Salvage of the USS GUITARRO (SSN 665)    I.

I.    Salvage of the USS GUITARRO (SSN 665)

1.1.    Brief

USS GUITARRO (SSN 665 ) was in an advanced state of construction
at the San Francisco Bay Naval Shipyard (lYlare Island Division).
On the evening of 15 May 1 969 uncontrolled flooding caused the
GUITARRO to sink. Salvage operations were conducted by the
Supervisor of Salvage.

The submarine was refloated at 1119 on 18 May 1969 by dewater¬
ing with pumps through cofferdams which had been constructed
for that purpose. Though the initial salvage plan envisioned
expelling watei by means of compressed air through the
salvage air fittings, this plan was abandoned in favor of
pumping when it became obvious that pumping would be much
faster .

After the submarine was surfaced, residual water was removed
from GUITARRO until a condition satisfactory for drydocking
was reached. Salvage operations were completed when GUITARRO
was docked at San Francisco Bay Naval Shipyard on the evening
of 18 May 1969. The salvage operation, from beginning of
mobilization through successful recovery, was particularly
short; only 3 days passed between the date of sinking and
drydocking of GUITARRO. The shipyard industrial assistance
and complete availability of all services, especially cranes,
made the salvage of GUITARRO possible in such a short time.

A similar submarine sinking, far removed from the industrial
plant capacity available at the San Francisco Bay Naval Ship¬
yard, would present a much more complex problem and probably
require much more time and effort for recovery.

1.2.    Narrative

On the evening of 15 May 1969, at approximately 2130 local
time, USS GUITARRO (SSN 665) sank alongside the pier at
Mare Island Naval Shipyard, Vallejo, California. The ship
sank due to uncontrolled flooding which originated in the
forward part of the ship. After sinking, the ship came to
rest with approximately a 6° port list; the fairwater above
the sail planes remained above water, as did the conning
tower access trunk. At the time of sinking no fissionable
material was aboard. The ship was in an advanced state of
construction. UJith the exception of the reactor, essentially
all equipment was aboard. Ballast tank flood ports were
temporarily tuelded closed and temporary covers were installed
on ballast tank vents. The forward and after access trunks
were open for normal personnel access. The following
temporary openings existed:

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Salvage of the USS GUITARRO (SSN 665)    I.

-    Sonar space. On the top side of the hull mere
two openings. A bolted access cover had been
removed. A temporary access about 22 inches
square had been cut. Two normally tight cable
ways into the sonar space at FR.11 were not water¬
tight due to work in progress.

-    Reactor compartment. A temporary access (approxi¬
mately 12 feet square) existed in the top of the
hull for installing reactor components.

-    Auxiliary Machinery Room Two (AIYIR -2) , A temporary
services opening existed in the top of the hull
for power and ventilation. A temporary services
trunk was welded to this opening, but was non¬
tight at the top where cables and ventilation
ducts entered.

-    Hole for missing engineroom high salvage air
fitting.

Initial efforts through the night and early morning of 15 -
16 lYlay were concerned with closing internal watertight doors
and hatches, clearing some of the maze of temporary service
wires that cluttered the topside of the submarine, and clos¬
ing or patching temporary access openings. Air hoses were
rigged to the salvage air fittings in the forward two
spaces (crew's living and operations spaces). Pressure was
applied and these spaces were found to be watertight.

At 0830 on 16 May, after a review of the situation, it was
determined that essentially all of the flood water must be
removed from the submarine. Since approximately one-third
of the hull was sunk into the mud, it was anticipated that
some positive buoyancy would be required to overcome the
effect of mud suction. The basic salvage plan was to make
the hull watertight, then remove the flood water. Two
basic means were available:

-    Air Blow - The preferred way to raise a sunken
submarine is by expelling flood water with air
through the salvage air system.

-    Erect Cofferdams - Since the conning tower access
hatch was above water and the after access hatch
and reactor compartments were only about 15 feet
below the surface, it was feasible to pump water
out through cofferdams.

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Salvage of the USS GUITARRO (SSN 665)    I.

o

The salvage plan actually used both methods. The forward
two spaces were blown for about eight hours. ILIhen it became
obvious that pumping would be much faster than blowing, the
blow was secured and pumping became the primary means for
dewatering. Pumping had two additional advantages:

-    Since the submarine could be entered during pump¬
ing operations, the exact status of buoyancy was known at
all times. This permitted the final refloating to be a
controlled operation.

-    Pumping permitted the removal of residual water
that could not be expelled by blowing. Low reserve buoyancy
made the removal of this water essential.

Calculations indicated that the ship was in a stable condi¬
tion, though righting arms were quite low due to the flooding
water. As flooding water was removed stability continually
improved because of the lowering of the center of gravity.

