EXPLOSIVE MATTERS

[Stanley]

EXPLOSIVE MATTERS

30 October 2000


Musing away merrily at my desk,(and yes, I did see the front page mention last week! Personally, I think they were just short of copy.), my mind started to wander around the imminent pet’s hell which we call Bonfire Night and Remembrance Day the week after and I was reminded of a reference to explosives I came across while researching Barlick. Also on my mind was a request I had last week from a bloke called Raoul Saesen who is a schoolteacher and battlefield guide in Ieper in Flanders who asked me to give him a short history of World War One explosives. It all seemed pretty topical at this time of year so this week we have a look at explosive matters.

The Barlick reference came in April 1890 when the Calf Hall Shed Company were in the process of buying Bracewell’s Wellhouse Mill for £8,000 off the Craven Bank who were evidently the owners because they had taken it in lieu of cash for debts owed to them by Billycock when he died in 1887. For some reason, and I haven’t bottomed this one yet, the Craven Bank had imposed conditions on the sale which meant that the bank scrapped the old engines and the Shed Company installed a new engine large enough to drive the mill and any subsequent extensions. I suspect that this may have been because the bank were financing the sale to the Shed Company and wanted to make sure that if they had to repossess, they would have a large mill with a modern power plant.

£8,000 plus approximately £3,000 further in new plant and repairs was a lot of money in those days. An average weekly wage for a skilled labourer would be about £1, relate that to about £300 for the same hours today and you get a figure of somewhere between two and three million pounds! So you can understand the Shed Company Director’s consternation when they found out that George Rushworth, the Colne scrap merchant who was taking the engines out of the mill was using dynamite to break up the castings! The Shed Company immediately fired off a letter to George Robinson, manager of the Craven Bank at Skipton, to ask him whether he was aware of this circumstance and whether the bank would pay for any damage caused by this dangerous practice. History so far hasn’t divulged what transpired but as there is no further mention of the matter I assume that George was reined in and no further damage was caused.

I wasn’t surprised by the use of explosives, black powder had been used for years in the quarries to fracture large faces, what did surprise me was the use of the trade name ‘Dynamite’ so I had to do a bit of research. I already knew a bit about explosives from my army career but when I started digging into the subject I found some fascinating stories.

Here’s where we get our link with Guy Fawkes and Bonfire Night. We think that black powder was first discovered by the Chinese in the 9th century. They discovered that a mixture of ground charcoal, sulphur and the white crystals that gathered on the walls near well-rotted manure (saltpetre or potassium nitrate) made an explosive mixture and the first use for it was in fireworks for ceremonial occasions. They soon found that the shock value was useful in battle as large explosions caused panic in troops who had never seen them before and assumed they were fire devils on their opponent’s side. As this effect wore off when the knowledge spread, the Chinese started to experiment with hollow bamboo tubes loaded with stones and arrows, the first recorded guns. The Arabs got into the technology towards the end of the 12th century and it is generally reckoned that when the English scholar Roger Bacon gave explicit instructions for making gunpowder in 1242 he did so because, being a scholar of the Arabic language he had picked up the formula during his researches. By 1314 there is a firm record of a shipment of iron guns from Ghent to England and the arms trade was born.

Black powder was the universal explosive for the next 500 years but in the early 19th century, the modern science of chemistry threw up some interesting and extremely dangerous new compounds. In 1845 a man called Christian Friedrich Schonbein spilt some nitric and sulphuric acid and wiped it up with his apron. He hung it to dry by the stove and was surprised when, shortly afterwards, it exploded! The combination of the acids with the cellulose in the cotton apron had produced nitro-cellulose, the basis of guncotton or cordite as it later became known. Other chemists were working on the same lines and in 1847 an Italian chemist called Ascani Sobrero formulated nitro glycerine which was so unstable it exploded if a drop hit the floor!

Many chemists worked on nitro glycerine and a depressing number were killed as their experiments exploded. One such unfortunate was Emil Oskar Nobel, brother of Alfred Nobel, who died when the family’s nitro factory blew up. Alfred redoubled his efforts and by 1865 had made the process reasonably safe, he invented the blasting cap in 1866 and in 1867 patented a solid explosive made by absorbing nitro glycerine into a special clay called kieslguhr and named it Dynamite.

So, I had solved my problem, George Rushworth could have been using dynamite in 1890, and the name was evidently well known.

Raoul’s question to me was whether dynamite was used in warfare in World War One and the answer was no. The main reason, apart from cost, was the fact that dynamite was very difficult to store. If it got too hot it started weeping nitro with obvious dangers, too cold (below 11 degrees C) and it froze and gave unpredictable results and on top of this it attracted water which damaged it further. One of the reasons why gunpowder had been so popular was the fact that if you kept it dry, say in a small keg or barrel, it had a virtually unlimited shelf life and normal ranges of temperature didn’t affect it.

