Compression Welding, 1917


A patented type of electrically-welded joint used at St. Louis since 1917

Edward S. Clark invented and patented a new type of weld joint to make electrical connection between the rails of a street railway in St. Louis in 1919, using an electric welding machine made by Thomson in 1894. A newspaper report and his patent are shown below:


New Type of Electrically-Welded Joint Successful

Process Used at St. Louis Believed to Eliminate Cracking of Rail Around Joint

Applicable to Old and New Track

Rail Chairs and 6-In. Rail Used When 9-In. Was Unobtainable

 

Electric Railway Journal, Vol. 53, No. 4, 25 January 1919, p. 182-183.[1]


   
The United Railways of St. Louis, Mo., operate 450 miles of track, with various types of rail, from the 132-lb. rail used under heavy traffic in the city; to the 60-lb. (30 kg/m) rail used on some country lines, furnishing a wide variety of conditions with which to cope. During the past year, more than 2000 joints have been electrically welded on this property by a new process known as the "compression" method. Prior to the use of this process breakages at the joints had amounted to more than 4 per cent, while since it has been used no breakages have occurred.
The joint is made with two fishplates and four 1 3/16-in. (ø30 mm) fillets, as indicated in Fig. 1. In the group Figs. 2 and 3 show two later stages in the formation of the joint. At present rivets are being used for fillets because they are most easily obtained. The two end fillets extend through the two fishplates and the rail web. While for the center fillets shorter rivets are used with the heads between the fishplates and the rail and butting into the hole in the web. This is to provide plenty of material to fill the holes in the web and the plates when the fillets are heated.
   

New type of welded joint used at St. Louis:   

Fig. 1 — Fishplate with center fillet ready to assemble on joint.    
Fig. 2 — Compression joint assembled ready for welding.    
Fig. 3 — Completed joint ready for service.

   

Center and End Fillets are Treated Differently

An electric welder, shown in Fig. 4, is first placed in position on one of the center fillets, these being nearest the ends of the rail. Pressure is applied hydraulically to the ends of the fillet until 2000 lb. is registered. Then a current of 20,000 amp., requiring 6 volts, is passed through the terminals for one minute.

   

When the metal begins to melt the pressure causes the fillet to fill the holes in the web and fishplates. With the fillet and surrounding metal at a welding heat the current is turned off and the pressure is increased to 4000 lb. and held there for fifteen seconds. The process is then repeated with the other center fillet. This gives a homogeneous weld of the fillet, fishplates and rail web.

   

To the two end fillets the initial 2000-lb. pressure is applied as before, but the current is left on for but fifteen seconds. The fillet and the immediately adjacent parts of the fishplates are brought to a welding heat and the hole in the web of the rail is filled, but the web is not heated to a welding temperature. It is believed that this plan will result in reducing the number of breakages which generally occur around the ends of the fishplates. The welding outfit is capable of handling an average of eighty joints per day of ten hours with three men at the welder and one operator.
  
The welding equipment is followed by a Kleinschmidt grinder, which includes two planer grinders equipped with rotary wheels. The horizontal traveler, which may be adjusted vertically, is supported on the rail by wheels at each end and remains in a level position. The grinding wheel travels back and forth on this support, catching the high spots. The horizontal distance through which the grinder travels may be changed to suit conditions, or the wheel may be held in one position.

   

Whenever it becomes necessary to re-lay portions of track, new 9-in. (229 mm) Lorain section is used when obtainable, but recently it has been necessary in many cases to use 6-in. T-rail in replacements. For this purpose use is made of a rail chair of dead soft steel measuring 7 in. x 6 in. (178 x 152 mm) across the top. After the old rail has been removed, the chairs are placed in position, one on each tie, and the rail is put down. The four clamps are then hammered down firmly over the base of the rail and the chairs are fastened to the ties with screw bolts, electrically driven. Where the old track had been laid in concrete new concrete is poured to a depth of 3 in. (76.2 mm) to bring it up to the base of the rail.

