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Rail bonds
Rail
Mar., 19o4 I
Bonds.
ELECTRICAL
213
SECTION.
Slated Meeting hem Thursday, Oclober S, z9o3.
Rail B o n d s . BY W. ]~. HARRINGTON.
General Manager Camden and S u b u r b a n Railway Company.
I Copl/i~zued/rom p. J2o. ) "UNITED
STATES"
RAIL BONDS.
T h e " U n i t e d S t a t e s " rail bond is m a d e with solid terminals and flat strips of copper, and is so designed t h a t it can be used inside the splice-bar of a rail-joint when the plate is only ¼ of an inch from the web of the rail. T h e leaves of the bond will fit into a space which is only ½ of an inch in thickness. T h e s e f e a t u r e s m a k e the bond applicable to certain cases in which strands c a n n o t be used satisfactorily. This bond is applied to the rail with a compressor. T h e " U n i t e d States " bonds are bonds in which copper strips and welded t e r m i n a l s are used. Fig. 3 8 shows top surface of t e r m i n a l of this type of bond. Fig. 39 shows the appearance of t e r m i n a l after insertion in the hole and before compression. FLUS. 4 ° shows the appearance of the t e r m i n a l after compression. Fig. 4 r is a section of rail web and t e r m i n a l s h o w i n g the result w h e n the compression has been completed properly. Fig. 42 is a bond of this type made in l e n g t h s from 5½ to 14 inches inclusive. L e n g t h s g r e a t e r t h a n 14 inches are considered special, and m a d e only to order. T h e screw compressor for applyifig the " U n i t e d States " rail bonds is shown in /,'~g. 43. Style " A " compressor. W e i g h t , 83 pounds. For T- and girder rails 7 inches or less in height. Style "B." W e i g h t , 225 pounds. For T- and girder-rails 9 inches or less in height. GENERAL
EI,ECTRIC C()MPANV BONI).
General Electric C o m p a n y bond is m a d e by p o u r i n g molten copper a r o u n d a b o u t wire s t r a n d s of body and a b o u t an iron
FI(;. 39.
FI6.38. FIG. 4° .
FI(;. 41.
FIG. 4 2 . - - " U n i t e d S t a t e s " rail-bond.
S t y l e No. 3.
FIG. 4 3 . - - S c r e w c o m p r e s s o r for a p p l y i n g b o n d .
Mar., 19o4.]
[~ail Bonds.
plug, which extends through of t h e e a s t t e r m i n a l .
2 r5
t h e a x i s of, a n d b e c o m e s p a r t
FIG. 44.--'~. i:Ic;. 44.--6. Steel core before and after compression.
FIG.
45.--Section through rail bond showing effect of compression.
Fiffs. 44 to 49 s h o w d i f f e r e n t f o r m s a n d a p p l i c a t i o n s of t h i s t y p e of b o n d . Figs. 50 a n d 5z s h o w t h e s o l d e r e d f l e x i b l e r a i l b o n d . I t
2 I6
H a r r i n g t o l z ."
lJ. F. I.,
is f o r m e d of a s e r i e s of fiat s t r i p s of a n n e a l e d c o p p e r b e n t in t h e f o r m of an a r c h to e n s u r e t h e g r e a t e s t d e g r e e of flexi-
FIG
~6.
FI(;. 47.--Form C bond under bottom flange for extreme flexibility.
b i l i t y , w i t h a p a i r of flat f e e t to p r o v i d e a c o n t a c t s u r f a c e . "Phe s t r i p s of e a c h f o o t a r e s o l d e r e d t o g e t h e r , m a k i n g a s o l i d t e r m i n a l , w h i l e t h e i n t e r m e d i a t e s t r i p s of t h e a r c h a r e u n -
Mar., I9o4.J
Rail
]3otzds.
217
a t t a c h e d to each other. T h e feet of this bond are soldered to t h e rails. Outfit. A n outfit for p l a c i n g this b o n d c o m p r i s e s one special rail-cleaner and e m e r y wheel, one special blow-torch, one w i n d . g u a r d , clamps, solder and acid.
FIG. 48.--Form B bond under fish-plate.
Fro. 49.--Bonds spanning fish-plate where there is insufficient room between rail and fish-plate.
I n s t r u c t i o n s for p l a c i n g : (I) Clean t he two surfaces of t h e rails w h e r e the bonds are to be applied by s c r a p i n g w i t h a file or b y an e m e r y wheel r u n on a flexible2shaft as s h o w n in F i E . 52. T h e s e s ur f aces m u s t be m a d e p e r f e c t l y clean an d b r i g h t , free from rust, etc., and should be s l i g h t l y
O
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Mar., I9o4.]
Rail Bomts.
