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U.S. Congress. House. Committee on Armed Services. Armed Services Investigating Subcommittee. The Sinking of the USS Guitarro. 91st Cong., 1st sess., 1 July 1969. Washington, DC: Government Printing Office, 1969.

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Sinking of USS Guitarro (SSN-665)

Letter of Transmittal

Hon. L. Mendel Rivers,
Chairman, Committee on Armed Services
House of Representatives Washington, D.C.

June 30, 1969

Dear Mr. Chairman: Attached is a report entitled "The Sinking of the U.S.S. Guitarro", unanimously approved by the appointed members of the Armed Services Investigating Subcommittee conducting this review. A comprehensive study was initiated pursuant to your instructions and hearings were held at San Francisco Bay Naval Shipyard, Mare Island, Vallejo, California, on May 26, 27, and 28, 1969.

I shall appreciate your early approval of the report so that it may be printed.

Sincerely yours,

Samuel S. Stratton
Chairman, Special Subcommittee To Investigate the Sinking of the U.S.S. Guitarro.

L. Mendel Rivers, Chairman.




Findings and Conclusions


Chronology of Events

Discussion of Events

The Guitarro's Achilles' Heel

Conflicting Operations

Improper Trimming Procedure

The End

The Sinking of the USS Guitarro


At approximately 8:30 P.M. (Pacific Daylight Time), Thursday, May 15, 1969, the nuclear powered attack submarine Guitarro (SSN-665) sank while tied up to the dock at the Mare Island site of the San Francisco Bay Naval Shipyard. The ship had been under construction since August 1965, and was due to be commissioned in January 1970. Sinking was caused by uncontrolled flooding within the forward part of the ship. It was refloated at 11:18 A.M. (PDT), Sunday, May 18, and after inspection damages were estimated at between $15.2 million and $21.85 million.


On May 19, Chairman Rivers directed the staff of the Armed Services Investigating Subcommittee to begin an immediate preliminary inquiry into the sinking of the Guitarro. On May 22, he announced that he had appointed the following Subcommittee Members to carry out the investigation:

Samuel S. Stratton, (D-N.Y.) Chairman
William J. Randall (D-Mo.)
John E. Hunt (R-N.J.)

The Subcommittee traveled to Mare Island and on May 26, 27, and 28 made a careful inspection of the Guitarro (then in drydock), examined all pertinent available records and took 605 pages of testimony, under oath, from those witnesses deemed most knowledgeable as to those facts bearing on the sinking.

Findings and Conclusions

As a result of its investigation the Subcommittee has concluded that, although the sinking of the USS Guitarro was accidental, the immediate cause of the sinking was the culpable negligence of certain shipyard employees. This, together with the contributing factors of inadequate coordination of both the ship construction activities and the assignment of specific responsibilities, will be discussed more fully in the body of this report.


That the Secretary of the Navy take immediate action to:

1. provide that during the construction of any Navy ship, whether nuclear or nonnuclear, there shall be at all times on duty at the site one single individual who shall have full responsibility and authority for its construction and safety;
2. insure that at Mare Island, as well as in all other construction yards, there is full and complete interchange of information on a regular duty basis with regard to all construction operations between nuclear and nonnuclear groups. Such interchange and coordination procedures should include the full and regular participation of both the single individual charged with the top authority for ship construction and safety, and the ship's prospective commanding officer;
3. require the establishment and enforcement of clear-cut lines of responsibility, at all construction yards, for ship safety and sound ship construction procedures;
4. have assigned to ship security billets only personnel fully trained and briefed on the requirements of their positions and with appropriate authority to enforce strict safety procedures;
5. consider the development and utilization of fittings for lines and cables which, in the event of an emergency, could be quickly disconnected at those points where, during construction, they are temporarily run through watertight door openings; and
6. instruct the Naval Ship Systems Command to undertake an immediate and thorough survey of the construction practices and procedures in effect in all Navy shipyards, to ensure the implementation and oversight of directives establishing clear-cut lines of authority and responsibility and providing for adequate exchange of information among all construction groups, in line with the recommendations set forth above.

Chronology of Events

During the afternoon and early evening of May 15, 1969, the following events occurred at the approximate times indicated:

