The Iron Age 1907-06-27: Vol 79 Iss 26

THE IRON AGE New York, Thursday, June 27, 1907. THE NEW PRATT & WHITNEY TURRET LATHE. A machine capable of handling both bar stock and castings and performing a greater variety of work than any other of its type, was sought when the Pratt & Whit- ney Company, Hartford, Conn., designed the open turret lathe herewith illustrated. It is a 2% x 26 in. size, or in other words handles 2% in. bar stock 26 in. long, and will take castings up to 14 in. in diameter. Several new features in its construction were prompted by the desire to avoid continually making special appliances and cut- ting tools, and to increase the convenience and rapidity of making ready for a job so that small lots of work can be handled economically. Much of the work now done in ordinary turret and engine lathes, it is believed, can be shaft at one time. The gears are extra strong and run continually in oil. In addition, the various spindle bear- ings are independently lubricated from the inside. The friction clutches have means for conveniently taking up any wear. The head is bolted to the bed, and no compli- cated means of supporting bars being machined or of con- necting motor drives are necessitated. The motor may be bolted directly to the top of the head or placed elsewhere and connected by belt to the machine. Eight variations of speed are obtainable, which are sufficient in most cases, but a two-speed countershaft doubles this range. The rod chuck is operated by a lever and a swinging link as shown in Fig. 1. It has extraordinary gripping Fig. 1—The New 2% x 26 In. Turret Lathe Built by the Pratt & Whitney Company, Hartford, Conn. more advantageously performed in this tool. Its extreme rigidity, powerful spindle drive, quick changes of speeds and feeds, heavy cross feed turret, and numerous adjust- able stops, enable it to do more accurate and rapid work than an engine lathe, while it has all of the flexibility and adaptability of the latter. Fig. 1 gives a general view of the lathe with most of its various attachments. The work holding spindle is unusually heavy and of special steel, and runs in bronze split sleeves externally tapered to fit conical seats in the head, allowing compen- sation for spindie wear. The thrust of the spindle is taken by a part of the head casting, and here also provision is made for taking up wear. The spindle is ground and lapped, and its front end is ground externally and inter- nally while running in its own bearings. The drive, from a constant speed single belt pulley, is clearly shown in Fig. 2, which is a top view of the head with the cover removed. The direction and variation of the speeds of the work holding spindle are obtained by levers operating friction clutches, so as to connect any desired train of gears. The clutches are keyed to their shafts, and are operated through revolving grooved cams so constructed that it is possible to connect only one set of gearing between the work spindle and main driving power, and its various parts, which are shown unassem- bled in Fig. 3, are ground. The collet jaws are supported up to their outer ends, which is particularly desirable in forming work from the cross slide. Another feature is the releasing action, which is readily understood from Fig. 4. Adjustment for different diameters is by means of the threading ring A. To remove the jaws, the outer ring B is moved to the left, and ring A unscrewed a few turns. The lever which opens and closes the jaws also controls the rod feeding device. The complete chuck can be read- ily removed from the spindle when the combination lathe chucks or special face plates are to be substituted. The positive screw feeding device for automatically feeding the rod forward to its stop is the same as has been used in the Pratt & Whitney turret lathes for sev- eral years. The bar that is to be fed may be round. square, hexagon or any irregular cross section, and need not be free from scale. A sectional drawing of the de- vice, as applied to this lathe, is given in Fig. 5. Under working conditions its operation is as follows: When the lever opening the collet jaws has operated by means of a long connecting link, the clutch A and the coarse pitch feeding screw B are moved to the right, en- gaging the clutch on the face of the gear C, which is in a a 1944 direct mesh with the gear D, on the rear end of the work spindle; this gear rotates in one direction only. As soon as the clutch is engaged the feeding screw rotates, caus- ing the rod follower C to bring the bar of stock forward. The ‘movement of the bar is arrested by an adjustable swinging stop on the front of the head. This halts the follower D, and the continued revolving of the feeding screw B, withdraws the clutch A, from the gear C. When the follower bar has moved its full distance, i. e., 26 in., the lever F is moved to shift the clutch and feed screw to the left, engaging a gear operating in the reverse direc- tion, thus returning the follower to its original position, where it becomes automatically disengaged similarly as in its forward movement. A follower bar is furnished which enables short pieces of stock to be as conveniently Fig. 2.—A Top View of the Head with Cover Removed. Zz DO 44 wa \S ) Wy eat] —),.. “SS SS << at pep o ZL LUD SN Lee : Ld = Vs Lidl © 4.