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many situations where ships of great effensive and defensive power and with high speed will be in urgent demand. These characteristics are peculiar to but one type of ship, the battle cruiser. Large navies of the near future will be at a disadvantage without vessels of this type. + + ¢ 1 0 Marine and Naval Boilers, by eCapt. C, A: Jones, U-:S.N., mem- ber, and Lieut. Commander Thorvald A, Solberg, U.S.N., visitor. The authors are particularly well qualified to discuss the subject of this paper. Captain Jones is head of design and construction division, bu- reau of engineering, navy depart- ment, and Commander Solberg is of- ficer in charge, naval boiler labora- tory, navy yard, Philadelphia. The following excerpts are quoted from the paper: The purpose of this paper is to discuss broadly the various aspects of the design and application of boil- ers for marine and naval purposes. Because of the complete adoption of watertube boilers by the navy and the rapidly increasing trend toward their use for merchant vessels, only this type will be considered. It ean be stated that as far as the navy is concerned, practically all new and modern vessels will be boil- ered with some design of small tube express boiler. In the merchant ma- rine it appears that there is a defi- nite trend toward some type of watertube boilers, and in the case of the higher power, combined passen- ger and cargo carrying ships, there seems to be an indication favoring the lighter small tube express boil- er. This is exemplified in the case of the Foster-Wheeler A type _ boil- ers installed on the Grace _ line steamships SANTA ELENA and SANTA PauLA and the Babcock & Wilcox boilers used in the United States line steamships MANHATTAN and WaASH- INGTON. There have been two recent devel- opments in sectional-header boilers; the use of small straight tubes be- tween the conventional headers, and the use of small curved tubes be- tween cylindrical headers in a de- sign known as the SX boiler. With the adoption of higher steam pressures and temperatures, some form of small tube express type boil- er is a necessary part of the modern installation. The principal advan- tages of sectional-header steam gen- erators are their comparative sim- plicity of design, ease of cleaning on both fire and water side, and facility of incorporating integral superheat- ers between passes or as inter-deck units. On the side of definite advantages for the three-drum (A-type) or sim- ilar express boilers may be listed the following: (a) Concentration of greater boil- er water heating surface in the same space at less weight (lower space and weight factors). (b) Greater structural per se. (c) Baffling within tube nests is unnecessary, (d) Excessive number of open- ings (handholes) obviated; there- fore less cost of material for over- head. (e) More rapid steaming and more rapid response to load fluctua- tions. (f) Some designs permit greater flexibility in burner arrangement and provide better flame support for complete combustion. (g) Ability to stand forcing with resultant high rates of evaporation. In conclusion it may be stated that although considerable improvement has been made in boiler performance during the past ten years there is still considerable room for _ refine- ment of design and _ investigation work looking toward general im- provement in boiler performance. With the use of high pressures and temperatures firmly established, it is predicted that the next ten years will see changes in marine and naval boilers equally as great, and perhaps entirely different from those of the past decade. There are, however, at least two vital reasons for the slow progress in the development of the marine boiler, First, a major casualty usual- ly results in a large loss of life, and, second, conclusive experimental work must be carried out on full scale and this is an extremely expensive mat- ter. strength ¢ ¢ ¢ Bunker Fuel Oil Problems, by 11. Capt. C. A; Jones, U.S.N., mem- ber, and: Lieut, J. BE: Hamilton, U.S.N., visitor. This is a valuable paper in calling attention to the desirability of study and investigation of the properties of bunker fuel oil for the purpose of improvement in quality and to obtain a better knowledge of methods of fir- ing to obtain satisfactory results. The authors point out that: The refiner’s objection to a close speci- fication for fuel oil is that his prod- ucts vary over wide limits in char- acteristics, some of which neither he nor anyone else fully understands. He can accept a standard of classi- fication which is about the best which has been generally imposed to date. With such a standard, formerly based on gravity but now largely on vis- cosity, a refiner could in effect do either of two things. First, he could run all of his fluid by-products into one set of tanks, putting them in whatever class they proved to belong by tests, and mar- ket but one class of fuel oil, or sec- ond, he could by maintaining any number of sets of tanks test his fuel oil products upon production and MARINE REVIEw—December, 1934 then run them into the group of tanks to which they belong and then market as many classes as he pro- duced. Fuel Oil Investigation It is realized that results gained to date from the fuel oil investiga- tion are not concluusive and ar far from having proved practicable ap- plications. Certain very clear indl- cations show the desirability of car- rying on the investigation indefinite- ly. To this end the first step has been taken of consolidating all re- search, tests and development work in connection with fuel oil at the naval boiler laboratory. It is expected that the work of the laboratory in connection with fuel oil rather than with equipment will follow four general lines. These are: 1. Further study of the data pre- sented in this paper. 2. Continued efforts to analyze further the A, to A, samples. Pos- sible methods to be studied are: (a) Gravitational separation fol- lowed by analysis of the fractions; (b) Fractionation by distillation followed by analysis of the fractions; and (c) Fractionation by solution fol- lowed by isolation and analysis of the fractions. 3. Continuous service tests of ad- ditional samples for obtaining more data and for testing conclusions reached on previous data. 4. Possible improved methods of control of atomization of fuel oil. ¢ ¢ + 12 Safety « Tankers, lund, member. in Design of Small by Martin G. Kind- The author is a partner, Kindlund & Drake, naval architects, New York. The following excerpts are quoted: It is the purpose of this paper to review the hazards connected with the transportation of gasoline and other highly volatile petroleum prod- ucts, and to consider means where- by these hazards may be minimized or eliminated. Particular attention has been given to vessels of the harbor type and others engaged in the delivery of petroleum products. The ques- tion of safety against fire and explo- sion appears to be of greater general interest and importance in the case of such vessels than in the case of large ocean tankers. There are several reasons why this is so. First, they are more numer- ous; second, they load and unload more frequently; third, they operate in waters adjacent to centers of pop- ulation and industry; fourth, the cost of installing and maintaining safety equipment is relatively great- er; fifth the personnel is usually less intelligent and experienced and sub- ject to more frequent changes; sixth, (Continued on Page 40) 15