By 1914 other explosives had been developed which were cheaper, more stable and could be modified to give different burning speeds. This is very important because you need different characteristics for different jobs. If you want to propel a bullet or shell out of a gun barrel you need a very progressive rate of burn to push the projectile rather than blast it out. At the other end of the scale, a torpedo needs the most powerful and highest speed explosive you can find. Another quality that was needed was castability, if you were filling a shell or a bomb it was an advantage if you could melt the explosive and pour it into the cavity of the shell. This is the reason why the standard method of extracting the explosive from a dud bomb or shell is to steam it out, a technique commonly used by bomb disposal squads.
Picric acid was a very common explosive used for shell filling but had the distressing side effect that anyone in contact with the fumes from it gradually acquired a yellow tint to their skin. The girls who worked on shell-filling at Woolwich Arsenal were nicknamed ‘The Canaries’ because of this.

In my wagon driving days I used to have regular run taking Barites, which is powdered, calcined marble, down to Cooke’s Explosives at Penryndydreuth in Wales. It was used as an inert filler in the manufacture of gelignite. That place always interested me, they used to take the battery off the wagon and you were towed around the place by a little propane fuelled tractor that was specially constructed to be flame proof. If you had hobnails in your boots you weren’t allowed through the gate. I was sat in the only place you could smoke in the factory one day, a glass box with a naked gas flame, in the middle of the canteen watching a sign writer working on a big sign behind the counter. I noticed that it celebrated the safety record of the works and the bloke was drawing a red line under the entries. I asked him what he was doing and he said they had had an accident. He took me to the window and pointed to a large crater in the field next to the works. This had been a hut where three ladies did some operation on the product. I don’t know what went wrong but there had been an explosion and they were all killed. I was a bit more wary about that place afterwards!

Right, you’ve got the history, now you can go out on Bonfire Night and let your squib off knowing some of the background. Funnily enough, the vast majority of fireworks sold in this country now are Chinese! They should be good, they’ve been making them for over a thousand years! But be careful, think about explosives in war which are used to kill and maim, the fireworks you are letting off in your back yard are equally destructive and dangerous if used in the wrong way. I’ll tell you a little Barlick story that I’ve told you before, but in this context it’s worth repeating. 70 years ago a little lad called Jack Platt was walking down Salterforth Drag. As he walked he was playing about with a small piece of copper pipe he had found in the quarry. He had worked out it was just the right size for slipping over the end of his pencil when it had worn down too far to be easily held. All he had to do was pick out the filling with a piece of wire he just happened to have about him. Half way down the hill he got into the filling with the wire and the innocent piece of pipe exploded and blew off the side of his hand. His ‘copper pipe’ was a detonator and he carried the scars for the rest of his life.

Think about Jack when you are on with your fireworks, don’t do anything stupid and never go back to one that hasn’t gone off, a ‘hang fire’, as we used to call them in the army, is the most dangerous thing there is. Leave it well alone and keep everybody away from it, the chances are it will go off by itself if you leave it alone.

Having given this advice I want to confess that in my time I’ve done some pretty stupid things with explosives. I think it must run in the family, my dad had an operation late in life for a traumatic cataract caused by an explosion in his youth in Australia. He wanted to find out what happened if you put a small piece of dynamite on an anvil and hit it with a hammer! He found out all right, it blew the hammer right through the roof of the smithy and he was blinded for a fortnight. In the army, familiarity bred contempt and we used to use 808 which is a plastic explosive, as a firelighter in our stoves. A knob of 808 and a shovelful of coal will give you a hot stove faster than anything else I know! Another trick we perfected….. on second thoughts, I’d better not tell you that one, it might give some of you ideas!

Have a good, safe time with your fireworks, think of the history of them and think also of the men who died in the wars because we got so good at using explosives. If you’ve got a dog or a cat, even if they don’t show signs of distress, give plenty of TLC and cuddles when fireworks are going off. Their ears are far more sensitive than ours and they go through hell at this time of the year. Stroking them is good for your heart rate as well so do each other some good.


SCG/30 October 2000
2029 words

[Stanley]

Bumped. It's as good a piece of history as it was over 20 years ago.

[Stanley]

Bumped again, the subject sti9ll fascinates me....

[Tizer]

And I'll bump this relevant post from January...
Talking of which, I recommend this book: `Gunpowder and Geometry: The Life of Charles Hutton, Pit Boy, Mathematician and Scientific Rebel' by Benjamin Wardhaugh, published by Harper Collins. LINK I borrowed it from the library and found it fascinating and enlightening. (Don't confuse the author with James Hutton, the famous geologist and another `North Briton' of note, and of the same era.) Charles Hutton

[Stanley]

You're tempting me to buy another book Peter!

[Tizer]

I borrowed it from our local library by ordering it online. Libraries are now much more interconnected and books are continuously travelling between them. Here we can get books from all over the south-west and I expect there will be something like it up where you are. I log in to the library web site, check whether it's shown as in our local library and if not order it from one of the other libraries listed as having it. It will take about a week because of the need to wait for it to be transferred to your nearest library. (If that's not in Barlick I'm sure someone would pick it up for you). It costs me £1 for each book I borrow. Beat that for value for money! Not only do I save money by using the library online but it means I'm not cluttering up my house in yet more books. Also the more we use the libraries the less likely they'll get shut down.

[Stanley]

But I am addicted to books Peter.....