—Section of the Rod Chuck. Fig. liandled as long bars, and at the same time serves to keep such pieces concentric with the spindle. The stock stop for gauging the length of stock is shown in Fig. 1, and consists of a stiff swinging member mounted on a bar moving longitudinally in uprights, cast solid with the head stock. An adjustable clamping ring deter- mines the forward position of this stop. When not in use the stop is moved forward and swung upward, so as not to interfere with the turret tools. The form of the turret favors precise locating of the various tools and their rigid backing, so that during heavy cuts, facing, &c., spring or backward movement is pre- vented. The rigid binding device, which clamps the re- volving turret to its base, permits long bars to pass through it, and is a distinctive feature of Pratt & Whit- ney lathes. The stiffness without clumsiness, which is obtained in this turret, is a feature strongly emphasized. The turret proper revolves about a large central conical stud firmly held in the cross slide. The locking bolt is horizontal, large, hardened and ground, and is accurately fitted to the cross slide with means for taking up wear, without disturbing any other member. This horizontal THE IRON AGE June 27, 1907 moving locking bolt is superior to one moving vertically, in that it has no tendency to lift the turret from its seat. In addition to side gibs, there are two straps for prevent- ing lifting. The construction also permits the use of a long, heavy spring, for positively locatfhg the turret. The lock bolt engages directly under the cutting tool. The means for withdrawing the lock bolt and indexing the tur- ret do not require any overhanging bars or greater floor space than that taken by the bed. The indexing is auto- matic at all positions of the cross slide or the turret may be rotated by hand . Possibly the most important new feature is the power feed, compound turret slide and its conveniently located stops, which may be seen in Fig. 1, and also in Figs. 5 and 7. The longitudinal turret slide travels on Vs and Fig. 3.—The Unassembled Parts of the Rod Chuck. is provided with gibs its full length, and also with a binder for clamping it to the bed at any point. This is convenient when using the cross slide for forming or while cutting off stock. The power longitudinal feed is Fig. 5.--Section of the Rod Feeding Mechanism. positive, the feed shaft being driven direct by gearing from the work spindle in both directions. Six variations are afforded, controlled by levers operating sliding keys which permit changes without stopping the work spindle. The carriage has an apron carrying a system of worm and spur gears, the latter meshing with an inverted rack. Six automatic longitudinal stops and six supplementary stops, all adjustable for length, give two positions to each turret tool. When necessary all 12 stops may be used for one or all tools in the turret, and the possible combinations effectively cover all requirements. The stops are held in a bracket adjustable along the front of the bed. The turret base is a cam, and the roller fol- lower is a rack, which, through a. pinion and shaft, &c., swings the arm. The latter is always backed up by the knock-off block, so that any pressure put on the arm by power or by the operator is transferred to it, avoiding any tendency to spring the lighter parts of the stop mechanism. The cam is so formed as to cause the arm to swing in line with the six automatic stops in the bracket. By releasing a locking bolt the arm may be swung in line with any of the automatic or supple- June 27, 1907 THE mentary stops. Both series of stops work in conjunction with the power feed and cause the knock-off block to stop the longitudinal slide at the point set. The power feed may also be disengaged by moving the lever on the apron to the right. The gearing in the apron runs con- tinually in oil. The supplementary stops are very useful when it is desired to run through a few special pieces, as they may be used instead of and without disturbing the regular stop adjustments. The extreme stiffness of the slide allows exception- ally long turret boring bars to be successfully used. By gearing there is sufficient leverage in the feeding of the turret slide forward by a star wheel to take heavy face cuts. The backward movement of the slide is limited, ac- cording to the work, by an adjustable back stop. The turret cross slide is fitted to the longitudinal slide with liberal bearing surface. A narrow dovetail guide, with means of taking up wear, accurately retains Fig. 8—The Taper Turning Tool. correct alignment. Under working conditions the cross slide is firmly held to the longitudinal slide by a strap extending its width, which overcomes any tipping tend- ency when using long boring bars or similar tools. It is so constructed as to permit the facing of the large diam- eter of castings with ordinary lathe tools, and using one set of turning and boring bars with simple inserted cut- ters for turning and facing varying diameters. Both hand and power feed are provided, and the six variations of the latter may be used in either direction. Bight ad- justable cross stops may be used in any combination de- sired with the turret tools. In addition to these an ad- justable micrometer ring is attached to the cross slide hand wheel, which assists in accurately traversing the cross slide and also in quickly setting stops in correct relation to each other. By turning the knob an abut- ment is brought into line with the stop to be used. To guard against breaking the gearing which operates the cross slide, an automatic adjustable friction driving de- vice is introduced. IRON AGE 1945 The central position of the turret is frequently re- quired, especially for drills, reamers, dies and taps. That its position may be accurately and quickly obtained, a large bronze nut is secured to the cross slide base into which its screw fits, and in moving the slide to its cen- tral position this nut is brought against a stop plug held against endwise movement in the bottom slide. A geared oil pump delivers a continuous flow of lubri- cant through flexible piping directly over the cutting tool. The turret is also arranged for internal lubrication of drills, counterbores, &c. Adjustable stock supporting bands, with revolving supporting jaws accompany each machine and prevent unnecessary noise and. preserve corners on square and hexagon stock. A cross slide is furnished to order, which is used on the bed between the turret and head for heavy cross forming, generally on bars or small castings. It has cross and longitudinal hand movements. When using the turret close to the Adj 4 a Cc ms é 4 Fig. 9.—The Taper Turning Tool with the Back Rest Removed. spindle the cross slide is moved under the spindle nose. The following are the lathe’s principal dimensions: Ue CUR NOR: + 002s teseenelcevnadadiewcasaeaawenee 19 in. Swing over special forming slide... ...ccccccccccccccces 10 in. - Diameter of hole through spindle...........seeeeereees 256 in. Largest capacity of standard collet............eeeee0% 2° Ag in. Py | EA eee Terre reer eT er 14 x3 in. Floor space without rod feed mechanism............ 