Kempton Park in the West of London is known for its horse races, but there is still another reason for a visit : Kempton Engine Trust, a former London waterwork pumping station with two giant triple steam engines, 62 ft from basement to top, one of them operating again. The second engine is in restoration and you can, because of its partially disassembled state, understand perfectly - if you want to - each detail of the working one. See http://www.kemptonsteam.org/index.html . It was interesting, to see the starting procedure of the big triple similar to a combustion engine with a kind of starter motor - in this case a small two-cylinder steam engine. That 'barring engine' is used to move the pistons of the triple into the correct starting position. The big one is a triple expansion engine, that means that the admitted steam is used three times, each time with lower pressure and bigger piston diameter.(The resulting force is the product of steam pressure times piston area and must be the same for all of the three cylinders). Well, I can give you an absolute recommendation for a guided tour - you'll get perfect explanations of any questions by real experts. Enjoy and thanks for watching!