that the character of fatigue was difficult to demonstrate because of lack of knowledge as to the volume and characteristics of traffic over a particular bridge.

This is not in my prepared testimony but it occurs to me that each one of these major toll facilities must, by the very nature of its operation, keep current records of the volume, character, weight, axle vehicles, everything else that moves on one of those major structures. There is a daily record computerized as this particular information. Now, as another suggestion, with traffic surveillance growth in engineering development, it is perfectly possible to provide traffic surveillance and control and scanning of vehicles that go over all of these structures if that should be necessary and is economical, but the procedure could be worked out. It is working on these toll facilities and I think it has been extremely helpful.

Now, if the committee permits, I have attached to my written testimony an exhibit. I have said in my testimony that the procedure to which I have testified is a matter of contract; it has worked as a valid procedure for the original design of these major structures; the same consulting engineers are obligated to inspect during construction; the same consulting engineers are obligated annually to make an inspection of the structure, and make their recommendations for the amount of money necessary to meet the requirements of their recommendations and transfers to reserve maintenance funds.

Now, as all of these projects are set up, all of these requirements must be met out of a budget before a nickel can be paid to interest or principal of bondholders. There is an assurance by contract that the first charge on gross revenues of these facilities is for this purpose.

Now, in my written testimony, the attached exhibit is an illustration of what a firm of consulting engineers of this character of national repute does in the actual inspection of a bridge project.

This is taken from our experience on our own Richmond-Petersburg Turnpike Authority, and I would be delighted to offer it for the files of the committee.

With the approval of the Committee, I would like to offer as exhibits xeroxed copies of examples of annual inspection reports by consulting engineers and examples of the legal covenants by the particular Authority or Commission which require the preparation of such reports. The exhibits which I offer relate to the following projects:

The Chesapeake Bay Bridge and Tunnel Commission in Virginia.
The City of Chicago Calumet Skyway.

The Coastal Highway District of Georgia, operating the Savan-
nah River Crossing.

The Davenport Bridge Commission, operating the bridge between
Davenport, Iowa and Moline, Illinois.

The State Highway Department of Delaware, the operator of the
Delaware Memorial Bridge.

The Elizabeth River Tunnel District, operating the bridge over
the Elizabeth River in Virginia.

The International Bridge Authority of Michigan.

The City of Kansas City, Missouri.

The Maine-New Hampshire Interstate Bridge Authority.
The Mackinac Bridge Authority.

The State Roads Commission of Maryland, operating toll bridges in the State of Maryland.

The New York State Bridge Authority.

The Virginia State Highway Commission, to which I have referred above.

The Washington Toll Bridge Authority.

(The exhibits presented by the witness are on file with the committee.)

Mr. PERSHING. Now, if I may clarify or enlarge that testimony within any time that you have available, I would be delighted to do so. The CHAIRMAN. One question only.

How many bridges are involved?

Mr. PERSHING. In my testimony, I have referred to the fact that the active membership of the International Bridge, Tunnel and Turnpike Association comprises the owners and operators of substantially all the major facilities in the United States and foreign countries.

In the United States the agency members of the turnpike association are owners and operators of 102 of the major toll bridge facilities in the United States, and 37 major toll roads.

In the foreign membership of the association are included members from Australia, Canada, France, Hong Kong, Israel, Italy, the Netherlands, New Zealand, Portugal, Spain, and the United States.

Again in my capacity as a layman and not a lawyer, the association has very active committees, one of which is a very important research committee chaired by Mr. Robert Foote of the Port of New York Authority.

I happen to know that the new bridge in Portugal has been designed and constructed to include facilities for measuring stress during the life of the bridge. That, I believe, is what they call the Salazar Bridge in Lisbon.

The CHAIRMAN. Thank you, Mr. Pershing.

I have had the responsibility of addressing one of the sessions of your organization in Pittsburgh. I wish that I were as articulate and astute and as thorough as are you.

Thank you very much.

Mr. PERSHING. Thank you, Senator.

The CHAIRMAN. Mr. Gray.

I believe, Mr. Fox, you come with Mr. Gray; is that correct? Mr. Gray, will you now for the record indicate who you are and also give us the name of your associate?

STATEMENT OF NOMER GRAY OF THE FIRM OF AMMANN & WHITNEY; CHAIRMAN, COMMITTEE ON PROFESSIONAL PRACTICE AMERICAN SOCIETY OF CIVIL ENGINEERS

Mr. GRAY. My name is Nomer Gray, a partner in the consulting firm of Ammann and Whitney in New York.

