aircraft , st ar starting high powered internal Comb . engines. ustlon
Explosives may also be Used in sec' C ases f or b "· d . tt· r1ve lng Using p lal explosive large die rivets, impact . presS1ngs. weldl'n g and
Quali ties
An explosive must have:-
1. chemical stability 2. sensitivity to ignition 3. sensitivity to detonation 4. velocity of detonation 5. explosiNe strength
History
PrObably Of the first known appll'C t. a 10n Chtan explosive material was by the nese in the 10th century, this material may have been a crude mixture of nitrates, sulphur and charcoal, and although some historians have reported that attempts were made to discharge stones from a crude bamboo muzzle loading gun, it is believed that the main application was in the use of 'stink bombs' which were wicker baskets containing burning sulphurous material which were thrown by means of catapults and slings into an enemy emplacement or ship to terrify them. It may also have been used for signals, rockets or fireworks.
In 1:32 AD the Chinese are believed to have used rocket propelled arrows against the invading Mongols.
Roger Bacon is reputed to have discovered gunpowder in the Western Himisphere in 1242 AD although this was written in latin and may have been translated from Arabic.
The Paduans in 1379 and the Venetians in 1380 are reported to have used rockets extensively in war.
Black powder is reported to have been used in mining in Germany in 1613 and in Schemnitz Hungary in 1627.
Nitro glycerine was discovered by an Italian chemist, Ascario Sobrero, in 1846 but it was found to be so unstable (only by being kept f rozen was it found to be safe) that it was merely a laboratory curiosity.
In 1867, Nobel, a Swedish . t d 1nven e dynamite by absorb1ng n1tro . . glycer1ne 1n th e k1'eselguhr and Idmou ' 1ng the result into sticks of . varying . S1zes before drying. Th1S . 1 mater1a was more stable and could . be handled a lot safer but it was . expens1ve. He then used wood pulp . . th . d f lnstea 0 k1'eselguhr and th1s 1S e method used today.
Another form was to dissolve cotton in a . f m1xture 0 nitriC and sulphuric acid to make -cotton. gun Gun-cotton . forms a dissolved in nitro glycerlne jelly producing gelignite.
Black powder is manufactured 10 - 12 tons at a time by mixing the sulphur 15% and the charcoal 10% in a paste with water in a ball mill, and whilst still wet adding the potassium nitrate 75%. The resulting paste was dried in trays, granulated and graded, then packed in boxes or bags of 10 kilos each.
"Ampho" commonly used in quarrying is a mixture of ammonium nitrate and diesel oil, this is mixed on the site as a rule, and strict Health and Safety Executive licenses are required to carry this out and use it.
NOTE The mixing of any explosives is the critical period, as the materials mix together so the stability may be reduced.
The manufacture of all explosives is strictly controlled and licensed by the Health and Safety Executive. Rigid and exacting tests are applied throughout. At all stages of manufacture regular samples are tested and reports entered in a register. All imported explosives are sampled and tested at every batch. Tests include hammer (impact) tests, spinning disc, electrical stability, speed of ignition (6 miles.per Ability to withstand deterloratlon ln reasonable storage conditions.
All detonators are manufactured in highly sophisticated plants where every effort is made to combine ease and safety of the processes and the safety of the staff involved. Small 'factories' surrounded by banks of earth, soft roof, strict control of personnel numbers rigidly enforced, and 9rotection against lighting and fire, with remote control used where possib le.
Closed circuit television can be used but NOT for electric detonators.
Accidents and incidents
In 1956 a dock labourer in Hull docks noticed some sticks of explosives in coal being loaded in bulk into a ship bound for a foreign port. He collected them (12) out them in his lunch bag and carried them in a public transport. and handed them in at the Police Station. Some of them were weeping (pure nitro glycerine), they were carefully placed in a bucket of sand, carried to the nearest open space and guarded until the disposal officers arrived from the Army Barracks at York and exploded them in a nearby open space.
