大象传媒

Ivor Ball was born in Ripley in 1923. He was in the RAF and went on a S.D.M.T. training course in Weeton in 1942 below is an introduction to his training notes. The full transcript, which is meticulously done is available by contacting his wife Una Ball via Amber Valley.
L.A.C. Ivor Ball 1691117

Introduction

1 BRIEF DESCRIPTION OF MOTOR VEHICLES

A motor vehicle normally consists of the following parts.

a)A CHASSIS, usually a steel structure supported by road wheels through springs, which take the road share when the vehicle is in motion; the chassis is also a convenient structure on which to carry all the following units and body. In some types the chassis and body are built as one unit.

b)AN INTEGRAL COMBUSTION ENGINE, with its components mounted in the chassis frame for producing power to propel the vehicle.

c)A CLUTCH AND GEARBOX, to transmit the power of the engine.

d)A PROPELLOR SHAFT and near axle with differential to transmit the power to the rear road wheels.

e) A FRONT AXLE AND STEERING GEAR to steer the vehicle in the desired direction through the front wheels.

f) A SET OF BRAKES for bringing the vehicle to a standstill acting on the road wheels.

g) THE BODY, consisting of the coachwork and its immediate attachments.

PETROL is carried and when mixed with air forms a combustible mixture which when ignited gives power to the engine.

OIL is carried to lubricate the moving parts.

COOLANT is necessary to remove the surplus heat which would otherwise cause trouble by destroying the properties of the engine lubricant and by distorting the working parts. Too much cooling however, leads to loss of power and irregular running. A constant correct temperature is desirable.

2 DRIVING

Driving, to be accurate and "kind" to the vehicle (which always pays), should be based on at least an understanding of the mechanical principles involved. Consider a motor vehicle to be divided into three main parts.

A - The Engine
B - An Intermediate Shaft
C - A final drive shaft, permanently geared to the back wheels.

B - the intermediate shaft, can be freed from either A or C, or both. It is freed from A (the engine) by disengaging the clutch. It is freed from C (the final drive to the wheels) by putting the gears into neutral using the gear lever.
When the clutch is engaged ie. with driving and driver discs clamped together and the gear and gear lever are in gear (any gear) e.e. the driving and driver gears "in mesh" - the power is connected right through to the rear road wheels.

REASON FOR THE GEAR BOX

If you have ridden a bicycle with three speed gears you will know that when it is hard to push you use a low gear and your feet go fast and the wheels go slowly. When conditions are easy, you use high gear and your feet go slowly and the wheels go fast. In a car, for starting from a standstill or climbing steep hills, a low gear is needed. There are usually two of three higher gears (and one reverse gear).

CHANGING GEARS - Different gears need to be engaged to suit different conditions. There are two main aspects of gear changing.

a) changing up as speed increases
b) changing down as speed decreases

A gear change does not take long and while it is taking place speed remains approximately constant. This means that the speed of the shaft C remains approximately constant also. So if we are changing up (low to higher) A and B will be required to go slower than they were (for the same speed as C). If we are changing down (high to lower) A and B will be required to go faster than they were.
Two separate gear wheels can be engaged smoothly and noiselessly only when their teeth are going the same speed; this means that their shafts must go at the speed appropriate to the size of the wheels. Hence the importance of the correct use of the accelorator during gear changes, when the clutch is momentarily engaged, with the gear lever in neutral, to transfer engine speed to shaft B.

GENERAL PRINCIPLES OF DRIVING

The fundamental principle you should have in your mind is that you take the car on a journey, and the car does not take you. A car is an obedient servant with no will of its own whatever it does you have ordered it to do through the medium of the controls. If it does something wrong it is your fault and you must learn to give it the correct orders from the start, therefore you must be determined to have perfect control of the speed and position of the vehicle you are learning to drive, a modern car will respond to the manipulation of the controls. The steering is light and accurate and the brake can bring you to a standstill in a very short time. But you must remember that however good the brakes are they can never stop a car instantly. Your first concern, therefore, should be to practice stopping first in a normal manner and then in an emergency until you have every confidence in your ability both to apply the brakes suddenly and to judge the distance that will be travelled before you come to a rest. The "Highway Code" is issued by the Ministry of Transport for your guidelance as a road user and must be carefully studied. It lays down the standard of conduct that is expected of all road users. You must consider other road users and ensure that you do not endanger their lives however unexpectedly or even stupidly they may act. To do this successfully you must be both watchful and correct in your own actions.

The following principles must be understood but the details and finer points can best be taught by demonstration and practice.

I) The speeding up or slowing down of the engine is governed by the accelorator pedal. The transmission of this speeding up or slowing down to shaft B only takes place if the clutch is engaged.

II) The speed of that half of the gear box is fixed by the road speed (constant during gear change). The speed of the other half can be varied to the required speed by using the accelorator pedal and at the same time engaging the clutch.

III) This must be done while the gear lever is in neutral (all gear wheels free) as it always is when in the middle of a gear change.

IV) The clutch must be disengaged every time the gear lever is moved. That is so that no power is being transmitted while the teeth is being put into mesh or taken out of mesh.

