Does Anyone Have A clue What's Going On Here?


#1

Found this pic on the net a while ago. Does anyone have an idea of what they are doing here? I cannot read the text.

Jason


#2

I think they are testing a new military ashtray…


#3

Just a SWAG - 5" projectile with one of the new molded plastic fuze ogives jammed in a fuze setter. Possibly from a manual to demonstrate how a projectile could get jammed by the moveable pawl in the setter.

Maybe Roundsworth can tell us what he thinks.

Ray


#4

" 5" PROJECTILE WITH MOLDED…EDGE OF STATIONARY SOCKET OVER MOVEABLE PAWL "???


#5

I do recall that VT fuzes on 3"/50s were molded. I would imagine that the same fuzes were used on 5"/38s. The chain-driven projectile hoist in the 5"/38 mount did have a pawl that rotated a mechanical time fuze as the projectile was raised into the gun mount. If a VT fuzed projectile was set into the ‘cup’, the pawl would really chew up the molded plastic(?). If I recall correctly, the standard 5"/38 projectile was about 55 pounds. That would apply a lot of force on the fuze in the cup. We launched a few 16" projectiles with electronic time fuzes during Desert Storm. They were made out of some sort of plastic and had metal rings on the very tip where contact was made with the fuze setting device.


#6

I am always so amazed and impressed by the knowledge of the IAA members on so many subjects. You guys really know your stuff. This photo really puzzled me and I thank you all for figuring it out. Just one question, what is a “PAWL?”

To, Roundsworth, and all the others who Served our Country, I thank you. Every time I read the footer under your name stating the years and ships you served on I get goose bumps. You guys rule and I thank you and really look up to you big time!


#7

Without running for a dictionary, I always think of a firearm extractor as something of a “pawl”, sort of a metal tooth to stop and/or direct motion. Sure it’s not exact, but might be real close.


#8

Ok, that makes sense. Thank you so much, Jon!


#9

Thank you kindly for the comments! The pawl is a little square lug protruding inside the cup on the hoist. It engages a recess on the rotating ring on the fuze to dial in the correct time. I was amazed when I saw the open, single, hand-ram 3"/50 on the USS Truckee, an active oiler (in 1979). The ammunition was fixed and the loader had to stick the fuze into the cup on the fuze setter while someone hand-cranked to set the time. There were dials and knobs to input the basic ‘fire control’ factors. I was a dinosaur in the modern Navy, and never would have seen E-8. I was a bit of a ‘has been’, but enjoyed every minute of it!


#10

Jason, it looks like the text reads “5" projectile with molded-out Mark 32 fuze armed under sharp edge of stationary socket of moveable pawl”.


#11

There you go! I was wrong about the configuration of the lug and ring. Thanks for posting.


#12

Thank You, Thank You, Thank You! Fantastic information. You guys are the best “Ammunition Detectives” :-)

Jason


#13

Here’s a description of the fuze setter mechanism used with 5" twin gun mounts Mark 28, 32 & 38:

Mark 32 fuze:


#14

Excellent information, Fede. These diagrams really help a lot.

Jason


#15

When a projectile with a lug (or setting notch) is inserted into a fuze setter, the spring loaded pawl is depressed and the setter makes one complete revolution so that the pawl engages the lug (or notch). After that, the setter makes a partial revolution to set the time. That way, a loader inserting the projectile into the setter does not have to concern himself with lining up the lug and pawl. A projectile that goes thru the fuze setter, and is not fired, has to have the fuze re-set to Safe using a fuze wrench.

The photo below shows a time fuze with a setting notch, and a VT fuze (MK 59).

A VT fuze is not “set” in the conventional sense. There is no lug and the pawl is depressed the entire revolution. In effect, the setter does nothing to the fuze.

Rapid fire guns use VT fuzes exclusively because there is no good way to incorporate a fuze setter into the mechanism.

APFSDS - Rounsworth and I know this stuff because, in another life, we did this for a living. Actually, Roundsworth did it for a living - I only did it for a few years in order to see the world on Uncle Sam’s dime.

Ray (Former USN GM2)


#16

Thanks, Ray! On many levels!

Jason


#17

I should add - these comments apply to USN guns. The Army Artillery guys do it differently.

Ray


#18

As stated by other members, it is indeed about the plastic wind screen cone on the Combination Variable Time fuze for the 5"/38 projectile as illustrated in the photograph.
If the projectile was dropped into the fuze setter ( common practice to do ) the plastic nose cap/wind screen would brake* and cause the fuze setting lug to strike the plastic or jam the lug. As the lug was gear driven by an axillary fuze setting chain , the projectile could not stall the setter from trying to spin, instead the projectile would back out, fall over and jam the primary drive chain for the hoist. This would cause the hydraulic motor which was over 25 HP to overload and stall out or worse the primary lifting chain could brake. Either way you had at least one if not more projectiles jammed in the hoist and that loading system was kaput. And I can tell you it was a nightmare to repair.
This fuze was a multi purpose fuze as it could be set to a time of interception of the target ( air craft ) or used as a self destruct fuze it the projectile could impact friendly troops or ships. If left in the 'Safe" mode, the time function was inert and the VT portion would function exploding close to the target or over the surface of the water. I have fired thousands of the projectiles in 5"/38 and 5"/54 Calibers. The fuze “cap” was very sensitive to shock if the projectile was roughly handled or even fell over on it nose in rough weather.
All US Navy projectiles are stored with the steel fuse protecting “nose-cap” installed until it is loaded into the gun.
*We did from time to time load the projectile with the plastic cap broken off when we had no other choice as we were running out of projectiles to shoot. The antenna for the VT function was mushroomed shaped and it loaded with no problems or malfunction in flight. I did not notice that the missing streamlined nose fuze made a very different sound as it flew to the target.
This type of projectile caused so many problems that it was no longer issued to the newer rapid fire gunned deployed ships. I served on Destroyers for 18 years and fired just about everything made for 5" guns. The early CVT fuze was the worse I saw of all of the fuzes.
These fuzes were never a problem on the 5"/54 guns as the fuze setter was a completely different device. The projectile was horizontal when the fuze was set.No weight was ever placed onto the fuze.


#19

Rapid Rob

Very interesting, to me, at least. The cartridge collectors are nodding off but this kind of stuff still interests me.

I was a Gunners Mate on the original 5"/54 slow fire guns on the Midway class carriers in the early 1950s. The combination Time/VT fuze had not been perfected at that time and we used the MK 73 type VT fuze almost exclusively. The fuze setter was incorporated into the projectile hoist from the handling room to the gunhouse and it still had the time fuze capability for those rare occasions when it was needed. I don’t recall an instance of the fuzes breaking or jamming in the setters. The 3"/50 RF guns used the MK 72 VT fuzes, as I remember, and they never saw a setter.

I had an opportunity to visit the USS Forrestal when she was new and the GMs gave me a demo of the 5"/54 RF guns. Eye opening is an understatement.

Ray


#20

One of my first live fire exercises on the San Diego proved very interesting. I never did find out whose bright idea it was to shoot VT-FRAG ammunition! They exploded at various distances. Why, I don’t know. That was my only experience with VT fuzes.