4:00 P.M.: A civilian construction group (nuclear) began an instrument calibration assignment which required the filling of certain tanks, located aft of the ship's pivot point, with approximately five tons of water.
4:30 P.M.: A civilian construction group (nonnuclear) began an assignment to bring the ship within a half degree of trim. This entailed the adding of water to tanks forward of the ship's pivot point, to overcome a reported two degree up-bow attitude.
4:30 to 7:50 P.M.: The nuclear group continued to add water aft.
4:30 to 7:45 P.M.: The nonnuclear group continued to add water forward.
7:00 P.M. and again at 7:30 P.M.: A security watch advised the nonnuclear group that by that time the Guitarro was riding so low forward that a one and a half foot wave action, stirred up by boats operating in the river, was causing water to enter an uncovered manhole in the most forward and lowest portion of the ship's deck. These warnings went unheeded.
7:45 P.M.: The nonnuclear group stopped adding water to the ballast tanks in preparation for their lunch break.
7:50 P.M.: The nuclear group completed their calibrating assignment and began to empty the tanks aft.
8:00 P.M.: The nonnuclear group left for lunch.
8:30 P.M.: The nuclear group emptying the water from the aft tanks and a member of the group noticed " sudden down angle being taken by the boat." At approximately the same time, the nonnuclear group and others, returning to the ship from lunch, observed in down sharply at the bow with a massive flooding taking place through several large open hatches.
8:30 to 8:45 P.M.: Efforts made to close watertight doors and hatches were unsuccessful due to lines and cables running through them.
8:55 P.M.: The Guitarro sank.

Discussion of Events

The Guitarro should not have sunk. It was not overwhelmed by cataclysmic forces of nature or an imperfection in design or an inherent weakness in its hull. Rather, it was sent to the bottom by the action, or inaction, of certain construction workers who either failed to recognize an actual or potential threat to the ship's safety or assumed that it was not their responsibility.

Certainly, the tragedy was not caused by any lack of formal directives. Over 300 pages of instructions, guidelines and organizational charts meticulously detailed and parceled out responsibilities and authorities. A review of material furnished the Subcommittee by the shipyard discloses the organizational structure which includes:

Three principal offices-Shipyard Commander, Management Engineer and Information, and Industrial Relations;
Ten departments;
Nine groups;
Seventy-five divisions;
One hundred and seven branches;
Two hundred and five sections; and 
Thirty shops.

In spite of the elaborate formulation of policies and procedures, something was lost in their translation into practice and the Guitarro went down. Its sinking could have been prevented by the timely exercise of very little commonsense and the taking of a few simple precautions.

The Guitarro's Achilles' Heel

In the most forward part of the ship is the bow structure sonar dome which contains the ship's sonar sphere. Entrance to the dome is through a manhole which has a bolted cover. At the time of launch, this opening was also protected by a cofferdam approximately three and a half feet high. This additional precaution was taken to make sure that occasional water did not run down onto the electronic gear which was exposed at that time.

The sonar's operation is dependent on a number of large electronic components known as transducers. Sometime after the sonar equipment was installed it was discovered that some of these components were faulty and would have to be replaced. To facilitate this work, the cofferdam and the bolted manhole cover were removed. This occurred in early March 1969 and neither the cofferdam nor the cover was ever replaced. At the time the Guitarro went down, the manhole cover was on the dock and the cofferdam was in the storage warehouse.

From the testimony and records before the Subcommittee, it can be reasonably concluded that on May 15 a simultaneous trimming operation and calibrating test caused a sufficient change in the Guitarro's draft to permit water to enter in quantity through the open sonar dome manhole. As the sonar dome became flooded, its weight caused the ship to further settle by the bow which permitted additional water to enter other openings. This soon allowed massive flooding through the large bow access and at this point the Guitarro was doomed.

Both the nonnuclear Ship Superintendent and the General Foreman No. 1 on the Guitarro had a responsibility for the safety of the ship. This included a responsibility for protecting it from the threat posed by the open sonar dome manhole. The Ship Superintendent testified that the bolted manhole cover should not have remained off without a cofferdam around the hole. However, he further testified that although he made daily inspections of the Guitarro he never noticed the uncovered sonar dome manhole and that no one ever brought the matter to his attention. The Subcommittee considers this to be an incredible bit of testimony in view of the fact that the dangerous condition had existed for two months.

A cofferdam could have been installed quickly and easily, but the general foreman testified that, although he recognized the open manhole as a potential threat to the safety of the ship, he felt a sufficiently close watch of it was being maintained and, therefore, there was need for a cofferdam. Unfortunately, no one was watching the night the Guitarro sank.

Conflicting Operations

In the chronology section of this report, reference has been made to two operations which were under way simultaneously on the Guitarro during the late afternoon and early evening of May 15. One operation was being performed aft by a nuclear group and the other was being performed in the forward part of the ship by a nonnuclear group. Neither group knew what the other was doing nor were they apparently aware of each other's presence.

As necessary background, it should be understood that in the construction of a nuclear submarine the work is divided into nuclear construction and nonnuclear construction. Each is done by a separate group and separation of responsibilities and operations is complete. However, of necessity, there is a mutual dependency which should require constant communication if operations are to be coordinated and scheduled in the most effective and efficient manner.