  

A photograph reproduced on below shows an interesting type of work which is being done with the welding equipment. This is a 20-in. (508 mm) insert, or "dutchman," and it has been welded just as with ordinary new track, six fillets being used, however. After this welding was completed, pieces of steel 1 in. thick, 2½ in. (63,5 mm) long and 3 in. (76.2 mm) wide were welded to the plate supporting the ends of the rails, to prevent the heads of the old rails from cracking and breaking off, which frequently happens when the supports are not used.

 

Installing the new-type welded joints on United Railways tracks:

Fig. 4 — Welding machine at work on a compression joint.  
Fig. 5 — Rail grinder smoothing off a completed joint.   
Fig. 6 — Rail chair construction with 6-in. (152 mm) rail replacing
section.   
Fig. 7 — Welded insert joint or "dutchman" with special support
for head of rail.   
Fig. 8 — Portable turnout and passing track for single-track
welding work.

    

In connection with the welding work, a new type of portable turnout and passing track has been developed in St. Louis to prevent welding on single track from interfering with car schedules. This construction is portable as an assembled unit. Whenever the joints inside the turnout are completed, one car of the welding equipment is attached to each end of the portable track and it is dragged to the next point where welding is to be done. In one instance a mile of temporary trolley wire was strung at one side of the permanent overhead and thus the delay due to shifting of the turnout was minimized and the cost was kept down.

   

The compression joint described herein was invented by E. S. Clark and patented by him in May, 1918. Mr. Clark is engineer of construction for the contractors for the work being done in St. Louis.

    


Rail Joint and Method of Making Same

Edward S. Clark, St. Louis, Mo

Filed July 27, 1917. Serial No. 183,071. (CI. 239 — 4.). US Patent No 1.265,051.[2]


1. A method of producing an electrically welded rail joint, characterized by arranging fillers or metal rods transversely in the webs of two abutting rails, arranging fish plates or bars longitudinally of the rails at opposite sides of the webs and thereafter heating said fillets by an electric current so as to weld them to the webs of the rails and to said fish plates.
  
2. A method of producing an electrically welded rail joint, characterized by arranging fillers or metal rods transversely in the webs of two abutting rails, arranging fish plates or bars longitudinally of the rails at opposite sides of the webs, and thereafter raising said fillets to a welding temperature and subjecting the fillets and fish plates to pressure so as to weld the fillets to the webs of the rails and to the fish plates.
  
15. A rail joint, comprising bars or fish plates arranged on opposite sides of the webs of the rails, and fillets or metal rods arranged transversely of the webs of the rails and welded to said webs and to said fish plates.
  
19. A rail Joint, comprising bars or fish plates arranged at opposite sides of the webs of the rails, toothed reinforcing elements Interposed between the fish plates and the webs of the rails, and transversely-disposed connecting devices electrically welded to the webs of the rails, fish plates and said reinforcing elements, the connecting devices at the center of the joint being welded to the inner sides of the fish plates and the connecting devices at the ends of the Joint being provided with heads that lap over the outer sides of the fish plates.
  
21. A rail Joint, comprising fish plates arranged at opposite sides of the webs of the rails, reinforcing elements Interposed between the fish plates and the webs of the rails and provided with teeth or ribs that are sunk into said parts, head supports and base supports at the center of the joint that reinforce the heads and the base flanges of the rails, said supports being permanently connected to the rails and to said fish plates, and fillets extending transversely through the webs of the rails and electrically connected to same and to said fish plates.
  
(Claims 3 to 14, 16 to 18, and 20 not printed in the Gazette.)
  

References

  1. New Type of Electrically-Welded Joint Successful. Electric Railway Journal, Vol. 53, No. 4, 25 January 1919, p. 182-183
  2. Edward S. Clark, St. Louis, Mo: Rail Joint and Method of Making Same. Filed July 27, 1917. Serial No. 183,071. (CI. 239 — 4.). US Patent No US1.265,051.