than one track, and the purpose was to ascertain the operation in the regular order of business, that is, conducting actual operation against the current of traffic at any time of the day. Of the forty-eight roads requested to give the information, thirty-three replied; fourteen of those roads gave full information as to the extent the operation against current of traffic was indulged in by them. I do not know that I can add anything to what has been stated in the report as to the operation of each individual road. We regret that one road which does operate against the current of traffic to a great extent, the Pennsylvania, did not furnish us a report in time to be introduced into this report.

The Sub-Committee therefore offers the conclusion on page 761 for approval.

(Motion carried.)

Chairman Rose:-Professor C. C. Williams will make some remarks on the report of the Sub-Committee in Appendix B, page 746.

Professor C. C. Williams (University of Kansas) :-The work of the Sub-Committee was divided into three sub-heads, the first being the effect of speed on the cost of maintenance of way; second, the effect of speed on the cost of transportation; third, the effect of speed on the cost of maintenance of equipment. Last year the Sub-Committee presented for information some studies on this first topic, but the Sub-Committee was unable to find verification of its results which seemed to justify final conclusions. However, the Committee saw fit to present as tentative conclusions the material given on page 746, which material is presented as information.

The Sub-Committee conducted a good deal of correspondence in an attempt to find operating results which would check or disprove these conclusions, but quantitative observations seemed not to be available. Operating men had impressions as to the effect of speed, but for the most part those impressions had never been reduced to quantitative statements. It is hoped, however, that in another year some further studies will add to this information.

One of the factors which so complicates observations on this subject, of course, is the effect of traction. It is so difficult to eliminate the effect of traction from the effect of speed in making observations that results have been obtained with a good deal of difficulty. This material is presented for information.

Mr. J. B. Jenkins (Baltimore & Ohio) :-I understand that "C" is merely a co-efficient.

Professor Williams:-That is correct. It is the cost of that item on any particular road under any particular conditions.

Mr. Jenkins-The report does not state what "C" means.

Professor Williams:-The fraction is the co-efficient, and "C" is the cost of operation.

Mr. Louis Yager (Northern Pacific):-The summary of the SubCommittee's efforts on the subject of "Methods for Analyzing Costs" is found on page 748.

1

Subject No. 4 is a continuation of a previous assignment. This covers the development of methods for analyzing costs for investigation in which the Committee might be concerned.

We concluded that the activities of the Committee might be very much extended so that a method for analyzing freight train and passenger train mile costs could be developed and used as a basis for many economic operating comparisons. Considerable work has been done on this phase of the subject and the work is to be continued during the year.

The next assignment is No. 7, which is a new one. This assignment we take to mean the determination of the relation between the use of a facility, i. e., transportation units produced, and the physical reparation that should follow that use; as well as the determination of the maintenance increment that would follow an increase of that transportation machine. The work of the Sub-Committee for the past year has been devoted to a partial resumé of the work that has previously been done on this subject in various lines. We have reviewed and made a study of the various transportation units that have been used in previous investigations or suggested as worthy of further study. We have also given considerable thought to the other unit which belongs with this subject, and that is the unit or units of plant, the transportation machine, which should be related to the use unit after we develop it-these two units are being studied together.

We are collaborating with a similar Sub-Committee from the Committee on Records and Accounts. Considerable progress has been made, and we hope during the first few months of the study this year to develop some tentative conclusions for the preparation of a questionnaire to the membership of the Association, which we hope will give us useful information not now available in the study of the subject.

Chairman Rose:-In the Committee's report for recommendations for future work we ask to have subjects 2, 4, 5 and 7 reassigned. We would like to change that and have subject 3 also reassigned. We want to try again. I want to say for some of the questions that the Sub-Committees have reported on, Engineers who have had to do with the planning of improvements and justifying expenditures will get considerable help from the train-hour diagram as a means of comparison of the line at different times.

I do not know that we can do very much in comparing one railroad with another, but we can use this method for comparing before and after. We can also use it somewhat for predicting what we will get if we make certain changes.

The matter that the last speaker referred to was handled last year by the Board. I can understand why we have that subject.

The question whether you can spend too much or too little on the maintenance of track is a very vital one nowadays. In order to make yearly or monthly allowances for maintenance of any work, an effort must be made to determine what is the right amount, and Engineers in

terested in that question should help the Sub-Committee with their work on that line, as it will help us and those having to do with appropriations for maintenance work.

Mr. R. H. Ford (Rock Island) :—I am glad that the Committee feels that they want to give this matter further study and trust that they will have the support of the membership during the coming year to permit a worth-while report to be made this year.

Mr. C. A. Morse (Chicago, Rock Island & Pacific) :-I am very much interested in what this Committee has done. I have had occasion to try to justify the installing of double track many times during the past twenty years, and every time I went into the literature to find out what had been said on the subject I found that everybody was steering clear of it. The Committee has it in hand, and I hope they will keep at it.

Outside of our double-track line on the Illinois Division, the heaviest traffic we have on the Rock Island Lines is between Kansas City and Herington, a distance of 140 miles, the first 66 miles of which is double tracked.

In 1915 I had some figures made as to the speed per hour of trains on the first 98 miles between these points. On the first 66 miles (double track) we were making at that time 16.1 miles per hour on drag freight trains, and on the next 32 miles (single track) we were making 7.5 miles per hour. We built an extension of six miles of second track at one end of the 32-mile stretch and four miles of second track with a terminal at the other end. The figures that we have on the building of this ten miles of second track show that the speed of the drag freight trains on the 32 miles has increased from 7.5 miles per hour in 1915 to 11.1 miles per hour at the present time, so that to-day with 22 miles of single track in the gap, four miles of second track at one end and six miles at the other, we are making 11.1 miles per hour over the 32 miles as against 16.3 miles per hour over the 66 miles of double track. Therefore, we have the difference between 11.1 miles per hour and 16.3 miles per hour as the additional speed we shall get for our drag trains by closing this gap with a second track.

