--Originally posted 4/17/09--
Last weekend I finished plugging the last void in the keel:
Click to Enlarge The crescent-shaped belly plate had to be split along the keel to best position the halves, and a final, keel piece was fished-in (top), using plastic dowel (white) as a "handle". Once secured, the dowel was then chopped off (center), flush with the keel. The more rounded belly profile now compares pretty well with my S-18 class drawing (bottom).
Time to address the top side:
Click to Enlarge To my drawings I added a plan view of the deck (left), and removed the Revell Nautilus sail, by scribing flush with the deck. "Flush" here is kind of a relative term, as the Revell deck is steeply crowned along the centerline (right). Note it is also planked (incorrect for Nautilus); the depiction created by stacking each inboard "plank" - thus creating the crowned deck (also incorrect for Nautilus) in the first place. The cambered deck is incorrect for any S-boat, AFAIK, and moreover the match between the S-18 class and Revell deck is not a very good one. The latter widens significantly aft of where it is needed for the S-18 deck gun platform; instead presenting a large hole from the sail cutout over the after half of this area.
Strike One. But can this build make use of the Revell planking in the narrower areas further forward, and/or aft; just how much of S-37's deck was planked, and where:

Click to Enlarge At left, two pictures (top) show, from left-to-right, front-to-back, S-36, -39. -42, -37 & -41, sometime in the early '30s. Judging by their appearances, S-37's deck was no doubt identical to S-36', which at full resolution (insets) is clearly seen to be planked on- and immediately forward of the gun platform. An overhead shot of S-37 from October, 1924 (bottom) is too grainy to define planks, but does confirm similar texture and brightness over the entire deck, with notable exceptions of the very dark circular gun platform and extreme forward- and aft deck tips; undoubtedly painted black.
However a closeup of S-37 from October, 1923 (right), shows a section of aft deck having no evidence of planking whatsoever; it is easily close enough to show individual planks, whose complete absence proves that at least the after third of her deck was, at that time, all-steel. For our depiction of S-37 in February, 1942, can we then assume her decks were, except for at the extreme ends, completely planked from 1923 onwards?
Not necessarily, it would seem:

Click to Enlarge At left, a pic from April, 1941 shows, from left-to-right S-37's close siblings S-30, -32 and -33 - again, appearing to be very near if not identical to each other. At full-resolution (inset), planking is unmistakeable on S-32's gun platfrom - again, uniquely painted (or stained) black - yet not clearly definable on the closer, lighter-colored deck which extends from there forward to ahead of the crew access hatch. Forward of which - at the bow tip formerly painted black on S-37 - the deck clearly transitions to rivetted and perforated steel, as expected. So, did only the gun platform receive planking, on some boats - or did they all have the rest of the deck planking removed by 1941? Or, was heavier planking substituted on the gun platforms only, by 1941? (Or some combination of all three?)
The only other clue found so far is in a picture of S-44 (right), immediately after her major refit in January, 1943, wherein the coarse, gun-deck planking can be glimpsed at far right, to continue aft, going towards (and presumably beyone) the sail. The Revell deck might be useful for depicting such heavy planking, except - maddeningly - it is insufficient at
exactly this location!
I am about ready to conclude that, early in WWII there were two basic fits for the S-18 class: one with only the gun platform planked, as (possibly_ on S-32, above; and the other with the entire deck heavily planked, as on S-44, above. But then, which would be more accurate for S-37, in February of 1942? The World (Still) Wonders...
But wait - it gets worse:

Click to Enlarge Preparing for major if not total deck replacement, at left I glued a pair of plates to the aft supporting pillar (top), making a bracket to sandwich-in a long central beam (bottom); to support the new deck. But exactly what
shape deck? Note on my deck drawing the dashed circle around forward hatch; it was prompted by pics at right which show S-37 (top) and S-41 (middle) with flaring hull bulges forward - no doubt to accommodate a forward escape trunk under the hatch. Although the former pic is undated, note both show all-black - i.e.,
wartime - paint jobs. And the S-41 pic dates from 1942. Meantime a pic of S-35 from May, 1943 (bottom) - again, after her major refit - shows no such bulge forward of her gun platform. So, did S-35 just never get one of these trunks - or could they have been added and then
removed again by mid-war? The lines in my drawing remain dotted....
Which brings us to the largest remaining set of "dotted lines" for this build:
Click to Enlarge As launched, the S-18 class hull casing aft (top-left) ended in a long fin, called a "skeg"; connecting the deck with the top of the rudder. The closeup of S-37 from October, 1923 (top-right) confirms she had one. However, even before the '30s, these skegs began to be cut down (center-left drawing), and ultimately were all but eliminated - replaced by a blunt, rounded termination of the casing, trailed by an after escape trunk, as seen on S-35 by May of 1943 (center). At bottom, I plotted in this wartime fit on my drawing - though not the line of modernized limber holes, which you may also note in the photo.
But the latter was not the
only possible appearance for this class during WWII:
Click to Enlarge Five additionaly possibilities - one of which is almost certainly accurate for S-37, in 2/42. At top-left, the aft casing simply chopped at a raked angle, was purportedly S-42's aft "Outline During War", as shown. This type of casing appears, in an undated pic at top-right, on S-36 as well as her squadron mates - including S-37 somewhere in there - moored behind. Drawings undoubtedly more accurate for this fit are at upper center-left and center-left; the former attributed to S-42 as early as
1925, and the latter purportedly "generic" for the class. At upper center-right, an undated pic of S-37 in all-black (presumed) wartime paint has an obviously chopped aft casing - though the view and sloping side prevents determination of the precise angle. However it does show a small rudder-top light post consistent with the S-42 drawing. Likewise, at lower center-right a 1942 pic of S-41 - in overall black and with forward escape trunk bulge, just as S-37, above - exhibits a raked-chopped fit of the aft casing.
The above would seem conclusive if not for the undated pic at bottom-right, showing S-37 - again, in overall black and now moored outboard her siblings, all of whom appear to have
vertical chopped casings. While grainy and dark, the pic suggests resemblance more to the drawings at lower-left; the upper depicting S-22 in 6/41, and the lower S-44, after her '43 refit. Note both include the small, rudder-top light post, consistent with the other S-37 pic, above. Certainly we've found "the ballpark" for S-37, in 2/42 - between the two, I'd choose the 6/41 (S-22) drawing as being closest in time.
To sum up, this is a Pain in The Aft Casing

still with nothing really certain - except that I'm gonna paint it black! But of course I'm going to push ahead anyway - stay tuned for that...
Cheers,
-Matty