a screw spike socket due to a rock having fallen into the socket. The remaining 72 ties were removed in January, 1921. These ties were cracked on the bottom directly under the rail, a distance of about 31⁄2 inches to 4 inches towards the top of the tie. No ties now remain in track.

MOORE CONCRETE TIES-Forty of these ties were installed in main track within yard limits at Lafayette, La., on January 31, 1917. They are subject to heavy traffic but not to high speed. One tie broke in two after one day's service and one tie was taken out in February, 1917, for inspection. Thirty-eight are still in track, of which one is entirely disintegrated and the others in more or less bad condition on account of broken and chipped ends and loose rail fastenings. The tie is illustrated in Fig. 8.

Southern Pacific Lines in Texas.

Kind-Indestructible, Percival.

Reported by-H. M. Lull, Chief Engineer.

Date-August 27, 1921.

INDESTRUCTIBLE-All of the ties installed in May, 1916, are still in track. Inspection on August 9th shows that they are apparently in the same condition as when installed.

PERCIVAL Of 50 ties installed in test No. 1 in October, 1906, three ties were removed account of derailment, four for inspection purposes, and thirty-two account failures in tie or fastenings. Eleven ties remain in track.

In test No. 2 thirty ties remain in track out of fifty-two placed in October, 1906, twenty-two ties having been removed account of failure in tie or fastenings.

Terminal Railroad Association of St. Louis.

Kind-Chamberlain.

Reported by H. J. Pfeifer, Chief Engineer.
Date-July 12, 1921.

CHAMBERLAIN CONCRETE TIES-The ten ties put in track at St. Louis in April, 1920, are still in service. They have cracked to a considerable extent but not sufficiently to make their removal necessary, as they are in a slow speed track.

Wheeling & Lake Erie.

Kind-Munslow Steel Tie.

Reported by John Sesser, Engineer Maintenance.
Date October 7, 1921.

Twenty-five of these ties were installed on September 15, 1916, in the main track about one-quarter of a mile east of Pennsylvania Crossing of Jewett, Ohio. The ties are hollow, made of -inch steel plates 81⁄2 feet long and about 3/4-inch wide, weight about 200 lbs. When pressed into shape the ties have a bearing surface of 8 inches on bottom.

The ties support 90-lb. rail in slag ballast, 1 per cent. grade, tangent track. Traffic is heavy, about twenty trains per day passing over these ties. Maximum speed is fifty miles per hour.

Twelve ties were removed in March, 1920, account of developed weakness in the metal under the rails. Of the ties remaining, eleven are broken and will have to be replaced.

EFFECT OF DESIGN OF TIE PLATES AND TRACK SPIKES ON THE DURABILITY OF CROSS-TIES, AND RESULTS OF IMPROPERLY PROTECTING TIES FROM MECHANICAL WEAR.

M. S. BLAIKLOCK, Chairman; F. BOARDMAN, G. F. HAND, A. J. Neafie, Sub-Committee.

This subject has been assigned since 1912 and the following reports have been made:

YEAR 1913-VOL. 14-PAGE 728

The report developed the extent of the use of flat and flanged tie plates, the size of tie plates in general use, the extent of use of cut and screw spikes and an opinion as to tie plate bearing area and distance plate should extend outside base of rail.

YEAR 1914 VOL. 15-PAGE 726

The report developed the effect on the tie of different features in the design and application of the plates and spikes as determined from a canvass of twenty-nine (29) railroads. It covered the damaging effect of tie plates of insufficient width and thickness or having deep ribs or claws, damaging effect of cut spikes and prolongation of life of tie by use of screw spikes rather than cut spikes, and desirability of boring ties for spikes before treatment. Appendices were attached as follows:

"A"-Comparative holding power of spikes.
"B"-Cut spikes vs. screw spikes.

"C"-Photographs showing the effects of tie plates and spikes
on ties from studies on the A. T. & S. F. Ry.

YEAR 1916 VOL. 17-PAGE 233

The report illustrates tendencies of good practice as regards rail fastenings in their effect on ties, and calls attention to the desirability of reducing or eliminating, if possible, movement between tie plate and the tie. Information is given as to size of tie plates and spikes used on certain railroads, with photographs of several designs used by the D. L. & W. R. R.

YEAR 1917-VOL. 18-PAGE 475

The report developed the cause of failure to protect the tie and reached certain conclusions respecting proper design of tie plates. Appendices were attached illustrating tie failures on the D. L. & W. R. R. and the development of the tie plate on the Penna. R. R.

YEAR 1919-VOL. 20-PAGE 226

The report made a study of the relative effect of cut and screw spikes on the durability of the tie and expressed the following opinions:

1. That there is not sufficient data available, due to lack of general use, to show that the use of screw spikes will increase the durability of ties except under special conditions.

2. That there may be specific forms of track construction where screw spikes prolong the life of ties, such as on elevated structures and so-called permanent track where there is more substantial foundation provided than on ordinary tie and ballast track.

YEAR 1920 VOL. 21-PAGE 580

The report deals with the screw spike and gives what, in the opinion of the Committee, is good practice in regard to a screw spike installation.

It is the purpose of this report to briefly summarize the conclusions arrived at which, in our opinion, continue to represent good practice. The principal effects of different kinds of tie plates and spikes on the tie have been described in previous reports and are matters of general knowledge.

1

It would be uneconomical to use material and labor in protecting the cross-tie from mechanical wear beyond what is necessary to prevent the tie failing from this cause before it has to be renewed because of decay or other reasons. It is impracticable to make an attachment between the tie and the rail it supports without in some degree injuring or distorting the fiber of the wood, and any safe method of attachment is satisfactory which does not limit the life of the tie so that it has to be removed account of spike killing or mechanical wear before its strength is exhausted because of decay. The use of preservatives which increase the life of the tie very greatly from a decay standpoint has justified additional expense in protecting the tie from mechanical destruction, and this has brought about the use of larger and stronger tie plates and improved methods of spiking. It should be borne in mind that the safety and cost of maintenance of the track depend largely on the continued efficiency of the connection between rail and tie, and the dictates of good practice in design of fastenings are the same whether from a tie protection standpoint or a track maintenance standpoint.

Tie Plates-Effect of Design.

The following features should be provided for to ensure a minimum of damage to the tie:

a. Adequate strength and area to prevent buckling and excessive settlement in the tie. The required bearing area and thickness will be governed by the kind of wood and character and amount of traffic. The distances the plate extends beyond either side of the rail base should be so proportioned as to prevent uneven settlement of the plate into the tie and consequent rolling of the rail. Allowance should be made for the deterioration of the tie plate which will normally take place, particularly near salt water or where there are brine drippings. b. It is important that the tie plate have a shoulder to maintain gage, so that the thrust from the rail is transmitted to the tie through the bearing area of the tie plate and the spikes as a unit, instead of being directly resisted by any spike.