Cast Welding of Rail Joints

Experiences with a Historic Welding Process Published in 1905

Cast-welding of rail joints is a historic welding process, which was particularly used to join rails of street railways. Fred G. Simmons, the Superintendent of Construction and Maintenance of Way at the Milwaukee Electric Railway & Light Co. reported on 27 September 1905 in the Daily Street Railway Review about his experience with the process as follows: [1]

The Cast-Welding of Rail Joints

Fred G. Simmons

Superintendent of Construction and Maintenance of Way
The Milwaukee Electric Railway & Light Co.

Among the first joints cast-welded under contract were those on Chippewa Street, St. Louis, on the lines of the Southwestern Railway, during the months of October and November, 1894. The first 744 joints applied at this time were very satisfactory, less than ½ per cent breaking.


During the following year the work of cast-welding joints on the street railway lines of Milwaukee was commenced, and some of the track welded at that time, consisting of a 5-in. 58-lb. tram-girder rail (i.e. with a height of 125 mm and a weight of 28 kg per metre), is still in place and in first class condition after continual service for 10 years.


It is not the intention of the writer to claim superiority in point of efficiency for the cast-welded joints, as compared with several other methods of accomplishing the same result. 


Fig. 1:  The utility motor car used in transporting the apparatus and material, and the cupola with the molten iron flowing is attached behind this car. The thin stream of white hot iron may be plainly seen on close inspection of the picture. 


We do, however, believe that many engineers and managers have avoided the use of the cast-welding process on account of the numerous erroneous arguments advanced against it, and it is the purpose of this article to lay before the public a simple description of the results obtained in the cast-welding of rail joints by the Milwaukee Electric Railway & Light Co., within the personal experience of the writer and under his supervision.


This description and the results obtained, we believe, conclusively show the possibility of cast-welding the rail joints in a manner absolutely satisfactory both as to efficiency and economy.


It is claimed that the mass of molten iron poured around the rail ends effects either a chemical or molecular change in the metal of the ball of the rail which makes this section of the rail softer than the remainder, the inference being that the carbon is burned out. With over 150 miles (over 240 km ) of cast-welded track, some of which has been in service 10 years, and with many miles replaced on account of the entire wearing out of the rail, no instance of a low cast-welded joint has been encountered; in fact when the work was properly and thoroughly handled, absolutely reversing this claim we have found that as our old girder rail wore out the cast-welded joint became the highest point in the rail, the thin metal on each side of it ironing down into depressions, leaving the rigidly supported metal of the joint high. Fig. 11 is reproduced from a photograph of such a joint, clearly showing the conditions as stated.


The entire process of pouring a cast-welded joint is illustrated in the accompanying cuts, made from photographs taken during the actual progress of the work.


Fig. 2: Enlarged view of the cupola car, showing this piece of apparatus in greater detail.


The sand blast is of a simple construction and requires no particular mention. The importance of thoroughly cleaning six or eight inches of each rail end to be welded cannot, however, be overestimated, as it is necessary to remove all scale as well as dirt, and the sand blast process is, of course, the most economical as well as the most efficient. 


Fig. 3: A very comprehensive view of the car containing the sand blast apparatus used to clean the rail ends.

Fig. 4: Joint after being cleaned


The heavy clamp-bar already referred to is also a very essential feature, as this weight of metal not only prevents "cocking" and "kinking" of the joint, but helps prevent an overheating of the ball of the rail. This bar is kept in place until all semblance of red heat has left the joint.


Fig. 5: The molds, car and clamps used in preparing the joint for the pouring of the metal. Attention is called to the strength of this apparatus and especially to the bar. The purpose of this bar is to prevent "cocking" or "kinking" of the joint while cooling, and it has been found entirely efficient.

Fig. 6: Two joints prepared for the pouring operation, the gate on one side and the vent on the other being very clearly discernible.

Fig. 7: The actual pouring of the joint. 

Fig. 8: View of a completed joint, showing particularly the ease with which paving of any kind may be abutted thereto.


Fig. 9: Completed joint


Fig. 10: A section of a joint showing clearly the perfect bond of the metals.


The process is so fully outlined in the illustrations that I will presume to make but few explanations. The heating of the iron in the cupola is in no sense different from the operations of any ordinary cupola, and the mixture used is the only point requiring special mention, this consists of 75 per cent good pig iron and 25 per cent soft scrap.

The sand blast is of a simple construction and requires no particular mention. The importance of thoroughly cleaning six or eight inches of each rail end to be welded cannot, however, be overestimated, as it is necessary to remove all scale as well as dirt, and the sand blast process is, of course, the most economical as well as the most efficient.


The heavy clamp-bar already referred to is also a very essential feature, as this weight of metal not only prevents "cocking" and •kinking" of the joint, but helps prevent an overheating of the ball of the rail. This bar is kept in place until all semblance of red heat has left the joint.


An absolute fusion of a portion of the ball and stem of the rail is necessary in achieving a successful cast-welded joint (a sleeve joint is of no value), and this is not a difficult result. During the last three years we have welded our own joints, having purchased the apparatus shown above from the contracting company, which had previously done the work, and during that time, although we have welded six to eight thousand joints, we have not had one pull or break.


Our electrical tests show the conductivity through these joints to be from 100 to 140 per cent of the conductivity of the abutting rail, and in no case of a proper weld docs this conductivity fall below 90 per cent. This applies with equal force to track just welded, and track that was welded six fo ten years ago, and is borne out by regular periodical tests.