:t 9
l a r g e r in a r e a t h a n t h e c o n t a c t s u r f a c e s of t h e f e e t ,4 t h e b o n d . T h e b o n d s h o u l d b e b e n t so t h a t t h e f e e t s h a l l t e t r u e on t h e c l e a n e d s u r f a c e s , a n d s h o u l d b e 7 i n c h e s in extreme length when applied. H e a t is a p p l i e d to t h e s e s u r f a c e s b y m e a n s of a s p e c i a l b l o w - t o r c h , Fzg. 53 ( u s i n g w i n d - s h i e l d s , F~,. 54, w h e n nece.~s a r y to p r o t e c t t h e b u r n e r s ) , u n t i l t h e s u r f a c e s h a v e r e a c h e d a t e m p e r a t u r e w h e n s o l d e r will m e l t . T h i s t a k e s b u t a f e w m i n u t e s , a n d c a n be d e t e r m i n e d b y r u b b i n g a s t i c k of s o l d e r o n t h e h e a t e d p a r t s . W h e n t h e s o l d e r r u n s freely, t h e sur-
FIG. 52.--Hand grinder, flexible shaft and emery wheel.
Fro. 53.-- Osborn torch
f a c e s a r e r u b b e d w i t h a flux ( p r e f e r a b l y zinc c u t w i t h m u r i a t i c acid), t h e n t h e s o l d e r is a p p l i e d u n t i l t h e s u r f a c e s a r e t h o r o u g h l y tinn~ed. T h e b o n d is p l a c e d in p o s i t i o n , w i t h t h e f e e t in level cont a c t w i t h t h e t i n n e d s u r f a c e s , t h e s t r i p of t h i n s o l d e r w h i c h is a t t a c h e d to t h e f o o t of t h e b o n d h a v i n g first b e e n lifted a n d t h e f o o t c l e a n e d w i t h a b r u s h w e t w i t h t h e acid solution. H e a t is a p p l i e d to t h e f e e t of t h e b o n d s u n t i l t h e l a y e r of solder runs. A b r u s h w e t w i t h s o l d e r i n g a c i d is t h e n p a s s e d a r o u n d t h e e d g e s of t h e f e e t to b a n k t h e s o l d e r w h i c h
cu
r~ c~ I-i
0
0
z~ 0
I
Mar., 19o4. ]
Rcti[ Boplds.
22 I
the various sections can easily be applied after the track is in place. T h e wind-shield and special torch e m p l o y e d in new cons t r u c t i o n are s h o w n in .P'71~Ts.56 and 57. A M A I , G AMArI'EI) BONDS.
Description. T h e solid copper bond, Figs. ¢8 to 62, is m a d e of a r e c t a n g u l a r plate of roiled electric copper, 3 or more inches long, ~ of an inch thick (or thicker) and J½ o1" more inches high. A cup-shaped projection is pressed near each end so as to give a contact a g a i n s t rail-web close to the
FIG.
57.--Osborn torch, with additions for underneath bonding when track is spiked down.
end of each rail. N e x t to the copper is a piece of sheet steel s u p p o r t i n g a pair of special s t e e l s p r i n g s : the steel is used to keep springs from w e a r i n g into copper. T h e s e pieces are held t o g e t h e r by a small steel staple passed over the center of b o n d and driven into a cork composition plate which is longer and wider t h a n the metal and serves to exclude dirt from the contact surfaces and to hold the springs in position. All m e t a l parts of bond are a m a l g a m a t e d to prevent rusting, and the c o n t a c t surfaces are covered w i t h plastic alloy. T h e bond is always laid out to suit each particular rail and joint, and does not interfere with the m e c h a n i c a l
I[[
o
r~ I &
~ }~,ii~/ii~~i~
Mar., 19o4.]
.~aU ]3oltds.
223
fit of angle-plate. W h e n in service the springs serve m e r e l y as distance pieces so long as joint is t i g h t ; if nuts loosen or plates wear, the springs still hold bond in contact. T h e n t i g h t e n i n g the track n u t s also t i g h t e n s the bond. T h e use of spring-lock washers is advised on track nuts to
Fro. 6o.--Verticai section through center of bond contact. keep t h e m f a s t ; these washers will then take up the wear of the plate. W h e r e clearance b e t w e e n web of rail and angle-plate will not p e r m i t the use of springs, a plate of flexible cork is placed so as to overlap the copper on top, b o t t o m and sides and give sufficient pressure to m a i n t a i n the contacts. (See Fig. 6i.) A n o t h e r cork plate is placed .between rail-ends to keep out dirt. To apply this bond it is only necessary to b r i g h t e n web
224
[~arrin~ton :
[J. F. I.,
of rail b e y o n d end bolt hole w i t h a hand-power g r i n d e r and flexible s h a f t w i t h e m e r y wheel. T h e surfaces are then a m a l g a m a t e d and covered with a t h i n layer of plastic alloy. T h e lubrication afforded by t h e plastic alloy p e r m i t s the rails to move in a n y direction w i t h o u t w e a r i n g a w a y m e t a l of bond. Sizes. T h e size of copper is varied to suit r e q u i r e m e n t s up to the full area of the space b e t w e e n rail-web and angleplate, and b e t w e e n end of bolt holes in rail. Bonds with copper plates over ~g of an inch are not cu Fshaped, b u t h a v e a shallow o u t w a r d bend opposite ends of
FIt;. 6~.--Front of No. 5/o solid copper bond, full size, with cork plate. the rails; this avoids scraping bond a g a i n s t sharp rail edges. T h e bond s h o w n in Fig. 6z has a vertical cross-section of more t h a n o'218 of a square inch, while the section of a No. 4 / 0 wire is b u t o'166 of a square inch. T h e bond, therefore, has a g r e a t e r c o n d u c t i v i t y ttian i~0- No. 4 / 0 copper wires. Conductivity. It has been claimed t h a t one No. 4 / / 0 solid copper b o n d laid upon a m a l g a m a t e d contact spots on head of 8o-pound T-rail so as to bridge the joint, carried 2,0oo amperes with a drop of "oi8 volt. T h e drop of i inch of this rail with the same c u r r e n t was "o0223 volt. T h e
Mar., 19o4.]
