GeoGraph - photograph every grid square

2000 tons of road are raised at a rate of half a degree per second, using 114 year old technology that was financed by medieval monks. The arms can go as much as 80 degrees. From 1894,when it was completed, the arms have been raised over 400,000 times; at the height of the Empire, the arms were raised more than 50 times per day, now it is 20 times a week, so we were fortunate to see a Thames barge TQ3380 : Thames Sailing Barge passing through when we were standing along the river bank. Up until 1974, this operation involved several skilled operatives using brass valves and steam valves. Now this is done using a joystick linked to a computer. Steam powered hydraulics were replaced with oil and electricity, though most of the moving parts remained the same. The power required is relatively low (two five horse power engines are used), due to the finely balanced counterweights. The bridge is due to be "spruced-up" shortly, including a complete scrub-down, sandblasting and the application of eco-friendly paint, over a four year period, before the 2012 London Olympics at a cost of £4m. At some time, it will have to be completely closed and 40,000 users a day will have to take an alternate route. The tax-payer, however, will not have to fork out a single penny as all five bridges that cross from the City of London are financed and maintained from a £700m fund called the Bridge House Estates from money that was wisely invested by monks 800 years ago. There is even a surplus amount of cash that be given away charity (£200m in the last 12 years) Not even any of the ships that pass though the bridge are asked to pay.