The latest rail adopted as a standard by the Milwaukee Electric Railway & Light Co. is a 7-in. "Shanghai" section of T-rail weighing 95 lb. to the yard (i.e. with a height of 178 mm and a weight of 47.5 kg per metre). The work shown and the joints illustrated in Figs. 8 and 9 are upon a section of track built of this rail. The weight of cast-iron used in this joint is 200 lb. The total cost of the joint approximates $3.50 for the joint proper and $1.00 for the opening and closing of the street; upon new track this last item is almost eliminated.


Our cast-welding work is treated as a business by itself, and the fairest method of showing the cost of these joints to us is to quote from our yearly report for the calendar year 1904:

Cast Welding

Account No. 180
Account No. 181
Account No. 182
Account No. 183
Account No. 184
Account No. 185
Account No. 186

Operating wages
Power & light’g expense
Injuries & damages, 5%
Interest, taxes, insurance



$ 1,590.78
$ 704.83
$ 40.10
$ 362.10
$ 288.00
$ 653.35

$ 6,680.46

per joint $ 0.659
per joint $ 0.292
per joint $ 0.016
per joint $ 1.260
per joint $ 0.150
per joint $ 0.119
per joint $ 0.271

per joint $2.767

The operating wages, repairs and supplies above contain a certain percentage of increase over actual amounts to cover general depreciation. The 2,414 joints were applied to rail ranging from 5 in. to 7 in. in height (i.e. a height of 125 mm to 178 mm). In addition to the above an average of $1.00 per joint must be added as expense in opening and closing the street. A large proportion of the joints were scattered over a wide area and were really welded under adverse conditions.


The foregoing is given as being an exact statement of fact, and is the reason for our belief that in the present development of any of the methods of welding rail joints, the cast-welding process comes most nearly striking the true average between economy and efficiency.


To provide a summary of the foregoing papers is necessarily an undertaking which can result in little definite.


A few correlated ideas assembled and arrayed for purposes of comparison is more exactly what we may hope to accomplish; and in so arraying this correlated data, the fact that the information upon which it is based may not in all cases be complete, or the deduction drawn may not be the true one, serves only to accomplish the end desired, namely, a discussion of the entire subject matter.[2]

Zinc Joints

No figures as to cost obtainable, these joints are controlled by the Lorain Steel Co.   

Electrically Welded Joints

Information received from the Lorain Steel Co. as follows: "Our prices are from $6.00 to $5.50 per joint, depending on the number of joints contracted for. Ordinarily we do not care to accept contracts for less than 3.000 joints, on which, of course, the price of $6.00 per joint applies, contracts for 10,000 or more joints are made at the lower figure."

Cast Welded Joints

The figures in this case show that the entire expense of applying a weld on a rail of average size (under disadvantageous conditions) is but little in excess of $2.75, with $1.00 additional for opening and closing the street. This, including interest, taxes and depreciation charges on the capital valuation of the apparatus. Therefore, in conclusion, and in advance of future enlightenment on this subject, which it is our earnest wish the forthcoming discussion may evolve, the writer seems to see that under present general conditions the cast welded joint is so much more economical, from both the view- point of mechanical efficiency and actual monetary expense, as to recommend itself for first consideration.


Fig. 11: Worn-out cast welded Joint, showing rail high at joint and depressed at each end of casting


Thermite Welded Joints

If, however, the first cost of the portion of thermit required to make a joint can be reduced to the extent of 50 per cent or more than quoted, the other inducements held out by this method are sufficient to give it first rank in point of desirability.  

Of the four methods of forming permanent joints illustrated above: three are properly designated as "welded," while the other (the zinc joint) cannot be classed exactly in this category. The deduction which the writer draws from the four papers, however, is, primarily, that it is possible, with the best knowledge, and by the use of sufficient and correct apparatus, to produce an almost absolutely satisfactory joint (as to efficiency) by any one of the four methods.


Thus narrowing down the field of speculation, the question of amount and availability of apparatus becomes a vital one, which seems clearly outlined as follows:
The electrical welding operation appears undoubtedly to require the most cumbersome and very much the most expensive equipment, to such an extent, indeed, that, except in case of the very largest systems, private ownership would be virtually impossible, and all work would necessarily have to be done through contractors.


The zinc joint appears to rank next in point of expensive apparatus, but is followed very closely in this respect by the cast-welded joint.


The thermit welding process certainly requires very much the least expensive apparatus, and from this viewpoint stands in a class by itself. The relation of the joint to the abutting pavement in city streets is a much agitated question, but it has been shown beyond dispute that this agitation is needless, as the shape of the joint can be regulated to meet the condition.

There are many minor points which might be taken up, and which can be brought out in discussion, but in the opinion of the writer the meat of the entire subject, as it affects the great majority of the electric railway interests, is in the relative cost of an efficient joint by any one of the methods. There are, of course, local conditions which may, in isolated cases, warrant a departure from the seemingly economical method, but our object is at all times to serve the majority, and therefore, while a much more exact comparison of cost will be easily obtainable during the discussion of this subject, such data as we have been able to secure is here assembled.



  1. Fred G. Simmons (Superintendent of Construction and Maintenance of Way, The Milwaukee Electric Railway & Light Co.): The Cast-Welding of Rail Joints. In: Daily Street Railway Review, 27 September 1905, p. 650-654.
  2. In the original version the table has inadvertantly been moved further down.