The only concern was the possibility of developing an up¬
setting moment caused by a free surface effect on the water¬
tight deck of the torpedo room. This was avoided by stripp¬
ing this space of all water prior to the refloating effort.

The daylight hours of 16 lYlay were spent in clearing an
access through the maze of temporary service lines by
divers so that all hull openings could be identified, templated,
and made ready for patches. Cofferdams had been designed and
were being constructed by shipyard personnel. The 150 ton
crane was connected to GUITARRO aft to provide additional
stability. During the evening of 16 lYlay preparations were
made to blow the main ballast tanks forward. Temporary
protective plates over the vent valves were removed by divers.
Since three vent valves were closed hydraulically, it was
necessary for divers to remove the entire vent valve mech¬
anism. This job was completed with the assistance of a
dockside crane on 17 lYlay.

On 17 lYlay all patching was completed. Cofferdams were
installed on the after access hatch and on the patch for the
reactor compartment. Blow fittings were installed on main
ballast tanks forward, and a fitting to pump the sonar dome
underwater was installed. At 0500 the forward two spaces
were pressurized and water expulsion commenced. This blow
continued until 1240, when it was decided to shift to pump¬
ing. These spaces were vented, and at 1825 the conning
tower access hatch was opened. Salvage crews entered the
submarine and found the water level forced down to about
three feet below the upper level. Prior to the entry of
personnel into the submarine, careful checks were made for
chlorine and hydrogen gas; none was found.

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Salvage of the USS GUITARRO (SSN 665)    I.

At 1700 pumping commenced through the reactor compartment
cofferdam and at 2355 pumping commenced through the engineroom
cofferdam. The recommended dewatering sequence was followed
as a guide, but when it became apparent stability would not
be a problem, the sequence was modified. It was decided
to completely dewater the submarine with the exception of
AIYIR-2. This flood water was used as ballast to prevent the
submarine from surfacing until all preparations had been
made .

Pumping and stripping operations continued through the early
morning of 18 (11 ay. By about 1030 pumping and stripping
operations had been completed with the exception of AIYIR-2.

All was now in readiness for the first refloating effort.

At 1057 pumps were started on AIYIR-2 and a 20 ton strain was
taken on the floating crane shackled to the stern. At
1119 the submarine rose to the surface. On surfacing the
submarine trimmed by the stern, with the top of the
rudder below water. The after trim was probably caused by
water from AIYIR-2 moving aft into the engineroom as the
submarine surfaced. Salvage crews then entered the sub¬
marine for the final stripping effort. At about 1700
stripping operations were complete and the submarine was
__    sufficiently buoyant to enter drydock.

On the evening of 18 lYlay USS GUITARRO entered Drydock #3,
lYlare Island Naval Shipyard, and salvage operations were
terminated.

1.3.    Detail Discussion of Height, Buoyancy, Stability,

and R ecommended Sequence oT Actions to Float
GUITARRO (SSN 6bb)    *

Buoyancy - (Height Factors (A)

Available evidence indicates that the submarine was float¬
ing at the top of the boot topping (which is 6" above
normal diving trim draft). This indicates the displacement,
prior to start of accidental flooding, was 4266 tons.

At the time lYlain Ballast 1, 2A, and 2B were full, lYlain
Ballast 3A and 3B contained 30 tons, the forward sonar
tank was dry.

Estimating the initial condition on the basis of the condi¬
tion A weight of the SSN 662, on the assumption that 55N 662
and SSN 665 are both very close to calculated (which was
the case in 662), gives:

NOTE :    Reference Submarine Guidance Plan, Figure 1-15

for compartmentation details.

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Salvage of the USS GUITARRO (SSI\I 665)    I.

Condition A    4002 Tons - Including Sonar Tank

-    143    - Sonar Tank

3859

+    273 main Ballast Tank 1 , 2A & 2B, Partial Main

Ballast Tank 3A & 3B and Variable Ballast

4132

-    49 Internal Tanks
4083 Tons

Therefore, initial condition range uias between 4083 tons and
4226 tons.

The flooded weight on the bottom is based on design dimensions
minus permeability factor times density of water (measured).
Variable ballast tanks are also considered on the basis of
the reported initial condition which is calculated to be
80.18 tons. minimum weight calculation assumes no further
flooding occurred. maximum weight calculation assumes
complete flooding of remaining volume which would be about
78 tons. main Ballast Tank 3A and 3B flooded an additional
58 tons. Forward sonar dome flooded 143 tons.

Based on the recommended sequence of actions in the following
section,
R ecommended Sequence , the estimated minimum and
maximum weights are shown in Table I. The net weight
holding the ship on the bottom is shown in Table II.

Stability (B)

Condition on bottom with all internal compartments flooded,

Bow Sonar Tanks and main Ballast Tanks 1, 2, & 3 flooded,
main Ballast Tanks 4, 5, and 6 dry, and assuming that all
internal tanks are dry, which would be the worst case,
positive stability (BG) equals about 0.17A.

