Model Fleet: Covering THE BULGE

Covering THE BULGE

Posted by Matty on May 30, 2009, 23:15:17, in reply to "S-BOAT: Details of Form and Fit, into WWII"
Message modified by board administrator June 3, 2009, 16:16:10

Although "Nothing Standard" should be the motto of this class, there was one feature which was nearly consistent; on almost all the boats, for the great marjority of their service lives: the forward casing bulge, to accommodate the deck gun platform:

Click on Image to Enlarge This roughly cylindrical flaring of the casing expanded to support the basically circular gun deck, fairing back into the casing fore- and aft both smoothly and fairly gradually. Its vertical sides (as opposed to outward-flaring sides, in other classes) are seen clearest from ahead or astern; appearing as early as the mid-'20s - as on S-40 in the early '30s, at top right - clear through to the WWII refits, as on S-28, -38 and -41 at top-left, bottom-left and bottom-right, respectively - all photographed during 1943.

However I did identify two exceptions - one general, and one individual:

Click on Image to Enlarge The general exception appears to be that most boats - including S-37, as shown at top-left - if not all of them, were launched without any gun platform, and no casing bulge(s) of any kind. Whether the platform and accompanying bulge were added during fitting-out, before commissioning, or refitted shortly thereafter was not explicitly learned.

However the second, individual exception I ran across - shown in the larger pic; of S-30 moored outboard S-32 (& -33) in April, 1941 - may provide a further clue. Note S-30, over two decades after launching, still does not yet have the full, standard bulge, but instead a much smaller. more sponson-like support; looking more "bolted-on" than integrated smoothly into the casing. The fact of its retention on S-30 - (at least) up until WWII - argues strongly that it functioned adequately; meanwhile the absence of this fit on any other S-18 boat, ever, argues equally strongly that it must have "taken second place" to the more widely adopted design, above. Thus, I conclude S-30 represents evidence of retrofit-prototyping program; to develop the best gun platforms and install them sometime after commissioning, but before the mid-'20s, certainly.

In fact, the next class of S-boats - the S-42 class - would adopt a smaller, sloping bulge for the gun platform; looking like a hybrid just about exactly halfway between this S-30 fit and the standard (vertical-sided bulge) of the rest of the S-18 class.

Cheers,

-Matty