914 x 4 ft. WEE, WEEE COMO ia ies head ddddctdacaades dias 5,200 Ib. The Turret Tools for Rods, A variety of turret tools adapted to meet practically all requirements are furnished. The universal turner shown at the front in Fig. 6 and at A and B in Fig. 10 is used principally for turning bar work up to 2% in. in diameter, and is equally effective working toward the spindle, as is usual on short work, or away from the spindle, which is frequently desirable on long, slender work. The cutting tool is held in a slide by two set screws. The cutter is “overshot” or tangent to the work, in which position heavy cuts may be taken, owing to its rigidity, and long life is insured, as regrinding is ae ae a ea 1946 on the end only.: The cutter is of high speed steel, may be adjusted for different diameters and for facing should- ers, and after facing a piece of work can be withdrawn from the stock to prevent marring it when the turret slide is returned. An adjustable positive stop, clamped to the slide operating screw, in conjunction with a stop bar, guides restoring the cutter to its original position for the next turning operation. The back rests are of V type, and are quickly and conveniently. adjusted in relation to the cutting tool. The strap which takes the backward thrust of the jaws may be swung away to leave the back rest jaws free, which is convenient when setting up new work or when changing the cutting tool; in the latter case no readjustment to the back rest strap THE IRON AGE from a long lever, which may be clamped to the pinion stud at any convenient angle. An adjustable stop limits the swing of the lever and thereby the extent of the slide movement. Tools may be carried on either or both ends of the slide, and rest on rockers to give correct cut- ting angles. A taper turning tool, for turning tapers either on forg- ings or on bar stock, is shown in Figs. 8 and 9, and June 27, 1907 at F in Fig. 10. For the former the back rest jaws are set to follow the cutting tool and to move radially to suit the changing diameter being produced, while for the lat- ter, if bright rolled stock is used, the slide holding the back rest jaws is clamped to prevent movement and the jaws are reversed, so as to precede the cutting tool. Fig. 10.—Some of the Tools and Attachments Used on the New Pratt & Whitney Turret Lathe. = Oar WLLL — WY Wee Fig. 11.—Sectional View of the Step Chuck and Closer with Adjustable Jaws. screws is required. This tool is also furnished with roller back rests for high speed roughing out operations. The open side turner, C in Fig. 10, is for turning short work above 2% in. in diameter, when back rest jaws are not necessary, and is otherwise similar to the universal turner. The bell mouth pointing tool shown at the left in Fig. 6 and at D in Fig. 10 is adapted for chamfering the end of a rough bar in advance of the turners. It has a single cutter, which is adjustable, and may be taken out for regrinding. The back rest jaws are inserted, and are of hardened tool steel. The end forming and pointing tool, as the name in- dicates, is generally used for end forming and pointing bar work, and for this purpose is provided with back rests ahead of the cutting tool for supporting the work. It is not adapted for pointing rough unturned bars. The turret cut-off and forming tool, the one in operat- ing position in Fig. 6 and at E in Fig. 10, has a body which is clamped to the turret of the lathe, and carries a cross slide. The latter is operated by rack and pinion Roughing and finishing cuts are taken, if desired, when the turner is used with the back rest following the cut- ting tool, the tool being advanced by the crank shown. To set the tool for given work a bar is prepared having a taper one-half that required on the piece to be turned. The principal parts of the tool are a body which is clamped to the turret of the lathe, a tool carrying slide, a back rest carrying slide, a taper bar and a lever which communicates movement from the tool slide to the back rest slide in proper relation to keep the V-back rest jaws in contact with the work. The movement of the tool carrying slide is controlled by the taper bar, which, as the turret moves forward, is forced between a block, adjustably mounted on the tool carrying slide, and the body. The action of a spring and that of the cutting tool tend to move the tool slide away from the work, and incidentally hold the block in con- tact with the taper bar. The tool slide has an antifric- tion roller to take the end thrust during cutting. The back rest is mounted in a bracket rigidly fastened to the ; 9 f t ¢ % a June 27, 1907 body. A lever pivoted to the bracket carries two blocks at unequal distances from the pivot. In using the taper turner, with the back rest following, one of the blocks engages a slot in the tool bearing slide and the other block a slot in the back rest slide. The pivot being sta- tionary, movement of the tool slide is communicated to the back rest slide, the latter traveling sufficiently faster than the tool slide to compensate for the angles of the back rest jaws. When the taper turner is to be used with the back rest stationary the lever is removed. In- dependent adjustment to each of the back rest jaws is afforded by the screws shown. A micrometer ring is pro- vided on the taper bar block adjusting screw. For threading purposes self-opening die heads are supplied, having roughing and finishing attachments. With this machine the 114-in. capacity is recommended for general work, but 2-in. die heads can be furnished. For centering and turning forged bolts, the heads of which may be more or less eccentric, a forging chuck and lever scroll chuck are used in combination. The latter is mounted in one of the turret slots. The forging chuck, which has two loosely fitted floating jaws on a right and left hand screw, is carried by a shank fitting the regular 2-in. chuck jaws in the spindle. The bolt is placed in the scroll chuck on the turret, its head coming where it may; the turret is advanced by hand until the bolt head comes between the jaws of the forging chuck, when the latter are closed by the right and left hand