Requesting Bormann Fuse Interpretation

[John D. Bartleson Jr.]

Below is a rendering of an actuall U.S. Bormann fuse.  Note ticks before 1 and after 5 second marks.
The U backwars S is a good indicator but is not always present.
Regards,
John

[Dave the plumber]

   okay all you guys that know more than me; I have a question.
 
  On the CS fuze the first 'tick' mark is a half second. How far would a 12 lb ball travel before it blew if the 1\2 second tick was punched in ??   
       Probably not far,  not far at all is my guess.  Maybe the US decided they didn't want to use an exploding round ball that might blow back schrapnel  in close quarters like that so they don't have the 1\2 second tick on thier fuzes.  I gather cannister would  be a  whole lot safer for the gunners when the opposing force is in your face.......

[Pete George]

Alwion wrote:
> Since the pie shape no longer confirms CS vs US, except the 90 degree being US,
> does the number of ticks before #1 also not confirm a CS fuse, if its a US with the smaller wedge shape?

  The number of ticks (raised lines) BEFORE the number 1 ALWAYS confirms whether the fuze is CS-made, or is US-made.

  If CS-made, there are two ticks/hashmarks/raised-lines before the number 1.  If there isn't two lines before the number 1, the fuze is US-made.

Regards,
Pete 

[Pete George]

Dave the plumber wrote:
> How far would a 12 lb ball travel before it blew if the 1\2 second tick was punched in ??

  The following answer is my best estimate," from doing mathematical calculation of the data given in civil war 12-pounder cannon Range Tables.  The calculation indicates a 12-pdr. shell whose fuze was cut for 1/2-second of burning-time would explode at "about" 170 yards (510 feet) from the cannon's muzzle.
   
 > Maybe the US decided they didn't want to use an exploding round ball that might blow back schrapnel [...]

  That would not happen.  The shell is traveling away from the gunners at over 600 miles per hour.  The shell's explosion is not enough to to REVERSE the fragments' forward speed, sending the frags back to the cannon's location.

If you are uncertain about believing that statement:
  The civil war era US Artillerist's Manual says that if you've run out of Canister ammo, you can pierce the Bormann fuze at the "zero point" and use Case-Shot shells as a substitute for Canister.  I doubt the Manual woud recommend doing that if it would cause casualties among the gunners.

  Of course, a Bormann fuze does not have a Zero marking on it, the zero-burning-time point would be either at the pie-slice (wedge shape) or in the very center of the fuze's face ...depending on how much of a safety-margin the gunner was comfortable with having.

  I think I should also mention that the Schenkl Combination fuze (used ONLY in Schenkl Case-Shot shells) has an actual Zero number on its time-index.

Regards,
Pete

[6lbgun]

  There is a report of Capt. James Brady, Battery H, 1st Pa Light Artillery concerning the battle of Fair Oaks in which he states that one section of the battery on using up all of it's cannister used case shot and shell with out any fuse at all.  The rounds burst as they left gun, with good effect.

Dan

[John D. Bartleson Jr.]

Without any fuse, the shells should have burst in bore.  I wonder why it is thought that they traeled the length of the barrel the burst at barrel exit.  some brave gunners.
Regards,
John

[Pete George]

I think the answer might be:
  In firing no-fuze Bormann shells, the presence of the fuze's support-plug/underplug (which has just a tiny flame-hole) might keep the shell's powder-charge from igniting absolutely instantanously upon firing... leaving just enough time for the shell to exit the cannon's muzzle before exploding.  And regarding that very slight delay, the ball's sabot and sabot-straps helped, by keeping the fuzehole/underplug facing away from the propellant powder charge.  Since we know a 12-pounder shell traveled 340 yards in one second, even a one-tenth of a second delay in the shell exploding is enough for it to get 100 feet down-range before exploding.

Regards,
Pete

[6lbgun]

I found a report by Cap. George McKnight, 12 NY Independent Battery, dated Aug 11, 1864.  He is talking about fighting along the Jerusalem Plank road on June 22, 1864

"... I continued firing canister and case-shot without fuse until the entire left gave way...."

Being this late in the war, can it be assumed that this would be Bormann  case shot?

Dan

[John D. Bartleson Jr.]

Pete,
Good point concernng the delay caused by the fuse support plug.
John

[Pete George]

  Yes, 6lbgun, the Case-Shot in the 1864 report would definitely be Bormann-type.

  In the first 12 months of the war, the yankees used only a very-very few Field-caliber roundshells with a wooden fuzeplug. (Those very-very few are believed to be "leftovers" from manufacturing in the early-1850s, before the US Ordnance Department officially adopted the Bormann fuze.)  Afterward the first 12 months of the war, 100% of yankee Field-caliber roundshells were Bormann-fuzed, except for a few Experimentals like the Tice and Wright fuzes.  That statement of course excludes mortar shells.

Trivia note: The reason I said "first 12 months of the war" is, I am aware of a few 12-pounder woodfuzed shells which were definitely fired by the yankees at West Virginia battlesites during 1861, and a few more yankee-fired ones from Shiloh (April 1862).  As usual, the obsolete Ordnance got shipped off to "the West."

Regards,
Pete

[John D. Bartleson Jr.]

To All Interested,
     Below is an excerpt from "Notes on Artillery" by W. Leroy Broun, MA Lt. Artillery. Va/Volunteers 1862:

"The Bormann fuze, now so well known, and used in all our field the great advantage of having the press-ure applied horizontally to the mealed powder, and thereby causing equal lengths of the fuze to burn in equal times. Some of the first issued fro'm the Ordnance Department were not well screwed in .the shell, and consequently •many burst very near the muzzle, if not in the gun, no matter for how 1 many seconds they were cut. The writer conceived that this premature explosion was in a measnre.due to the flame passing between the thread of the screw and the shell, and had the fuzes, of all th6 shells in the battery to which lee was attached, screwed in as tight as possible with the fuze wrench, and then
had the space around the exterior rim of the fuze very closely glazed with a mixture 'of white lead and litharge. When this glazing hardened he had the satisfaction, on subsequent trials, of witnessing very few premature explosions. If the metal is
. cut away so as to expose a surface as large as the fourth of a
half dime, explosion will take place. Of course the fuze end .
of the shell is placed towards the muzzle ; if towards - the charge, the.violent exploSion of.the powder would drive the' fuze into the shell and cause it to burst in the gun."
Regards,
John

[Jine]

Thanks for this latest input, John and for the earlier fuse image. Thank you also, emike123 for your images of CS v. US fuses; those were fabulous and should help eliminate confusion; and thanks for the input of everyone else, perhaps Pete in particular for sharing from your depth of knowledge.

I've been gallivanting with history north of the Mason-Dixon Line, and have missed the recent goings-on here in the process. It's great to come back to!

[Dave the plumber]

       John,              That was a great piece to find. It kinda sums up all we have been talking about. Thank you !!

[6lbgun]

Great post John,
   Don't have that book.  I'll buy it tonight.
Dan

[Dave the plumber]

    I wonder about something;        if they were just shooting balls with underplugs, and we summerize  here that there was enough of a delay for the shell to get out of the barrel before explosion,  - then how could a Bormann fuze just not screwed down tightly  blow up in the barrel when the flame has to pass along all the tight threads, make it through the leather washer and then through the underplug ??
            I'm not an ordance  guy, but I would think a shell with just an underplug would blow instantly when the pressure in the barrel is 30,000 lbs [ correct ?? ] at detonation of the propellant charge.....
            Thoughts ??