Modelling the Kerr-Stuart Brazil Class 0-4-2ST locomotive in 16mm scale. - Keith Bucklitch
As this is an internally fired loco, you will need an electric blower to initially raise steam.
An electric blower can be made using a cheap 3 volt motor. You will also need three disks of brass. Two should be 2 1/2" diameter, one should be 2" diameter. Six vanes are silver soldered to the small disk, taking care to see that they are equally spaced both radially and circumferentially. A hub is soldered to the centre of this disk with a hole just fitting the shaft of the motor. The two larger disks have central holes in them, one is screwed to the motor. The second has a piece of 8 mm pipe soldered to it to fit into the chimney. If you wish you can make this tapered. The two disks are held by four 6 BA screws and nuts so that they are parallel, with space for the fan disk to rotate clear. Obtain a battery holder, solder two wires from this to the motor. (It does not matter which way round the motor rotates.) If you can fit a switch in the circuit so much the better, otherwise you have to remove a battery to stop the fan.
Fill the boiler to about 3/4 up the glass. Oil around the valve gear and motion work. Fill the lubricator with steam oil. Fill the spirit tank, open the control valve and let the sump fill. Place the blower in the chimney. Insert a taper below the firebox and light the wicks. Switch the blower on. After a few minutes the pressure should start to rise. When there is about 15 pounds of steam pressure on the gauge, open the steam blower valve and remove the electric blower from the chimney. The pressure should continue to rise. Adjust the steam blower valve to give the most efficient use of the blower. Too much, will waste steam unnecessarily, too little will allow the fire to die. When the safety valve lifts, top up the spirit tank, put into gear, open the regulator and we should be away.
When you bring the loco to a stop, close the regulator and open the blower valve to maintain the fire. If you initially place a mirror beneath the loco, so that you can observe the fire, you will soon find the optimum position for the blower control.
If you have any questions, or comments or find any errors in these notes please contact me by email. Email Keith Bucklitch.
Copyright © 1998, Keith Bucklitch
Last Edited - November 1998