I am appearing here on behalf of the American Society of Civil Engineers.

I suspect I was chosen because of my rather extensive experience in bridge construction rather than the fact that I am also chairman of the committee on professional practice.

In the interest of saving time, I would say that following the very extensive questioning of Mr. Masters, there is not very much I can add except perhaps to reenforce some of the points that he made.

The CHAIRMAN. At this point, I am going to ask you a question. You remember I asked Mr. Masters if he had the opportunity to review the procedures outlined in the guidelines of March 1968. Have you had the opportunity?

Mr. GRAY. I have not had but I will be very happy to review them and comment, if you wish.

The CHAIRMAN. I would like to give you a copy and then have you supply for the subcommittee your comment and that will be included as a part of your testimony.

Mr. GRAY. Very good.

I might just make one comment. Mr. Masters suggested the use of professional engineers who served in the various States to supervise the inspection teams. I would go perhaps a step further. Since this licensing procedure involves people that are specialists in a variety of civil engineering branches, I think it would be essential to choose a licensed engineer with particular experience in bridge design and preferably in bridges of the character that are being inspected.

I certainly subscribe to the idea that in general the persons assigned to the inspection of existing bridges are frequnetly employees with rather limited understanding of the behavior of bridges with respect to the stress conditions. In fact, a great many of the discoveries that have been made over a period of time have been made by persons involved in such operations as the painting maintenance and things of that kind.

It probably is worthwhile emphasizing the fact that while tremendous interest has been generated and attention focused on this subject as a result of this most unfortunate catastrophe on the Ohio River, that the number of major bridge failures in the last few decades is extremely small and in the case of at least one of them was attended by no loss of life whatever.

So, this perhaps would be reassuring that the situation is not quite as bad as it might appear on the basis of this recent catstrophe.

It is also worth perhaps mentioning that many of the steel bridges in this country are now becoming very old. I was involved in a study of the Brooklyn Bridge in 1943, 1944, and 1945, at a time when that bridge was 60 years old, which means today it is about 85 years old. The Cincinnati-Covington bridge is about 100 years old.

I don't single this out because I have any doubt of its capacity but only because it is a very old bridge. It may be that while we have had relatively few major failures, we may be entering a period when there will be more due to the great age of many of these bridges.

Large bridges are in a class by themselves, of course, as regards investigations and they are almost invariably investigated by people that are rather carefully selected and on the basis of their experience and likely to produce a knowledgeable report.

I might comment on the relative cost of such an inspection as compared with the value of the bridge.

For instance, Brooklyn Bridge, when it was originally built, was built for a relatively modest sum of about $15 milllon in the 1870's, finished in 1893, and would perhaps have a replacement cost today of $100 million. The inspection that was made at that time, which was,

I would judge, pretty complete, it took place over a period of perhaps a year and 3 months, cost only about $80,000.

Similar bridge inspections, depending, of course, upon the scope and the funds available of large bridges today, may be running between $200,000 and $500,000, but we are talking of structures that may be of the order of $100 to $200 million in replacement cost.

I would think certainly on that basis that such inspections at reasonably frequent intervals of, say, 5 to 10 years would be fully warranted. Clearly, the older the bridge, the more necessary it is to examine it.

I don't think anyone would suggest an immediate inspection, for instance, of such a new bridge as the Verrazano-Narrows Bridge in New York, which was only opened in 1964.

I believe that Mr. Masters fully covered many of the points I would be interested in.

In the interest of time, I think I will terminate my present discussion here and offer to answer any questions you may have.

(The information supplied by Mr. Gray follows:)

COMMENTS ON INFORMATIONAL GUIDE FOR INSPECTION OF HIGHWAY BRIDGES OF THE BUREAU OF PUBLIC ROADS

I shall comment below in the sequence in which the material occurs in the "Informational Guide" which is not by any means in the order of importance. Such a check list has a certain limited usefulness, particularly where the personnel to be employed in the inspection do not have an adequate background for this important work. The list can never take the place of the experience and imagination of a trained observer in detecting possible sources of danger. It can have some use in the training of inexperienced personnel working under the guidance of an experienced bridge engineer.

Page 1, line 2: In listing the information required for the Bridge Inventory, I would add following the word "type" the word "material." For a number of reasons it is important to know if one is dealing with a steel, concrete or timber bridge.