screw gripping the bolt head; the scroll chuck is next opened, the turret run back and indexed to the first turner required, and the turning proceeded with. Fifteen sets of collet jaws are all that are required to handle all sizes of round stock, from % to 2% in., inc!lu- sive; square stock, from % to 1% in. across the flats, and hexagon stock, from % to 23-16 in. across the flats. Hach jaw is capable of handling rods from one-sixteenth under to one-sixteenth oversize, and in these cases a parallel line contact is retained. Tools for Oastings and Forgings and Chucking Work. The triple tool holder for boring and turning shown at the front in Fig. 7 and at G and H in Fig. 10 is very adaptable, and is convenient for boring, facing and cut- ting grooves. In some cases several cutting tools are used simultaneously and frequently independently. It is useful for general work, and with one boring bar in conjunction with the sliding cross turret is suitable for boring and recessing holes of widely variating diameter. The end facing and recessing tool (I, Fig. 10) is rec- ommended for flat facing and grooving. There are three independent clamping screws, so that three separate cut- ting tools may be used at one time when desired. The facing and boring tool post holder at the right in Fig. 7 is designed to use ordinary lathe tools, and is especially suitable for facing work. It is frequently fur- nished with two tool posts, for simultaneously cutting with two tools. The hight of the cutting tools is ad- justed by the step collar shown. The offset single and double tool post holders are identical, except for the length of the tool post carrying arm, and are similar to the holder just described, but with the arm offset for turning instead of facing. The double holder is only used on long work, when it is possible to use two cutting tools. These holders are stiff, and well adapted for other purposes than outside turning. The tool bar with straps instead of tool posts is otherwise similar to the offset double tool post holder, and is recommended where the circular tool holder and step collar would interfere with the work and necessitate offset cutting tools. Die heads and drill holders of the form shown at the left in Fig. 7 and at J and K in Fig. 10 securely hold ordinary drills and boring bars and the regularly fur- nished die head. There are two sizes, 24%, and 3 in. capacity, with bushings for 1%4, 2 and 2% in. sizes. The face plate equipment consists of a face plate fitting the head spindle, and a set of straps, clamping bolts and bunters. It is convenient for holding quite a variety of work during a first or second operation. When holding work, such as cylinders, gear blanks and pulleys, for a second operation, a locating plug. to enter a hole previously bored in the work, is generally utilized. The THE IRON AGE 1947 clamping screws and bunters are tapped into nuts, fit- ting radial slots in the plate, and consequently work of varying diameters can be readily held. A 15-in. combination three-jaw chuck (L, Fig. 10) is recommended for casting and forging work. The chuck is rendered universal or independent by the meshing or unmeshing of a circular rack with a double pinion on the screw. In holding eccentric or irregular work, the jaws may be placed in any desired position and the rack and screw pinions meshed, forming a chuck with eccentrically placed, but simultaneously moved jaws. An extremely useful and new tool is the step chuck and closer, with adjustable jaws, shown in the sectional drawing, Fig. 11. When performing the second operation on a piece, such as a gear being finished On both sides where the first operation would be finished while the gear is held in the three jaw chuck, the step chuck is particu- larly useful. The closer of this chuck is made of gun iron and is screwed solid on the end of the spindle. The step chuck itself is of steel, split in four places; in each section is a bevel slot. A bevel nut conforming to the slot is drawn up against the side of the slot when tighten- ing the jaws, which gives an extremely tight grip. After the jaws are fastened approximately the right distance from the center, a plug is inserted in the hole, of the same dimension as the hole, when the step chuck is closed by the closing mechanism at the rear of the spindle, which consists of an eccentric operated with a wrench. Next, the boring tool is brought forward from the turret and the jaws are stepped out to the desired diameter, which will be the same as the diameter of the finished end of the piece made in the three jaw chuck at the first operation. The closing mechanism is then released and the plug re- moved, after which the piece is inserted in the jaws and the step chuck closed. The piece will then run true on the sume center it had during the first operation. Other accessories which are furnished are as follows: Blank face plates of sufficient outside diameter -to be fitted to any size jaw chuck finished to suit the end of the spindle; boring bars with adjustable cutters (M, Fig. 10), of steel, hardened and ground, in which the cutter is securely clamped by a wedge shaped pin and the adjust- ment obtained by a headless set screw; Morse taper drill and reamer adapters of cylindrical shape on the outside to suit the die head and reamer holders, provided with Nos. 2, 3 and 4 Morse tapers to receive drills and reamers of these dimensions ; a floating reamer holder of such con- struction that it always holds the reamer by its own cen- ter, yet in a flexible manner, so as to allow it to adjust itself to the hole being reamed; and a releasing tap holder which is convenient in tapping holes to exact depth. —— +e During the month of May the Allis-Chalmers Com- pany shipped from its works 553 cars of machinery, which was a gain of 20 cars over the record established in April. In April the aggregate weight of shipments was 21,680,- 847 Ibi, while for the month of May the figure had risen to 23,772,242 lb., making a total weight for the two months of 45,463,089 Ib. Cars bearing this enormous quantity of machinery, if coupled in ore train, would have covered a distance of about 8 miles. On Thursday, June 20, ground was broken near Cold- Spring, N. Y., west