LIGHTING OF PUKEKOHE.

Pukekohe & Waiuku Times, Volume 3, Issue 254, 8 December 1914, Page 1

LIGHTING OF PUKEKOHE.

Expert's Report.

The following report on tbe proposed Municipal Gas Works for Pukekohe from the Consulting Engineer (Mr J. W. Blackmail, of Masterton) was presented at the meeting of the Borough Council on Friday last, consideration being adjourned pending its publication in the " Pukekohe Times " : In accordance with your instructions I have the honour to report as follows

The most important factors in deciding as to the advisability or otherwise of installing a coal gas works in any town are, first the cost of coal, delivered into the works, and secondly, given coal at a reasonable price, will the consumption of gas be large enough to allow a margin of profit sufficient to pay the interest and sinking fund on the amount of loan necessary to inatal the proposed works, mains, and other equipment. Dealing with the question of Coal supplies and cost thereof.- -The coal largely used in the Auckland District, at such gas works as Hamilton, Thames, Waihi, Paeroa, etc, is a mixture of Greymouth small and Huntly or Taupiri, slack, usually in the proportions of two thirds Greymouth to one third Huntly. The costs as quoted to me recently are as under Per ton s. d. Greymouth small coal delivered F. 0.8. Onehunga 17 3 Kail freight to Pukekohe 5 3 Total £l2 6 Per ton s. d. Huntly Black F.O.R. 5 0 Railway freight to Pukekohe 4 1 Total 9 1 Allowing the use of the twe coals in the proportion of two-thirda 'Jrey to one-third Huntly, coal will cost about 18s per ton delivered in trucks at Pukekohe, say 20s per ton delivered into gasworks. This price for coal is considerably lesa and compares very favourably with the cost of coal to gasworks where the Huntly coal is not obtainable. Grey coal coats the Masterton gasworks 24s 3d per ton in works, and considering that the mixture as foresaid will produce from 11,000 to 11,500 cubic feet per ton, it is evident that the cost of coal even at a higher rate than quoted would still be a favourable factor. With regard to the second factor, viz., the possible consumption of gas in Pukekohe, in estimating this, local considerations and conditions naturally influence the position. Coal gas at one time was used almost entirely for lighting purposes only, but in recent years the improvements in the manufacture of gas cookers, gas engines, and the numerous other appliances, domestic and industrial, for which gas is necessary, have been so marked that the advantages of its use for cooking, heating and power purposes are recognised to such an extent that with many gas undertakings the output of gas during the hours of daylight ia from 50 per cent, to 60 per cent, of the total production. This will at once make it clear that •where under the condition that revenue from lighting only could be depended upon a gasworks would not pay, under the existing conditions, with the demand practically doubled, at no increase in capital expenditure, atanding charges or labour costs, beyond the cost of coal, a gasworks will pay its way with a good margin ot profit. The use of gas for lighting by a large percentage of the residents in a'town can always be depended upon. The use of gas for cooking, heating and power purposes, depends to some extent on looal conditions, and the price at which gas