Explosives in Coal Reported Occurrences
killed killed killed injured, but in cases only was explosives proved
1972: Coaster and its cargo contaminated with nitro glycerine whilst carrying 100 tons of explosives, further handling was deemed unsafe. It was towed out into deep water and blown up. 1949: Raining, and a man returning already armed charges into a store, (illegal) and must have dropped them, 500 lbs plus,
Thefts of explosives Attempts Successful
Stolen Recovered 1969 440lb (350) 1970 1300 (850) 1971 1300 (180) 1972 220 (130) 1973 427 (294) 1974 As well as detonators and fuse. 38 30 31 30 35 14 35 29 28 28 32 9 Successful believerl for criminal purposes
27 21 23 17 15 5
exploded causing damage up to 1,000 yards. 1934: Spraying weeds with potassium chlorate, the spray covered his clothes and later in the house when dry, it was ignited by a match cigaratte (fatal). 1921: Mannheim, silo in fertiliser factory containing 4,500 tons of double salt ammonium nitrate and ammonium sulphate which sets hard in silo and the practice is to blow it down with explosive. By mistake an ammonium nitrate explosive was used and the whole exploded killing 600 people, injuring 500. Obliterating the town. 1974: An attempt made to enter steel explosive store using oxyecetylene when the whole store exploded. Railway waggon entered and five cases removed but all recovered intact. Attempt through the roof of a magazine failed.
Safety
Moqt explosives deteriorate if exposed to moisture, gunpowder and nitropropellants become weak and ineffective.
explosives, however, become highly unstable and will exude a sticky liquid - nitro glycerine - and become extremely dangerous to handle.
Detonators are usually small cooper or silver coloured items about the size of an elongated .22 cartridge case and in the case of electric detonators there are two coloured wires attached. Do not handle them roughly, don't pull on the wires, if you have to handle them hold them by the wires only, the heat of the hand can exploda them and they can deftly remove fingers and eyes.
DO NOT USE a transmitter (radio) within 50 yards of a detonator store.
The successful and safe use of any explosives can only be assured by the meticulour care and attention to detail cleanliness and sure and expert training.
Large quantities may be acquired, usually for use in one single operation, but if required to be kept for more than a short period must be kept in a safe place, safe from entry, and the local authority 1nformed with the possibility of registry. (Registered premises Section 22).
NOTE: . In the above cases there is no authority for inspection by an explosives inspector, unless he that explosives are being kept for an excessive period.
REGISTRATION BY LOCAL AUTHORITY
Order in Council No 16
REGISTRATION MODE A
60lb explosive and detonators or 2001b gunpowder. Kept in a substantial building, wholly detached from any dwelling house. A safe distance being not less than 15 yards from any public place or thoroughfare.
ACQUISITION
Order in Council No 12
Order in CounCi 1 No 13 Private Use
Irrunedi a te Use 10lb Blasting Explosive or 30lb gunpowder, 100 detonators, Police Certificate necessary to purchase (Control of Explosives Order) (1953/SI No. 1598)
It is not necessary for Police Certificate for purchase of Nitro Compound for use in cartridges exclusively for small arms.
Explosives other Ni tro Compound. purchase only. than gunpowder, or Valid for one
l5lb explosives and detonators or 50lb gunpowder, kept in a substantial cupboard, box or drawer. Only gunpowder may by kept in a fireproof safe. All detonators stored separately.
Each of these modes may include 500lbs powder contained in ammunition of 1st Div Class 6 provided it is in secure storage, i.e. steel cabinet or box. Note: 500lb in 35 grain units would represent 100,000 cartridges.
MAGAZINES (Defining a store containing more than 4,0001b of explosives)
Controlled by Home Office and licensed by them. Any quantity, as laid down by requirements of H.M. Explosives Inspectors. Not inspected by local authority only by police for security.
STORE CONSTRUCTION
Brick, stone or concrete block walls are not now acceptable for new stores. Existing stores so constructed only permitted to continue if sound and fitted with sophisticated alarm system, and must be provided with further outer skin of not less than 5 inches of reinforced concrete, so that it overlaps the roof and is tied in with the roof.
Walls of brick or stone at least 9 inches thick and provided wjth alarm. Or at least 14 inches including the 5 inches of reinforced concrete if without the alarm. Single brick walls must include a minimum of 10 inches reinforced concrete.
Fenced, if in the open and so required by local authority. Steel stores manufactured to strict specification as laid down by the Heal th and Safety Executive.
VENTILATION
Staggered openings. Bolted guards.
OVERHEAD ELECTRIC CABLES
A break in the cable must not allow it to fall across the store.
LOANING A STORE
Only the licensee may have a key and all material must be compatable.
STEEL STORES
See drawing in Nobel's handbook. All stores must have separate compartments for detonators and explosives and all modifications to Home Office requirements completed. Note the 9 ineh distance between detonator store and explosives store.
LIGHTNING CONDUCTORS
Div. C.D.E. Pole not less than 6 feet from store and the store must be within 600 from the top of the pole.
SECURITY
Any person who enters without permission trespasses upon, Factory: Magazine, Store or the land adjoining, is guilty of an'offence and may be removed by Constable, occupier or agent or servant duly authorised.