of the Hudson River, for one of the greatest engineering projects of the times. Huge reser- voirs are to be constructed in the Catskills and an aque- duct is to bring water from there to the city of New York, 100 miles distant. The work will cost at least $160,000,- 000 and will add 500,000,000 gal. daily to the present Croton supply. The Institution of Mining and Metallurgy of London has suggested and recommended the adoption of the fol- lowing definitions: That the ton be a weight of 2000 Ib. avoirdupois; that the miner’s inch be a flow of 1.5 cu. ft. per minute; that the gallon be the gallon of 10 lb.; that all temperatures be expressed in degrees centigrade; that gold and silver returns be stated in terms of fine metal and not as bullion; that the gold contents of ore be ex- pressed in the Troy ounce of fine gold, worth $20.67, or 85 shillings: 1948 THE IRON ee AGE June 27, 1907 The American Society for Testing Materials. Discussion on Steel Rails at the Atlantic City Meeting, Held June 20-22. The tenth annual meeting of the American Society for Testing Materials was held at Atlantic City, June 20, 21 and 22. Evidence of the large place the society is filling in its important field was given by the record at- tendance at this meeting, by the magnitude of the inter- ests represented, and by the important contributions made in papers and discussions to the literature of ma- terials of construction. Naturally the consideration of steel rail specifications, in the light of the discussion that has gone on for the past few months, attracted larger delegations than usual from railroads and rail manufac- turers. The session devoted to the subject may have disappointed those who looked for sharp passages be- tween producers and consumers. Railroad representa- tives and inspecting and consulting engineers contributed most of the discussion. The steel works engineers for the most part confined themselves to correcting state- ments that did not tally with their experience and to em- phasizing some particulars in which railroad practice was responsible for rail troubles. After several years of irreconcilable differences be- tween the railroad and the steel works members of the Committee on Iron and Steel, a rail specification was finally approved for letter ballot, a fact that makes last week's meeting noteworthy. From the standpoint of scientific progress the feature of the meeting was the paper of Allerton 8. Cushman, Assistant Director, Office of Public Roads, Department of Agriculture, Washington, D. C., on “The Corrosion of Iron.” It detailed experiments of great significance bear- ing on the theory that rusting is a product of electrolytic action, and it may pave the way for an important ad- vance in the practical handling of the problem of corro- sion. The meeting emphasized a condition made plain in previous years—that two and a half days, with those in attendance dividing into two sections for two half days, crowds the sessions greatly and deprives many of the oj)- portunity of hearing discussions in which they are in terested. It is probable that next year four or five days will be given to the meeting and the programme so ar- ranged that not more than one session will be held at a time, the topics being grouped so that a member may comfortably hear the proceedings of special interest (» him within a period of, say, three days. The registration of members and guests was 268, the largest in the history of the society. THURSDAY AFTERNOON. The president, Dr. Charles B. Dudley, Altoona, Pa., who was absent in Europe at the time of the last con- vention, was warmly welcomed upon taking the chair at the opening session Wednesday afternoon. The Status of the Society. The annual report of the Executive Committee was submitted in printed form. It showed that the member- ship had grown in the year from 835 to 925, not reach- ing the expectation that the 1000 mark would be passed by the present meeting. The last volume of Proceedings contained 712 pages, as against 565 pages in the preced- ing year. The receipts of the year were $6675, and the e.:penditures $6416, leaving a balance of $259. The so- ciety ceased in 1906 calling on contributing members, but in view of outstanding obligations slightly in excess of the amount on hand, contributing members will be asked for dues for the current year. Within the year, in pur- suance of last year’s action, a new Committee, V, on the Corrosion of Iron and Steel, was organized. The Execu- tive Committee decided to abandon the attempt to or- ganize a Committee on Standard Specifications and Tests for Wire Rope and to postpone indefinitely the organiza- tion of a Committee on Chain Iron and Steel, Chains and Chain Cables. The effort to extend the society’s membership is be- ing pushed forward, and the secretary, Prof. Edgar Mar- burg, University of Pennsylvania, Philadelphia, Pa., will be glad to receive applications from firms and individuals interested in the work the society is prosecuting. The Buying of Raw Materiais, The first paper Thursday afternoon, on “The Raw Material Supply,” prepared by P. H. Knight and C. B. Skinuer of the Westinghouse Electric & Mfg. Company. East Pittsburgh, Pa., was read by Mr. Skinner. The writers discussed a number of points connected with the purchase of materials for a large manufacturing com- pany, such as the one with which they are connected. One surprising statement was that this company’s list con- tains no less that 850 items representing distinct classes or grades of material. The term raw material was used in the paper to cover all material purchased, on which work has to be done by the manufacturing company, or which is consumed in the manufacturing process, as cut- ting compounds, fuel, oils, coke, &c. Questions relating te specifications, purchases by brands, variations in qual- ity, &c., were discussed, with other engineering and com- mercial phases of the relations between producer and consumer. Government Coal Specifications. An interesting feature of this session was the presen- tation of data concerning the purchase by the United States Government of coal under specifications. J. E. Woodwell, who has carried on the work of introducing and developing