Page 1, 3rd paragraph: There is room for a detailed description of what is meant by "qualified personnel." Actually, a team should be used. Inspection of bridges is a field exercise and it requires persons who are, by temperament and experience, accustomed to working under hazardous conditions. These personal traits are usually at variance with the characteristics essential to careful observation and the imagination to search for possible causes of potential danger. For this reason the active types performing the actual inspection should work under the close guidance of a structural engineer familiar with the structural behavior of the type bridge being examined. Only such a combination of talents can make a meaningful inspection.

Page 1, last paragraph: The comprehensive inspection every five years, combined with the less detailed inspection at two year intervals, should be adequate. Page 2, Part I: The breakdown into nine categories is unnecessarily complicated. It should be sufficient to separate the bridges into groups by:

1. Age, with oldest getting highest priority.

2. Span length, with the long span bridges (over 1,000 feet) getting high priority.

3. Bridges likely to be subjected to higher live loads than designed for, due to changing traffic patterns on temporary detours.

Page 3, last line: The importance of documenting the inspection cannot be overstated. Human nature being what it is, the writing down of observations will compel closer attention to detail as well as providing a record from which analyses can be made.

Page 4, line 6: "Accumulation of birds' nests" is hardly likely to seriously damage bridge supports which are commonly of concrete or stone masonry. Per"haps this was included for comic relief in an otherwise serious document.

Page 5, line 7: The word "surveyed" could be made clearer by changing it to "referenced." Very often the word "survey" is used to mean "observe." Actually, to reference the substructures of a bridge so as to detect possible movement over the years is a very difficult matter, especially for a wide river crossing

of many piers. Where it can be done it is unquestionably desirable and a great effort should be made to carefully preserve the old records.

Page 8, line C-3: "Deterioration of material and reduction of Section" is by far the most important of these six items and I would place it first.

Page 10 Profile check: This is completely meaningless for most long span bridges unless a careful record is made of temperature and the live load controlled. For suspension bridges it is impossible, unless the bridge be closed to traffic because, due to flexibility, the profile changes from minute to minute. The CHAIRMAN. Thank you very much.

Do you wish to testify, Mr. Fox, at this point?

Mr. Fox. Thank you.

The CHAIRMAN. You go ahead, sir.

STATEMENT OF GERARD F. FOX OF THE FIRM OF HOWARD, NEEDLES, TAMMEN & BERGENDOFF; PAST CHAIRMAN, STRUCTURAL DIVISION, AMERICAN SOCIETY OF CIVIL ENGINEERS Mr. Fox. My name is Gerard F. Fox, and today I am representing the American Society of Civil Engineers. Last year, I was chairman of the structural division of the society.

I am a partner in the firm of Howard, Needles, Tammen & Bergendoff, consulting engineers.

During the past 40 years, my principal activity has been in the planning and design of numerous bridges, both small and large. At the present time, our firm is under contract for the yearly inspection of bridges with many commissions and toll road authorities.

In the interest of time, I will subscribe to the remarks of Mr. Gray and answer any questions that you might have.

We would be very happy to comment by the way, for our firm on this criteria that you spoke of.

The CHAIRMAN. I was just going to indicate to you that if you could give us the same sort of response that I have asked of Mr. Gray that that would be helpful.

Thank you, Mr. Fox, and again thank you, Mr. Gray, for your testimony. Your attention to this subject is important. We will go very thoroughly into what you have given us even though the members are not here.

Mr. GRAY. Thank you.

The CHAIRMAN. Thank you.

(The prepared statement presented by Mr. Gray is as follows:) STATEMENT OF NOMER GRAY, PARTNER, AMMANN AND WHITNEY, NEW YORK CITY; CHAIRMAN, ASCE COMMITTEE ON PROFESSIONAL PRACTICE

This opportunity to present information at the time your committee is studying bridge safety is appreciated.

We are appearing as representatives of the American Society of Civil Engineers, because of the extensive organized effort of the Society which is related directly to bridge safety. More than this, however, we are appearing because of our own involvement, as individuals, in the professional practice of engineering, specifically relating to bridge safety.

The safety of bridges, or the safety of any structure serving the public, is not a new matter of concern to civil engineers. This is a very substantial area of the professional practice of civil engineers. In the American Society of Civil Engineers, this concern led to the establishment of extensive and continuing committee work, many published professional papers, and periodic national meetings and specialty conferences for the exchange of information and continuing education of the profession.