On or about May 13, the nuclear group had progressed to a point where Atomic Energy Commission test procedures required the calibration of certain tanks by filling them with water in increments of 100 gallons, recording various data and then blowing them down and venting them. The particular tanks involved hold approximately 1200 gallons of water, weighing approximately five tons. Although the actual tests were to be performed by the nuclear group, it was the responsibility of the nonnuclear group to place the ship in the required trim condition.

Early on the morning of May 14, the Guitarro was put in trim and during that day tests were run. However, on May 15, at approximately 3:50 P.M., a representative of the nuclear side advised the nonnuclear Foreman that the tests had to be rerun and requested that the ship be checked for required trim. A nonnuclear man was sent to make the check and he reported that the Guitarro was one degree down at the bow. Therefore, although the day shift was about to go off, they began to move water from the forward trim tanks to the aft trim tanks in an effort to correct the reported down-bow attitude. The work was then turned over to the swing shift for completion.

The swing shift Foreman to whom this work was assigned testified before the Subcommittee that he had never before attempted to trim a ship and did not feel qualified to do so, although he had participated to some extent in the trimming operation on the 13th. He stated that although he was told that the Guitarro was bow down he had it checked by one of his workers who reported the bow up two degrees.

Obviously, someone was wrong and it is not beyond the possibility that both the day shift and the swing shift measurements were in error and that as a matter of fact the Guitarro was still in trim from the operation just completed the day before. This latter possibility finds ample support in the draft entries in the Guitarro's log and in the vessel's below-decks check-off sheet and the below-deck security log. As of 11:30 P.M. on May 13, the entries in both of the said logs and the check-off sheet showed the draft of the Guitarro to be 21 feet, 11 inches forward and 29 feet, eight inches aft. On May 14, during the graveyard shift (midnight to 8:00 A.M.) the Guitarro was put in trim and at that time the three aforesaid records all agree on the new draft readings, 23 feet, six inches forward and 28 feet, seven inches aft.

The check-off sheet for May 15 has not been located. However, the ship's log and the security log for the 15th show that as of 3:30 P.M. on that day the relative positions of the bow and stern had remained unchanged for the past 24 hours. It shows a draft of 23 feet, eight inches forward and 28 feet, nine inches aft, an increase in draft of 2 inches at both the bow and stern. Since the Assistant Chief Design Engineer for Naval Architecture at Mare Island testified that theGuitarro's bow would have to go down two feet and the stern come up two feet to make a half degree change in trim, and since the draft had only changed 2 inches, it can be reasonably be concluded from the draft entries in the ship's log that on the afternoon of May 15 the Guitarro was still in trim. This possibility becomes a virtual certainty when we consider the fact that no witness before the Subcommittee was able to offer any reasonable suggestion to explain how the ship could have gotten out of trim in that 24-hour period. Nevertheless, the swing shift, assuming the correctness of their own readings, proceeded to reverse the flow of water in the trim tanks, moving it forward in an attempt to bring the bow down.

At or about the same time, the nuclear group began filling tanks aft. Ironically, the success of their assignment was dependent on the ship being first in trim. However, at least two factors would have led them to believe that this condition already existed:

1. they knew that the ship had been placed in trim only 24 hours previous; and
2. they were advised by the nuclear day shift, whom they were relieving, that preparations for the calibration tests were complete. This would necessarily include the required trim condition of the vessel.

The Nuclear Power Superintendent of the shipyard testified that he would also have interpreted this latter advice to mean that the ship was in trim. Later, however, he stated he would have expected the nuclear calibrating group to make an independent check as to the truth of what they had been told. If, as this indicates to the Subcommittee, such a lack of confidence exists as to the validity or correctness of orders or assignments among the nuclear construction personnel, then something is sadly lacking in the quality of their supervision and administration.

It further appears from the testimony before the Subcommittee that only the Nuclear Ship Superintendent and a subordinate knew on the afternoon of May 15 that the nonnuclear side had been requested to recheck the ship's trim-and there is no evidence that they brought this intelligence to the attention of the swing shift nuclear group slated to run the calibration tests or to anyone else on the nuclear side. This suggests that communication within the nuclear section was no better than communication between the nuclear and nonnuclear groups.

Meanwhile, in the forward part of the ship the nonnuclear group was not having much success in reducing the up-bow attitude they believed to exist. Moving the water to the forward trim tanks had not produced the desired result and, therefore, they decided to put water in the forward ballast tanks.

As is normal in a submarine under construction, plates are welded over the ballast tanks flood ports to prevent water from getting into the tanks and putting the submarine in an unsafe condition. Therefore, in order to frustrate this safety measure, it was necessary for the nonnuclear group to put a fire hose down the tank's vent pipe and force it past the check valve.