There is a difference of half a mile in the distance between Kansas City and Fort Worth over our line and over the line of one of our competitors; we are each trying to make a record in securing business, and every additional mile of double track that we get helps out in the competition.

Just these things that the Committee has taken up are of vital importance in increasing the capacity of the road. My argument is that the roads having the most second track have a decided advantage and will earn the most money.

The President:-Did you only consider the speed per hour and not the tonnage per hour?

Mr. Morse:-We were drawing the same tonnage, the same trains. The President:-The Committee is dismissed with the thanks of the Association.

(For Report, see pp. 706-726.)

Mr. W. H. Hoyt (Duluth, Missabe & Northern):-The Committee on Wooden Bridges and Trestles had for consideration this year three main subjects. The first is Revision of the Manual. This work has been in the hands of the Sub-Committee, of which Mr. Ridgway is Chairman, and I will ask him to present the recommendations of the Committee on that subject.

Mr. A. O. Ridgway (Denver & Rio Grande) :-For a good many years this Committee has been hoping to see some substantial changes adopted in the arrangement of the Manual. We have been told that it was not possible to effect that just now, so we have been confining our work to such changes of definitions as come to our notice.

I move the adoption of these changes and the addition of one definition to the Manual.

(Motion carried.)

Chairman Hoyt:-The second subject assigned to the Committee is "Wooden Trestles-open deck, multiple-story and ballast deck." The Committee has spent a good deal of time on this part of our report. Last year we submitted a progress report, and supplied information based on the results of questionnaires which the Committee sent out. We also received some discussion and communications which were of interest, and the Committee this year have brought together that information and now submit it to you for your consideration. Mr. Van Auken, the Chairman of the Sub-Committee, has been called away, and I will therefore submit the report for him. It appears on pages 709-13. Your Committee has submitted a boiled-down synopsis showing the basis on which its recommendations are made. The recommendations are shown on page 714 and subsequent pages.

I would move that the plans for standard open-deck trestles, light design, and also heavy design; standard open-deck frame trestles, light design and heavy design, shown on pages 714-17, inclusive, be approved and published in the Manual.

The President:-This is a splendid report, and if there is anything to be said or changes to be made, we should hear them now. The report shows a great deal of study and work.

Mr. A. F. Robinson (Santa Fe) :-This set of plans for timber bridges is one that requires an immense amount of study and labor. It is essential that we provide for the unit stresses and the impact. The present set of plans has dodged the impact question entirely. In my opinion this report is all right if it is submitted as a progress report and not submitted for publication in the Manual. I do not care how good a set of plans is, we should not approve them unless they cover the entire proposition. When they go into the Manual, they are there to stay for some time.

The Committee has submitted three panel lengths for their bridge, and two depths of stringers. They have also gone quite largely from the two-panel length basis to the one-panel length basis.

There are features in these plans that I do not think any of us would want to accept in the way that they are given. In the first place, as to the details of the plans. The scales are altogether too small, and the letters and figures too small in the original drawings to permit their proper showing on these small sheets, but that can be overcome. There are some features that are admirable, others not so good. For example, the plans do not give any working dimensions. They say a 12 by 14-inch cap, a 7 by 16-in. stringer, and all these must have working depths, every one of them, especially where you are using creosoted material. Another item on the sheet shows that the frame bents are on concrete. They are only frames in name. They have the braces at the bottom, but if you are to have a bent that will do service it is best to have one with a cap and a sill.

I do not think the longitudinal bracing has been carefully studied out. In the bracing shown here you have holes, and in a little while the bolts bend or the holes in the bracing (3 by 10 in.) wear longer. We should have a longitudinal brace that braces. This bracing is not effectual, and costs more than a stiff rigid system of bracing.

To go to the ballast deck, you will find 8 by 8 ballast guards with vertical bolts down through them. You will not be able to hold these in that position without "S" straps. These steel bars or straps go from the top of the guard timber down at a proper angle to the surface of the floor timber, and the guard rail bolts or holding bolts go through the "S" strap, through the stringer, and at the other end they are held with a lag screw.

It would be interesting, perhaps, to know something about how the unit stresses in the stringers run. I note that they show 7 in. by 16 in. stringers and 9 in. by 18 in. The plans also show 12 by 14 in. caps, and also 14 by 14. They ought to be made one or the other.

In running over hurriedly the 12-foot panels, the light design, I find if we allow the impact conditions that are required by our steel bridge specifications under the E-60 loading, the fiber stresses show 3,290 lb. per sq. in.; under the E-40 2,440 lb. per sq. in. In the 16 ft. panel, light design, the fiber stresses in the stringers E-60 are 3,520 lb. per sq. in., for the E-40, 1,445 lb. per sq. in., and with the heavy design for the 12-foot panels, E-60 loading, with its impact, gives 2,465 lb. per sq. in. fiber stress, and in the 16-ft. span 2,657 lb. per sq. in. In the ballast deck with the regular allowance for impact the fiber stresses shown are 2,480 lb. per sq. in.

I do not think it is wise for the Association to multiply sizes of stringers and panel lengths. I see no reason why we should not adopt one size of stringer with uniformity in the size of the cap, and a uniform panel length, whether for light lines or heavy lines.