specifications for the purchase of coal for various buildings throughout the country under the jurisdiction of the 'Treasury Department, read a paper giving the results of the work. Experience with a speci- fication which penalizes a deficiency in heating value only has developed an average deficiency of about 3.5 per cent., which on contracts aggregating $200,000 has meant a saving of $7000, of which not more than $1000 can be charged to testing. Individual deliveries have shown as high as 47 per cent. of ash, where the contract standard was about 6 per cent., while the heating value was only about half that stipulated. Mr. Woodwell was followed by Dwight T. Randall, who appeared in the stead of Prof. J. A. Holmes, Mr. Randall is in charge of the smoke investigations of the United States Geological Survey. As indicating the im- portance of getting coal up to the quality paid for, Mr. Randall said that the United States Government coal bill was $6,500,000 per annum. In the past year the Bureau for the Testing of Fuels has visited 159 coal mines in 23 States and thus has obtained a good idea of the characteristics of various coals. The necessity for specifications appears in the fact that run of mine coal contains about 30 per cent. more ash, as shown by actual deliveries, than was contained in the mine sam- ple. The necessity of careful sampling is shown by the fact that in car samples 8 per cent more ash is found in coal taken from the top than in coal from the bottom. Mr. Randall stated the Fuel Department of the Geologi- cal Survey will conduct experiments. at Norfolk, Va., to determine the extent to which the combustion of bitumi- nous coal can be made smokeless. S. 8. Voorhees, Washington, D, C., gave details of the methods of testing coal carried out by the Govern- ment. The printed specifications as now enforced by the Treasury Department were distributed among the mem- bers. It was stated that regular tests had been made in the past year of coal delivered to 24 Government Build- ings, under these specifications. They provide the per- centages of ash, volatile matter and sulphur which may not be exceeded, as well as the limit on dust and fine coal, and the required number of British thermal units is specified. H. M. Wiison, who is associated with Prof. J. A. 8g TOF ERI SIF June 27, 1907 Hoimes in the fuel testing work, said that the St. Louis plant, excepting the coking plant, had been moved to Norfolk, Va., to test the various coals reaching that port for naval vessels. The coking plant goes from St. Louis to Denver, where it will be used in making tests of coals from Government coal lands. The work which will be carried on at Norfolk during the Jamestown Exposition will include tests of peats from Maine, the Dismal Swamp and Florida, also tests on lignites, machinery be- ing provided for briquetting the latter. Another impor- tant feature will be tests of denatured alcohol, which will be used in engines in comparison with gas and gasoline. Discussion, In the discussion on this subject the chairman re- ferred to the Government specification for coal as the best in that line he had seen. Mr. Woodwell said it had been noticed that the anthracite coal producers are less willing than the bituminous producers to deliver coal under specifications. In the coming year about 30 Goy- ernment buildings will receive coal under the specifica- tions which have been prepared. Naturally these will have to be adjusted to localities: From some districts the coal would run 5 per cent, in sulphur, while in other districts the specification peg could be set at 1 per cent. Producers of high grade coal are beginning to appreciate the fact that they are benefited by specifications. The object of the specifications adopted by the Government is not to cause rejections of coal, except for repeated failure to come up to the standard; the point is rather that the consumer simply pays what the coal is worth to him, making deductions where the standard is not reached and allowing premiums where the number of British thermal units called for is exceeded. It was observed by R. W. Lesley that the coal producers are now going through what the cement manufacturers experienced a few years ago, when many of the latter were unwilling to bid to specifications. To-day the entire cement out- put is sold under specifications. Specifications for Coke. In the absence of C. H. Zehnder, chairman of Com- mittee J, on Standard Specifications for Coke, Dr. Richard Moldenke made a progress report. The committee has corresponded in the past year with coke consumers and manufacturers regarding their methods of sampling and analysis, Many replies have been received, from which the committee expects to compile data to be submitted to the members later. Failures of Cast Iron in Service. Robert Job, of Booth, Garrett & Blair, Philadelphia, read a paper on “Causes of Failure of Cast Iron in Service,” from which we make some extracts: Many service failures in the writer’s experience have been caused directly by neglect to obtain a uniform composition of cast iron suited to the service. In cases in which locomotive cylinders and wheel centers failed within a short time, it was found that the phosphorus averaged nearly 1 per cent., while the silicon was over 2% per cent. The iron was so weak that little tenacity under impact could have been expected, although the price paid was considerably higher than the market rate for quality far better adapted to the service. A careful study was made to determine both the composition and physical condi- tion and structure which gave the best service under different classes of requirements, and to determine the means necessary to secure this quality in the output. In many cases of failure it was found that the difficulty was due wholly or in large part to the presence of blowholes or to porosity or sponginess of the iron, and at times to the presence of considerable proportions of oxide of iron and cinder in the iron. In the daily routine of our foundry general locomotive cast- ings were made ranging all the way in size from locomotive cylinders and wheel centers to small castings about 4 in. thick, and most of the castings required machining in some