]~ai/ ]flonds.
225
bond merely laid on top of rail and held in contact by nothiJlg but its own weiff/zt was equal in resistance to but S¼ inches of rail. T h e drop of u n b o n d e d joint, with same current, was "423 volts. Guarantees. M a n u f a c t u r e r s g u a r a n t e e t h a t the bond will t r a n s m i t c u r r e n t at the rate of 2,ooo amperes per square inch of vertical section w i t h o u t h e a t i n g beyond t e m p e r a t u r e of rail.
FIG.
62.--Cast-iron feeder terminal.
T h e y f u r t h e r g u a r a n t e e u n d e r above conditions t h a t at the end of two years' service, the c o n d u c t i v i t y of the bond will be practically the same as at the start, provided the joints have been m e c h a n i c a l l y m a i n t a i n e d in proper condition for o p e r a t i n g cars. Cross Bonds. Copper cross-bond terminals for No. 2 / o and N o . . 4 / o wires. T h e s e are f a s t e n e d to rail web with 1}-inch bolts, whose ends should be riveted after nuts are set tight. T h e end of the wire is a m a l g a m a t e d and slipped VOL CLVII. No. 939. l~
226
Harrillgton
:
[J. F. I.,
t h r o u g h hole in l u g upon b o t t o m of terminal. A roundnosed tool is placed at r i g h t angles to wire in the hole below bolt-hole and the wire kinked by a h a m m e r blow, forcing it into a cored cavity. T h e hole is t h e n filled with plastic alloy and the t e r m i n a l bolted a g a i n s t a m a l g a m a t e d contact spot on rail web. On exposed road where copper track wire m i g h t be stolen, use a steel cross bond i~ inches square, which c a n n o t be r e m o v e d w i t h o u t special tools. For rail feeders and loops a r o u n d crossings, switches and special work, use cast-iron terminals for one or two No, 4 / 0 wires and for 25o,ooo and 500,000 C.M. cables. T h e s e hold a cork case a g a i n s t web of rail, f o r m i n g a receptacle into which is placed the end of the wire and some of the plastic alloy. In each case the wire ends are a m a l g a m a t e d , as are also the contact spots on web of rail. T h e s e terminals are f a s t e n e d to rail web w i t h ~-inch bolts, whose ends should be riveted after n u t s are set tight. PLASTIC RAIL BOND.
For track with h e a v y rail and angle plates, this bond, Figs. @-66, is composed of two p o r t i o n s : a plastic alloy or putty-like m e t a l c o m p o u n d which m a k e s c o n t a c t between the rail and the splice bar or angle plate, and a flexible, elastic cork case to hold the same in position as n e a r end of the rail as possible. T h e initial thickness of the cork ease is nearly double the distance between web of rail and inner surface of angle plate ; it is therefore compressed about 40 per cent. w h e n in place and after pressure has been applied it adheres to the rail and plate, completely sealing tile plastic alloy. T h e cork case is made of a c o m p o u n d of cork and oxidized linseed oil and is practically indestructible. It is elastic and will m a i n t a i n seal even w h e n plate has loosened ~\~ of an inch. T h e c u r r e n t passes from one rail t h r o u g h one plug to the angle-plate, and t h e n t h r o u g h second plug from the plate to the next rail (see arrows in P'io¢. 73). Contact spots about 2 inches in d i a m e t e r on both rails and angle plates are
~4 0
0
0 0
I
0
I
228
t[arriJz~ton :
[J. F. l..
