The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

14 MARINE REVIEW. [ May 30, A LAKE ENGINEER ON THE BOILER QUESTION. Editor Marine Review:--The use of Scotch boilers in a large num- ber of new steamers, built during the past winter in our lake ship yards, has been taken by most of our engineers and vessel owners as an indica- tion that the Scotch boiler is a winner in the fight for supremacy with the so-called water tube generator. To the progressive engineer this view brings a feeling of disappointment. He feels that it has been brought about through lack of knowledge of the merits of the water tube boiler and its superiority as an economical steamer. Our modern lake engineer not only wishes to be progressive but has a desire to be a leader in the science of steam engineering. This desire has brought about the inven- tion and adoption of improvements in the construction and management of the lake water tube boiler, to the extent that today the lake engineer leads the world in the matter of handling economically the water tube type of boiler. The serious difficulties met and overcome by engineers in charge of these boilers may be summed up as follows: First we had the plugging up of the inside of the tubes with mud and scale from lack of time in port to properly clean and remove these deposits of carbonates of lime, magnesia and iron, and sulphates of lime. As all sulphate of lime in water is deposited or precipitated at a tempera- ture of 300° Fah., the introduction of the feed. water into and through a feed water heater and precipitator before entering the boiler has removed this first and great difficulty. By blowing out our heaters and precipitators twice a watch we are now able to run our water tube boilers continuously for six and eight weeks, and then find so little deposit that they can be cleaned thoroughly in eight hours. This was the actual prac- kaa Lage LEE Se A hy TT i La stokers, making the trip from a Lake Erie port to the head of Lake Superior and return, a distance of about 1,800 miles, upon a fuel consump- tion of 225 tons of slack coal. When we remember that 225 tons of the best lump coal was used in making the same trip by the most economical eee steamer of ten years ago, the progress is certainly to be won- ered at. The third difficulty has been that of tending water. The small quan- tity of water carried and the rapid evaporation of the same necessitated the constant attention, night and day, of a man to tend water. -- For this labor the engineer had nothing to show at the end of the trip, to say nothing of disastrous results that would follow slight inattention on the part of the water tender. The invention and adoption of the feed water controller and pump governor brought. about a surprising change. Steamers equipped with this device run from one end of the trip to the other without %4 in. variation of water line in the boilers, regardless of checks, stops or cleaning fires. Engineers exhaust their vocabulary in its praise, while still only beginning to appreciate the advantages of a steady water line. For the first time in the history of steam engineering we have an automatic water tender, self-cleaning and under perfect control, thoroughly reliable and producing good results along the line of economy. The fourth and last, although not the least, difficulty has been the handling of the high steam pressures. The sudden jump from 150 to 250 and 270 lbs. has found us unprepared, and only by experience and hard knocks have we been able to meet the situation. New methods have been forced upon us, ofttimes resulting in entire failure. and where old methods have been applied to the new conditions, disheartening effects have mocked our best efforts. During this severe apprenticeship we have ===> Se z EE RS =~ Lane: : Se ee yl SB ynel ole' "prin [cee ee eS BOTH SHAMROCKS AND SIR THOMAS LIPTON'S STEAM YACHT ERIN OFF THE BRAMBLES BEFORE THE START OF ONE OF THE TRIAL RACES, WHICH PROVED DISASTROUS. tice on many steamers last-year, without one minute delay to the ship and not one cent for repairs to boiler tubes or furnaces at the end of the sea- son. As a second difficulty it may be noted that the evaporative efficiency of the water tube boiler decreases rapidly in a few hours from the loss of heating surface in many of its tubes. These tubes, placed close together, are soon coated with a heavy deposit of soot. The spaces become closed entirely to the passage of the hot furnace gases. Upon forcing the fires the soot becomes ignited (resulting sometimes in a red hot breeching, up-take and smokestack), leaving an accumulation of solid ash and clinker between the tubes, which, increased from time to time by more soot and more burning, impedes the circulation of heat around the tubes, with a noticeable loss of heating surface. Where a forced draft, under the grates, into a closed ash-pit, has been adopted, keeping a steady air pressure of about 5 in. regardless of wind or weather, much better results have been obtained and less sooty deposit found than when run- ning under natural draft. By means of steam flue-blowers inserted in holes with loose covers, and also through large cleaning doors, aided by powerful steam jets in the smokestack, much of the sooty matter is blown off and carried up overboard. Where this is done once in every twenty-four hours, nearly all of the lost heating surface is cleaned and regained. As nearly all the difficulties and losses enumerated under this second heading can be traced directly to the one condition--a state of imperfect combustion in our furnaces--and as the remedy to be applied is that of creating a state of perfect and complete combustion, the lake engineer has succeeded by the introduction of the automatic stoker in removing most if not all of the troubles under this head. It is well known that without perfect combustion a great portion of the heat which the fuel is capable of yielding is not developed and hence loss results, and it is also known that smoke and soot are sure evidences of imperfect combustion. Still we must remember that it does not necessarily 'follow that where there is no smoke there is perfect combustion. The automatic stoker produces a smokeless combustion, but that it also produces a state of perfect combustion is still an open question. However, the automatic stoker is here to stav beyond all question, and there is every evidence that it will be greatly improved. Already we have the truly wonderful sight of our 7,000-ton ships, equippea with water tube boilers and automatic asked for no sympathy but have kept our nerve and "'tried, tried again." until now we see success crowning our earnest desires. In conclusion, it is probably in order to say that while we notice with much pleasure the satisfactory results obtained from the propelling machinery of such steamers as the Black, Murphy and Shaw, still they prove nothing one way or the other, and until two steamers exactly alike in model and machinery, differing only in the type of boiler, have been run under the same management for several seasons will we be ready to admit "who is the winner."' May the best man win, is the wish of Cleveland, May 28, 1901. YE MARINE ENGINEER. NEWPORT NEWS DRY DOCK. Newport News, Va., May 29.--The three ships which first entered the immense new dry dock at the ship yard here--the Plant liners Olivette and Miami, and the Chesapeake & Ohio steamer Louise--have been repaired and have given place to the Chesapeake & Ohio steamer Acco- mac, which has gone in to have her bottom painted. There were no formal ceremonies in connection with the opening of the dock, these exercises being reserved for an occasion of more importance. It is said that the battleship Illinois and another battleship, if one is available, will be used on the occasion, in order to demonstrate the capacity of the new basin, which is capable of receiving the largest vessel afloat or building, and which can accommodate two first-class battleships; or, as was the case on the opening, accommodate three vessels of moderate proportions. The new dock is 800 ft. long and has a depth over sills at mean low water of 30 ft. The three steamers first docked in the basin presented a peculiar appearance, the upper deck of the largest one coming hardly above the top of the dock. The North German Lloyd steamship Main occupies the old 600-ft. dry dock to the south of the new basin and will probably be there sixty days longer. This immense hull looms way up above the top of the dock and fills it almost completely. All around the bottom of the keel and up around the sides staging has been erected and it looks as if the old vessel will be practically new when she leaves the yard. All of her injured plates are being replaced with new ones. and a glance at the work now being done is sufficient to show even a tyro in ship building affairs that the price of $700,000 was not too great for the repair job.