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Building & Contents Grade 2 listed by English Heritage. "is a remarkably complete example of a relatively small plant"

 

Winners of a Listed Status Award from the Institution of Mechanical Engineers. 

 

History of Coleham Pumping Station - a short video by Ian Cooper. here.

 

The sounds of the pumping station working during 1968. here.

Engines

Manufacturer:.......................... W.R.Renshaw of Stoke-on-Trent

Date of Installation:................ 1899

Type:........................................ Woolf Compound Rotative Beam Engine

Cylinders:................................. 1 High Pressure 13ins bore, 38 ins stroke 1 Low Pressure 20ins bore, 54ins stroke

Horse Power:........................... 25 (an approximate value based on a calculation using the pump

capacity and the discharge pressure)

Speed:....................................... 16 revolutions per minute. Speed controlled by a Porter Centrifugal

Governor

Flywheel Diameter:................... approximately 16ft

Weight:...................................... approximately 10 tons (10.16 tonnes or 1016 kilogrammes)

Pumping Capacity:.................... 1.2 million gallons per day (5,455,000 litres)

Estimated (in service) total revolutions:       248,000,000

 

Explanations

Beam Engine:

This is the oldest type of steam engine, using a beam to transmit the up and down motion of the pistons into an up and down motion of the pump plungers. The rotative beam engine transmits this up and down motion of the beam, via a connecting rod, to a crankpin, to give rotation to the crankshaft and flywheel. The rotative beam engine has the following advantages: If a fault occurs with the valve timing of a plain beam engine, the piston rod can exceed its designed stroke and damage the cylinder. By fitting a connecting rod to a crankshaft, the movement of the beam and the stroke of the pistons are controlled and the piston will not hit the cylinder ends. The inertia of the heavy, rotating flywheel maintains a steady speed, whilst also ensuring the engine passes top and bottom dead centre of the crankshaft.

Woolf Compound Engine:

Named after a Cornishman, Arthur Woolf.

This is a rotative beam engine. It is double acting, with two vertical cylinders side by side at one end of the beam. The high pressure cylinder (HP) takes high pressure steam from the boilers and exhausts into the low pressure cylinder (LP), which exhausts to the condenser.

This way of using the steam in two cylinders is called compounding and is more efficient than having only a simple cylinder to provide the same power. When the steam leaves the HP cylinder it is at a lower pressure but has greater volume than when it entered, so the LP cylinder must have a larger capacity than the HP cylinder, which is why it has a larger diameter.

At working load, the LP cylinder produces about the same power as the HP cylinder because, although the steam pressure is less, the diameter is greater and the force on the LP piston will be the same as that on the HP piston.

Valve Gear:

The HP cylinder has Meyer valve gear with two slide valves operating together. The LP cylinder has balanced double beat valves operated by cams and pushrods.

Cylinder Bore:

The inside diameter of the cylinder. The piston fits neatly inside the cylinder and has sealing rings to prevent steam passing the piston.

Stroke:

The distance the piston travels from top to bottom of the cylinder. As the LP cylinder is further from the beam centre bearing, its piston will have a longer stroke than the HP piston.

Horse Power:

This is a measure of the rate at which the engine is doing work. It was originally used by James Watt to show the relative power of his engines. He calculated 1 horse power as raising 5501bs 1 ft in 1 second (or 33,0001bs raised 1 ft in 1 minute)

Speed:

This is measured in revolutions made by the shaft every minute and is referred to as RPM (revs per minute)

Governor:

Controls the speed of the engine. When the engine reaches it’s working speed the weights are thrown out by centrifugal force, operating a system of levers to close a valve in the steam supply to the engine. If the load on the engine increases, it will slow down slightly, the weights will fall and open the steam valve, to supply more steam to maintain the speed.

Parallel Link Motion:

The system of bearings and links above the HP and LP cylinders, invented by James Watt to allow the piston rods to move up and down in a straight line while connected to the end of the beam, which moves in a slight arc. As the piston rods are moving in a straight line, it is possible to have a gland (seal) where the rod passes through the cylinder cover and thus supply steam to the top of the piston as well as below it. This means work is done on both up and down strokes (called double acting.)