cleared of scale and rust and t r e a t e d with the solid alloy, which i n s t a n t l y silvers the surfaces and prevents t h e m from rusting. T h i s fills the surface irregularities and penetrates the m e t a l s for a perceptible distance, l e a v i n g a surface to which the plastic alloy adheres. Plastic-plug Rail Bond. T h i s can be used on all forms of rail where the fish-plate overlaps rail base by I inch or more. Several different forms to m e e t v a r y i n g r e q u i r e m e n t s are shown in a c c o m p a n y i n g cuts, ]"l~s. 65-66. T h e application of the plastic.plug bond is made after the completion of the track, so t h a t delay t h r o u g h interference of two different g a n g s is avoided. Between the first and second bolt holes from the end of each rail, a hole ~} to
FIG. 64.--Horizontal section. of an inch in d i a m e t e r is bored d i a g o n a l l y d o w n w a r d t h r o u g h the flange of angle plate, into, b u t not t h r o u g h , the base of rail. T h e hole is nearly at r i g h t angles to plate flange and as near[the vertical web as possible. An o r d i n a r y r a t c h e t drill and a J-shaped clamp passing u n d e r the base of rail are the only tools necessary. T h e drill point is l u b r i c a t e d with a solution of pearline and w a t e r instead of oil, so as to avoid the trouble which follows the use of an i n s u l a t i n g fluid on m e t a l contact surfaces, and the hole is usualIy drilled to ½ of an inch from b o t t o m of rail base. T h e drill chips are removed with a p e r m a n e n t m a g n e t , and the proper depth d e t e r m i n e d by t e m p l a t e or collar fastened on drill. The plates m a y be drilled before d i s t r i b u t i n g a l o n g the road;
blar., 19o4. ]
]~?// Bonds.
229
this is more t h a n double the n u m b e r of joints which can be bonded in a day. A f t e r the hole is drilled it is a m a l g a m a t e d by filling with water and r u b b i n g with the end of a rod of the solid alloy. On bonds of large diameter, an a m a l g a m a t e d copper tube is driven into the hole so as to completely seal the crack between the m e e t i n g surfaces of rail and angle-plate as shown on r i g h t side of Fig'. z2. T h i s is u n n e c e s s a r y with the small sizes. T h e hole is then p a r t l y filled with the plastic alloy, w h i c h adheres to the a m a l g a m a t e d surfaces of the steel. A n a m a l g a m a t e d copper plug, which is T-shaped in section, is then driven to seal the hole and to complete the
FIG. 66.--Section of plastic plug bolld.
circuit b e t w e e n the rail and angle-plate by d i p p i n g into the plastic alloy. It is locked in place by a h a m m e r blow on a blunt chisel, m a k i n g a burr in angle-plate j u s t above the top of the plug. F @ @ shows completed joint with s t a n d a r d plastic-plug rail bond. Fig'. 66 shows section of same. In one form of this bond the lower part of the p l u g is a little out of c e n t e r with the top, since less clearance is required on the i n n e r side of hole because f u r t h e r motion of angle-plate i n w a r d can occur only after rail and plate surfaces have worn. T h i s eccentricity allows a groove to be m a d e in top of the plug, and this groove should always face the outside of the rail. The grooves serve to prevent air b i n d i n g as plug is driven
230
Notes a n d Colnments.
[J. F. I ,
home, and are then closed b y a tap of the h a m m e r on the edge. T h e r e is a modification called the plastic screw plug for very h e a v y rails carrying s t e a m road service on b r i d g e s and in tunnels, in which provision is m a d e for easy e x a m i n a t i o n and repair. T h e hole in plate is of larger d i a m e t e r and is screw-threaded and a m a l g a m a t e d before distribution along the road. A h a r d e n e d steel jig is s c r e w e d into hole to properly locate rail drilling. W h e n this hole is drilled and a m a l g a m a t e d a copper t u b e is driven h o m e and around the top of the t u b e is placed a diagonal strip of elastic packing. T h e hole is then partly filled with the plastic alloy and the plug screwed down to compress the packing and seal the joint. [ To be concluded.]
SELF-HARDENING STEELS. One of the recent notable developments in the metallurgy of steel has been the manufacture of what is known as self-hardening or high-speed steels, which are adapted for tools working at a high rate of efficiency. There is a great variety of these steels on the market, and they show wide differences in composition, although usually containing some of the rarer metals, such as tungsten, molybdenum and chromium. Tools made front these steels can work without injury at a temperature of 500 ° or 6oo ° C. T H E MT. V E S U V I U S RAILWAY. What is said to be the most dangerous railway in the world is that recently completed up the side of Mr. Vesuvius for the benefit of the many tourists who annually visit this famous volcano. It is a cable railway of the monorail type, tile one car comprising the active rolling stock being supported by two wheels, one at each end of the car. The center of gravity of the ear is below tile top of the supporting rail, so that it balances without the aid of supporting wheels at the sides. The railway line runs to within nominally I,ooo feet of the crater mouth, but the distance changes from day to day on account of the rapid changes t h a t take place; accretions to the sides of the crater may materially increase the distance one day, and the fall of a huge slice into the seething gulf 5oo feet below may considerably lessen the distance the next day. The maintenanee of the line in proper alignment is a difficult matter. Fissures opening, the flow of lava, falling cinders, and sliding of the roadbed require constant watchfulness and labor by gangs of laborers who eonstantly patrol it during the periods of operation. The " t r a i n " has no fixed time table, the trips depending on the activity of the volcano and diree. lion of the wind; some days t h e y are entirely abaudoned.--IF[ackinery.
