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N. B. S. 2
        AND REFER TO No.

  C-DD372/L9 (814)




Washington, D.C.

From: The Chief of the Bureau of Ships
To: The Commandant, Navy Yard, Mare Island.
SUBJECT:  U.S.S. CASSIN (DD372), U.S.S. SHAW (DD373) -Action Damage Repairs.

 (a)  OPNAV ltr. Op-23G-EIK(SC)L9-3/DD Serial 0206423 of December 18, 1941.
C&R Plan #  Title 
(b)  192810-L Faired Lines from Mold Loft Offsets.
(c)  192811-L Frame Offsets from Mold Loft Offsets.
(d)  192838-L Mold Loft Offsets, Shell Seams, Longitudinals, Bilge Keel, and Breast Hook.
Enclosure: h.w. (3 sets)
 (A)  Photostatic copy pages 17,18,19 - Shipbuilding and Shipping Record of July 3 , 1941 - Title: "An Interesting Repair."

     1.   On the basis of preliminary reports, the Bureau believes that it will be feasible and practicable to undertake complete salvage and repair work on the CASSIN and SHAW recently damaged in battle. In reference (a) the Chief of Naval Operations assigned availability at the Navy Yard, Mare Island for the work involved.

     2.   Initial information received indicates that the SHAW will require a new bow from frame 68 forward. The after portion of the ship from frame 87-1/2 is reported to be in excellent condition, and it is presumed that only moderate repairs in this section will be required. The condition of number one fireroom is not known at the present time. The Bureau believes it will be practicable to construct a new bow section on building ways, subsequently launching this section and joining it with the after section of the ship in drydock. A similar repair was recently performed in a British shipyard and is described in general terms in excerpts of the July 3, 1941 issue of Shipbuilding and Shipping Record, which are furnished as enclosure (A).

C-DD372/L9 (814)


To  :  NYMI

     3.   Although complete detailed information on the conditions in the SHAW is not available at the present time, the Navy Yard, Pearl Harbor has salvaged the after section of this ship and will fit a short false bow to permit towing to Navy Yard, Mare Island. When this operation will be completed is not known at the present time, but in anticipation of the eventual arrival of the stern section of the SHAW at the Navy Yard, Mare Island, it is desired to proceed immediately with the construction of the forward bow section.

     4.   The yard shall therefore proceed immediately with all advance planning, procurement of material and fabrication, as necessary, to erect a bow section from frame 68 forward. The yard shall determine the manner in which this bow section is laid down, giving consideration to the suggestion of erecting this section on the lower end of one of the submarine building ways. The Bureau has not made any launching calculations which should be done if it is decided to adopt the above suggestion, so that questions of launching stability and trim may be determined.

     5.   The yard shall undertake procurement of all materials required, including steel, aluminum, furniture, hull fittings, laundry and galley equipment, except as noted below. The Bureau will provide the following items and any additional items which the Navy Yard may request:

      (a)   Anchor windlass.
(b) 5" Ammunition Hoists.
(c) Vent sets (the Navy Yard is requested to furnish a complete list of ventilating sets required to allow the Bureau to select necessary items from material now under purchase.)
(d) Standard compass.
(e) Anchors.
(f) Chain.
(g) Gyro Compass.
(h) QC Gear.
(i) IC Generators.
(j) Ice Machines.
(k) Radio outfit.
(l) Echo sounding equipment.

When the condition of number one fireroom is known, the yard will be informed what machinery units for this space will be procured by the Bureau.

- 2 -

C-DD372/L9 (814)


To  :  NYMI

     6.   The Bureau has requested the Navy Yard, Philadelphia, to forward by airmail to the Navy Yard, Mare Island, the molded lines and offsets for the SHAW as originally constructed. It is believed that the Navy Yard, Mare Island has on file all detail working plans for the PRESTON and SMITH (constructed in that yard), which can be used for the building of the bow section for the SHAW. In the event this understanding is not correct, it is requested that the Bureau be so advised in order that these plans can be furnished to the Navy Yard from other sources.

     7.   By copy of this letter, the Navy Yard, Pearl Harbor, is requested to keep the Navy Yard, Mare Island informed of the progress of the preparations for towing the SHAW, and if practicable, to furnish a more detailed report on the condition of this ship before this work has been completed.