Dewater Operations Compartment, Forward Room, and
Sonar sphere ........................... BG    =    0.53    ft.

Dewater Engine Room ..................... BG    =    0.82    ft.

Fill main Ballast Tanks 4    and 5 ......... BG    =    0.80    ft.

Dewater Auxiliary machinery Room ........ BG    =    0.82    ft.

Blow main Ballast Tank as    recommended ... BG    =    will    increase

Recommended Sequence (C)

The submarine should remain on the bottom until a controlled
effort to raise it is ready.

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Salvage of the USS GUITARRO (SSIM 665)    I.

Precise weights and conditions are not achievable; a bandwith
of possible error, on both sides of the best estimate, is re¬
quired to insure control. The potential error quantities are:

-    condition of variable tanks

-    amount of residual water ramaining

-    lack of precise knowledge of initial weight of
the ship before the casualty

An excessive trim circumstance is undesirable during the trans¬
itory conditions.

The following sequence is proposed:

-    Dewater Operations Compartment and Forward Room
and strip to lower flat (deck).

-    Dewater Engine Room and strip to bottom of bilges.

-    Fill aft Main Ballast Tank group Tanks 5A and 5B.

-    Dewater Auxiliary Machinery Room.

-    Do not dewater Reactor Compartment or Forward
Sonar Tank.

-    Blow Main Ballast Tanks in following sequence:

1    .    5A, 5B, and 1

2    . 3A and 3B

3. 4A and 4B and 2A and 2B
Ship should rise (See Table II)

-    If ship does not break free, refill main ballast
tanks and pump down Reactor Compartment.

-    Blow forward and aft main ballast tanks per
prior sequence.

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Salvage of the USS GUITARRQ (SSN 665)    I.

1.4.    Bottom Breakout Forces

When GUITARRO sank approximately one-third of the hull
settled into a very soft mud. In view of the anticipated
difficulty in completely dewatering GUITARRO, it was feared
that bottom breakout forces due to mud suction might became
important.

Preparations were made to overcome the mud suction effect
if required. These included (l) hydraulic lances connected
to a jetting pump for washout of mud, (2) the use of tugs
to rock GUITARRO, and (3) the use of a 150 ton crane to
provide additional lift. GUITARRO surfaced before any of
these actions were required. The initial surfacing displace¬
ment of GUITARRO was about 80 tons. This force is estimated
to be approximately the bottom breakout force.

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TABLE I

ESTIMATED MINIMUM AND MAXIMUM IUEIGHT FOR l/ARIOUS CONDITIONS

ESTIMATED WEIGHT

Minimum

Maximum

Original Condition (Calculated
Displacement) ..........................

4083

4226

All Compartments ..

2752

2752

Flooded Condition

Sonar Dome ........

143

143

Internal Tanks and
Partial Main Ballast
Tank 3 ............

0

1 36

6978

7257

Deuater Operations Compartment
(-1103) ................................

5875

6154

Deuater Forward Compartment (-262) .....

5613

5892

Deuater Engine Room (-804) .............

4809

5088

Fill Main Ballast Tank 5A and B (+137)..

4946

5225

Deuater Auxiliary Machinery Room (-281).

4665

4944

Retain Reactor Compartment Water and
Sonar Tank (301 and 143) ...............

4665

4944

ESTIMATED MINIMUM AND MAXIMUM
UJEIGHT EOR VARIOUS CONDITIONS.

TABLE 1-1

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TABLE II

WEIGHT, DISPLACEIYIENT, AMD NET WEIGHT HOLDING SHIP
ON BOTTOM, ASSUMING REACTOR COMPARTMENT FLOODED

MINIMUM
WITHOUT
RES IDUAL

MAXIMUM
WITHOUT
RES IDUAL

MAXIMUM
WITH 150 TONS
RESIDUAL

Weight Submerged .....

4665

4944

5094

Submarine

Displacement .......

4684

4684

4684

Net Weight Holding

Ship to Bottom .....

-19

260

410

Blow Main Ballast

Tanks 5A and B Plus
Main Ballast Tank 1.

-221

58

208

Blow Main Ballast Tank
3A and B .........

s

-309

-30

120

Blow Main Ballast Tank
2A and B .........

3

-391

-112

38

WEIGHT, DISPLACEMENT, AND NET

Weight holding ship on bottom,

ASSUMING REACTOR COMPARTMENT
FLOODED.

TABLE 1-2

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Classes of US NAVY Submarines 1.5.

1.5.    US NAVY Submarines

The US NAVY operates several classes of submarines. For
complete specifications, booklet of general plans, stability
information or other information necessary for submarine
salvage, contact:

Supervisor of Salvage
(Ships 00C)

Naval Ship Systems Command
Department of the Navy
Washington, D.C. 20360

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