OPERATIONS OF CONTROLS

I) To change up (engine speed needs to be reduced).
(A) Disengage clutch, put gear lever into neutral and raise the accelorator - all together - then re-engage clutch.
(B) When engine has slowed to the correct speed disengage clutch, put your lever into next higher speed; re-engage clutch and depress accelorator.

II) To change down ( engine speed needs to be increased).
(A) Disengage clutch move gear lever into neutral, re-engage clutch and depress accelorator slightly, both together.
(B) Disengage clutch, put gear lever into next lower gear and re-engage clutch and depress accelorator further according to road or gradient.
Note: With the older type of "crank" gear box the above procedure must be carried out when changing gear. Otherwise you will not be able to engage the new gear. However, the more modern "synchromesk" gear box covers multitude of drivers sins and gears can be changed, even if the above points are neglected. Such neglect causes the whole transmission from the engine to rear tyres to be severely strained and this leads to unserviceability and costly overhauls as well as stamping the driver as an amateur. The amount of slowing down or speeding up of the engine during gear changes will vary with the road speed at which the change is done.

III) To stop in an emergency press both clutch and brake together. To stop normally apply brake pedal as required remembering to disengage clutch before the car comes to rest.
(a) When stationary apply hand brake and then release foot brake.
(b) Before taking foot off the clutch after stopping, put the gear lever into neutral.
(c) When more experienced you will not disengage clutch until the car is nearly stopped.
(d) When stopping other than in emergency, look in your mirror first.

(IV) To start vehicle moving on road.
(a) Start engine with gear in "neutral".
(b) Disengage clutch.
(c) Put gear lever in lowest gear.
(d) Accelorate slightly.
(e) Engage clutch gradually but firmly, at the same time release handbrake.
Note: If starting off on a hill use more acceloration than on the level.

(V) Steering
(a) A good car tends to go straight - give it a chance to do so. If it goes from side to side, probably you are making it.
(b) Cornering - The golden rule is to drive your car round the corner don't let it take you. In other words the engine should be pulling the car round, as opposed to the car travelling round the corner under its own momentum. The difference in the amount of control you will have is very great. When cornering there should always be a margin "for tightening" the turn if something is in the way and a margin of engine to use as a brake if necessary. The slowest speed attained during cornering should be at the end of the straight, approaching the corner immediately before beginning the turn.
Note: 1) The sharper the turn, the slower you need to travel before starting the turn. Sharp corners need to be taken so slowly that the car cannot accelorate in top gear and a change down is necessary. Change early and use the lower gear to help slow down before taking the corner. Do not change gear while rounding the corner.
2) Don't be ashamed to stop when coming out of a side road even if there is no HALT sign, make sure other road is clear both ways.

(VI)Reversing - When reversing normally, look over your left shoulder, through the back window in a lorry - look out of the driver's side window and go very slowly if passing a gate post or other obstructions put the vehicle in motion as already explained for starting, with gear in reverse. Practice will tell you which way to turn the steering wheel when reversing.

(VII) Turning about - If you wish to turn the other way "overshoot" a mirror turning back into it, and drive out. Never turn into an opening and back out into the main road traffic.

3. ENGINE STARTING - The driver must know how to start the engine and what checks should be carried out before starting. Further details will be given later, briefly, the procedure is as follows.
(I) Action before starting - Check the following items.
(a) Sufficient water in the tank.
(b) Correct amount of oil in engine (check with dipstick), gear box and back axle.
(c) Fanbelt at proper tension.
(d) Radiator filled with water.
(e) Ignition leads correctly and firmly fixed to the sparking plugs.
(f) Vehicle otherwise generally fir - tyres at correct pressure.

(II) Starting engine (told) (a) Turn on petrol (if tap is provided). If there is a mechanical petrol pump with a hand lever, operate this to pump the carburettor full of petrol. If there is an electric petrol pump, switch on the ignition switch to set it working. When the clicking noise stops switch off again. Occasionally, provision is made for flooding the carburretor, if so, it may be used.
(b) Feel that the gear lever is in "neutral".
(c) Pull out the choke.
(d) Pull up the starting handle two or three times, this frees the engine and helps to suck in a rich charge.
(e) Switch on.
(f) Press starter button, in cold weather use the starting handle, this saving the battery. Immediately the engine fires, release the starter button, directly the engine is running smoothly, push in the choke.
(g) Check that the water pump is working by removing the radiator cap and seeing that the water is being circulated. (Ifg a thermostat is fitted, water circulation will not show till the engine is hot).

(III) Starting engine (hot) A Hot engine will usually start when the starter (or starting handle) is operated after switching on, no carboretter flooding or the use of the choke is needed, and if employed may make starting difficult. If the engine is only warm, choke operation may be needed, but try to start without it in the first place.

POWER UNIT

(I) Engine - The principle parts of a motor car are as follows.
(I) The Cylinders are cast in blocks of two, four and six, it is in, these cylinders that the piston is able to move up and down thereby turning the crank-shaft.
(II) The cylinder head is bolted on the top of the cylinder block forming a chamber or space at the top into which the "gas" is drawn.
(III) Crankcase - this forms the "backbone" of the engine supporting the crankshaft in its main bearings (usually three or five in number) enclosing the main working parts providing means of attachment.

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