and he received his preliminary education here in the public schools. He married Miss Florence Krapp in 1888, and is survived by her and eight children. They are Mrs. Theodore Hotard, Mrs. B. Kroutter, Foster, Francis, Aidan, Ethel, Ira and Miss Sidney Olroyd.

Practically his whole professional career has been identified with electrical work, his first position having been with the Baltimore and Ohio Telegraph Company in 1886. After two years of service with this company he joined the ranks of the Western Union Telegraph Company. He shortly afterwards became connected with the Edison Electric Light Company and remained in their service until 1895. He resigned from this company to become Superintendent of the Algiers Waterworks and Electric Company, and was responsible for the development of that system. In 1901 he was appointed City Electrician, which office. he filled with credit and distinction until the time of his death.

Mr. Olroyd became a member of the Louisiana Engineering Society in 1901. He later resigned, but again resumed his membership in 1915 and was a member until he died. He was also a member of the Choctaw Club, the Jovian Order and the International Association of Municipal Electricians.

PAPERS AND DISCUSSIONS

NOTES ON SHIPBUILDING.

By

F. J. FRENCH,

Engineer, Mexican Petroleum Corporation.

(Read before a joint meeting of the Louisiana Engineering Society and the Local Chapter of the A. S. M. E., Sept. 10, 1917.)

I have been asked to outline, in as few words as possible, the problems which present themselves to the prospective shipbuilder; rather with a view to promoting discussion on the subject with especial reference to local conditions than with any intent to disseminate uninteresting and unimportant data on the subject of design.

Let us assume first that the shipyard owner is approached by a client who desires a vessel built for his particular service. His requirements will be primarily governed by ships that he already has in service; modified by the recommendations of his Marine Superintendent and his Port Engineer as to type of cargo, desired carrying capacity, draft, speed, and indicated horse power, and further modified by that very misleading factor "cost per deadweight ton," which is so widely quoted, regardless of speed required.

To illustrate the fallacy of using this unit of cost, take a vessel of 5,000 tons deadweight capacity and assume, from data already to hand, a speed of 10 knots with an I. H. P. of 1500. If the owner desires his ship to make 13 knots instead of 10, it will be found that (as, for normal speeds, the power varies with the cube of the speed) the required I. H. P. will be in the neighborhood of 3300, or more than double the original figure, and the power plant weight and cost will, of course, be in similar proportion.

The primary characteristics having been decided upon, the problem now passes to the builder's Naval Architect, who corelates all of the factors determined upon by the principals and sends to the estimator the weights, horse-power, etc., who in turn makes an estimate of cost upon which the contract is

finally signed. It goes without saying that the estimate takes into full account whether or not the vessel is for bulk oil or molasses, which requires a much higher grade of workmanship than for package freight.

In addition to the particular requirements of the owners, it will also be specified that the ship is to be built to the requirements of either Lloyds, The American Bureau of Shipping or some other recognized classification society, and the surveyors of the chosen society will see to it that their requirements are lived up to. It may be pointed out in passing that the rules of the various societies specify, to the thirty-second of an inch, the size and thickness of all members entering into the structure of the ship, as well as the size and type of all fastenings; their rules being based primarily upon the theoretical strains experienced by ships subjected to the action of deep sea waves, but modified by scores of years of experience covered by comprehensive reports of hundreds of catastrophes at sea, these reports being made by surveyors of the societies who are themselves sea-faring men, and who have carefully investigated the probable causes, and possible preventive measures, in each particular case.

Let us now assume that all the particulars of the ship to be built have been decided upon; the contract plans completed and the contract signed, and place ourselves in the position of the successful bidder.

We find that we have on our hands a contract to furnish all material to construct, launch, power and equip a ship of 5,000 tons deadweight, which is (say) 350 ft. in length by 48 ft. in width by 28 ft. in depth, and has engines of 1500 to 2000 I. H. P.

Perhaps, under present conditions, we have not done much. more than select our site for building. If this has been done, it goes without saying that a frontage was chosen on as deep and wide a waterway as was compatible with financial and engineering considerations, and also that the site selected is reasonably accessible to a labor market.

The next step is to lay out our building ways to suit the water into which we propose to launch. We have now a choice

of two methods of launching, i. e., stern first, or sideways. The stern-first method is universal at all Atlantic Coast yards and wherever the required width and depth of water is obtainable. The side launching is largely confined to the yards on the Great Lakes and to other points where for various reasons it is found desirable to build on the banks of a narrow waterway.

For the stern-first method, the following conditions will govern. The building ways will be so located that the stern of the vessel will be close to the water's edge and three to four feet above the ground. From this point back they will be given. a rise of about five-eighths inch per foot which would put the keel line at the bow of a three hundred fifty-foot ship some twenty-one feet above water. A yard having a natural easy slope toward the water is therefore desirable as facilitating the construction of the underbody of the ship without the necessity of filling to the desired grade. The building ways consist of a series of blocks spaced about four feet centers and made up of 12"x12" timbers five or six feet long set transversely and resting on piling.

The launching ways consist of two parts, the standing and the sliding ways, and are parallel to the centerline of the ship and about one-third to one-half the half breadth from it. They are constructed of heavy longitudinal timbers laid on piling and are usually given a camber or round-up of about a foot in their length for the purpose of overcoming the resistance of the water as the vessel nears the end of the ways.

A customary slope is about 1/2" per foot at the bow of the ship, increasing to 3/4" per foot at the submerged end of the ways. This lower end should be five or six feet below the surface and should be well supported by clusters of piles, as at the moment before the bow drops off the end, nearly half the weight of the ship bears on this point. The construction outlined is the common practise in tidewater yards and the datum plane taken is that of high tide.

It will at once be seen that we meet insurmountable obstacles when we propose to adapt this method to a river such as the Mississippi, where a variation occurs of twenty or more feet, and this so gradually that months may elapse be

Nomination-Upon motion of Mr. Riess, seconded by Mr. Olsen, J. M. Robert was elected Acting Secretary from July 1st, at $30.00 per month, with the understanding that if this amount did not cover his expenses, that such expenses would be reimbursed to him by the society.

There being no further business before the meeting, the same adjourned.

J. M. ROBERT, Secretary.

Regular Meeting of the Society, September 10, 1917.

The meeting was called to order at 8:20 with President Dusenbury in the chair and fifty-nine members and guests present.

The minutes of the June meeting were read and approved.

Mr. H. L. Hutson introduced a resolution that the Society offer its services to the New Waterways Commission. These resolutions are appended and made a part of these minutes. Mr. Coleman seconded Mr. Hutson's resolutions and upon vote of the Society, the resolutions were passed.

The technical exercises of the evening consisted of an illustrated lecture by Mr. F. J. French of the Mexican Petroleum Corporation, entitled "Notes on Ship Building". This lecture called forth several interesting discussions from various members and guests. A rising vote of thanks was tendered Mr. French.

There being no further business, the meeting adjourned.

J. M. ROBERT, Secretary.