Protective coatings were generally satisfactory.  The surfaces of the ballast tanks were noticeably clean.  The only exception to the foregoing was the underbody paint, which did not inhibit marine growths at Portsmouth.  
          The color of the interior paint was darker than that used in the U.S. Navy, and there was much woodwork with bright finish.  As a result, much light was absorbed which, with the limited illumination provided, should have been reflected.  
          Galvanizing is normal in extent and character.  Corrosion protection for the main engine circulating water system, including waterjackets, is provided as a necessary part of the circulating system.  
          Tankage painting is believed worthy of further review.  No report on the samples submitted is, however, available at this time.  
July, 1946


C  O  N  F  I  D  E  N  T  I  A  L
          Information with respect to paints used and their application is contained in NavTechMisEu Technical Report No. 482-45 and other documents referenced therein.  
          Descriptive matter herein will be confined to a discussion of which protective coating were used throughout the vessel.  
          According to specifications, interior painting is as follows:  
Base Coats
Finish Coats
a) Maneuvering and engine room (above the flat) 2 white lead rapid drying B1.11 or 2 lead-free rust inhibiting R.S. 13 2 fire resistant ivory - FS 74
b) (Below the flat) Same as (a) 2 fire resistant FS 74, and bilge paint FS 75
c) Bilges
3 tank paint Z 70
    - 1 -


Base Coats
Finish Coats
d) Torpedo room, control room, galley, W.C. & provision room. Same as (a) 2 white or ivory deck paint, 60 above & below flat.
e) Painting under linoleum. Cleaned
f) In back of ceiling where fitted. Same as (a) 2 gray deck paint 62
g) Battery wells, incl. foundations & supports. 2 acid-resisting red lead 78a 1 acid resisting white 78B and 1 acid resisting light gray RAL - 7001-No. 78C.
h) Tanks and bunkers, variable tanks, negative, trim, wash water tanks.
3 tank paint
i) Lub oil tanks Clean Oiled
j) Drinking water tanks. Clean 3 Portland cement
k) Woodwork in the way of radio & sound rooms, firing for ceiling
Very fire resistant covering unspecified.
l) Other woodwork Left bright and rubbed.  
m) Piping and tubing Same as compartment. Interior of salt water piping is coated with tank paint.  Exterior of piping is marked in color code to indicate service.
n) Aluminum 2 aluminum base coats LM 80a. 2 aluminum finishing coats, light or dark gray, LM81 or LM82.
o) Handwheels & levers   Quick venting - red; others aluminum bronze.
        Exterior painting is as follows:
a) Below waterline 2 white lead B1.11 or 2 lead-free rust inhibiting R.S. 13 1 boot topping gray W.L. 23a & 1 W.L. III 23b.
    - 2 -


Base Coats
Finish Coats
b) Above waterline, including fittings on deck, but where galvanized z priming coats are omitted Same as (a) 2 camouflage, oil resistant, Type 58, 581 or 582
c) Ballast keel interior
2 special solution
d) Wood decking Impregnate with wood tar or carbolineum, black  
e) Steel deck Same as (a) 2 black - non-skid, Tr. D. 59
          Individual vessels have differed from the forgoing.  Some have aluminum in lieu of bilge paint below the walking flat.  All vessels seen have handwheels and levers which are to be opened under "rig for dive" conditions painted red, and wheels and levers which are to be closed on "rig for dive" painted green.  Notation of this last only appears on the type XXI hull specifications.  
          In addition to the foregoing, equipment which is shock or sound mounted is identified by rose-red marking.  
          Luminous paint is used extensively, both to make gauge dials visible and to locate certain units in the absence of other light source.  The lighting is very effective, and the amount of it had led to informal question on the part of operating personnel as to whether it would interfere with dark adaptation.  
          Before departing from the subject of paints, a word should be added with respect to the color coding of piping systems.  The coding is used throughout, and together with the sketch book (which also employs the same coding) permits ready tracing of any desired piping system.  
          Cementing is kept to a minimum.  Fresh water tanks are the only ones where Portland cement is used.  Elsewhere, in places where water may not be easily vacated, drainage is provided by filling the space with bitumastic in such a way  
    - 3 -


  as to drain the space.  Bitumastic is not used, however, in residual water spaces below flood openings and flood valves in ballast and fuel ballast tanks.  
          Cork was not used except as refrigerator insulation.  
          Interior paint on all vessels observed was very dirty, as a result of snorkeling operations, and amount of soot varying with the distance from the engine room.  The use of ivory in lieu of white accentuated the below-standard illumination of the vessel, while the soot completed the gloomy picture.  The extensive use of wood for bulkheads, lockers and trim, which was normally provided with a dull rubbed finish, also accounted for excessive absorption of light.  
          Exterior paint departs from that given in the specifications in that all black paint is used on all vessels of the type which have been seen.  The specified gray vertical surfaces are not in evidence.  
          The underbody paint used does not notably inhibit marine growth at Portsmouth.  Each vessel which has been docked has been foul underwater and has required extensive cleaning.  
          Tanks have been remarkably clean.  Paint samples have been forwarded to the Bureau of Ships for analysis, which has not been received as of the preparation date of this section.  
          With the exception of the underbody paint, the paints used have served their purpose.  Some of them may be synthetic resin paints, as the word appears in the painting specifications without, however, reference to any particular paint.  
          Galvanizing is used extensively, Superstructure plating and frames, topside fittings, shafting and steel fittings in the superstructure, sheet steel, all steel fittings inboard below the walking flat, and all steel pipe is galvanized.  
          Protection of interior surfaces of pipes, cooling chambers, surfaces of heat exchangers, and all other surfaces within the vessel exposed to salt water is provided by a corrosion-protective oil.  
          This is introduced into the circulating and cooling water system by means of the cooling water hand pump in the engine room, which takes suction from the oil container by way of a hose connection.  
     - 4 -


          The oil employed is a mixture of "Korrosionsschutzoel" (corrosion preventative oil) in accordance with specification ZdM17 (See Zusammenstellung der Marine-Schmierstoffe, Ausgabe 1943) (Summary of Naval Oils and Greases).  This is an emulsifying oil, viscosity 25 Englert (1900 cSt), specific gravity .950, flash point (Pensky-Martens) 90 degrees C., with water 2.5%.  It is to be free of alkali, alkali-earth hydroxides, ammoniac and mechanical impurities, and is to meet certain emulsifying and corrosion protective tests specified in the specifications.  
          Corrosion protection for battery wells from spilled electrolyte is provided by means of the so-called lime-milk system (Kalkmilchanlage).  This is merely a pipe fitted with a funnel or hose connection at the upper end, and with a perforated section or a bilge strainer at the lower end in each battery well.  By pouring milk of lime (slaked lime in water solution) into the upper end, an alkali to neutralize the battery acid is, in older vessels, sprayed onto the wing bulkheads of the battery wells from whence it finds its way to the bottom of the battery well.  On newer vessels the solution is delivered directly to the bottom of the battery wells.  
          The solution is normally evacuated by way of the drain system.  
          Care is taken to avoid electrolysis by avoiding bimetallic contact and by making extensive use of zinc wasters and washers.  Many valves are fitted with a blank flanges or with pipe plugs on the inner face of which is a plug or a disc of zinc.  Removable piped flanges are found in certain salt water lines, which have zinc doughnuts inside them.  
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