Pep pipe Ejector Blower Brake valve Sander Dampers Cylinder cocks Lubricator Whistle Injector Injector Gauge frame Water gauge Pressure gauge Vacuum gauge ATC Fire Regulator Reverser 7202 Footplate Controls
Select a control or click on the picture
Automatic Train Control (ATC) is detailed on the Didcot Railway Centre map pages, click here for details. The bell is the most obvious device in the cab, but the battery box is also here.
The blower is a series of jets of steam up the chimney to draw air through the fire, this will increase the rate of combustion of the coal. The blower is also used when there is a danger of the the fire coming in the cab, called a blow-back, at times such as entering a tunnel or when the regulator is closed.
This control operates 3 cocks on each side of the engine, 2 for cylinders and 1 for the valve, they allow steam and water to escape from these areas, this is needed when the cylinders are cold to allow any condensed water to escape otherwise the engine may be damaged.
Dampers are doors underneath the fire that can be opened to allow more air in to the fire, thus making it burn hotter, they are also opened to allow the ash to be racked out at the end of an operational duty.
The fire hole doors, operated by a lever are where the coal is put on to the fire, the doors are hollow with a passage way to allow some air on to the fire. When more air is required the doors can be opened and a flap put up that covers only part of the hole, this reduces black smoke by allowing complete combustion of the gasses.
The water level in the boiler is shown on this gauge in a glass tube behind a protector. There are shut of valves operated from one lever so that should the glass break it can be easily isolated, remember this is at boiler pressure! Should the gauge be out of use for some reason, there are 2 test cocks to open to see if the water level is above or below them.
Injectors are devices that combine steam and water in such a way that they overcome boiler pressure and put water in to the boiler.The injector steam valves control the steam supply to the injectors, of which there are 2. The water to the injectors is controlled by valves mounted on the bunker, so are not visible here.
Lubrication to the cylinders and regulator is done by using condensed steam to displace oil, which is released at a controlled rate as seen in the glasses, before being piped to the cylinders or regulator.
The pep pipe, also known as a slack pipe, is used to wash down the footplate and damp down the coal to reduce dust, the feed is taken from the left hand injector, so that must be running to use the pep pipe.
The pressure gauge shows the steam pressure in the boiler, which on a 72xx will be up to a maximum of 200 Ibs/sq.in. even though this gauge shows 225 lbs/sq.in.
The regulator acts like a throttle, controlling how much steam is allowed to the cylinders, the wider open it is the more steam is allowed.
The reverser adjusts the valves to control when steam is allowed in to or escape from the cylinders, by doing this you can work more efficiently and change direction.
Sand can be applied either in front or behind the engine to give it better grip when starting or stopping, this may be important when you have 2000 tons behind you!
The brake valve allows air in the train pipe, destroying the vacuum and putting the brakes on. The vacuum is created by the ejector. See also the vacuum gauge.
The ejector creates a vacuum to take the brakes off, the brakes are then applied by the brake valve. See also vacuum-gauge.
The vacuum gauge shows the vacuum in both the train pipe and reservoir, it is the difference between the two that is the braking force applied to the wheels. See also ejector and brake valve.
The whistle valves are in the cab, connected to the steam fountain on the top of the boiler. The valves are operated by pulling one of the chains. The GWR used 2 whistles, one a standard warning, which has a chain both sides of the cab, the other to call for braking assistance from the guard operated by the driver only.
The water gauge on the side of the tank shows how much water is left in the tanks, which on a 72xx can be 2500 gallons.

Home