can be supplied for these special purposes. It ia an acknowledged fact that in all rising towns tlie supplies of firewood are yearly becoming more difficult to obtain, and therefore more costly, the economy and labour saving conveniences of gas when used for cooking, beating or power are soon appreciated, and with coal at the prices hereinbefore mentioned, gas could be supplied at such rates as would enable tbe use of cookers and other domestic appliances to become to a gieat extent universal. In addition, there would be the revenue derived from power gas, the sale of the residuals, cuke and tar (the latter ever becoming of more importance in roadmaking under modern conditions of traffic), also from the lighting of the streets, for which a fair and equitable amount should be paid to tbe gas department. In view of tbe foregoing, and with my knowledge of the financial success of similar undertakings in towns about the same size as Pukekohe, 1 am of the opinion tbat a municipal gasworks would practically from the first year be a profitable business for the ratepayers. At the end of this report will be fuund a pro forma balance sheet giving figures that will confirm this statement. # # * * Tbe estimated loan expenditure may be summarised as follows: £. Manufacturing plant and machinery, etc. 3000 Building for gasworks, sal. iron 600 Manager's cottage, wood 450 Gas maina as specified 2826 Lamp posts fitted complete with lanterns, automatic controllers, burners, etc., say, 40 at £8 320 Gas meters itnd service connections for, say, 150 customers, at £4 10s 675 Total for plant, etc 7870 Add cost ot site and contingencies, 10 per cent 787 Total 8657 Allowing for all contingencies, and the payment of the first year's interest and sinking fund out of loan, together with the expenses of raising same, a loan of £IO,OOO will be ample for all requirements as specified. With the foregoing expenditure the Council would posseos a plant capable of an output of from five to seven million cubic feet per annum; and by adding retorts as necessity •dufoanded until the full number of fifteen is installed a winter day's output of 70,000 cubic feet could be maintained without any added capital expenditure tor benches, clinkering cellar, etc. Averaging the summer and winter output, aud allowing for one arch off duiing summer months for replacing retorts, the work as recommended would be capable of so output of from 18 to 20 million cubic feet per annum, equal to the requirements of a poulation of some 4000 people. Street lighting.—l have allowed in the estimates for 40 street lamps; the number may be more or less as tbe Council in its wisdom may decide. 1 may say, however, tbat well lighted streets are one of tbe best advertisements to encourage residents to use gas themselves for lighting. Tbe modern system of automatic controllers for the lighting and extinguishing of street lamps from the gasworks is now very largely adopted. Briefly, the system is as follows:—The controllers are fitted to a lamp, at lighting time the pressure in tbe town main is increased by 15 to 20 tenths, the controllers are immediately operated, tbe whole of the lampa being lighted simultaneously. Tbe pressure is then reduced to normal, the bells ii the controllers come back to the rest position. At extinguishing time, say 11 p.m., a similar wave ot pressure iB sc... .

through tbe mains, tbe bells in the controllers are raised, turning off tbe gas to each lamp, pressure is again brought back to normal until the next Jighting-up period. The whole operation rarely takes more than three minutes—for ligbting-up or extinguishing—and entirely does away with the old and expensive system of hand lighting and extinuisbing. I have included tbe cost of suitable controllers in tbe estimate for atreet lighting. Site for gasworks.—ln the installation of a gasworks not the least important factor bearing on the

future success of the undertaking is that of the site on which the proposed works should hs erected. This should be so situated that the raw material coal can te delivered into

the works at tha lowest possible cost, and in an inhnd town should be as near to the railway station as may be possible. It eh:u!d be of such configuration as to enable buildings to be erected with th; least expenditure, and to be so set out that future extensions enn be added with the minimum of expense and trouble. The sub-soil should be solid and a* dry as possible, because with tha modern regenerative furnac a the producer and clinkering cellar require a depth of at leeat six feet below the retort house floor, and where foundations are in ground that is constantly saturated with water a large amount of fuel is wasted in drying up the moisture that is constantly rising into the heated mass of brick work comprisirg the retort bench. Also in the ordinary daily woiking of the plant it is necessary that the works, mains, valves, siphon pots, etc., shoulJ be above wat?r level. The area of the site should be not less than one, and preferably two, acre*. Failing a site into which a railway siding could be run (if required in the future), I would recommend a site on section marked "A" on the plan, providing tbat same could be obtained at a reasonable price. Coal would requite to be carted, but in other respects it is a most suitable position. At tbe same time, if ownets asked an exborbitant price it can be remembered tbat once coal is loaded into a dray the queation of carting a few cbaina further baa not much effect on the cost of cartage, in other words the cost of cartage for, say, a quarter of a mile would not be less than for half a mile. Financial.—Dealing now with the question as to whether tbe works, if installed, would be a payable undertaking, I submit a pro forma balance sheet hereunder, I have, of course, bad to assume a price that will be charged for gas, and this question of price has an important bearing on the financial success or otherwise of a gasworks, the 1 cheaper the service the more universally it will be availed of, and I see no reason wby with coal at the price hereinbefore mentioned gas should not be sold in Pukekohe at 8a 4d per 10C0 feet for lighting and 6s 3d per 1000 feet for cooking and power purposes. At these prices with an output of only three million cubic feet per annum, the figures would be within a few pounds as follows: Receipts. £. IA million feet pas at 8s 4d per 1000 625 1} million feet gas at 6s 8d per 1000 500 Total 1125 40 street lamps at 80s 160 80 tons coke at 25s 100 3000 galls, tar at 4cl 50 lotal 1435 Expenditure. £. To 300 tons coat at 21s per ton 315 Wages, manager and assistant 250 Clerical (T.C. office) 50 Purification 10 Maintenance and sundries 60 Total 675 Interest and sinking fund, 6 per cent on £IO,OOO 600 1275 Balance 160 Total £1435

