John W. wrote:
Was just putting together some info to pass along to Steve on HORNET and I noticed something that may be well known, but I haven't seen any mention of it. So at the risk of hearing this is already well known, I'll say that it appears HORNET's tripod mast is further aft of the tripod masts on the two sister ships. How far? Looks like 8 - 10' - I'm having a little trouble matching it to frame markings. I noticed it when I used a light table and laid my Webb's Warships CV-5 plans (scaled to 1/350) on top of my MD Silver plans for CV-8 (also scaled to 1/350). All major details and assemblies on both islands align - except the tripod and its platforms. Roger, I know HORNET's spotting platforms were a bit different - that's not the source of the offset. When looking at either set of plan's view of the pilothouse roof, and comparing the forward (of the three) mast location, on CV-5 it is forward of the two MG mounts and slightly forward of the aft end of PriFly. On HORNET, this same mast is aft of the two MG mounts and well aft of the aft end of PriFly. Another good point of comparison in the starboard profile view is that CV-5's forward leg of the tripod is well forward of the vertical pole of the boat crane, on CV-8 the same mast pole is aligned vertically with the boat crane pole. As I said, everything else is aligned on the two plans as far as major stuff.
Feedback welcome - like to give Steve the most accurate info possible. Scans I have made are way too large a pixel count to post, unfortunately.
A whole new mystery to solve! You might be on to something John. Checking MD Silver books for all three, here is what my best reading glasses determined. First let me say that the MD Silver book on CV-8 is the best of the bunch. The CV-5 and 6 sets have outdated drawings and early copies of revised drawings in them. Okay, to the meat. The masts themselves were initially identical, as built. Hornet's lower tripod platform was cut down considerably while her sisters, completed earlier, had theirs built up with additional structure prior to CV-8's existence.
The drawings I referenced in the books all had frame number notations, so any scaling errors are eliminated. The distance between frames was 4'0" so that gives us the starting point. All notations were at the top of the pilot house and air plot level, 109'6" above base line. The poles are all 2 feet in diameter. The center point of the vertical leg and the aft legs are 10'6" apart measured fore and aft.
The CV-5/6 drawing shows the vertical forward pole centerline as being 18 inches aft of frame 80 and the centerline of the aft poles as being dead on center with frame 83. At 4 foot spacing, that works out to 10'6" apart, a figure confirmed in one of the many drawings
The CV-8 drawing shows the vertical forward pole as being six inches forward of frame 82. That puts the aft legs at 24 inches aft of frame 84 (or midway between frame 84 and 85). While not notated on the plan, my ruler falls at that very spot for aft legs. This gives us 6 feet farther aft on the aft legs, and 6 feet farther aft when figured from the forward vertical leg.
So, CV-8's tripod legs were mounted 6 feet farther aft than her sisters.
Well Done, John W!
Theory: the reason for this was radar. The FD radar atop the forward Mk 37 director might have needed a better arc or greater clearance from the tripod structure. Hornet had design modifications to the original plans to accommodate radar, and this may be one of them.
Now that this is confirmed, I studied photos with the relationship in mind, and it is practically smacking me in the face! Compare similar views of CV-8 and CV-6. Note the distance between funnel mast and director locations. Double face palm!