The old Victorian water pumping station at Kempton, just off the A316, heading West out of London, holds "steaming" weekends a couple of times a year. On these days they open the building to the general public & fire up one of the old steam pumping engines. I thought the 6 quid entry fee for the museum building was a fair price as you also get a one hour tour of the non running “Number 7” engine. The working steam engine was fired up for approximately half an hour each time at 11:30, 12:30, 14:00 and 15:00. A slide show was running in the corner of the building showing how the engine house was built. Apparently the pumps were used as a stand-in for the engine rooms in the James Cameron “Titanic” movie.
This particular weekend included a gathering of classic cars. Not many there on the Saturday when I attended, but I'm told there were more on the Sunday. The pumps are amazing. They stand 3 storeys high & are beautiful. This is the sort of engineering that made Britain great. Even the building that houses them is impressive & is as much a landmark in North West London now as it was when it was built over a hundred years ago.
If you have any interest in engineering at all, you’ll love Kempton.

Pump video clip 1 www.youtube.com/watch?v=MaaigMSYT1Q
Pump video clip 2 www.youtube.com/watch?v=VsYD-TgknUM

-Renegade

The following is taken from Kempton pumping station’s own literature:
  
You can see the magnificent Engine House of Kempton Park Waterworks next to the A316. Look out for the two tall brick chimneys.
Each day from 1928 until 1980, both of the 2 huge triple expansion engines would pump 19 million gallons of drinking water to North London, via Cricklewood. At 62ft high and weighing in excess of 1000 tons, (flywheels weighing 32 tons each), the No.6 engine produced 1008 horsepower. Today it is known to be the largest Triple in steam in the World. These engines operated 24 hours per day 7 days per week, using steam at 2000psi, and 150o F of superheat. With the engine turning at 18rpm, visitors can experience the warmth of the engine as it rumbles up and down, the smell of warm oil and the action of the massive components. Marvel at the leading technology of 1928. The engine house in all its municipal magnificence is a registered National Monument – No.153, the highest classification a building can have.

Steam Technology at its finest, housed in Municipal Magnificence
The engines that you will see were the heart of the water treatment works at Kempton Park in Middlesex, supplying North London with drinking water, taken from the Thames.
BIRTH: As first built in 1897, by the New River Company, the works had two holding reservoirs supplying 12 slow sand filter beds, using two Lilleshall Triple Expansion engines to lift water to the reservoirs, and three to pump to Cricklewood. Steam came from 6 hand fired Lancashire boilers. In 1915 a narrow gauge railway was constructed to deliver the coal.
LIFE: In 1902 the company was acquired by the Metropolitan Water Board, who in 1928, completed the new engine house, including the two Worthington Simpson Triples which you see today. Two turbines and a water turbine were added in 1933. The D.C. electrical control board also survives. Each triple was of 1008 horsepower and pumped 19 million gallons per day against a 200 foot head. At 62 feet high, they are the largest built in the U.K. They ran 24 hours per day, 7 days per week. Steam was provided by 6 moving-grate boilers. In 1963 the site employed 144 men, and delivered 86 million gallons per day.

DEATH: In 1945 the 2’ railway which delivered the coal was scrapped. Then in 1968 the Lilleshalls were scrapped and their boiler house pulled down, and the reservoirs went out of use. In 1980 the moving grate boilers were scrapped and the Triple house “went cold and dead”. The electric pumps, housed in the Lilleshall House, now deliver 75 million gallons per day. Site staff number 14.
RE-BIRTH: In 1995 the Trust was formed; by 2002 a new boiler house was built for the trust by Thames Water and the no 6 engine was running, sort of. On December 13th 2002, His Royal Highness, The Prince of Wales, inaugurated the museum.
The two 'Great Engines' at Kempton Park, numbers 6 and 7, are of the inverted vertical triple expansion type. The three cylinders, in which the steam is expanded in succession before passing to a condenser, are arranged in line directly over the crankshaft, with the plunger pumps below it. The layout originated in the USA where Edward P. Allis introduced it to a waterworks in 1886, though ships' engines on a similar plan had been used many years earlier.
The Kempton examples are thought to be the biggest ever built in the UK and date from 1926-1929. Efficiency and reliability of engines of this type were hard to beat though the initial cost, including the tall engine house, was high. At one time about a third of all waterworks pumping engines in the UK were of this type though the Kempton engines were the last working survivors when they stopped in 1980.
Mechanically the arrangement is attractive by virtue of the 120° crank setting, which not only helps to balance the moving parts but provides a steady input of power from the engine and a steady discharge of water into the pressure main. There are never less than two steam cylinders driving and one plunger pumping at any time.
Each engine stands 62 ft tall from basement to top of the valve casings and weighs over 800 tons. They were supplied with steam by a battery of water-tube boilers at a pressure of 200 PSI, at 150° F of superheat.
The engines were designed for 24-hour, 7 days-a-week operation, though in practice they were run overlapped, (9 months on; 3 months off). Coal consumed amounted to a maximum of 13 tons per day, equal to the best electricity generating stations of the day.
The two steam turbine driven pump sets, numbered 8 and 9, were installed in 1933 in an area of the engine house originally intended for a third triple expansion engine. They were designed and built by Frazer and Chalmers Ltd of Erith, Kent.
Each unit comprises an 11 stage turbine coupled to a David Brown reduction gearbox which in turn drives a pair of Worthington Simpson centrifugal pumps installed one behind the other.
Research into our archives reveals that the specified power output of each turbine was the same, (1008 water horsepower), as each reciprocating engines. However, due to gearbox losses and less efficient centrifugal pumps, each turbine probably produced about 1300 shaft horsepower at 5870 rpm with a pump speed of 1116 rpm. The turbines used steam at the same pressure and temperature as the reciprocating engines.
The weight of each turbine set including condenser, gearbox, two pumps and baseplate is about 20-25 tonnes, compared with 800 tons for the reciprocating engine, so it is obvious how cost savings were obtained by advancing technology, in the space of only 10 years.

We are partially dismantling No 9 turbine, condenser, gearbox and one of the pumps to display their internal features.
The boiler housel originally contained 6 Babcock & Wilcox boilers providing steam at 200 lb/square inch with 150° F superheat. The boilers were double drum water tube units, each with a total heating surface of 2690 square feet. Each had an economiser with a heating surface of 960 square feet. The coal fired chain grate stoker of each boiler had a grate area of 72 square feet.  Coal and ash handling were fully automatic. In 1951 two additional boilers were installed next to the Babcock & Wilcox boilers. These were John Thompson water tube boilers designed to burn up to 40% low grade coal or coke breeze in “sandwich” firing with regular coal.
The total length of tubing within these boilers was approximately 1½ miles. Each boiler produced 15,000 pounds of steam per hour at a temperature of 600o F. Measured overall thermal efficiency was 84.567% during a trial lasting 14 hours in which 13,000 readings were taken. All the boilers were scrapped in 1981 but some of the doors from the Babcock and Wilcox boilers were preserved and are on show at the museum. 

For more info and times etc go to http://www.kemptonsteam.org/kempton-index.html