Des. No. 4.-Rail bent, flange cut for clearance as above, and furnished with bolts. Des. No. 5.-Rail bent, flange cut for clearance as above, and furnished with clamps. (5) Details. If special bend is required, send a sketch. (6) State number of items required. VIII. Derailing Devices for Electric Roads. This refers to the derailing switch in electric road tracks placed in front of a steam road crossing, which requires for its operation that the conductor cross the steam road tracks to close the switch to allow the car to pass. The material required consists of the switch, the ground throw or other operating device, and the connecting-rods or wire rope. (1) State whether an ordinary split switch is required, or a tongue switch for use in paved streets. (2) Give section of rail (see I) of which switch is to be made. (3) Are cars to be derailed to the right or left hand? (4) What type of operating device is required: a ground throw with gas-pipe throw rods, or a handle-box with galvanized-wire rope in pipe conduit? (5) State any preference as to design (to suit depth of paving, etc.) (6) Give distance between switch and ground throw or handle-box (75 ft. is usual). (7) Send sketch showing spacing and size of splice-bar holes; also bond holes, if required. (8) Material Supplied. State which of the following items are to be supplied and which are not to be supplied: (a) For Split Switch and Ground Throw Installation: Switch rail, head-rod with spring, switch lugs and friction plates with braces; ground throw; throw rods, turn-buckle, bell-cranks and connectingrod. (b) For Tongue Switch and Handle Box Installations: Tongue switch complete with spring and guard steel; handle-box complete; galvanized-wire rope throw with pipe conduit, and crank box (at switch) complete. (9) Number of items required. (Note that two sets are required for a single-track crossing.) IX. Street Railroad Work (1) Send a plan of the curves, turnouts, etc., required. (2) Give section of train rail as per I; also of guard rail. (3) Send sketch showing size and position of splice and bond holes. (4) Gauge of track? (5) Show on the drawing radius of curves, distance between track centres, width of each street between curbs, angle of intersection of streets, direction of traffic, etc.. (6) State any special requirements. (7) Number of items required? DERRICKS AND DERRICK IRONS (1) Kind of Derrick required: Guy; Self-slewing Guy; Stiff Leg; Full Circle Stiff Leg; Traveling Stiff Leg; Crane Derrick; Tower Derrick; Jinniwink; or special. (2) Is derrick to be constructed of steel or wood? Or is boom to be of steel and mast, etc., of wood? (3) Are members to be in short lengths, i.e., is a sectional derrick required? (4) Heaviest load to be lifted? (5) Length of boom? Length of Mast? Size of Boom? Size of Mast? (6) For a guy derrick, state number of guys de sired, and their lengths. (7) Power. State whether hand, horse, steam, or electric power is to be used, and any special requirements of either. In case of electric power, state the voltage, and whether direct or alternating current; and, if the latter, give also the phase and frequency. (8) Will derrick be slewed by hand or power? (11) For what service is derrick to be used? (13) Number of units required? Load. FIG. 50.-Typical diagram for cableway dimensions. Note.-Usual maximum span is from 1,800 to 2,000 ft., which, however, may be exceeded under favorable conditions. (3) Kind of material to be handled? Describe completely enough so that buckets, etc., may be designed to handle same in a satisfactory manner. (4) Average load in pounds? Note. The average load for loose rock is from 6,000 to 12,000 lb. (5) Maximum load in pounds that will have to be carried? Frequency with which such loads will occur? (6) Capacity to be handled per hour in pounds? Note. If figures are given in tons, be sure to state whether "short" tons of 2,000 lb. or "long" tons of 2,240 lb. are meant. (7) Total amount of material to be handled by the installation? (8) Amount to be handled per year? (9) Is the ground where cableway is to be located level, rising or hollow? (10) If not on a level, how much higher will base of one tower be than base of the other? (11) Submit a sketch similar to Fig. 50, filling in the dimensions indicated. This sketch should preferably be to scale, but not necessarily so. Carry profile lines back as far as necessary from towers, so that location of anchorages may be determined. (12) State whether there are any buildings or elevations over which cable is to pass, indicating position and height on the profile sketch. (13) From what points is the material to be taken? (14) To what points is it to be delivered? (15) Are both towers to be stationary, both traveling, or one stationary and the other traveling? (16) Will steam, electricity or compressed air be used for operating the cableway? If steam or air, give pressure per square inch at the hoist. If direct current, give voltage; if alternating current, give voltage, phase and frequency. (17) At which end may hoist be most conveniently placed? Note.