The foregoing tiguies show that with an output of three million cubic feet per annum at the prices suggested, a gasworks would tjive a fair margin of profit after paying interest and sinking funds on a 6 per cent loan (say, 5 per cent interest and 1 per cent sinking fund) of £IO,OOO. And I am of the opinion that this position could be reached in two years, if the sale of gas for day consumption, viz.,. cooking, heating and power, is energetically pushed. In allowing £SO per annum for maintenance, etc., 1 am well within the mark, as at any rate for the first two or three years nothing like that amount should be required, though it is a wide policy to inaugurate a tund for future wear and tear expenses (renewal retorts) from the commencement. It will bd noticed that 1 have allowed for each ton of coal to produce only 10,000 cubic feet of £B9, whereas at least 11,000 cubic feet should be made per ton of coal. It must, however, be remembered that the street lamps will use a certain quantity; and alto there is possible unaccounted for. A nett sale of 10,000 cubic feet per ton is probably under what actual results would be. If the Council cai secure the railway station business, with the lighting of all signal and ground disc lamps when the interlocking equipment is installed, the Department would be a good customer. In the matter of the pumpirg engine at the waterworks, though CO3I gos will not be as cheap as producer gas, there are many occasions, as for short runs, or such times as the producer plant requires overhauling, starting up engine, etc., it will be found both convenient ar.d economical to'have the gas supply connected up as a stand-by. For this reason I have allowed for a four inch diameter main from Manukau road to the

pumping station. Re supply of gas cookers, gas fittings, etc. —ln the mat er of the supply and fixing cf gas fittings, cookers and other appliances for the use of gas, 1 would strongly recomrmnd that the Council follow the siar.ciinK practice of other municipal gasworks, and urdeitakc this branch of the business thsmselves. There is nothing that popularises the use of gas so much as the fact that the ratepayers fe?l and understand that in dealing with the Municipal Gas Department they are dealing with a business lhat belongs to themselves; a business lhat is being run, not to make a large profit out of them, but to place at their disposal the benefits and conveniences of coal gas at the lowest possible cost for installing the necessary fittings, etc., in their houses and other premises. I may also Btate that whete busintss premises or private residences are fitted up and lighted with acetyler.e gas the same pipes can be used, all that is required being to fix a meter to the rising main of the building (an hour's work, more or less) and

fit the proper incandescent burners in place of the acetylene turners, which can be dene for liom 3s to 5s 6d par burner, according to the value of the globes. Without glob s the burners cost 2s 6d each, complete with mantle and chimney. In conclusicn, gentleiren, the estimates given for the plant should cover all charge?, leaving a eum ample to finance the first supply and stock of gas fittings and cookers, which expenditure would in due course, as accounts came in, be recredited to capital account, and later on, if desired, could be used for extension ot mains or business generally. In the matter of supplying buckland with gas.—This township can be very easily supplied, providing the business to be übtained will pay the interest, etc., of the capital outlay on the mains. Two miles of four inch main would cost, approximately, £IOOO, and would supply with the ordinary pressure that would be available at your works about 2000 cubic feet per hour. Two miles of three inch pipes would cost, approximately, £800; discharge capacity about 1000 cubic feet per hour. Two miles two inch wrot iron screwed tubes would cost, approximately, £500; would tupply about 400 cubic feet per hour. If the work is to be carried out at any time, I would recommend £IOOO be allowed for the supply main, and the tour inch diameter pipe used. Either three inch or two inch diameter could be laic,', but in a year or two, if the district expanded, it would be necessary to boost to keep up a reasonable supply at the discharge end of tbc main, whereas with the four inch mair. machinery for raising pressure vould not be required for many years, unless Buckland developed into a district requiring gaa largely for power purposes. A bjosticg plajjt with gas engine would cost installed £l5O. Any desired pressure could then lie maintained at the farthest point of supply during the hours of maximum demand. The advantage of the : larger diameter mains is that the supply is entirely automatic. Con- | venient and effective as boosters ; aro where a business has out-grown the existing main capactiy, there is , always the running and maintenance costs attached to them. It is usual when supplying an ana outside a borough to charge a slightly higher ! rate for the gas than is charged to the local customers. This is. however, a matter entirely at the discretion ut the supplying authority; otherwise a Council has full statutory authority to supply gas j for light, heating and power purposes outside their own administrg*