Mar., 19o4 I
Bonds.
ELECTRICAL
213
SECTION.
Slated Meeting hem Thursday, Oclober S, z9o3.
Rail B o n d s . BY W. ]~. HARRINGTON.
General Manager Camden and S u b u r b a n Railway Company.
I Copl/i~zued/rom p. J2o. ) "UNITED
STATES"
RAIL BONDS.
T h e " U n i t e d S t a t e s " rail bond is m a d e with solid terminals and flat strips of copper, and is so designed t h a t it can be used inside the splice-bar of a rail-joint when the plate is only ¼ of an inch from the web of the rail. T h e leaves of the bond will fit into a space which is only ½ of an inch in thickness. T h e s e f e a t u r e s m a k e the bond applicable to certain cases in which strands c a n n o t be used satisfactorily. This bond is applied to the rail with a compressor. T h e " U n i t e d States " bonds are bonds in which copper strips and welded t e r m i n a l s are used. Fig. 3 8 shows top surface of t e r m i n a l of this type of bond. Fig. 39 shows the appearance of t e r m i n a l after insertion in the hole and before compression. FLUS. 4 ° shows the appearance of the t e r m i n a l after compression. Fig. 4 r is a section of rail web and t e r m i n a l s h o w i n g the result w h e n the compression has been completed properly. Fig. 42 is a bond of this type made in l e n g t h s from 5½ to 14 inches inclusive. L e n g t h s g r e a t e r t h a n 14 inches are considered special, and m a d e only to order. T h e screw compressor for applyifig the " U n i t e d States " rail bonds is shown in /,'~g. 43. Style " A " compressor. W e i g h t , 83 pounds. For T- and girder rails 7 inches or less in height. Style "B." W e i g h t , 225 pounds. For T- and girder-rails 9 inches or less in height. GENERAL
EI,ECTRIC C()MPANV BONI).
General Electric C o m p a n y bond is m a d e by p o u r i n g molten copper a r o u n d a b o u t wire s t r a n d s of body and a b o u t an iron
FI(;. 39.
FI6.38. FIG. 4° .
FI(;. 41.
FIG. 4 2 . - - " U n i t e d S t a t e s " rail-bond.
S t y l e No. 3.
FIG. 4 3 . - - S c r e w c o m p r e s s o r for a p p l y i n g b o n d .
Mar., 19o4.]
[~ail Bonds.
plug, which extends through of t h e e a s t t e r m i n a l .
2 r5
t h e a x i s of, a n d b e c o m e s p a r t
FIG. 44.--'~. i:Ic;. 44.--6. Steel core before and after compression.
FIG.
45.--Section through rail bond showing effect of compression.
Fiffs. 44 to 49 s h o w d i f f e r e n t f o r m s a n d a p p l i c a t i o n s of t h i s t y p e of b o n d . Figs. 50 a n d 5z s h o w t h e s o l d e r e d f l e x i b l e r a i l b o n d . I t
2 I6
H a r r i n g t o l z ."
lJ. F. I.,
is f o r m e d of a s e r i e s of fiat s t r i p s of a n n e a l e d c o p p e r b e n t in t h e f o r m of an a r c h to e n s u r e t h e g r e a t e s t d e g r e e of flexi-
FIG
~6.
FI(;. 47.--Form C bond under bottom flange for extreme flexibility.
b i l i t y , w i t h a p a i r of flat f e e t to p r o v i d e a c o n t a c t s u r f a c e . "Phe s t r i p s of e a c h f o o t a r e s o l d e r e d t o g e t h e r , m a k i n g a s o l i d t e r m i n a l , w h i l e t h e i n t e r m e d i a t e s t r i p s of t h e a r c h a r e u n -
Mar., I9o4.J
Rail
]3otzds.
217
a t t a c h e d to each other. T h e feet of this bond are soldered to t h e rails. Outfit. A n outfit for p l a c i n g this b o n d c o m p r i s e s one special rail-cleaner and e m e r y wheel, one special blow-torch, one w i n d . g u a r d , clamps, solder and acid.
FIG. 48.--Form B bond under fish-plate.
Fro. 49.--Bonds spanning fish-plate where there is insufficient room between rail and fish-plate.
I n s t r u c t i o n s for p l a c i n g : (I) Clean t he two surfaces of t h e rails w h e r e the bonds are to be applied by s c r a p i n g w i t h a file or b y an e m e r y wheel r u n on a flexible2shaft as s h o w n in F i E . 52. T h e s e s ur f aces m u s t be m a d e p e r f e c t l y clean an d b r i g h t , free from rust, etc., and should be s l i g h t l y
O
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Mar., I9o4.]
Rail Bomts.
