Hitting myself with a rat

From infectious hotels to her favourite power tools - Scottish writer and comedian AL Kennedy's bril

Since winning the Costa Prize for my last novel, Day (which I’m assuming was a nice thing) my life has turned into shrapnel and I spend most of my days replying to emails from strangers who want something, slinging huge amounts of snailmail into the recycling bin and running up and down my nearest high street in flight from more of the same.

The only thing working efficiently is my paper shredder. Faced with a choice of researching a novel, adding to a collection of short stories, or hitting wheezy scripts with a stick until they squeak, I have only managed to buy a box set of James Mason DVD’s and make a few quarts of cullen skink.

All my activities are of the displacement variety. Having adjusted to being in my own flat for more than seven days in a row, I have cleaned the house to within an inch of its mortar and it now looks enough like a hotel for me to feel at home. (The room service is, of course, terrible but this is balanced by the presence of many ornaments and items of clothing that I seem to recognise from long ago and far away.) I have also been able to catch up with friends. Two of them have developed a whole extra child of considerable size since I saw them last – a healthy, square-headed chap - my current schedule means he’ll be going through his second divorce before I see him again.

But I am in work – quite possibly more work than I can do. And numbers of the courteous public continue to attend readings. So I can have that kind of fun.

My plan for this week was actually to get all caffeined-up and fly at a new story, having recovered from a) the coldest and smallest hotel room in London – I was, very literally, huddled up and yet this provided no warmth at all - followed swiftly by b) a tangibly infectious hotel in Wolverhampton with a bathroom like a mad fishmonger’s storage area and c) another London hotel erected between two bypasses and equipped with clog-dancing and mysteriously rapping neighbours and a number of electrical devices which proved to be entirely beyond me, tired and tearful as I was.

Technology and I have compatibility issues – my computers toy with me, mangle files, crash whenever they can and force me to wander the globe laden with memory sticks and paper copies of anything that might conceivably become important. Meanwhile, I travel in constant fear that Something Vital will arrive for me on my mobile phone (which loses messages) or by email (almost entirely inaccessible while on the road) and I will miss that key opportunity to discuss my favourite power tools on Radio Five, or hit myself with a rat for six weeks while a Swedish man films it for an art installation. These things being rumoured to aid sales. Sadly, six nights with no sleep at all and a number of train journeys spent typing furiously to avoid contemplating how little time I have to type furiously left me with no more than a deep desire to lapse into unconsciousness for – say – a year and a half.

Next week involves three comedy gigs in Scotland (cue much pacing up and down my living room carpet while talking to people who aren’t there) followed by another dash South of the Border to present an hour of comedy about writing to an assembly of students at Warwick. Then it’s back to Glasgow for more of the same. Dear Godhelpus.

A year on from the Spending Review, the coalition's soothsayer has emerged to offer another gloomy economic prognosis. Asked by ITV News whether he could promise that there wouldn't be a double-dip recession, Vince Cable replied: "I can't do that.

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Inside Big Ben: why the world’s most famous clock will soon lose its bong

Every now and then, even the most famous of clocks need a bit of care.

London is soon going to lose one of its most familiar sounds when the world-famous Big Ben falls silent for repairs. The “bonging” chimes that have marked the passing of time for Londoners since 1859 will fall silent for months beginning in 2017 as part of a three-year £29m conservation project.

Of course, “Big Ben” is the nickname of the Great Bell and the bell itself is not in bad shape – even though it does have a huge crack in it.

The bell weighs nearly 14 tonnes and it cracked in 1859 when it was first bonged with a hammer that was way too heavy.

The crack was never repaired. Instead the bell was rotated one eighth of a turn and a lighter (200kg) hammer was installed. The cracked bell has a characteristic sound which we have all grown to love.

Big Ben strikes. UK Parliament.

Instead, it is the Elizabeth Tower (1859) and the clock mechanism (1854), designed by Denison and Airy, that need attention.

Any building or machine needs regular maintenance – we paint our doors and windows when they need it and we repair or replace our cars quite routinely. It is convenient to choose a day when we’re out of the house to paint the doors, or when we don’t need the car to repair the brakes. But a clock just doesn’t stop – especially not a clock as iconic as the Great Clock at the Palace of Westminster.

Repairs to the tower are long overdue. There is corrosion damage to the cast iron roof and to the belfry structure which keeps the bells in place. There is water damage to the masonry and condensation problems will be addressed, too. There are plumbing and electrical works to be done for a lift to be installed in one of the ventilation shafts, toilet facilities and the fitting of low-energy lighting.

Marvel of engineering

The clock mechanism itself is remarkable. In its 162-year history it has only had one major breakdown. In 1976 the speed regulator for the chimes broke and the mechanism sped up to destruction. The resulting damage took months to repair.

The weights that drive the clock are, like the bells and hammers, unimaginably huge. The “drive train” that keeps the pendulum swinging and that turns the hands is driven by a weight of about 100kg. Two other weights that ring the bells are each over a tonne. If any of these weights falls out of control (as in the 1976 incident), they could do a lot of damage.

The pendulum suspension spring is especially critical because it holds up the huge pendulum bob which weighs 321kg. The swinging pendulum releases the “escapement” every two seconds which then turns the hands on the clock’s four faces. If you look very closely, you will see that the minute hand doesn’t move smoothly but it sits still most of the time, only moving on each tick by 1.5cm.

The pendulum swings back and forth 21,600 times a day. That’s nearly 8m times a year, bending the pendulum spring. Like any metal, it has the potential to suffer from fatigue. The pendulum needs to be lifted out of the clock so that the spring can be closely inspected.

The clock derives its remarkable accuracy in part from the temperature compensation which is built into the construction of the pendulum. This was yet another of John Harrison’s genius ideas (you probably know him from longitude fame). He came up with the solution of using metals of differing temperature expansion coefficient so that the pendulum doesn’t change in length as the temperature changes with the seasons.

In the Westminster clock, the pendulum shaft is made of concentric tubes of steel and zinc. A similar construction is described for the clock in Trinity College Cambridge and near perfect temperature compensation can be achieved. But zinc is a ductile metal and the tube deforms with time under the heavy load of the 321kg pendulum bob. This “creeping” will cause the temperature compensation to jam up and become less effective.

So stopping the clock will also be a good opportunity to dismantle the pendulum completely and to check that the zinc tube is sliding freely. This in itself is a few days' work.

What makes it tick

But the truly clever bit of this clock is the escapement. All clocks have one - it’s what makes the clock tick, quite literally. Denison developed his new gravity escapement especially for the Westminster clock. It decouples the driving force of the falling weight from the periodic force that maintains the motion of the pendulum. To this day, the best tower clocks in England use the gravity escapement leading to remarkable accuracy – better even than that of your quartz crystal wrist watch.

In Denison’s gravity escapement, the “tick” is the impact of the “legs” of the escapement colliding with hardened steel seats. Each collision causes microscopic damage which, accumulated over millions of collisions per year, causes wear and tear affecting the accuracy of the clock. It is impossible to inspect the escapement without stopping the clock. Part of the maintenance proposed during this stoppage is a thorough overhaul of the escapement and the other workings of the clock.

The Westminster clock is a remarkable icon for London and for England. For more than 150 years it has reminded us of each hour, tirelessly. That’s what I love about clocks – they seem to carry on without a fuss. But every now and then even the most famous of clocks need a bit of care. After this period of pampering, “Big Ben” ought to be set for another 100 or so years of trouble-free running.

The Conversation

Hugh Hunt is a Reader in Engineering Dynamics and Vibration at the University of Cambridge.

This article was originally published on The Conversation. Read the original article.