-Hoist should, as a rule, be placed at highest point. (18) State what material is to be furnished and what is not to be furnished, as follows: Special material of the cableway proper, including main cable, fall rope, trolley rope, cable carriage, fall block, trolleys, bucket; material for tower tops complete; irons for towers; wood for towers (not usually supplied); irons for anchorages; hoisting engine, and boiler. SEC. III. MATERIALS OF CONSTRUCTION ORDERING STRUCTURAL MATERIAL Methods and details of ordering structural material differ somewhat in various shops, not only among different companies but also in different shops of the same company. The differences occur both in the forms used and in details affected by shop methods. The directions given below refer to average conditions. With regard to the forms used in ordering, it may be remarked that in the smaller shops the order list is made out and completed by one man who makes the necessary allowances for clearance, milling, multipling, etc.; while with the larger bridge companies it is the custom to have the ordering engineer make out a detail list, leaving to another man (more familiar with stock, shop customs, etc.) the summarizing of the items, ready for handing to the mill. General Place orders promptly for main material and details which will take longest to get out, or which are required at building site in advance of main shipment. A variation of 3/8 in. either way is allowed the mill, and all ordering must take care of this possibility. In ordering material for many similar pieces, roof-trusses for example, it conduces to accuracy to bill, say, one-half of the truss and call for total number of half-trusses required. For this purpose the "Advance Bill" should have two rulings, one for the detail list and the other for the summary or "Ordered" number and length. Beams and Channels Bill beams in foundation neat. Bill beams framing to beams, 1 1/2 in. short (to nearest 1/2 in.) of distance c. to c. Bill beams framing to columns, 1 in. short (to nearest 1/2 in.) of metal-to-metal distance. Bill beams framing to riveted girders, same as for col's. Bill beams with mitred ends, 1 in. long to allow for shop cut. Bill beams for crane runways, resting on bracket, 1 in. short (to nearest 1/2 in.) of c. to c. distance. Bill purlins 1 in. short (to nearest. 1/2 in.) of c. to c. distance. If end-connections are to be milled after riveting on, increase thickness of connection angles. Column Material Bill main column material 1/2 in. long for milling one end, 3/4 to 7/8 in. long for milling both ends. Bill to nearest 1/4 in. Deduct for cap plate. Bill column details (shelf-angles, stiffener-angles, etc.) in 30-ft. lengths, stating approximate lengths to which same are to be cut. If ends are to be milled after riveting on of cap angles, increase thickness of same. Bill lattice bars in 20-ft. lengths. Order thick "slabs" (for column bases) by number and finished dimensions (i.e., as sketch plates) and call attention to same so that mill may make proper allowance for cutting. Plate Girder Material Distance b. to b. of flange-angles should be 1/2 in. more than the width of web plate which should be of even inch width. Bill web plates of girders not milled at ends or at splices, 3/4 in. short of over-all distances. If milled at end or splice, allow 1/2 in. for one, 3/4 in. for two millings. Bill flange angles 3/4 in. long. For curved end-angles, add 6 in. Bill full-length cover-plates 3/4 in. long; less than full length, neat length: mark "U.M." (Universal Mill, i.e., rolled edges). Bill stiffener angles with fillers under, 1/4 in. long; crimped stiffeners, add depth of each crimp plus 1/2 in. for each crimp; for fitted stiffeners over 5/8 in. thick, add 1/2 in. for one, 3/4 in. for two millings; end stiffeners to be milled, increase thickness. Bill fillers under stiffener angles exact length, i.e., 1/4 in. clear each end, making allowance for over-run of angles. Bill web-splice plates, reinforcing web plates, etc., as for fillers. Bill lateral angles scaled length plus 1 1/2 in. Bill lateral plates in lengths of about 20 ft.; detail wing plates so as to "multiple" (Fig. 51). Roof-truss Material FIG. 51.-Ordering wing plates "Multipled." Bill chord angles 3/4 in. long. Bill web members 1 1/2 in. longer than scaled length, and multiple to lengths of about 30 ft. Bill gusset plates in lengths of about 20 ft.; detail wing plates so as to "multiple" (Fig. 51). Miscellaneous For milling ends, in general allow 1/2 in. if milled one end and 3/4 to 7/8 in. if milled both ends. Plates planed on edge, add 1/4 in. for each edge. Plates planed on top or bottom, add 1/16 in. for each side planed up to 36 in. × 36 in. in size, over that add 1/8 in. Plates over 7/8 in. thick, add 1/16 in. to above allowances, or for slabs add 1/8 in. Detail wing plates so that they will "multiple," saving cuts and material; Plates should not be ordered as "sketch plates" unless they are over about 36 Up to 4 in. diam. allow 1/8 in. 4 1/4 in. to 6 1/2 in. diam. allow 1/4 in. 6 3/4 in. to 10 in. diam. allow 1/2 in. and order of nearest size larger regularly rolled in case the addition does not give an even figure. Long channels, etc., for bridge web-members, etc., not requiring milled or beveled ends, order neat length, as the 3/8-in. variation does not affect. STEEL PLATES FOR BOILERS, TANKS, ETC. This material is usually ordered by gauge, but paid for by weight (the actual shipping weight). Prices are quoted per 100 lb. of material for a stated delivery. The customary allowable overweight on material of various widths and thickness when ordered to gauge, as adopted by the Assn. of Am. Steel Mfrs., is given in various steel handbooks; plates thus ordered are not liable to under-run in weight. For Dished Heads, see p. 197. An example of a specification for this class of material is given on the following page. ( |