:t 9
l a r g e r in a r e a t h a n t h e c o n t a c t s u r f a c e s of t h e f e e t ,4 t h e b o n d . T h e b o n d s h o u l d b e b e n t so t h a t t h e f e e t s h a l l t e t r u e on t h e c l e a n e d s u r f a c e s , a n d s h o u l d b e 7 i n c h e s in extreme length when applied. H e a t is a p p l i e d to t h e s e s u r f a c e s b y m e a n s of a s p e c i a l b l o w - t o r c h , Fzg. 53 ( u s i n g w i n d - s h i e l d s , F~,. 54, w h e n nece.~s a r y to p r o t e c t t h e b u r n e r s ) , u n t i l t h e s u r f a c e s h a v e r e a c h e d a t e m p e r a t u r e w h e n s o l d e r will m e l t . T h i s t a k e s b u t a f e w m i n u t e s , a n d c a n be d e t e r m i n e d b y r u b b i n g a s t i c k of s o l d e r o n t h e h e a t e d p a r t s . W h e n t h e s o l d e r r u n s freely, t h e sur-
FIG. 52.--Hand grinder, flexible shaft and emery wheel.
Fro. 53.-- Osborn torch
f a c e s a r e r u b b e d w i t h a flux ( p r e f e r a b l y zinc c u t w i t h m u r i a t i c acid), t h e n t h e s o l d e r is a p p l i e d u n t i l t h e s u r f a c e s a r e t h o r o u g h l y tinn~ed. T h e b o n d is p l a c e d in p o s i t i o n , w i t h t h e f e e t in level cont a c t w i t h t h e t i n n e d s u r f a c e s , t h e s t r i p of t h i n s o l d e r w h i c h is a t t a c h e d to t h e f o o t of t h e b o n d h a v i n g first b e e n lifted a n d t h e f o o t c l e a n e d w i t h a b r u s h w e t w i t h t h e acid solution. H e a t is a p p l i e d to t h e f e e t of t h e b o n d s u n t i l t h e l a y e r of solder runs. A b r u s h w e t w i t h s o l d e r i n g a c i d is t h e n p a s s e d a r o u n d t h e e d g e s of t h e f e e t to b a n k t h e s o l d e r w h i c h
cu
r~ c~ I-i
0
0
z~ 0
I
Mar., 19o4. ]
Rcti[ Boplds.
22 I
the various sections can easily be applied after the track is in place. T h e wind-shield and special torch e m p l o y e d in new cons t r u c t i o n are s h o w n in .P'71~Ts.56 and 57. A M A I , G AMArI'EI) BONDS.
Description. T h e solid copper bond, Figs. ¢8 to 62, is m a d e of a r e c t a n g u l a r plate of roiled electric copper, 3 or more inches long, ~ of an inch thick (or thicker) and J½ o1" more inches high. A cup-shaped projection is pressed near each end so as to give a contact a g a i n s t rail-web close to the
FIG.
57.--Osborn torch, with additions for underneath bonding when track is spiked down.
end of each rail. N e x t to the copper is a piece of sheet steel s u p p o r t i n g a pair of special s t e e l s p r i n g s : the steel is used to keep springs from w e a r i n g into copper. T h e s e pieces are held t o g e t h e r by a small steel staple passed over the center of b o n d and driven into a cork composition plate which is longer and wider t h a n the metal and serves to exclude dirt from the contact surfaces and to hold the springs in position. All m e t a l parts of bond are a m a l g a m a t e d to prevent rusting, and the c o n t a c t surfaces are covered w i t h plastic alloy. T h e bond is always laid out to suit each particular rail and joint, and does not interfere with the m e c h a n i c a l
I[[
o
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~ }~,ii~/ii~~i~
Mar., 19o4.]
.~aU ]3oltds.
223
fit of angle-plate. W h e n in service the springs serve m e r e l y as distance pieces so long as joint is t i g h t ; if nuts loosen or plates wear, the springs still hold bond in contact. T h e n t i g h t e n i n g the track n u t s also t i g h t e n s the bond. T h e use of spring-lock washers is advised on track nuts to
Fro. 6o.--Verticai section through center of bond contact. keep t h e m f a s t ; these washers will then take up the wear of the plate. W h e r e clearance b e t w e e n web of rail and angle-plate will not p e r m i t the use of springs, a plate of flexible cork is placed so as to overlap the copper on top, b o t t o m and sides and give sufficient pressure to m a i n t a i n the contacts. (See Fig. 6i.) A n o t h e r cork plate is placed .between rail-ends to keep out dirt. To apply this bond it is only necessary to b r i g h t e n web
224
[~arrin~ton :
[J. F. I.,
of rail b e y o n d end bolt hole w i t h a hand-power g r i n d e r and flexible s h a f t w i t h e m e r y wheel. T h e surfaces are then a m a l g a m a t e d and covered with a t h i n layer of plastic alloy. T h e lubrication afforded by t h e plastic alloy p e r m i t s the rails to move in a n y direction w i t h o u t w e a r i n g a w a y m e t a l of bond. Sizes. T h e size of copper is varied to suit r e q u i r e m e n t s up to the full area of the space b e t w e e n rail-web and angleplate, and b e t w e e n end of bolt holes in rail. Bonds with copper plates over ~g of an inch are not cu Fshaped, b u t h a v e a shallow o u t w a r d bend opposite ends of
FIt;. 6~.--Front of No. 5/o solid copper bond, full size, with cork plate. the rails; this avoids scraping bond a g a i n s t sharp rail edges. T h e bond s h o w n in Fig. 6z has a vertical cross-section of more t h a n o'218 of a square inch, while the section of a No. 4 / 0 wire is b u t o'166 of a square inch. T h e bond, therefore, has a g r e a t e r c o n d u c t i v i t y ttian i~0- No. 4 / 0 copper wires. Conductivity. It has been claimed t h a t one No. 4 / / 0 solid copper b o n d laid upon a m a l g a m a t e d contact spots on head of 8o-pound T-rail so as to bridge the joint, carried 2,0oo amperes with a drop of "oi8 volt. T h e drop of i inch of this rail with the same c u r r e n t was "o0223 volt. T h e
Mar., 19o4.]