There are three pairs of ballast tanks forward and the group found that two pairs had already been filled the night before. Therefore, they proceeded to fill the remaining tanks, 3A and 3B. Their method was to turn the hose on full for five minutes first in one tank and then in the other and then check the trim. This continued until 7:45 P.M., by which time, according to their calculations, the bow still had a three-fourths degree up angle. At this point they shut off the hose, removed it from the vent pipe and went to lunch. They estimated that by that time they had put approximately 3,000 gallons in the tanks. As has already been noted, on two occasions during this operation the security watch informed the group that wave action was causing water to enter the sonar dome, but nothing was done to stop it.

Had the security watch stander adhered strictly to the regulations then in effect, he would have also made a telephone report of the submarine's condition to his superior. However, he did not do so. One can therefore only speculate whether such a call would have saved the Guitarro. The chances are it would not for the Subcommittee was informed that there was seldom a rapid response to security watch reports. Just why this should be is not entirely clear, although the Subcommittee noted the existence of several factors which could contribute to this negative attitude. For example, despite the importance of their job, the security watch standers are, for the most part, among the lowest paid of the Shipyard workers. And from the testimony it received, the Subcommittee was also given the distinct impression that throughout the Shipyard there exists a presumption that at least the senior employees know their respective jobs and can be counted upon to do them in a proper manner. Such an assumption tends to result in a rather casual attitude toward the reportings of the security watch.

The Subcommittee also learned that the security watch is given no course of formal training. Nor is the performance of his duties subject to periodic review and evaluation. He is furnished with a copy of the printed text which delineates his responsibilities and general procedures to be followed in carrying them out. From that point on, he is on his own.

At about the same time as the nonnuclear group went to lunch, the nuclear group, having 1,200 gallons in the tanks aft and having completed their calibration test, began to empty the tanks. This latter operation took 30 or 40 minutes and just as it was completed the submarine assumed a sudden down-bow attitude. This was the beginning of the massive flooding.

The alarm was sounded and personnel began an effort to close the hatches and the watertight doors in the bulkheads to prevent further flooding. However, numerous cables and lines running through these openings made futile this last ditch effort to save the submarine.

The Subcommittee does not intend to suggest that in a submarine the size of the Guitarro the amount of water added to its tanks on the afternoon and evening of the 15th would cause any large change in the vessel's trim. However, it is obvious that water added aft would have an offsetting effect on water added forward. Furthermore, instead of obtaining maximum expected reduction of the up-bow angle, such an operation would have more of a tendency to cause the entire submarine to sink lower in the water and thus make it more vulnerable to wave action and flooding through the open sonar manhole. This latter condition was becoming more critical with each passing minute and the Subcommittee is convinced that the relatively rapid emptying of the tanks aft was the final straw which tipped the bow the last fraction of an inch needed for rapid flooding of the sonar dome.

Improper Trimming Procedure

To examine the correctness of the method used to trim the Guitarro the Subcommittee questioned a submariner with extensive experience in submarine construction and operation. Because of its importance, portions of his testimony on this point are set forth below:

"To put water into a main ballast tank, to a person in submarines, is-you don't do this unless you want to submerge, or unless it is a very deliberate, controlled evolution.

"At times in port we will put water into ballast tanks to list the ship or to flood down forward, but it is an evolution where you have people, personnel stationed throughout the ship. Usually the captain is on the bridge when it happens. It is very deliberate. You have phone talkers throughout the ship and you have officers spread throughout the ship. It is something you don't do very often and when you do, you make sure it is done [only] under extreme conditions."

There was no such supervision on the Guitarro. The witness also testified that in the shipyard there is a multitude of concrete weights which you can normally place on deck in the position necessary to give you the trim you desire.

Another witness testified that submarines submerge by filling ballast tanks and by no other means. He further stated that by flooding the forward ballast tanks, as was done in this case, the submarine was put in a dive posture. It therefore occurs to the Subcommittee that what the Guitarro did thereafter was only what it had been designed to do-sink.

The End

After reviewing all pertinent facts, it is still difficult to understand how all the circumstances which had to be present in order to sink this vessel fell into place on the evening of May 15. One would surely expect that with all the security and precautionary directives such a disaster just could not happen. However, there was one vital defect in the system-a lack of centralized control and responsibility for all construction.

A memorandum dated March 27, 1969 describes a meeting held on March 15 at which the prospective commanding officer (i.e. the naval officer who would be given command of the ship after completion of construction) urged an agency of this nature. According to the memorandum this suggestion was opposed by the shipyard representatives. One enlightening paragraph of that memorandum reads:

"CO 665 [the prospective commanding officer] pointed out the need for a central controlling agency in the nonnuclear construction areas of the ship. Shipyard representatives (Lampson and Sheldon) pointed out the fact that the shipyard had been building ships for a long time without the need for such a procedure and no one had been killed or equipments damaged yet. CO 665 replied that they had been lucky."

On May 15, the shipyard's luck ran out.



Written - 6 November 2003

Published: Tue Oct 31 12:17:17 EDT 2017