Test Questions for Engineers.
An efficient engineer must certainly be able to determine any practical question that may arise in the management, not only of his engine and boiler, but also in that of such shafting, pulleys, gear wheels, etc., as may constitute the driving gear connected with the engine.
A very moderate examination of an engineer (whether to test his suitability for employment or for promotion) should therefore include questions tending to determine his capability to give such directions as may be necessary when the engine or shafting breaks down, or when alterations are to be made and he is consulted with reference to them. The following questions have been framed with a view to include such information as a first-class engineer, and even an assistant or night engineer, may be expected to possess, and a large proportion of these questions have been taken from actual engineers’ examinations in various parts of the country.
In many cases engineers of manufactories are required to make, as far as possible, their own repairs and sometimes indeed also the repairs to the machinery the engine drives, but to give questions covering this ground would be to refer the reader to nearly every page in the two volumes, which is manifestly impracticable.
Matching gear wheels.—Suppose you were running a hoisting engine whose pinion had 15 teeth, driving a wheel with 150 teeth in it; if the pinion had teeth with radial flanks, what orders would you send to get another wheel that would work with the pair?—For answer, see [Volume I., page 15].
Radial flanks.—If a pinion has radial flanks what information does that give to the engineer if at any time he requires to order another wheel to work with it? [I. 15].
Teeth of gear wheels.—What is the difference between an epicycloidal tooth and an involute tooth of a gear wheel? [I. 8], [13].
Ordering bevel gears.—Two lines of shafting are to be connected by a pair of bevel gears and one is to run twice as fast as the other; how would you find the bevel of the wheels so as to be able to tell the maker what was wanted, and what dimensions would you give, leaving the pitch and the shape of the teeth out of the question? [I. 22].
Ordering taps.—Suppose you were ordering a set of taps for use in the engine room, what precautions would you be obliged to take as to the shape of the thread in order to get proper taps? [I. 85].