This article appeared in the Spring 2000 issue of Spikes, Ties & Rails, the publication of the North American Railroad Maintenance of Way Association.  They are behind in getting issues out---this one was mailed out in January 2001!  Visit their website at
http://www.drbens.com/narrmowa.htm.
 

Screw dowels (trenails) on the Santa Fe

by Jeff Oaks

All M-O-W folks know that the primary function of tie plates is to eliminate rail cutting.  Ties without plates are often badly damaged due to the action of the rail on the wood, which can be particularly bad on softwood ties.  I personally have seen plateless ties cut down a full inch by the rail.

There are other advantages to tie plates as well---just read over any book on railroad engineering.  One problem of mechanical wear they do not address is the holding power of spikes---especially those which are removed and then replaced in the same hole.  When replacing spikes, a tie plug is used, but in softwood ties even the first spikes can work their way loose.

It was only at the turn of the century, when treated softwood ties were first being used in vast numbers, that these mechanical problems received serious attention by American railroads.  Tie prices were on a steep rise, and railroads could no longer afford to use untreated, unplated ties which would be discarded just as rot and mechanical wear made them unserviceable.  Many railroads finally took up tie treating in the first decade of the century, and in order to protect this investment, they worked out ways to prevent mechanical wear.

Tie plates had existed for some time, of course, but they were not always made of steel!  In February, 1904 the Santa Fe began using wooden tie plates.  By 1905 thousands were being tested from Illinois to Texas.  They were made from cypress, gum, and elm, and were from 1/4" to 3/8" thick.  Cost was the big plus for these plates---they were far cheaper than steel tie plates (from Railroad Gazette, January 20, 1905, p. 54).

        Wooden tie plate used by the Santa Fe.  From Railroad Gazette, January 20 1905, p. 54.  The words on the plate on the right read "width varies".

Another, more bizarre material for tie plates was adopted by some French railroads.  As of 1901 "tarred tie-plates, of animal felt, have heretofore been in use, but are now replaced by creosoted poplar tie-plates, which cost less than 1 cent each, and are said to be giving perfect satisfation'' (Am. Soc. of Civil Engineers, June 1901).  Here is where we see more precisely the way in which tie plates protect the ties.  It isn't the weight of the rail on the tie which causes rail cutting, but rather the motion of the rail on the tie.  Ties are "filed down'' by the rails, not crushed.  In this light the felt tie plates make sense: they were used "solely to protect the wood against the mechanical action of the base [of the rail].'' (Sellew, Railway Maintenance Engineering, 1919, p. 164).  The same goes for the wood plates.
 

Screw dowels, also called trenails

But this article is not about tie plates.  It is about trenails, also called screw dowels. These are described in the 1904 Proceedings of the American Railway Engineering & Maintenance-of-Way Association:

"Attention has been called to a method developed abroad, whereby the wear under the rail or at the spike in a soft wood tie can be materially decreased.  This consists of the insertion of a hardwood trenail, so-called, being a wood screw of two or three inches diameter, having a spike hole bored in the center.  This trenail is screwed into a hole tapped in the tie, and a spike driven or screwed into it.  This method has been followed for the past six years in France, with very satisfactory results, the trenails being applied either to new ties or to old ones which had begun to make trouble through failure to hold the spike.  It is understood that several of the railroads in the United States have agreed to test these trenails, and it is hoped some valuable results may be derived therefrom."  (page 76)

    An illustration of screw dowels for both cut and screw spikes, from p. 52 of The Elements of Railroad Engineering by William G. Raymond (1917).

Here is another quote from the same volume:

"The upper part of the dowel is somewhat larger than the body.  A hole somewhat less than the diameter of the screw or spike is bored through the center of the dowel.  The dowel is heavily creosoted.  The dowel is put into the tie in the following manner:  A hole is bored somewhat less than the diameter of the dowel, and by means of a threading device a thread is cut in this hole.  The dowel is then screwed in either by hand, when there are a few ties to be provided with dowels, or by machinery, when a large number are to be provided.  In France and Germany the dowelling process is usually carried out in connection with the treating plants.  The dowel makes a perfect fit with the tie...Should any of the wood around the spike wear out, the dowel is removed and another is screwed in its place.  The body of the tie is thereby saved from destruction.  The tops of the dowels at the same time act as tie-plates, preventing the wearing out of the wood of the tie, and in many cases have rendered the use of expensive steel plates almost unnecessary.  A further advantage of the dowel consists in the very much increased holding power which the dowel gives to the spike or screw, principally in the matter of resisting the lateral pressure." (pages 96-97)


    My drawing of how screw dowels (trenails) were used.

Screw dowels on the Santa Fe, 1919

Screw dowels have been found in a particular stretch of track on the Santa Fe between Chilocco, OK and Arkansas City, KS.  I found records of this test section in different volumes of the Proceedings of the American Wood-Presevers' Association (1928, p. 101; 1934, p. 212; 1937, p. 168).  At least 14,155 creosoted and dowelled southern yellow pine ties were laid there in 1919.  Four dowels, each about 1 3/4" in diameter, were used in each tie.