]~ai/ ]flonds.
225
bond merely laid on top of rail and held in contact by nothiJlg but its own weiff/zt was equal in resistance to but S¼ inches of rail. T h e drop of u n b o n d e d joint, with same current, was "423 volts. Guarantees. M a n u f a c t u r e r s g u a r a n t e e t h a t the bond will t r a n s m i t c u r r e n t at the rate of 2,ooo amperes per square inch of vertical section w i t h o u t h e a t i n g beyond t e m p e r a t u r e of rail.
FIG.
62.--Cast-iron feeder terminal.
T h e y f u r t h e r g u a r a n t e e u n d e r above conditions t h a t at the end of two years' service, the c o n d u c t i v i t y of the bond will be practically the same as at the start, provided the joints have been m e c h a n i c a l l y m a i n t a i n e d in proper condition for o p e r a t i n g cars. Cross Bonds. Copper cross-bond terminals for No. 2 / o and N o . . 4 / o wires. T h e s e are f a s t e n e d to rail web with 1}-inch bolts, whose ends should be riveted after nuts are set tight. T h e end of the wire is a m a l g a m a t e d and slipped VOL CLVII. No. 939. l~
226
Harrillgton
:
[J. F. I.,
t h r o u g h hole in l u g upon b o t t o m of terminal. A roundnosed tool is placed at r i g h t angles to wire in the hole below bolt-hole and the wire kinked by a h a m m e r blow, forcing it into a cored cavity. T h e hole is t h e n filled with plastic alloy and the t e r m i n a l bolted a g a i n s t a m a l g a m a t e d contact spot on rail web. On exposed road where copper track wire m i g h t be stolen, use a steel cross bond i~ inches square, which c a n n o t be r e m o v e d w i t h o u t special tools. For rail feeders and loops a r o u n d crossings, switches and special work, use cast-iron terminals for one or two No, 4 / 0 wires and for 25o,ooo and 500,000 C.M. cables. T h e s e hold a cork case a g a i n s t web of rail, f o r m i n g a receptacle into which is placed the end of the wire and some of the plastic alloy. In each case the wire ends are a m a l g a m a t e d , as are also the contact spots on web of rail. T h e s e terminals are f a s t e n e d to rail web w i t h ~-inch bolts, whose ends should be riveted after n u t s are set tight. PLASTIC RAIL BOND.
For track with h e a v y rail and angle plates, this bond, Figs. @-66, is composed of two p o r t i o n s : a plastic alloy or putty-like m e t a l c o m p o u n d which m a k e s c o n t a c t between the rail and the splice bar or angle plate, and a flexible, elastic cork case to hold the same in position as n e a r end of the rail as possible. T h e initial thickness of the cork ease is nearly double the distance between web of rail and inner surface of angle plate ; it is therefore compressed about 40 per cent. w h e n in place and after pressure has been applied it adheres to the rail and plate, completely sealing tile plastic alloy. T h e cork case is made of a c o m p o u n d of cork and oxidized linseed oil and is practically indestructible. It is elastic and will m a i n t a i n seal even w h e n plate has loosened ~\~ of an inch. T h e c u r r e n t passes from one rail t h r o u g h one plug to the angle-plate, and t h e n t h r o u g h second plug from the plate to the next rail (see arrows in P'io¢. 73). Contact spots about 2 inches in d i a m e t e r on both rails and angle plates are
~4 0
0
0 0
I
0
I
228
t[arriJz~ton :
[J. F. l..