part. Some doubt was felt whether a single grade of pig iron would meet the requirements. At the outset, however, we drew up specifica- tions for a strong medium iron and upon receipt of each ship- ment sampled and tested each carload before acceptance. The same practice was also adopted with reference to our coke supply, and the proportions of ash and of sulphur were held down to reasonable amounts. At the same time methods of treatment of the iron in the ladle and in the cupola were intro- duced to decrease hardness and to remove oxide of iron and blowholes, and to increase the fluidity and density of the iron. As a result of these changes excellent results were obtained from the_very start. The single grade of iron, with the careful control of the quality, gave a degree of uniformity which had THE IRON AGE 1949 never before been possible, and by means of systematic treat- ment the properties of the iron could be veried as far as was desirable for the different purposes. In the machine shops the change had an immediate effect, for hard castings, ‘‘ porous iron’ and blowholes almost entirely disappeared. Within a few months breakages in service had fallen off to a very marked extent owing to the toughening of the iron, and at the end of a year the scrap coming in was insufficient for the needs of the foundry. In order the better to keep track of the service we stamped each wheel center as it was cast with the date, and after a lapse of three years not a single one had broken in service—a marked contrast to former conditions. Dr. Moldenke was glad to see that the question of Oxidation is getting more attention. Now that so much steel scrap is being melted in iron foundries the element manganese assumes more importance in this connection. At one time the speaker had held the idea that since manganese burned out there was little reason for using it. But to-day, with so much low carbon material em- ployed, the steel scrap often running up to 40 per cent. of a mixture, manganese becomes a valuable element in eliminating oxides and preventing blowholes. _ The remaining items of the afternoon programme were the report of Committee Q on Standard Specifica- tions for the Grading of Structural Timber presented by Hermann von Schrenk, chairman, and a paper on “The Effect of Moisture on the Strength and Stiffness of Wood,” by H. D. Tiemann. The result of the ballot for members of the Executive Committee for the next two years was announced at the close of the session. W. A. Bostwick and W. R. Webster were chosen, each receiving 154 votes. THURSDAY EVENING. The presidential addresses of Dr. Dudley have al- ways been able and practical, and that of this year, given at the Thursday evening session, was received with warm approval. It presented with eminent fairness and per- spicuity the issues arising out of the enforcement of specifications and so ably and thoroughly covers the ground as fairly to make it one of the classics of testing literature. It is given in full elsewhere in this issue. Interesting contributions to the records of concrete testing were made at this session in the following papers, which were illustrated by lantern slides: “ Tests of Con- crete Columns,” A. N. Talbot, University of Illinois, Ur- | bana, Ill.; “ Additional Notes on Tests of Concrete Col- umns,” by James E. Howard, Watertown Arsenal, Water- town, Mass., and “Testing of Wooden and Reinforced Telegraph Poles,” by R. A. Cummings, consulting engi- neer, Pittsburgh, Pa. The paper of W. H. Walker and Colby Dill on “ The Influence of Stress Upon the Corro- sion of Iron” was read by title. Electrolysis the Cause of Iron Rust, The paper of Allerton S. Cushman, Washington, D. C., on “The Corrosion of Iron,” was one of the most noteworthy in the annals of the society. Accompanied by lantern slide views of the exhaustive experiments Mr. Cushman has conducted and made effective by the actual projection on the screen of brilliant chemical phenomena supporting the theory that rust is a product of electro- lytic action, the paper made an unusual impression. We present a synopsis of the argument: The three theories which have been held to account for the rusting and corrosion of iron and steel are the carbonic acid, the hydrogen peroxide and the electro- chenical or electrolytic theories. The first two theories, which have from time to time been vigorously defended by various investigators, have not been found adequate or borne out by critical investigation. Moody, in Eng- land, is the chief modern defender of the carbonic acid theory, but he has committed the error of propounding the theory and then forcing his experiments and obser- vations to agree with it. Solutions of chromic acid and its salts, such as the chromates and bichromates of potash and soda, have been found to exercise an inhibitive action on the rusting of iron and steel. This inhibitive action is all the more striking from the fact that the chromates are strong oxidizing agents. A solution of potassium bichromate no stronger than one-six-hundredth normal will indefinitely prevent the rusting of polished specimens of metal in cold water, even if free access of air and carbonic acid is provided for. Under the same conditions at a boiling 1950 THE IRON AGE temperature no rusting or pitting takes place if the con- centration of the bichromate is above two-one-hundredths normal, BICHROMATE SOLUTIONS OPPOSE ELECTROLYSIS. If iron in any of its forms is immersed in strong solutions of bichromate for a few hours the surface be- comes passive, even after it is removed from the solu- tion, washed and wiped. The tendency to rust is inhib- ited as well as the electrolytic exchange with copper, if the metal is dipped for a short time in 1 per cent. copper sulphate solution, This passive condition lasts for some time under ordinary conditions, and steel wire nails that have been chromated may be kept under water for much longer periods without rusting than untreated nails. The passive condition gradually disappears and can be removed by heating, scouring, or by placing the metal in a vacuum. The explanation appears to be entirely electro-chemical. No film of oxide is formed, but the metal appears to have acquired an oxygen film and is