On the Santa Fe screw dowels were usually used in untreated ties, as can be seen in this 1920 quote:

"Neither Port Orford cedar nor redwood ties are treated for the reason that they are removed from the track on account of mechanical wear before they really begin to decay.  This mechanical life is now being very substantially increased by the use of hardwood dowels into the tie for the reception of cut or screw spikes.  These hardwood dowels are treated with a preservative before being screwed into the redwood tie and greatly reduce rail cutting and spike killing, which are particularly great in the case of the soft redwood timber.  The necessity for the use of these soft wood ties on the Pacific Coast is because there is no hardwood timber available." (1920 Proceedings of the American Railway Engineering Association (AREA), p. 287)

But the 1919 test, one year before the AREA article quoted above, was of creosoted pine in Oklahoma, not untreated cedar or redwood in California.  We need to go over some details of the 1919 ties to determine just what the Santa Fe was testing.  But to do that, some background information is necessary.

Date nails

In case you don't know what a date nail is, a typical example is 2 1/2" long with a 1/4" shank.  It has the last two digits of the year stamped in the head, so a "15'' would have been driven into a tie in 1915.

Here is a chronology of Santa Fe date nail use:
 
1901 The Santa Fe abandons stamps in ties for records and begins using date nails in all treated ties and timbers.  The nails have round heads and indented figures, and through 1909 they have a single digit representing the year.
1910 Due to the mountainous records involved, they stop using date nails in all ties and timbers.  Instead they concentrate their records on special test sections of track, where date nails are still used.
1921 They revert to the practice of using date nails in all ties and timbers, though they continue to monitor only those in the test sections.
1926
This year the Santa Fe switches to the use of nails with raised figures.
1969
Last year for Santa Fe date nails.

(I am not going to discuss the diamond, square, and pentagon nails used by the Santa Fe in this article.)

Even though date nails were used only in test sections from 1910 through 1920, nails from this period are not rare.  The Santa Fe had over 800,000 ties under observation in these years.

Santa Fe test sections (beginning 1910) "may be divided into three general classifications:

    1. Those comprising complete section foreman's territories, generally one on each operating division.  [26 in total]
    2.  Those known as A.R.E.A. tests, the condition of which is reported from time to time by the Wood Preserving committee of the American Railway Engineering Association, and by the Tie Service Records committee of this Association.
    3.  Other tests inaugurated for special purposes.'' (from the 1941 Proceedings of the American Wood-Preservers' Association, p. 190)

The Chilocco test falls into the second category, and it was the only one with screw dowels.

There are only two exceptions to the rule that pre-1926 Santa Fe nails have indented figures: some raised 22's were found in a special test section (3rd type) in California by Mel Smith, and raised 19's were used in the Chilocco test.  These 19's were manufactured by the C.C. & E.P. Townsend Co.

The ordinary Santa Fe 19, used in all other tests, has indented figures, and was manufactured by the American Steel & Wire Co.  While the indented 19 is a nail which was used by many railroads, only the Santa Fe used the Townsend raised 19.

    The Townsend Co. 19 (left) was used only in the Chilocco test section.
    The standard Santa Fe 19 (right), made by American Steel & Wire Co.,
    was used in ties in all other test sections.

Dale White, a nail collector in Arkansas City, gave me some more information.  In all, he and other collectors probably pulled over a hundred raised 19's from the five mile stretch of track between Chilocco and Arkansas City.  The ties in the bridge over the Arkansas River had the standard Santa Fe round indent 19's.

Tie plates on dowelled ties?

By the time nail collectors were busy yanking all those 19's, the ties had tie plates.  The question is:  Did they have tie plates in 1919?  After reading the description of trenails in the AREA articles, you might think it wouldn't make much sense to use them with plates, since they serve pretty much the same purpose.  But recall that one aspect of mechanical wear is not addressed by tie plates:  the holding power of the spike.  For softwood ties like those used in the Chilocco test, the dowel really improves holding power, both of the original spikes, and especially of replaced spikes.  When a spike is replaced a dowelled tie, the old dowel is removed and a new one screwed in, obviating the need for tie plugs---and more effective, I would guess.

I wouldn't be suggesting that the 1919 ties originally had plates without some good reason, and it has to do with the date nails.  Why did the Santa Fe go to the trouble of ordering raised 19's from a different steel company just for this test?  An answer like "to distinguish the dowelled ties from the undowelled ties'' is no explanation at all unless the ties were plated.  Without plates, the dowels would have been very visible.  With plates, the dowels would have been hidden.

Don Blake, a nail collector in Texas, first suggested that the ties originally had plates, and the raised 19's were necessary to distinguish the ties with trenails.  After all, indent 19's were used in the bridge on the same stretch of track, and those ties, I believe, were not dowelled.

So my tentative conclusion, based on a convoluted argument (I admit that!), is that the Chlilocco test of 1919 was designed to determine if screw dowels would be a cost effective way to improve the holding power of spikes.

Don sent me two very clear photos of one of the test ties.  There are three holes at each rail.  Two have the screw dowels, and the third hole, inside the rail, has an ordinary tie plug.  It seems that the ties had two spikes per rail originally, then three spikes later on.  Still later the third holes were plugged, after which they used only the two spikes in the dowels.


    Drawing of the tie Don Blake photographed.
 

Back to the main page