Occupier must take all to
prevent accidents due to flre or explOSion, and for preventing the access of unauthorised persons.
STORAGE OF EXPLOSIVES
Store
Quantity Distance from Distance from Protected Work Class 1 Class 2 Di vision Division Division Division Di vi si on A B C D E 150lb 300lb 1000lb 2000lb 40001b & & & & & detonators detonators detonators detonators detonators 75 75 146 230 352 ft ft ft ft ft 85 130 292 460 704 feet feet feet feet feet
Division, quantity, and warning notice on inside of door.
Keys must be in the hands of a responsible person, kept in a safe place, not at home, not under a brick and the number of keys an absolute minimum.
All locks secure, lock plate welding intact, outside welded lock guard intact and secure. Check all welded joints round the roof.
No damage to door or fittings, all door stiffeners intact, and securely welded, all hinges covered with plastic tape.
Walls, floor, door and ceiling covered with wood and with no protruding iron nai Is.
Floor clean and dry.
Nothing to be kept in the store other than the explosives and any non-ferrous tools necessary for use in the store. No rags or cleaning cloths of any kind in the store.
Vegatation around the store to be kept down and clear from the sides.
Lightning conductor where required to be complete. Check where the strip enters the ground, the pole sound, and the top complete and not damaged by tree branches.
Check detonator store as for main store see that horizontal and vertical flanges provided in the attachment to the main store are secure but note the air space must not be boxed in;
In the case of an attached detonator store the maximum number of detonators permitted is 1,000.
Check the normal use of detonators to ensure that an abnormal number are not being carried. (see Shotfirer's Record Book) _
Bear in mind that the main requirement of subversive elements is the detonator particularly the electric type.
Class 1
Dwellinghouse
Shop Room of any kind
Workshop of any kind
Mineral or private Railway
Furnace, Kiln or fire
Magazine for explosives
Store for explosives Registered premises Highway, public footpath, promenade or open place In occupation of licensee or wi th consent in writing of occupier
Open to public or for persons engaged in trade or business
Canal or navigatable waters Dock, river wall or seal wall
pjer or jetty
Reservoir Class 2
Dwe 11 inghouse
Shop
Room of any kind
Railway
Furnace
Magazine
Store
Registered premises Factory of any kind Without the consent of the occupier
Building in care of ministry of works Place of public worship Educational establishment
Hospital or similar
Court of justice Theatre, cinema, market where the public assemble
Government or Local GI vernment building
Check the explosive register, is it up to date? Do the deliveries and quantities used tally. Does it record what is left in the stores accurately?
FILLING SHOTGUN CARTRIDGES
Whilst it was never envisaged that commercial loading of cartridges would be carried out otherwise than in a registered and licensed factory, nevertheless this section covers such a contingency.
Only a maximum of 5lb of propellant is permitted at any time in the filling room. The remainder must be kept (maximum 200 lb) in a fireproof safe in a separate building securely locked.
All filled cartridges to be kept in a securely locked store separate from the filling room.
No rifles or shotguns to be kept in this store.
The floor of wood in the filling room must be complete and with no protruding iron nails.
The floor must be kept clean at all times. All shelves, tables and lamps to be kept free from dust.
No work whatever may be carried out in the filling room unconnected with the actual filling of cartridges unless all propellant and filled cartridges are removed and the place washed down.
No smoking, no matches or lighters, no nails in boots"
OTHER STORAGE
Fireworks and Cartridges in Shops
Fireworks are to be kept in metal, wood, or glass containers so that although they may be seen by a customer the customers cannot handle them and there must be no smoking in the shop.
Cartridges must be kept in locked cupboards and at night kept in locked steel cabinets, unless the buildings are suitably wired for alarms and secure.
Multiple Registered Premises at Collieries and Quarries
A maximum of 60 lb of explosives is allowed in each cupboard. All explosives to be carried in the leather bags provided, all detonators in a separate bag and all booked out to the shotfirer and any returned, hooked in, strict records to be kept.
The store itself to be of an approved type laid down by the Health and Safety Executive Explosives Division.
SALE OF EXPLOSIVES
No sale of any explosive (other than ni tro compound propellant) unless the buyer possesses a police certificate to purchase.
Complete records are kept of all transactions, type, quantity, etc. name and address of purchaser.
Any "FOUND" explosive material or device must be treated with extreme suspicion. DO NOT TOUCH IT. It can only be dealt with by explosives experts usually from the Army Bomb Disposal Section whO are contacted by the police and authorised to deal with it - "NO HEROICS",
o
Se e
; : :::z:::