thus polarized in the sense of becoming an oxygen electrode. Iron does not rust in perfectly pure hydrogen peroxide, in which solution oxygen can be made to boil off the surface of polished specimens of iron without producing any speck of rust, even after prolonged periods. Iron rusts in distilled water if oxygen is present, because the iron is attacked by the hydrogen ions supplied by the normal dissociation of water. Iron passes into solution as ferrous hydroxide, which is immediately oxidized to the insoluble red hydroxide and appears as rust. Acids, acid salts and substances which hydrolize in solution with an acid reaction stimulate rusting by in- creasing the concentration of the hydrogen ions. On the other hand, alkalies inhibit rusting in sufficient concen- tration, by preventing the existence of hydrogen ions. THE ROLE OF OXYGEN SECONDARY. The rusting of iron is therefore not due to the direct attack of oxygen combined with water. The role of the oxygen is a secondary one and the underlying cause of rusting and corrosion is an electro-chemical or electro- lytic problem. Interpreted from this point of view, the rusting of iron invariably proceeds as follows: Iron passes into solution as a ferrous ion by replacing hydro- geu which is set free; oxygen then oxidizes the ferrous iron to the ferric condition with the formation of a hydrated oxide. All soluble inhibitors, such as alkaline solutions or chromic acid and its salts, act either by preventing the presence of hydrogen ions or by electro- chemically preventing their attack. The rusting of iron being essentially an electro-chem- ical process, is invariably accompanied by electrolytic effects. Differences of potential are established on the surface of the metal, owing to imperfect distribution of metallic impurities, and for other reasons, Positive and negative points, nodes and areas are thus formed, leading to local action and pitting. This electrolytic action can be demonstrated as a universal accompaniment of the rusting of iron. Agaragar and gelatin jellies impreg- nated with phenol phthalein and potassium ferricyanide invariably show red and blue nodes on specimens of iron and steel imbedded in them. The speaker showed on the screen these alternating red and blue nodes on a wire nail on which rusting was in progress. This combined indicator has been called “ ferroxyl.” The blue nodes are the positive poles where iron is going into solution; the negative zones are shown in red. No rusting takes place in the red areas except when a change or reversal of the poles takes place. Pitting is simply a case of persistent positive poles, whereas superficial rusting of a surface is due to frequent changes of potential, with reversals of the positive and negative polar areas. The formation of eraters and cones of ferric oxide on the surface of rust- ing metal was demonstrated by lantern views and ex- plained by the speaker. As a result of laboratory experiments in demonstra- tion of the electro-chemical theory of rusting, as original- ly propounded by W. R. Whitney, Mr. Cushman urged that bichromate prevention of iron rust be tried on a practical and useful scale. The paradox is presented by the experiments thus far performed of the prevention of oxidization by one of our strongest oxidizing agents. June 27, 1907 These experiments show that the active cause of rust is not oxygen but hydrogen; and the action is not oxida- tion but hydroxidation. What should be aimed at is the inhibition of electrolysis by cutting down the in- purities in iron and steel or the unequal distribution of these impurities, as in segregation. FRIDAY MORNING. Two sections were in session Friday morning, one dealing with cement and the other with preservative coatings. The report of Committee E, on Preservative Coatings for Iron and Steel, was presented at the open- ing of the latter session by the chairman, S. S. Voorhees. The series of paint tests planned last year and described in the report of the committee at the last convention has been started. Nineteen different paints have been ap- plied to 600 ft. of the double track deck bridge erected by the Pennsylvania Railroad over. the Susquehanna River at Havre de Grace, Md. These paints were manu- factured by 16 different firms, and include nearly all the leading types—red lead, carbon as graphites, lamp black and carbon black, oxide of iron, with varying amounts and classes of inert materials, zinc oxide, as- phaltums and special pigments. The vehicle is linseed oil in the majority of cases. Subscriptions amounting to $3895 have been made by paint manufacturers to cover the expenses of the tests. The Technological Branch of the United States Geological Survey and the Bureau of Standards at Washington have expressed a desire to co- operate with the committee in the work. W. H. Walker presented some further data on the corrosion of iron and st-el, based on the theory elab- orated by Mr, Cushman at the Thursday evening session that corrosion is an electro-chemical phenomenon. In the discussion that followed, Mr. Cushman, as chairman of the Committee on Corrosion of Iron and Steel, said that several methods of testing had already been developed by which it is possible to get information, in advance of use, of the resistance of iron and steel products to corro- sion. Preservative Coatings. F. P. Cheesman, New York, presented a paper on “ Linseed Oil and Paint as Priming Coats for Metal Sur- faces.” He said that the use of boiled linseed oil, which was general previous to 1885, was now infrequent, though some. engineers still invite corrosion by its use. Authori- ties were cited in opposition to the use of an oil coat for priming and troubles due to its use were enumerated. It is safe to use a selected high grade natural ore iron oxide paint, while in many localities a blue lead paint would be best, in others a combination of red lead and graphite, or a carbon black paint. A paper on “ Deleterious Ingredients in Paints” was presented by L. S. Hughes. The general point was made that the wear of a paint depends upon the fineness and chemical stability of its predominant pigment. G. W. Thompson, in the discussion of the paper, suggested that the Committee on Preserva