Steam rolling saves money as well as suffering, and the legislature have recognised the importance of a sanitary authority becoming possessed of a steam roller by permitting money to be borrowed for the purchase of a roller as for a permanent work. (Sect. 234 Glenn’s Public Health Act 1875, footnote to Sub. Sect. (1).)
Mr. Albert W. Parry, the Borough Surveyor of Reading, has prepared some tables on the subject of steam road rollers, from information he received on this subject, in answer to some questions he addressed to the surveyors of a number of towns a few years ago. It appears from this tabulated statement that thirty-three 15-ton steam rollers were in use, six 10-ton rollers, one 21-ton roller, one 8-ton roller, one 9¹⁄₂ ton roller, one 14¹⁄₂-ton roller, one 17-ton roller, and one 25-ton roller; this latter not being much used, as it was found to be too heavy.
The average gross cost per annum of necessary repairs to the rollers, other than those which could be effected by the men in charge of it, amounted to 35l. 12s. The number of men employed to attend to the roller and cost of labour per day varied considerably, from one case (South Shields) where “one engine-man at 26s. per week, and an old scavenger with the flag” were found to be sufficient; to another (Gloucester) where the cost per day is stated as follows: “one man works the engine at 5s. per day, one boy with signal flag, 1s. 8d., two men spreading gravel or sand at 3s., two men watering and sweeping to keep water from running off in channels.”
Some of the older rollers require a steersman as well as a driver, and the Locomotives Amendment Act requires two men with flags, but this is seldom really necessary. The sweepers, spreaders and sprinklers should be taken as irrespective of the actual cost of the roller, which may therefore be assumed to be the wages of the engine-man, say 5s. per diem, and a boy or old man with a flag at 2s., thus making a total for labour of 7s. per diem.
The fuel that is consumed by a 15-ton roller seems to be from 3 to 5 cwt. of coke per diem, common gas coke being generally used, though steam coal would no doubt answer equally well, some of the smokeless Welsh descriptions being of course necessary.
With regard to the question “When not used for rolling roads, to what other use (if any) do you put the engine power?” there are not many towns that use the machine for any other purpose than rolling, but the following uses may be enumerated to which the machines have been applied:—Driving a stone-breaker, a mortar-mill, a saw-bench, a chaff-cutting machine, a bean-crusher, etc. It has also been used in connection with pumping, and to produce the necessary power for the electric light, and it is frequently employed as a traction engine.
The driving rollers usually have provision by which spikes may be fitted into holes in their faces, in order that they may be used for lifting or chequering roads. These, however, apparently do not answer; the working of a machine in this manner is said to shake and strain it considerably, and the holes in the rollers, which are plugged with wood when not in use, are objectionable, as these plugs wear out and the road metal gets into the holes, and the surface of the road is picked up as the rolling proceeds; besides this, the spikes seem to have no effect unless the surface of the roadway being operated upon is soft.
With reference to the use of binding material, the most commonly used and that which receives most favour is road grit or scrapings,[44] sharp sand is also employed, as well as gravel if clean, and also stone chippings and screenings; these should be of the same material of which the road is made, if possible, and no doubt newly constructed roads require more care in the binding material than simple repairs. The steepest gradient upon which a roller will act appears to be 1 in 9 in Blackburn, with a 15-ton roller, but this must require a very heavy pressure of steam, and 1 in 14 seems to be a gradient that gives no trouble to roll either up or down; in going down hill, of course it is a mere question of sufficient break power.
The number of superficial yards rolled per day must vary extremely with circumstances: the class of material, the amount of binding and water used, the gradient and pressure of steam maintained, and the amount of rolling considered necessary,[45] being amongst the various influences. From the above returns I find that the number of square yards rolled varies from 500 to 3000 per diem, the average for 42 towns being 1105 square yards per diem.
The cost per square yard rolled, including all charges, may be assumed to be between ¹⁄₂d. and 1d., and the cost of binding material about 3d. per square yard. With reference to the necessity of binding material, the following, facts are interesting.