CIVIL ENGINEERING. (OLD REGULATIONS.) The Board of Examiners. 1. A railway cutting of considerable length, and varying from nothing to 40 feet deep, is to be excavated in Silurian clay and soft rock, and the material is to be deposited in an embankment about 30 chains away, the grade falling from the cutting to the embankment. Describe fully how you would accomplish this. 2. A wrought-iron water pipe of approximately 2 feet diameter is intended to bear an internal pressure of 150 lbs. per square inch, and is to carry its own weight over a clear span of 40 feet. Design this pipe, and with a complete specification of material and workmanship. 3. Design a suitable centering for a brick arch of 60 feet span and 15 feet rise, the springing being 15 feet above the bed of the creek, which is hard rock, and nearly dry in summer, and specify the building of the arch. CIVIL ENGINEERING.-PART II. FIRST PAPER. The Board of Examiners. 1. The channel of a creek is 60 feet wide and about 6 feet deep from the level of the adjoining country. It is usually nearly dry, but occasionally carries 4 feet of water, flowing at the rate of about 2 miles per hour. The bottom and sides are rocky, with a good many loose boulders scattered about. The country abounds with tall, straight, and easily splitting timber of from 6 inches to 3 feet diameter. Design a very cheap bridge for coach and waggon traffic. 2. A three-chain street in a good residential suburb has a longitudinal fall of 1 in 100, and the ground is very nearly level transversely. Draw to a suitable scale a cross-section of the street as finished, showing metalled carriage-way, tarpaved footways, bluestone kerbing and channelling, the latter to carry the drainage of 20 acres of ground, including the street itself; also show provision for four lines of trees, and make drawings of suitable tree-guards, and state what trees you would plant, and how far apart. 3. A cable-tram engine-house running three separate cables, faces upon a street having a longitudinal grade of 1 in 20. Twenty yards below the enginehouse, a nearly level street runs off at right angles on the opposite side to the engine-house, along which the branch line of tramway goes. The branch joins the main line by a curve directed away from the engine-house. Show by a plan drawn to scale, how you would arrange the cables, what pulleys you would use, and how you would place them; also describe mode of working the traffic. 4. An electric tramway, five miles long, is nearly level for the first three miles, but rises at a grade varying from 1 in 30 to 1 in 15, with sharp curves for the remaining 2 miles. State where you would place the power-house, and how you would arrange the system of conductors; also give any particulars you can as to engines, dynamos, motors, and cars, and mode of support of overhead conductor on straight lines and curves. CIVIL ENGINEERING.-PART II. The Board of Examiners. 1. The large Baldwin passenger locomotives used in New South Wales have cylinders 21 inches diameter and 24 inches stroke, and driving wheels 61 inches diameter. Steam at 150 lbs. per square inch was admitted to the cylinders, and cut off at of the stroke, and the back pressure averaged 20 lbs. per square inch. Compute the indicated horse-power at 20 miles per hour, and also the load that the engine would pull up a grade of 1 in 40. How many coupled wheels should such an engine have, and what should be the total adhesion load, the line being laid with 70-lb. steel rails and well ballasted? 2. Make a dimensioned sketch of an engine of the above proportions adapted to traverse curves of 528 feet radius, and give such particulars as you can as to its weight, speed, cost, and fuel consumption. 3. Make an accurate sketch of the air-pump, driver's valve, and triple-valve of the Westinghouse brake, and explain their action. 4. Write an essay on the construction of lighthouses on small rocks submerged at high tide. APPLIED MECHANICS. (OLD REGULATIONS). The Board of Examiners. 1. A railway viaduct consists of masonry piers of rectangular section, carrying iron girders. Show how to determine the stresses at any given course under the combined effect of the super incumbent load and wind pressure. 2. How would the stresses referred to in the preceding question be modified under action of a continuous brake? 3. A beam, supported at each end, is subject to a load varying uniformly from zero at one end to a maximum at the other. Investigate the equations of the bending moment, and shearing force curves. 4. Make an outline sketch of a "hog back" lattice railway bridge, and explain carefully how you would determine the stresses due to the weight of the structure itself, the effect of the train, and the wind pressure; and state what you would consider to be the maximum permissible stresses in tension, compression, and shear in various parts of the structure, the material being mild steel, and the dead and live load being equal. 5. Write an essay upon the resistance of tubes to collapse under external pressure. 6. A suspension bridge consists of a cable of parabolic form, connected by numerous vertical rods to a stiffening girder hinged at the ends and centre. Determine the tensions on the cable and suspending rods, and the bending moments and shearing forces on the stiffening girder, under a load per unit length over the whole span, and w' per unit length from one end to the adjacent quarter span. 7. Show how to determine the probable deflection of a lattice girder under any given distribution of load. 8. Describe the apparatus you would use, and the way in which you would proceed, in order to determine the tenacity, modulus, and limit of elasticity and ductility of a specimen of mild steel; and state approximately what results you would expect to obtain. NATURAL PHILOSOPHY. The Board of Examiners. 1. Distinguish between the strength and the rigidity of a shaft used for transmitting power, and prove that iff be the shearing stress that will cause rupture of the material the moment that will cause rupture is Пров where r is the radius of the shaft. 2. If a rigid body be rotating on an axis, determine completely the conditions that the resultant of all the centrifugal forces should produce no strain on the axis. |