cleared of scale and rust and t r e a t e d with the solid alloy, which i n s t a n t l y silvers the surfaces and prevents t h e m from rusting. T h i s fills the surface irregularities and penetrates the m e t a l s for a perceptible distance, l e a v i n g a surface to which the plastic alloy adheres. Plastic-plug Rail Bond. T h i s can be used on all forms of rail where the fish-plate overlaps rail base by I inch or more. Several different forms to m e e t v a r y i n g r e q u i r e m e n t s are shown in a c c o m p a n y i n g cuts, ]"l~s. 65-66. T h e application of the plastic.plug bond is made after the completion of the track, so t h a t delay t h r o u g h interference of two different g a n g s is avoided. Between the first and second bolt holes from the end of each rail, a hole ~} to
FIG. 64.--Horizontal section. of an inch in d i a m e t e r is bored d i a g o n a l l y d o w n w a r d t h r o u g h the flange of angle plate, into, b u t not t h r o u g h , the base of rail. T h e hole is nearly at r i g h t angles to plate flange and as near[the vertical web as possible. An o r d i n a r y r a t c h e t drill and a J-shaped clamp passing u n d e r the base of rail are the only tools necessary. T h e drill point is l u b r i c a t e d with a solution of pearline and w a t e r instead of oil, so as to avoid the trouble which follows the use of an i n s u l a t i n g fluid on m e t a l contact surfaces, and the hole is usualIy drilled to ½ of an inch from b o t t o m of rail base. T h e drill chips are removed with a p e r m a n e n t m a g n e t , and the proper depth d e t e r m i n e d by t e m p l a t e or collar fastened on drill. The plates m a y be drilled before d i s t r i b u t i n g a l o n g the road;
blar., 19o4. ]
]~?// Bonds.
229
this is more t h a n double the n u m b e r of joints which can be bonded in a day. A f t e r the hole is drilled it is a m a l g a m a t e d by filling with water and r u b b i n g with the end of a rod of the solid alloy. On bonds of large diameter, an a m a l g a m a t e d copper tube is driven into the hole so as to completely seal the crack between the m e e t i n g surfaces of rail and angle-plate as shown on r i g h t side of Fig'. z2. T h i s is u n n e c e s s a r y with the small sizes. T h e hole is then p a r t l y filled with the plastic alloy, w h i c h adheres to the a m a l g a m a t e d surfaces of the steel. A n a m a l g a m a t e d copper plug, which is T-shaped in section, is then driven to seal the hole and to complete the
FIG. 66.--Section of plastic plug bolld.
circuit b e t w e e n the rail and angle-plate by d i p p i n g into the plastic alloy. It is locked in place by a h a m m e r blow on a blunt chisel, m a k i n g a burr in angle-plate j u s t above the top of the plug. F @ @ shows completed joint with s t a n d a r d plastic-plug rail bond. Fig'. 66 shows section of same. In one form of this bond the lower part of the p l u g is a little out of c e n t e r with the top, since less clearance is required on the i n n e r side of hole because f u r t h e r motion of angle-plate i n w a r d can occur only after rail and plate surfaces have worn. T h i s eccentricity allows a groove to be m a d e in top of the plug, and this groove should always face the outside of the rail. The grooves serve to prevent air b i n d i n g as plug is driven
230
Notes a n d Colnments.
[J. F. I ,
home, and are then closed b y a tap of the h a m m e r on the edge. T h e r e is a modification called the plastic screw plug for very h e a v y rails carrying s t e a m road service on b r i d g e s and in tunnels, in which provision is m a d e for easy e x a m i n a t i o n and repair. T h e hole in plate is of larger d i a m e t e r and is screw-threaded and a m a l g a m a t e d before distribution along the road. A h a r d e n e d steel jig is s c r e w e d into hole to properly locate rail drilling. W h e n this hole is drilled and a m a l g a m a t e d a copper t u b e is driven h o m e and around the top of the t u b e is placed a diagonal strip of elastic packing. T h e hole is then partly filled with the plastic alloy and the plug screwed down to compress the packing and seal the joint. [ To be concluded.]
SELF-HARDENING STEELS. One of the recent notable developments in the metallurgy of steel has been the manufacture of what is known as self-hardening or high-speed steels, which are adapted for tools working at a high rate of efficiency. There is a great variety of these steels on the market, and they show wide differences in composition, although usually containing some of the rarer metals, such as tungsten, molybdenum and chromium. Tools made front these steels can work without injury at a temperature of 500 ° or 6oo ° C. T H E MT. V E S U V I U S RAILWAY. What is said to be the most dangerous railway in the world is that recently completed up the side of Mr. Vesuvius for the benefit of the many tourists who annually visit this famous volcano. It is a cable railway of the monorail type, tile one car comprising the active rolling stock being supported by two wheels, one at each end of the car. The center of gravity of the ear is below tile top of the supporting rail, so that it balances without the aid of supporting wheels at the sides. The railway line runs to within nominally I,ooo feet of the crater mouth, but the distance changes from day to day on account of the rapid changes t h a t take place; accretions to the sides of the crater may materially increase the distance one day, and the fall of a huge slice into the seething gulf 5oo feet below may considerably lessen the distance the next day. The maintenanee of the line in proper alignment is a difficult matter. Fissures opening, the flow of lava, falling cinders, and sliding of the roadbed require constant watchfulness and labor by gangs of laborers who eonstantly patrol it during the periods of operation. The " t r a i n " has no fixed time table, the trips depending on the activity of the volcano and diree. lion of the wind; some days t h e y are entirely abaudoned.--IF[ackinery.