The Falkirk Wheel lies at the end of a reinforced concrete aqueduct that connects, via the Roughcastle tunnel and a double staircase lock, to the Union Canal. Boats entering the Wheel's upper gondola are lowered, along with the water that they float in, to the basin below. At the same time, an equal weight rises up, lifted in the other gondola.
This works on the Archimedes principle of displacement. That is, the mass of the boat sailing into the gondola will displace an exactly proportional volume of water so that the final combination of 'boat plus water' balances the original total mass.
Each gondola runs on small wheels that fit into a single curved rail fixed on the inner edge of the opening on each arm. In theory, this should be sufficient to ensure that they always remain horizontal, but any friction or sudden movement could cause the gondola to stick or tilt. To ensure that this could never happen and that the water and boats always remain perfectly level throughout the whole cycle, a series of linked cogs acts as a back up.
Hidden at each end, behind the arm nearest the aqueduct, are two 8m diameter cogs to which one end of each gondola is attached. A third, exactly equivalent sized cog is in the centre, attached to the main fixed upright. Two smaller cogs are fitted in the spaces between, with each cog having teeth that fit into the adjacent cog and push against each other, turning around the one fixed central one. The two gondolas, being attached to the outer cogs, will therefore turn at precisely the same speed, but in the opposite direction to the Wheel.
Given the precise balancing of the gondolas and this simple but clever system of cogs, a very small amount of energy is actually then required to turn the Wheel. In fact, it is a group of ten hydraulic motors located within the central spine that provide the small amount, just 1.5kWh, of electricity to turn it.
Despite the magnificence of this structure, the main attraction for the majority of visitors here today, was the presence of Freddie Flintoff, promoting his fish and chips at 'Flintoff's Fish Bar'!
The book names rowns 'from the dull and lifeless, to the ugly and depressing' - and St Andrews is number seven on the list!
'Crap Towns - The 50 Worst Places to Live in the UK', is the brainchild of Sam Jordinson and Dan Kiernan, both journalists working for The Idler magazine. The idea for the guide came after they wrote pieces about towns they knew well and hated, then posted them on the magazine's website.
Inviting others to do the same, they received a deluge of complaints from irate citizens the length and breadth of the UK. St Andrews, which now suffers the ignominy of featuring on the 'Crap Map', was one of the places nominated most by the public on the website.
Described by a contributor as being home to "thousands of nauseating toffs", the student population came in for fierce criticism as the town's biggest headache.
"So absurd is the wealth of these students and so great is the clamour to meet Wills, that rents in the town have rocketed to Kensington levels thereby pricing out regular students and the long-suffering locals," says the guide.
It continues: "Having failed getting into Oxford or Cambridge, yet desperate to cling onto their bizzare public school sub-societies, they flock to St Andrews. Worse still are those who didn't go to public school and are now desperate to get in on all the body warmer/ ridiculous accents action."
Other than the university and the golf, St Andrews has little else to offer. There is the abbey ruins which is little more than a collection of stones and has an entrance fee. There is also the castle on the beach. This visit has never gone down badly with our customers but it is one I would like to see taken out of the itinery. There are so many other things we could be doing instead. While we were here today it poured with rain and few people ventured out of a cafe to see anything, which was a shame. We had a scenic drive and arrived at the hotel at 4:30pm.
We had a very uneventful evening and I went off to my room to have a long soak in the bath.
Today we are heading home. Friday of Bank Holiday weekend and the first day of the Creamfields festival and I have the joy of travelling the whole length of the M6 and I'm expected to arrive on time so I hope my crystal ball is working!
Our first stop was at Moffat Woollen Mill where several people went for a walk into town for some Moffat Toffee and to see what was missing from the Moffat Ram.