     8.   After a study of the work involved, the Navy Yard, Mare Island is requested to advise the Bureau if arrangements for space on the building ways, procurement of special materials and all other problems involved, can be satisfactorily made by the yard.

     9.   Information concerning damage to the CASSIN is not sufficient to permit the yard to proceed with advance planning for the repair work involved. As this information is received, it will be furnished to Mare Island.

     10.  Charges for repair work will be lodged against project order 1932/42, to be established at the Navy Yard, Mare Island, in sufficient amount to cover the expected cost of the repairs. Full details on this project order will be furnished in separate correspondence.

Copy to:



- 3 -




An Interesting Repair

The after portion of an oil tanker, torpedoed in the Atlantic, was
navigated to a British port where a new fore end was constructed

  Since the war started, shipyards all over the country have carried out a number of complicated damage repairs to ships and engines which would have been considered impossible not many years ago. The repairing of ships is often a tricky business, but improved methods, and modern tools and machinery have enabled repairers to surmount former difficulties.
  In this connection it is interesting to review the work involved in attaching a new fore end to the original after part of the oil tanker Imperial Transport torpedoed in the Atlantic. In the way of No. 6 oil tank the torpedo struck the bottom of the vessel a glancing blow on the port side. At the time of the impact Nos. 1, 3, 4, 6 and 7 tanks were empty, and ballast was carried in Nos. 2, 5, 7 and 9 tanks.
  When the crew had left the ship they observed that the vessel had been broken in halves, and that both portions were afloat, so they returned to the after portion. The oil-tight bulkheads at the end of the tanks had saved the hull from foundering, and the captain decided to try to salve it by arranging to navigate from the after end, and sailed for a port in the U.K. After arrival, a survey was held, when it was decided to build a new fore end to suit the after end. The two ends were united, and the ship now is as good as new.
  The after portion of the ship was docked first on centre and bilge blocks, and all distorted material removed, then a launching cradle was built to receive the new forward portion when Docked. Standing ways 24 in. x 10 in. extending from 15 ft. below the after portion to within 30 ft. of where the stem of the forward portion would come when, this was docked were then erected.

No declivity
  Sliding ways 190 ft. x 24 in. X 10 in. were placed on the top of the standing ways. These were placed 16 ft. apart between the inside edges, and were laid on ground blocks 3 ft. apart. No camber or declivity was given to the ways, they were kept dead level.
  On both the standing and siding ways, a ¼-in. thickness of grease was spread over the surfaces with a liberal coating of soft soap on top. When docking the fore end great care was taken to maintain the vessel's correct sheer and camber. To prevent the after portion floating when docking the fore end, it was docked at dead low water to within 9 ft 8 in. of the after portion already docked.
  In order to ensure that no slewing movement did occur during the launching operation, two H sections 12 in. x

10 in. were bolted on both sides of the ship, and these extended 16 ft. forward of the after portion to receive the fore end. The centre keel blocks when docking the fore end were kept 2 in. higher than those in place under after portion ; this was done to ensure, if there was any sag, both keels would be in line when finally united.
  Large eye plates were bolted on both sides of the ship on forward and after portion placed midway between the gunwale and bilge strakes, and the shell stiffened at the back

of the eyeplates. Shackled to the eye plates were four sheave purchase blocks capable of taking 3 in. circ. steel wire, the lead being taken from these to a capstan on the quay. Two 150-ton hydraulic jacks were placed on to the ends of ways; this was done to give the fore end a start when launching.
  The fore end commenced moving aft as soon as the pressure was put on the jacks, and then the purchase wires took control and kept it moving. During the first 3 hours the fore part travelled 9 ft., after this the travelling was slowed down, in order to obtain the correct alignment of the overlaps of the shell and decks with those on the after portion. Every part had to be joined up perfectly with the corresponding part on the after portion of the ship, and this was accomplished in approximately 7 working hours from the commencement of the launching operations.
  The success of the undertaking was due to the careful examination of all the technical problems, and the practical experience of those employed supervising the operations.


The news bow section ready for joining to the original afterpart


Stern part of the "Imperial Transport" beached off the British coast at the end of her amazing voyage. Although 300 miles from land when torpedoed, the after part of the vessel was towed to port and has been joined to a new fore part.

National Archives & Records Administration, San Francisco Branch
Record Group 181, MINSY General Corespondence Files 1941-46

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